>p^^. iO* ,i^Lr* > •: %.** •*^"« \./ ••^'V %.** •'^•- \./ o, ♦^Tv;» v'^ <> '^.1* .0^ "^ *'T?r»' A <. 'r.T*' .0^ '^ ♦.":^»' -A <, :. -n^o^ ». 'bV" >. ••V.' ^^ . « * A ^ «^"' ''h. '' .. •" cv • VV •>i..*' oV^Siia'- '-^^^-^ -Jm^^r^. -^^^ -I^M^' '^MrS ^O^ •.CSftM>o iPvl rA^ •bv %^^ "♦bv* HO*. . ^S'Cn 9^ tV ♦ 1 * l-^^ c t>w^t,t u y Information Circular 8821 Availability of Critical Scrap Metals Containing Chromium in the United States Superalloys and Cast Heat- and Corrosion-Resistant Alloys By LeRoy R. Curwick, Walter A. Petersen, and Harry V. Makar UNITED STATES DEPARTMENT OF THE INTERIOR Cecil D. Andrus, Secretary BUREAU OF MINES Lindsay D. Norman, Acting Director As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water re- sources, protecting our fish and wildlife, preserving the environmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also has a major re- sponsibility for American Indian reservation communities and for people who live in Island Territories under U.S. administration. ^^^' ^J^ »-'' 0^ This publication has been cataloged as follows: Curwick, LeRoy R Availability of critical scrap metals containing chromium in the United States. Super alloys and cast heat- and corrosion- resistant alloys. (Bureau of Mines information circular) Bibliography: p. 38.- Supt. of Docs, no.: I 28.27:8821 1» Scrap metals— Recycling, 2, Chromium, I. Petersen, Walter A., joint author. II. Makar, Harry V,, joint author. III. Title. IV. Series: United States. Bureau of Mines. Information circular ; 8821. -jPNaasOH [TD794.5] 622s [333. 8'5] 80-607102 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 (.5 (1^ CONTENTS Page Abstract , 1 Introduction 2 Methods and assumptions used for this study 3 Model 3 Definition of alloys 4 Sources of information 6 Reliability 6 Rounding 6 Assumptions 6 Information gaps 7 Results 7 Alloy production 7 Production efficiencies 13 Melt charge makeup and scrap utilization 13 Scrap generation 15 Scrap export 17 Discussion 17 Materials balance 17 Use patterns of the alloy-producing industry 17 Scrap utilization 23 Remelted 23 Material losses 24 Downgraded 25 Exported 27 Efficiency of recycling , 28 Scrap price considerations 29 Quantity of chromium required for melting 29 Relationship to total U.S. chromium requirements 31 Past trends in alloy production and scrap generation in the super- alloy and heat- and corrosion-resistant alloy casting industries, pro j ec ted to the year 2000 32 Comments on improving the model and continuing surveillance of field 33 Summary 34 Conclusions 36 Bibliography 38 Appendix A. — Definition of terms 39 Appendix B . — Development of materials flow model , 44 Appendix C . — Chemical compositions of specific alloys 48 Appendix D. — Companies and organizations contacted during this study.... 51 ILLUSTRATIONS 1 . Materials flow circuit used for production model 4 2. Annual primary nickel consumption for high- temperature alloys, 1958-78 11 ^^ S^ 3. Annual primary production for heat- and corrosion-resistant alloy castings , 1958-78 12 ii ILLUSTRATIONS—Continued Page 4. Investment cast nickel- and cobalt-base alloys materials flow circuit 18 5. Hardfacing cast nickel- and cobalt-base alloys materials flow circuit 18 6. Wrought nickel- and cobalt-base alloys materials flow circuit 19 7 . Wrought nickel-iron-base alloys materials flow circuit 19 8 . Heat-resistant alloy castings materials flow circuit 20 9. Corrosion-resistant alloy castings materials flow circuit 20 10 . Overall materials flow circuit 21 11 . Schematic diagram showing interclass scrap flow 22 TABLES 1. Nominal composition ranges of the classes of alloys studied 5 2. Estimated production of primary product for investment cast nickel- and cobalt-base alloys in 1976 8 3. Estimated production of primary product for hardfacing cast nickel- and cobalt-base alloys in 1976 8 4. Estimated production of primary product for wrought nickel- and cobalt-base alloys in 1976 8 5. Estimated production of primary product for wrought nickel-iron- base alloys in 1976 9 6. Estimated production of primary product for heat-resistant alloy castings in 1976 9 7. Estimated production of primary product for corrosion-resistant alloy castings in 1976 9 8. Annual primary nickel consumption for superalloys, other nickel and nickel alloys, cast nickel alloys, wrought nickel alloys, high- temperature and electrical resistance alloys, and nonferrous alloys , 1958-78 10 9. Annual primary production of heat- and corrosion-resistant alloy castings , 1958-78 12 10. Production efficiencies by alloy class for raw materials to primary product and for primary product to finished product 13 11 . Estimated production by alloy class in 1976 13 12 . Melt charge raw materials 14 13. Published producer prices of various forms of chromium and other selected primary metals in February and May 1979 14 14. Prices quoted for identified solid scrap and calculated metal value for several alloys in February and May 1979 15 15 . Quantity of home scrap generated in 1976 16 16 . Quantity of prompt industrial scrap generated in 1976 16 17. Quantity of obsolete scrap represented by finished product produced in 1976 and obsolete scrap available in 1976 16 18. Quantity of nickel waste and scrap exported and imported annually, 1965-78 17 19. Scrap requirements for remelting, by alloy class and scrap form and origin 23 iii TABLES—Continued Page 20. Sources of lost scrap, by alloy class and scrap origin 24 21. Sources of scrap downgraded, by alloy class and scrap form and origin 24 22. Sources of solid scrap exported, by alloy class and scrap form and origin 25 23. Scrap recycling, by alloy class and scrap disposition 26 24. Calculated recycling efficiency for the six classes of alloy 28 25 . Calculated weighted average composition, by alloy class 30 26. Chromium content of melt charge components, by alloy class 30 27. Chromium content of scrap not directly recycled in 1976... 31 28. Quantities of primary metal chromium used in the melt charge in 1976 32 29. Relation between primary chromium consumed for the six alloy classes and total primary chromium consumed for metallurgical applications in 1976 32 30. Quantity of contained elements in products and scrap in 1976 34 31. Source, form, and quantity of scrap generated in 1976 35 32 . Scrap disposition by source and form in 1976 35 C-1. Compositions of cast nickel- and cobalt-base alloys 49 C-2 . Compositions of wrought nickel- and cobalt-base alloys 49 C-3 . Compositions of wrought nickel-iron-base alloys 50 C-4. Compositions of major heat- and corrosion-resistant alloy castings. 50 Bureau of Mines Information Circular 8821 AVAILABILITY OF CRITICAL SCRAP METALS CONTAINING CHROMIUM IN THE UNITED STATES. SUPERALLOYS AND CAST HEAT- AND CORROSION-RESISTANT ALLOYS by LeRoy R. Curwick, Walter A. Petersen, and Harry V. Makar ERRATA Page 7, sixth line from the bottom should read as follows: category "Other" may in some cases represent a major portion of production, Page 16, Table 15: The total for the column headed "Grindings" should be 7.9. Page 16, Table 15, Footnote 2 should read as follows: Grand total: 317.5 million pounds. Page 24, Table 21, Footnote 4 should read as follows: Grand total: 104.9 million pounds of scrap containing 18.9 million pounds of chromium. Page 25, Table 22, Footnote 2 should read as follows: Grand total: 19.7 million pounds of scrap containing 3.3 million pounds of chromium. Page 34, second line should read as follows: industries, it is clear that more comprehensive and specific data are required. AVAILABILITY OF CRITICAL SCRAP METALS CONTAINING CHROMIUM IN THE UNITED STATES Superalloys and Cast Heat- and Corrosion-Resistant Alloys^ by LeRoy R, Curwick,^ Walter A, Petersen,^ and Harry Vt Makar^ ABSTRACT This Bureau of Mines report presents the results of a study conducted to assess the domestic availability of chromium from superalloy and cast heat- and corrosion-resistant alloy scrap material. Six alloy classes included in this survey were investment cast, hardfacing, and wrought nickel- and cobalt-base alloys, wrought nickel-iron-base alloys, and heat- and corrosion-resistant alloy castings ~ Data were collected for 1976 on metallic scrap generation, use patterns, and production practices for these alloy producing and using industries. A model was developed that allowed an assessment of the materials flow circuits within the industries that produce these alloys. The types, amounts, sources, secondary products, and ultimate destinations of chromium- containing metallic scrap for the six alloy classes were determined. Regard- ing the overall recycling efficiency of these alloy producing and using industries, of the 580.9 million pounds of scrap generated from these six alloy classes in 1976, about 72 percent (416.8 million pounds) was remelted by the same alloy-producing industries, about 18 percent (104.9 million pounds) was downgraded into stainless and low-alloy steels, about 3 percent (19.7 million pounds) was exported, and about 7 percent (39.5 million pounds) was lost through landfill or other disposal or service wastage. The lost material is primarily contaminated oxides for which recovery is currently uneconomic. However, the 124.6 million pounds of scrap material downgraded or exported in 1976 contained potentially recoverable critical strategic elements. The amount of scrap material lost to the six alloy-producing industries in this manner contained 22.1 million pounds of chromium, 53.4 million pounds of nickel, 5.9 million pounds of cobalt, 35.9 million pounds of iron, and 7.3 million pounds of other alloying elements. ^This report was prepared by Inco Research & Development Center, Suffern, N.Y., under Bureau of Mines Contract J0188056. ^Project Manager — Development, Inco Research & Development Center, Suffern, N.Y. ^Senior project engineer, Inco Research & Development Center, Suffern, N.Y. '^Research supervisor, Avondale Research Center, Bureau of Mines, Avondale, Md., and technical project officer for Contract J0188056. INTRODUCTION There is growing concern that nonmarket factors may affect the price and availability of many of the metals used for military and other high- techno logy applications. Chromium (Cr) is of particular concern because the major ore bodies are concentrated outside the United States in areas that may be subject to political disruption. Chromium is technologically important and has no sub- stitutes for the most critical applications. Other metals of concern are cobalt (Co), nickel (Ni) , tungsten (W) , molybdenum (Mo), columbium (Cb), and tantalum (Ta) . All of these metals are used in substantial quantities in the alloy classes covered in this study; that is, in nickel-, cobalt-, and nickel- iron-base alloys and to a lesser extent in heat- and corrosion-resistant alloy castings. The chromiiom supply and consumption situation was recently reviewed in detail (1) . ^ The industries covered in this study can be categorized as "producers," "fabricators," "manufacturers," "users," and "recyclers"^ of the alloys men- tioned above. In general, the major participants are high-technology compan- ies which are conscious of product quality requirements and which work closely with user companies on materials problems. These industries already use as much available scrap as they can within the metallurgical limits imposed by product quality specifications and furnace operating practices. The most acceptable, least costly, highest quality scrap for the alloy producer is "home scrap." Home scrap is generated during the "raw material" melting to "primary product" production phase by the alloy producer industries. Home scrap consists of "solids," "turnings," "grindings," "skulls," "spills," "slags," "scales," and "dusts." In general, all home scrap solids and turn- ings are reused internally to make up a large portion of the raw materials for the "melt charge." The grindings and "mixed melt shop scrap" (skulls and spills) are mixed with oxides and are usually sold for refining and eventual use for steelmaking. Dusts, scales, and slags are contaminated and undesir- able for existing recycling systems and thus are largely discarded. "Prompt industrial scrap" consists of solids, turnings, grindings, "sludges," and "liquors" generated by fabricators and manufacturers during the primary product to "finished product" phase of equipment manufacture. Most alloy producers use some prompt industrial scrap in the raw materials charge for melting. This material is generally in the form of solids pur- chased either directly from the manufacturing source or indirectly through recyclers. "Obsolete scrap" is generated by users and recyclers when used equipment is overhauled and parts replaced, through "service wastage," and when equip- ment is dismantled at the end of its useful "life cycle." The usable scrap generally occurs as solids and grindings. The generation of obsolete scrap occurs over the entire life cycle of the equipment and thus introduces a time scale variable into this study. SUnderlined numbers in parentheses refer to items in the bibliography preceed- ing the appendixes. -Terms in quotation marks are defined in appendix A. It is common practice in the alloy melting industry to make maximum use of scrap as a raw material for melting. This is done because scrap metal is usually less expensive than primary metals and sometimes more readily avail- able. Qualitative information on generation and use of valuable scrap metal by the chromium alloy producing and using industries exists in the litera- ture (3-4^). However, a comprehensive quantitative study has not been done. This study was undertaken to fill this need. The principal objective of the study was to assess the domestic availability of superalloy and cast heat- and corrosion-resistant alloy scrap. Information to be developed included types, quantities, sources, secondary products, and ultimate destinations of scrap for the alloy classes mentioned previously. A companion study (7) deals with chromium-containing wrought stainless steel and heat-resisting alloy scrap. A secondary objective of the study was to provide data that could be used to estimate the quantity and quality of superalloy and cast-heat and corrosion- resistant alloy scrap that could be used for chromium recovery processes. Such processes are being developed under separate contracts . The processes under development will refine metallic scrap and produce pure chromium, nickel, and cobalt and other metals of a quality suitable for recycling to the original alloy producers or to other high-value uses. The implications of the results of the scrap study will be discussed in separate reports dealing with the development of these processes. The current study and the process development research were sponsored by the Federal Emergency Management Agency (formerly Federal Preparedness Agency) through the Bureau of Mines, U.S. Department of the Interior. METHODS AND ASSUMPTIONS USED FOR THE STUDY Model It was recognized that it was not possible to gather complete and reli- able data on all phases of the alloy producing and using industries. There- fore, a "model" of these industries was developed which, given available data and reliable estimates of overall industry practices, would allow derivation of the information required to meet the objectives of this study. The model used is shown in figure 1. This is a materials flow diagram which follows the alloys from the raw materials stage through the primary and finished product stages to obsolescence. Once the model was completed for the six alloy classes covered in the study, it was possible to address the study objective. A detailed description of the model is contained in appendix B. The numerical data for the flow diagram were developed in the following manner: First, the quantity of primary product was estimated from available data for the six alloy classes. The raw materials to primary product cycle was filled in, using available information on "production efficiency," rela- tive proportions of materials in the melt charge, and relative quantity and type of home scrap generated. The primary product to finished product and finished product to obsolescence cycles were filled in by estimating the quantity and forms of scrap generated at each stage. SCRAP FOR SALE SCRAP FOR SALE SCRAP DEALER EXPORT PRIMARY METAL T PURCHASED SCRAP HOME SCRAP •> I f RAW MATERIALS WASTE PRIMARY PRODUCT WASTE HOME SCRAP iUl FINISHED PRODUCT OBSOLETE SCRAP WASTE Once the model was com- pleted, its accuracy was verified by comparing pre- dicted quantities with data from independent sources, such as chromium consumption figures and scrap exports. Definition of Alloys Alloys included in this study were the chromium- containing nickel-, cobalt- and nickel-iron-base alloys and heat- and corrosion- resistant alloy castings. These generic alloys were divided into six broad classes whose alloy composi- tion ranges are shown in table 1. The alloy classi- fications adopted do not correspond precisely to those used in other industry and Government reports. They were carefully selected to encompass products of dis- tinct alloy-producing indus- tries . These classifications greatly simplified develop- ment of the production model and facilitated understand- ing of the scrap flow pat- terns . Tables with the nominal compositions of some specific alloys that fall within these broad classes appear in appendix C. These tables cover the major alloys of the classes shown. Note that certain alloys may appear under two classes if they are produced in two product forms (cast and wrought). Note that the term "superalloy" was not used to designate an alloy classification because it was considered to be too restrictive and imprecisely defined. Three of the six alloy classes listed in table 1 (classes 1, 3, and 4) comprise the alloys that are considered by most, but not all, alloy producers to be superalloys. As noted above, the classes were defined more by producing industry than alloy composition. Thus, alloys listed within a given class are often produced by similar techniques for use in similar components. Using this classification scheme, the type and relative quantity of scrap generated can be more readily defined. Comments concerning the industries and production methods that help to distinguish the classes follow: REFINERY DIRECT SALE STEEL INDUSTRY FIGURE 1. - Materials flow circuit used for production model. 1. Investment Cast . Cast alloys used primarily in gas turbine components. Usually made by two-step manufacturing method consisting of production of master melt ingot and then remelting for casting to shape. These alloys are melted in relatively small furnaces and have the most stringent purity requirements of the six classes. 2. Hardfacing Cast . Alloys produced in the form of powders or rods for subse- quent use for hardfacing of metal components . 3. Wrought Nickel- and Cobalt-Base . Alloy production characterized by casting of ingots which are hot-worked to bar, sheet, plate, or wire. Extensive use of AOD refining by this industry permits use of lower purity raw materials than for invest- ment cast alloys of similar nominal composition. 4. Wrought Nickel-Iron Base . Production methods and product fonus very simi- lar to previous category „ These alloys are often made by stainless steel producers who may not make wrought nickel alloys. Also, scrap that is high in iron cannot be used in those alloys. 5. Heat-Resistant Alloy Castings . Alloys in this category usually contain carbon for strengthening, and components are made by centrifugal casting (tubes) or sand casting (furnace hardware) . 6. Corrosion-Resistant Alloy Castings . Alloys are normally made by companies specializing in casting components for handling corrosive fluids. The procedures and alloy compositions are generally similar to those used for heat-resistant castings. TABLE 1. - Nominal composition ranges of the classes of alloys studied ^' ^ Composition, percent Melting Alloy class ~ Cr Ni Co Fe methods Min. Max. Min. Max. Min. Max. Min. Max. 1. Investment cast nickel- and cobalt-base. 2. Hardfacing cast nickel- and cobalt-base. 3. Wrought nickel- and cobalt-base... 4 . Wroueht nickel— iron— base 5 5 15 12 15 10 30 30 25 30 30 20 10 5 75 75 80 45 35 30 70 70 80 20 25 39 39 20 20 20 55 88 88 a, b b, a c, a, b c, a. b 5. Heat-resistant alloy castings 6. Corrosion-resistant alloy castings b, c b, c ^A few alloys that fall outside these ranges are undoubtedly included in the avail- able statistics; however, these definitions account for a large majority of the alloys covered. ^Individual alloys may contain substantial quantities of additional elements includ- ing molybdenum, tungsten, columbium, tantalum, hafnium, titanium, aluminum, manganese, and silicon. See appendix C for actual compositions. ^Listed in order of relative importance, a — Vacuum, b — Air induction, c — Electric arc furnace plus argon-oxygen decarburization. Sources of Information Data on alloy production, melt charge make-up , scrap generation, and scrap disposition were gathered from a wide variety of sources including unpublished information, open literature, and verbal responses to direct industry inquir- ies. The authors had access to the market research efforts, purchased surveys, and in-house industry-related expertise of The International Nickel Co., Inc. The following were available from the literature: trade association reports. Government statistical reports, and Government-sponsored surveys and reports related to nickel alloy utilization, scrap generation, and disposition. The general literature sources used in this study are listed in the bibliography. Because 1976 was the year for which we had the most complete set of data on alloy production and distribution, it was chosen as the base year for this study. It is recognized that 1976 was an atypical year in that alloy produc- tion was lower than normal. Consequently, where pertinent, reference in the discussion is made to the situation expected for normal and high-production years . A survey was conducted, by telephone or personal interview, of technical or purchasing personnel of 53 organizations involved in producing or using the alloys covered by this study. This was done to obtain data for this report and to verify derived data and conclusions . The organizations contacted are listed in appendix D. This list is not totally inclusive but is a representa- tive sample of the industry. Reliability Most of the data contained herein are estimated or derived, since there is no mandatory reporting of this type of information by producers, manufac- turers, or scrap processors. Also, there are significant differences in pro- duction practices and terminology between various companies. Furthermore, in those reports that are available, there is considerable variation in the alloy industry and product nomenclature. Industry contacts were asked to give an overall assessment of their industry. The responses showed a 20-percent range in the estimates of scrap generated and utilized. Based on the variability found in the estimates of the quantity of product produced in each alloy class, an error of ±20 percent was estimated. Rounding Numbers contained in the data tables were rounded to the nearest tenth (generally percent or million pounds). Thus, some small inconsistencies may appear in the data tables due to rounding error. Assumptions Several assumptions were made with respect to the disposition of prompt industrial and obsolete scrap . Most of these assumptions were based on responses to our industry survey. They represent widely accepted industry views on scrap materials disposition on which specific data were not available. In the absence of quantitative data from scrap recyclers, it was assumed that only "identified" clean, solid scrap would be purchased by the alloy producer to make up the "purchased scrap" portion of the melt charge. Solids would be preferred over turnings for this purpose. It was also assumed that scrap was only recycled within the same alloy class. This was done to simplify the analysis, although some interchange takes place. The effects of this assump- tion on the results of the model are discussed in a later section. It was assumed that half of the remaining solid prompt industrial and obsolete scrap was exported and half was recycled within the United States as a charge material for stainless steel, cast iron, and low-alloy steel. The assumption that chromium-containing alloy scrap is exported was substantiated by study responses and by inference from Bureau of Mines statistics on related generic alloy classes. It was assumed that only the highest quality chromium-containing alloy scrap not being fully utilized by U.S. industries would be exported. There- fore, it was assumed that essentially all of the prompt industrial scrap turn- ings are recycled to the U.S. industries mentioned above. It was further assumed that grindings and mixed melt shop scrap (sometimes referred to as "refinery-grade scrap") are reprocessed for use in the U.S. steel industry because they are unsuitable for export or direct use in the melt charge and require special refining. Information Gaps The largest single information gap occurs with respect to the disposition of the large quantity of prompt industrial and obsolete scrap which is handled by the scrap dealers, reprocessors, and secondary refiners. This is a highly competitive industry, and quantitative responses to our inquiries were not forthcoming. Clearly, a broadly based survey of this industry would fill a major information gap. A representative of the National Association of Recycling Industries stated that the association did not keep separate sta- tistics on the materials covered by this study. RESULTS Alloy Production Estimates of 1976 production of primary product were made for the six alloy classes defined in table 1. These production figures are the baseline data used to calculate the additional data on raw materials and scrap genera- tion and disposition needed to complete the model. Estimates of production for individual alloys within each alloy class are listed in tables 2 to 7. Estimates are shown only for the most widely used alloys. Although the category other may in some cases represent a major portion of production, this classification includes many alloys that are produced in relatively small quantities. To assess the historical trends in alloy production and the quantity of obsolete scrap available, data were acquired on primary product sold over the period 1958-78. TABLE 2. - Estimated production of primary product for investment cast nickel- and cobalt-base alloys in 1976^ Alloy designation Quantity, million pounds Percent of subtotal Nickel-base alloys: Alloys 71 3C and 7i: B-1900+Hf JLC 5.0 2.0 2.0 1.5 1.0 6.0 28.6 11.4 RENE 77 11.4 INCONEL alloy 738 8.6 INCONEL alloy 718 5.7 Other 34.3 Subtotal 17.5 100.0 Cobalt-base alloys: X-40 2.0 1.0 1.0 1.75 34.8 FSX-414 WI-52 17.4 17.4 Other 30.4 Subtotal 5.75 100.0 Total 23.25 NAp NAp Not applicable. ^Alloy compositions contained in table C-1. TABLE 3. - Estimated production of primary product for hardfacing cast nickel- and cobalt-base alloys in 1976 Alloy designation Quantity, million pounds Percent of total Nickel-base cast rod^ . Nickel-base powder^... Cobalt-base cast rod^v Cobalt-base powder^ ... Total 8,1 100.0 ^Average composition, in percent: 59.5 Ni, 16 Cr, 8 Mo, 4 W, 5 Fe, 4 Si, 3 B, 0.5 C. ^Average composition, in percent: 52.8 Co, 5 Ni, 29 Cr, 2 Mo, 6 W, 3 Fe, 1 Si, 1.2 C. TABLE 4. - Estimated production of primary product for wrought nickel- and cobalt-base alloys in 19761 Alloy designation Quantity, million pounds Percent of total WASPALOY , INCONEL alloy 718 , INCONEL alloy 600 series , INCONEL alloys 750, 751 , INCONEL alloy 700 and UDIMET alloys 500, 700, RENE 41, 95 , HASTELLOY alloy X , HASTELLOY alloy C-276 , Other Total, 100.0 lAlloy compositions contained in table C-2 . TABLE 5. - Estimated production of primary product for wrought nickel-iron-base alloys in 1976^ Alloy designation Quantity, million pounds Percent of total INCOLOY alloys 800, 801, 802, 825 INCOLOY alloys 901, 903 A-286 16 10 5 10 5 34.8 21.7 10.9 ARMCO 20-45-5, V-57, N-155, RA-330, PYROMET 860. Other 21.7 10.9 Total 46 100.0 ^Alloy compositions contained in table C-3. TABLE 6. - Estimated production of primary product for heat-resistant alloy castings in 1976^ Alloy designation Quantity, million pounds Percent of total HK 20.2 11.2 8.0 3.7 2.1 2.1 1.5 1.1 1.1 1.1 1.1 38 HH 21 HT 15 HC 7 HP 4 HU 4 HN 3 HL 2 HF . 2 HD 2 Other 2 Total 53.2 100 ■^ Alloy compositions contained in table C-4. TABLE 7 . - Estimated production of primary product for corrosion-resistant alloy castings in 1976^ Alloy designation Quantity, million pounds Percent of total CF-8M 51.8 11.0 9.9 6.6 6.6 3.4 3.3 3.3 2.2 2.2 9.9 47 CF-8 10 CA-15 9 CN-7M 6 CB-30 6 CA-6NM 3 CF-3M 3 CD-4MCU 3 CF-8C 2 CA-40 2 Other 9 Total 110.2 100 ^Alloy compositions contained in table C-4, 10 For nickel-, cobalt-, and nickel-iron-base alloys, no data are available on historical production. Most relevant are the nickel consumption data from the Bureau of Mines Mineral Industry Survey ( 10) , but even these present prob- lems, since nickel consumption is reported for various alloy classes that are not precisely defined and that do not correspond to the alloy classes used in this survey. In addition, the alloy classifications used by the Mineral Industry Survey have changed three times over the past 20 years. This made it difficult to estimate historical production data for the alloy classes covered for this study. Instead the nickel consumption data for 1958-78 for the Mineral Industry Survey alloy classifications that are most nearly related to the four nickel-, cobalt- and nickel-iron-base alloy classes covered in this study were used to estimate alloy production figures. These data are given in table 8 and plotted in figure 2. It was assumed that the primary product growth rate for these four alloy classes followed the same growth rate as the nickel consumption statistics. This annual average growth rate is 2.1 percent over the period 1958-78. TABLE 8. - Annual primary nickel consumption (10) for superalloys, other nickel and nickel alloys, cast nickel alloys, wrought nickel alloys, high-temperature and electrical resistance alloys, and nonferrous alloys, 1958-78 (Million pounds) Year Super- Other 1 Cast nickel Wrought nickel HT and Nonferrous 3 Total alloys alloys alloys ER2 1958 NC NC NC NC 14.5 28.5 43.0 1959 NC NC NC NC 20.8 40.4 61.2 1960 NC NC NC NC 19.8 42.3 62.1 1961 NC NC NC NC 21.7 45.7 67.4 1962 NC NC NC NC 24.4 43.2 67.6 1963 NC NC NC NC 26.1 38.1 64.2 1964 NC NC NC NC 28.9 35.4 64.3 1965 NC NC NC NC 34.4 56.7 91.1 1966 NC NC NC "^91. 5 10.8 NC 102.3 1967 NC NC 7.1 74.2 8.6 NC 89.9 1968 NC NC 13.2 66.8 7.8 NC 87.8 1969 22.8 52.7 NC NC NC NC 75.5 1970 21.8 70.1 NC NC NC NC 91.9 1971 13.5 53.6 NC NC NC NC 67.1 1972 22.2 56.0 NC NC NC NC 78.2 1973 22.6 74.9 NC NC NC NC 97.5 1974 22.2 85.8 NC NC NC NC 108.0 1975 11.4 72.3 NC NC NC NC 83.7 1976 15.5 61.6 NC NC NC NC 77.1 1977 19.6 60.7 NC NC NC NC 80.3 1978 27.1 76.1 NC NC NC NC 103.2 NC Not categorized. ^ Other nickel and nickel alloys . ^High-temperature and electrical resistance alloys . ^Nonferrous alloys less 15.8 percent for copper base ^Cast and wrought. alloys 11 150 o 2 3 O Q. 100 50 X - NICKEL CONSUMPTION FOR HIGH TEMPERATURE ALLOYS (5.; D- WROUGHT NICKEL AND COBALT BASE. A-WROUGHT NICKEL-IRON BASE- V - INVESTMENT CAST NICKEL AND COBALT BASE. O- HARDFACING CAST NICKEL AND COBALT BASE. -V- 1960 1970 1980 1990 2000 FIGURE 2. Annual primary nickel consumption for high-temperature alloys, 1958-78 (10). Estimated primary production growth curves for investment cast, hardfacing cast, and wrought nickel- and cobalt-base alloys (dashed lines). The quantity of primary product produced for heat- and corrosion- resistant alloy castings was compiled by the American Iron and Steel Institute and based on estimates provided by the U.S. Bureau of the Census (,9) is given in table 9. Figure 3 shows the production of primary product for heat- and corrosion-resistant alloy castings over the 20-year period 1958-78 and indi- cates probable trends for the near future. 12 TABLE 9. - Annual primary production of heat- and corrosion-resistant alloy castings, 1958-78 (Million pounds) Year Heat Corrosion Total Year Heat Corrosion Total resistant resistant resistant resistant 1958 38.7 41.3 80.0 1970 47.2 97.8 145.0 1959 36.1 36.2 72.3 1971 42.5 88.1 130.6 1960 35.0 36.8 71.8 1972 36.6 75.7 112.3 1961 33.5 40.9 74.4 1973 39.9 82.6 122.5 1962 37.3 44.9 82.2 1974 69.4 72.6 142.0 1963 40.8 49.1 89.9 1975 65.2 100.1 165.3 1964 41.4 60.0 101.4 1976 53.2 110.2 163.4 1965 41.1 85.2 126.3 1977 45.2 93.6 138.8 1966 55.8 115.7 171.5 1978 51.8 107.4 159.2 1967 52.5 108.7 161.2 Source: Reference 9_ and Inco available) . internal reports (data for 1968 and 1969 not 300 6 - TOTAL O- CORROSION RESISTANT D-HEAT RESISTANT CO 200 o z O Q. 00 J_ X _L I960 1970 1980 1990 2000 FIGURE 3. - Annual primary production for heat- and corrosion-resistant alloy castings, 1958-78 (9). 13 Production Efficiencies Based on responses to this study, "production efficiency" for raw materi- als to primary product and for primary product to finished product was esti- mated. These values are listed for each alloy class in table 10. TABLE 10. - Production efficiencies by alloy class for raw materials to primary product and for primary product to finished product Alloy class Investment cast nickel- and cobalt-base, Hardfacing cast nickel- and cobalt-base. Wrought nickel- and cobalt-base Wrought nickel-iron-base Heat-resistant alloy castings Corrosion-resistant alloy castings, Primary product efficiency^ Finished product efficiency^ 40 60 54 54 98 98 ^Ratio of primary product to raw material melted. ^Ratio of finished product to primary product expressed in percent. The quantities of primary product produced for each alloy class (taken from tables 2 to 7) are listed in table 11, column 2. Using these data and the estimates of production efficiencies (table 10) , the raw materials melted (column 1) and finished product produced (column 3) were derived and are shown in table 11. TABLE 11. - Estimated production by alloy class in 1976^ (Million pounds) Alloy class Raw materials melted Primary product Finished product Investment cast nickel- and cobalt-base... Hardfacing cast nickel- and cobalt-base... Wrought nickel- and cobalt-base Wrought nickel-iron-base Heat-resistant alloy castings Corrosion-resistant alloy castings 29.1 10.3 180.0 92.0 102.3 234.5 23.3 8.1 90.0 46.0 53.2 110.2 9.3 4.8 48.6 24.8 52.2 107.9 Total 648.2 330.8 247.6 ^Derived from tables 2 to 7 and table 10. Melt Charge Makeup and Scrap Utilization In addition to production efficiencies, information on melt charge make-up was obtained through our study responses. Based on these responses, estimates were made of the percentage of "primary metal," home scrap, and purchased scrap used in the melt charge make-up for each of the six alloy classes. These percentages are given in table 12. Also given in this table are the quantities of raw materials that go into the melt charge make-up. 14 These quantities were calculated from the data of table 11 and the percentage esti- mates as shown in table 12. TABLE 12. - Melt charge raw materials Primary metal Home scrap Purchased scrap Alloy class Million pounds Percent 1 Million pounds Percent Million pounds Percent Investment cast nickel- and cobalt-base Hardfacing cast nickel- and cobalt-base Wrought nickel- and cobalt base.... Wrought nickel-iron-base Heat-resistant alloy castings Corrosion-resistant alloy castings. 13.0 6.5 72.0 36.8 22.5 54.0 45 63 40 40 22 23 2.4 0.8 84.6 43.2 41.0 105.6 8 8 47 47 40 45 13.7 3.0 23.4 12.0 38.8 74.9 47 29 13 13 38 32 Total^ 204.8 32 277.6 43 165.8 25 ■^Percent of total raw materials for melt charge. Grand total: 648.2 million pounds. To assess the economic forces affecting melt charge make-up, "producer" and selected "merchant" prices were obtained for primary metals and chromium-containing alloy scrap. This information is shown in tables 13 and 14. For comparison, pri- mary metals and scrap quotations are shown for February and May 1979. Note that the primary metals and scrap markets were extremely volatile in mid-1979 owing to gener- ally strong demand for metals and shortages of some elements . Cobalt and molybdenum prices were particularly volatile during this period. In addition to the quoted scrap prices shown in table 14, the metal value contained in these alloys was calcu- lated based on the producer price for the contained elements . These values are shown for comparison. TABLE 13. - Published producer prices of various forms of chromium and other selected primary metals in February and May 1979 (10,000-pound minimum lot size) Material Price per pound, dollars 1976 range February 1979 May 1979 Low-carbon f errochromiuml High-carbon f errochromium-'- Chromium metal Nickel pellets Ferronickel^ Iron squares (4-inch) High-quality steel scrap Cobalt , electrolytic Molybdenum pellets Titanium sponge Aluminum ingo t Tantalum powder , Columbium pellets , ^er pound of chromium. Per pound of nickel. ^"Merchant" price — $37.50 per pound. ^"Merchant" price — $32.00 per pound, 0.85- .41- 1.00 .50 2.44 2.20- 2.41 2.10- 2.34 .11- .13 .02 4.00- 4.90 5.60- 6.85 2.70 .41- .48 35.40-48.00 18.00-25.00 0.75 .42 3.10 1.93 1.75 .17 .06 25.00 10.51 4.00 .56 67.35 55.00 0.85 .46 3.20 2.85 2.80 .17 .05 325.00 ^11.15 6.50 .58 82.50 55.00 15 TABLE 14. - Prices quoted for identified solid seraph and calculated metal value for several alloys in February and May 1979 (10,000 pound minimum lot size) Alloy class Price per pound, dollars February 1979 May 1979 Alloy designation Quoted scrap price Calculated metal value^ Quoted scrap price Calculated metal value^ INCONEL alloy 718 WASPALOY Wrought nickel- and cobalt-base do 2.50 5.50 1.75 2.75 5.00 2.72 5.54 1.61 2.63 8.57 5.98 8.50 2.76 5.04 9.98 3.26 6 35 INCONEL alloy 600 Alloy 713C B-1900+Hf do Investment cast nickel- and cobalt-base. do 2.34 3.35 9.96 "•This material was classed as vacuum grade by the scrap dealer. -Based on producer prices for the contained elements as pure metals or master alloys. Scrap Generation The survey revealed three sources of alloy scrap generation. Home and prompt industrial scrap is generated by alloy producers and users during the raw material melting to primary production phase and the primary product to finished product phase of the production cycle. Scrap from both of these sources is generated rela- tively soon (less than 1 year) after the raw material melting operation. This scrap is assumed to be available for recycling in the same production year. Therefore, the quantity of available home and prompt industrial scrap can be calculated from production figures. Obsolete scrap, on the other hand, is generated long after finished product manufacturing. This form of scraj) is the result of parts and equip- ment replacement and service wastage. Obsolescence may occur any time after manu- facture and will depend on the design lifetime of the part, maintenance schedules, and the nature of the service. For the purpose of this study, based on responses to our survey, life cycles of 5 years for investment cast and hardfacing cast nickel- and cobalt-base alloys and 10 years for the other classes of alloys covered by this study were estimated. The survey information and the experience of the International Nickel Co. with industry practices made it possible to estimate the proportions of the various forms of scrap (solids, turnings, grindings, skulls, spills, slags, dusts, scales, wastes) generated from each source. The quantity and form of home scrap generated in 1976 are given in table 15. This same information is given in table 16 for prompt indus- trial scrap. Note that these data were derived from estimated production figures and efficiencies and estimates as to the form and relative proportions of scrap generated thereby. Table 17 shows the quantity and form of obsolete scrap which will be available, in the future, when finished products produced in 1976 from the chromium-containing alloys covered in this study are removed from service. The quantity of obsolete scrap available for use in 1976 was calculated using historical primary production data (fig. 2-3) as the base. Linear regression analyses were performed to determine the average annual primary production for 1958-78. It was assumed that the rate of obsolescence has a statistically normal distribution based on the average service life. Consequently, the average quantity of finished product produced in the year corresponding to start of the product life cycle was used to estimate the quantity of currently available obsolete scrap. These quantities are also given in table 17. 16 Note that the data used in subsequent sections on scrap utilization in 1976 are for currently available obsolete scrap. TABLE 15. - Quantity of home scrap generated in 1976, by scrap form and alloy clas s (million pounds) Alloy class Solids Turnings Grind ings Mixed 1 Waste Investment cast nickel- and cobalt-base. Hardfacing cast nickel- and cobalt-base. Wrought nickel- and cobalt-base Wrought nickel-iron-base Heat-resistant alloy castings Corrosion-resistant alloy castings 2.4 .8 79.2 40.4 40.0 103.3 5.4 2.8 1.0 2.3 0.8 .4 2.7 .7 1.0 2.3 1.0 .4 1.0 .7 6.1 14.1 1.7 .6 1.7 1.4 1.0 2.3 Total^ 266.1 11.5 7.8 23.3 8.7 ■'^ Mixed melt shop scrap . ^Grand total: 317.4 million pounds. TABLE 16. - Quantity of prompt industrial scrap generated in 1976, by scrap form and alloy class (Million pounds) Alloy class Solids Turnings Grindings Waste Investment cast nickel- and cobalt-base Hardfacing cast nickel- and cobalt-base Wrought nickel- and cobalt-base Wrought nickel— iron— base 11.3 12.6 6.4 0.7 1.5 18.9 9.7 1.0 2.3 1.6 1.5 7.2 3.7 0.4 .3 2.7 1.4 Heat-resistant alloy castings Corrosion-resistant alloy castings Total^ 30.3 34.1 14.0 4.8 ■"^Grand total: 83.2 million pounds, TABLE 17 . - Quantity of obsolete scrap represented by finished product produced in 1976 and obsolete scrap available in 1976, by scrap form and alloy class (Million pounds) Alloy class Future obsolete scrap •'• Current obsolete seraph Solids Grindings Waste Solids Grindings Waste Investment cast nickel- and cobalt-base Hardfacing cast nickel- and cobalt-base Wrought nickel- and cobalt-base Wrought nickel-iron-base 8.4 2.4 42.3 21.6 44.0 77.4 2.7 1.4 3.1 7.0 0.9 2.4 3.6 1.8 5.1 23.5 7.6 2.2 33.5 17.1 35.3 48.5 2.1 1.1 2.5 4.4 0.8 2.1 2.8 1.5 Heat— resistant alloy castings 4.1 Corrosion-resistant alloy castings 14.7 Total^ 196.1 14.2 37.3 144.2 10.1 26.0 ^Represents scrap that will occur when finished products produced in 1976 are removed from service through repair, service wastage, or dismantling. ^Represents scrap available for use in 1976 derived from earlier years' production. ^Grand totals: 247.6 million pounds of future obsolete scrap and 180.3 million pounds of current obsolete scrap . 17 Scrap Export Data on exports and imports of nickel waste and nickel alloy in 1965-78 were available from the Bureau of Mines (10) and are given in table 18. Some of the material included in this compilation is not included in the alloy classes covered by the current study; however, there is a large degree of overlap. Thus, these statistics serve as a useful cross-check on the results of the present study regarding alloy scrap exports. TABLE 18. - Quantity of nickel waste and scrap exported and imported annually, 1965-78 (10) (Million pounds) Year Exports Imports Net export 1965 1966 1967 1968 1969 13.4 11.7 27.8 30.5 34.2 17.7 11.2 14.9 12.5 12.5 16.3 31.9 16.8 9.3 4.6 3.7 4.4 7.8 6.4 5.2 2.7 4.6 5.3 7.4 4.7 4.7 6.4 7.4 8.8 8.0 23.4 22.7 27.8 1970 1971 12.5 8.5 1972 10.3 1973 7.2 1974 1975 5.1 11.6 1976 27.2 1977 10.4 1978 1.9 Average 18.6 5.4 13.2 DISCUSSION Materials Balance The data on primary and finished product production, distribution of raw materials for melting, and types of scrap generated and utilized for the U.S. alloy producing and using industries covered in this study are presented as materials balance flow charts in figures 4 through 9. These figures show the form of material and scrap and its flow from the raw material melting stage through primary and finished product production to component obsolescence. Figure 10 shows an overall weighted average material balance flow chart for the industries covered in this study. Use Patterns of the Alloy-Producing Industry The alloy-producing industry use patterns shown in figures 4 through 10 have been in existence for at least the past 10 years. This study revealed no significant evidence that these use patterns will change in the near future, These alloy producers favor the use of the maximum amount of home scrap (43 percent) of the "same alloy" composition supplemented with purchased scrap 18 i X o .n ' "o UJ Q- o 5 ^ c/) CO d ex. O z tr o H in in 5; X T3 o ■■; is on left side ounds is on r sit shop scrap en 9 _i o CO CO b CO en o Q 2 CC CO in in 2; - ^ E Q UJ CO a. < < I cr o o cr CO Q- o Cfl C\J _J 5 < < cr (T UJ < to CJ o o >- q: < q: o O o Q UJ X en 2 U- 1- o 3 Q O (E Q- 00 «D O -D n -5 -?: " CN CO ^ — UJ 1- C/) 1 ID ci UJ 1 rn ro UJ PJ 1- cn 1 " > ro 00 CM in ro (0 — ro O UJ X CO 2 Q ■z C3 ■9 6 W cO Q 00 a> (/) D _Q -1- D _Q O U • ^M -n •— r _) o ' u fl> _ii: ^ o o c M- .,_ w o o u ^ 0> u> c o u E o (/) -n >- L. u o ~~ X a LO LU Q^ ID O LL 1 O -Q f 'o UJ o X Q. < cr o en 00 CO X -a is on left side jounds is on r elt shop scrap tn Q _i o CO 00 00 CO g _j o en ro en ro o o -u u :^ Qj Q_ -S -5^ Q UJ 10 < X o cr 3 a - K 5 Q m ro 00 O CO Q UJ X en 2 u. t- o 3 a o q: Q. ro &i OJ lO ^ - tN n ^ ^^ UJ V- en < 5 1^ UJ t- en < 5 ci in UJ d 1— en < rO >- cr < cr CO _i < t- UJ O ro in ro O UJ X s O in ro CO o 2 Q 2 cr C3 lO IT) en o 2 Q 2 E en r^ d in OJ CO o 2 2 cr 3 1- r^ 6 in 00 ■a- t^ 00 a -J o >> O w o O _Q O U -a c D (U _iii U +- o w E D i i LU O 19 — «i o (C III _ 1- _ < ^ « Jd in ^ w ^ n :=: rr in o -^ a> (n — a CM 1 o 0) r\j a E w >> o (U w o c o i- o LU 3 O 4) O -D U ■- (1) «i) III rO 1- 0) < * ^ _^ tn h- o rvi 2 *■ (T in O ~ (n — 9 1 t <) (/) o (U w o O o . U 4- c u -^ o "c (/) en 'i- S: E NO LU O 5?i;_Q7n n 20 CJ o >- (/) T (T 1 < ^ q: UJ Q 2 cr CD - C/) ro O OJ 2 2 or -) H - — m O t „ E Q l- UJ o X r) CO Q ig U. Q. o 4) O -D U ■- . o c o w w 0) • r 3 o w () o ^ o o U *4- o LU O UJ Q. o o Q 05 III CU CO a < < I er (T CO -) CL 00 5 -J E ^ OJ in pj CM CO C\J _) o 5 < < tr tr UJ 1- 5 o CO 9 o 2 2 cr 3 u cj X u CO Q 2 O — tr CJ. Q. o w X n ■D C Q. O O E ^ o u (/) fl) — a o> l/l o c c -o o c »/) ^^ l/l 3 ^ w ~ O. 0) o r r o a> o -o u 0) X o c a +- w r) 0) ^ u D ^ O o X ::;i oo LU cm ZD O 21 PRIMARY METALS PURCHASED SCRAP HOME SCRAP Wuif RAW MATERIALS GRINDINGS 1.2 7.8 WASTE .3 8.7 SOLIDS 41.1 266.1 TURNINGS 1.8 11.5 PRIMARY PRODUCT SOLIDS 1.7 10.9 TURNINGS 4.5 29.3 GRINDINGS 1.9 12.5 WASTE .7 4.8 SOLIDS 3 19.4 (25 percent) of the same alloy, if possible, or alloy class . This is done primar- ily for the sake of economy and materials availability. Because of its intrinsic metal value and ready avail- ability, home scrap is equal to primary metal as a melt stock. Under noinnal eco- nomic conditions, purchased scrap is priced at about 80 percent of the primary metals price and has compar- able availability. This may not be true for complex alloys produced in small quantity (those in the other category) . Such alloys will require more primary metal because some alloy scrap is less available. On the whole, however, alloy pro- ducers use all their suit- able home scrap and as much purchased scrap as is allowed by metallurgical considerations . Use of a substantial quantity (32 percent, or about 200 million pounds) of primary metals in the raw material charge is dictated primarily by metal- lurgical considerations. In the cast and wrought nickel- and cobalt-base alloy-producing industries, larger percentages of primary metals are used in the raw materials charge. The main reason for this is to minimize the pickup of iron and other "deleterious trace elements," such as lead and tin, small quantities of which are harmful to high-temperature properties. For example, in investment cast nickel- and cobalt-base alloys, about 45 percent of the raw materials charge is primary metals, as compared to about 22 percent for heat-resistant alloy castings. About 63 percent of the charge is primary metal for the cast nickel- and cobalt-base alloys used for hardfacing owing to unavailability of scrap of suitable composition. TURNINGS I 6.3 FINISHED PRODUCT 1 ' ' y ' SOLIDS 30 196.1 GRINDINGS 2.2 14.2 WASTE 5.8 37.3 Percent is on left side of box« Million pounds is on right side of box Mixed melt shop scrap^, FIGURE 10. - Overall materials flow circuit. In developing the model, it was assiomed that scrap not recycled within an alloy class is downgraded or exported. This was done to simplify the cal- culations and because it was felt that the results would not be significantly altered. In some cases, this assumption is true; that is, cast nickel-base alloys cannot be readily used in the other alloy classes because of the 22 NICKEL BASE COBALT BASE INVESTMENT CASTING HARDFACING HARDFACING WROUGHT NICKEL piresence of undesirable ele- ments. A schematic diagram indicating a likely pattern of interclass scrap flow is shown in figure 11. This diagram indicates a net flow of scrap into the hardfacing cast nickel- and cobalt-base alloy categories and a prob- able inflow of stainless steel scrap for melting heat- and corrosion- resistant castings. Quanti- fication of this hypotheti- cal flow pattern will require a more detailed industry survey. It is unlikely that the superalloy and heat- and corrosion-resistant alloy casting industries will sig- nificantly increase the average percentage of scrap utilized in raw material charges. A major break- through in alloy melting and refining technology will be needed to allow recycling of additional high-alloy scrap. There is a trend in these industries for the alloy producers to buy prompt industrial and obso- lete scrap directly from fabricators , manufacturers , and end users rather than obtaining this scrap indi- rectly through scrap dealers. Several companies have recently set up scrap reproc- essing facilities to improve their utilization of scrap. Others are investi- gating processes to increase the efficiency of recycling home scrap material presently unsuitable for direct remelting. The trend is taking place because producers wish to develop more assured supplies of raw materials in time of severe primary metals shortage. While these new practices change the flow pattern of the purchased scrap component of the raw materials charge, they will not affect the relative quantity used. WROUGHT NICKEL-IRON HEAT RESISTANT ALLOY CASTINGS CORROSION RESISTANT ALLOY CASTINGS FIGURE 11. - Schematic diagram showing interclass scrap flow. 23 Scrap Utilization The disposition of the scrap generated in 1976 by the industries covered in this study was estimated from the general assessments given in response to inquiries or key assumptions where information was not available. Four cate- gories of scrap utilization were defined: "remelted," "lost," "downgraded," and "exported." The quantities of scrap distributed in these four categories are given in tables 19-22. Each category is discussed separately below. For convenience in comparing all four scrap utilization categories, this informa- tion has been summarized in table 23. TABLE 19. - Scrap requirements for remelting, by alloy class and scrap form and origin (Million pounds) Scrap of same alloy class Scrap of other alloy classes Alloy class Home Prompt industrial Obsolete solids Scrap totals Solids Turnings Solids Turnings 1 Investment cast nickel- and cobalt- base 2.4 0.8 79.2 40.4 40.0 103.3 5.4 2.8 1.0 2.3 11.3 5.4 2.7 3.0 1.0 2.3 2.4 18.0 9.3 35.3 48.5 ^2.5 ^24.1 16.1 Hardfacing cast nickel- and cobalt- base 3.8 Wrought nickel- and cobalt-base Wrought nickel-iron- base 108.0 55.2 Heat-resistant alloy castincs 79.8 Corrosion-resistant alloy castings 180.5 Total "^ 266.1 11.5 19.4 6.3 113.5 26.6 443.4 •'•Includes grindings. ^Requirement for average 24 percent chromium-20.5 percent nickel-balance iron alloy may be made up using wrought stainless steel and/or wrought nickel- and nickel-iron-base alloy scrap. ^Requirement for average 18.6 percent chromium-8.9 percent nickel-balance iron alloy may be made up using wrought stainless steel scrap. ^Grand total: 443.4 million pounds. Remelted Table 19 shows the sources of scrap for remelting by alloy class and scrap form. This information was derived from the scrap source data in tables 15 through 17 and the information on scrap use preferences received from previous inquiries. Note that in all alloy classes, except hardfacing nickel- and cobalt-base alloys, it was concluded that solid scrap is utilized to fill out the necessary scrap segment of the melt charge. In the case of 24 the hardfacing nickel- and cobalt-base alloy industry, there is a lack of suitable solid scrap and available turnings and grindings are therefore recycled as scrap feedstock. As noted previously, some solid scrap from other cobalt-base alloy classes may be used in the raw materials charge. TABLE 20. - Sources of lost scrap, by alloy class and scrap origin (Million pounds of contained metal) Alloy class Home Prompt industrial Obsoletel Total Contained chromium^ Investment cast nickel- and cobalt-base Hardfacing cast nickel- and cobalt-base Wrought nickel- and cobalt-base Wrought nickel-iron-base Heat-resistant alloy castings Corrosion-resistant alloy castings 1.7 .6 1.7 1.4 1.0 2.3 0.4 .3 2.7 1.4 0.8 2.1 2.8 1.5 4.1 14.7 2.9 3.0 7.2 4.3 5.1 17.0 0.4 .7 1.3 .6 1.2 3.2 Total 8.7 4.8 26.0 39.5 7.4 iRepresents current obsolete scrap available for use in 1976 derived from earlier years' production. ^Calculated from average compositions of table 25. TABLE 21 . - Sources of scrap downgraded, by alloy class and scrap form and origin (Million pounds) Home Prompt industrial Obsolete2 Total Contained Alloy class Grind- Mixed 1 Solids Turn- Grind- Solids Grind- chromium^ ings ings ings ings Investment cast nickel- and cobalt-base 0.7 1.0 18.9 1.6 2.6 6.6 0.9 Hardfacing cast nickel- and cobalt-base .4 .4 2.2 3.0 .7 Wrought nickel- and cobalt-base 2.7 1.0 3.6 18.9 7.2 7.8 2.1 43.3 7.9 Wrought nickel - iron-base 0.7 0.7 1.8 9.7 3.7 3.9 1.1 21.6 3.2 Heat-resistant alloy castings.... 1.0 6.1 2.5 9.6 2.3 Corrosion^resistant alloy castings .... 2.3 14.1 4.4 20.8 3.9 Total^ 7.8 23.3 5.4 29.3 12.5 16.5 10.1 ^Represents current obsolete scrap available for use in 1976 derived from earlier years . ^Mixed melt shop scrap. ^Calculated from average compositions of table 25 . "^ Grand total: 104.9 million pounds of scrap containing 18.9 million tons of chromium . Material Losses Dust, scale, and slag are generated during the production of the primary prod- uct. This material is contaminated and unsuitable for presently known recycling 25 technology. Table 20 shows the amount of this material, along with estimates of the amount of unsuitable scrap generated during the production of finished products (pickle sludges, electrochemical and electrodischarge machining wastes, and scales) and the amount of service wastage. The 40 million pounds of material lost in this manner in 1976 represents 6.1 percent of the alloy raw materials melted in that year. Included in this figure is 1 to 2 percent of solid scrap that is inadvertently lost during the scrap reclamation processes owing to misclassification. TABLE 22. - Sources of solid scrap exported, by alloy class and scrap form and origin (Million pounds) Alloy class Prompt industrial solids Obsoletel solids Total Contained chromium Investment cast nickel- and cobalt-base Hardfacing cast nickel- and cobalt-base Wrought nickel- and cobalt-base Wrought nickel— iron— base 3.6 1.9 2.6 7.7 3.9 2.6 11.3 5.8 0.3 2.1 0.9 Heat-resistant alloy castings Corrosion-resistant alloy castings Total^ 5.5 14.2 ^Represents current obsolete scrap available for use in 1976 derived from earlier years. ^Grand total: 19.7 million pounds of scrap containing 3.3 million tons of chromium . Downgraded This study revealed that a large quantity of superalloy scrap is under- utilized, in the sense that it is downgraded. This includes both solids and turnings, which may be of high quality, and grindings and mixed melt shop scrap (skulls and spills) , which are of lower quality. Downgrading is defined as reuse of alloy scrap as a raw material feedstock or reprocessed feedstock for remelting in an alloy class that has less stringent quality requirements. Scrap flow within the six alloy classes surveyed was not included in this anal- ysis. The quantity of scrap that is currently downgraded is given by alloy class and scrap form in table 21. This information was derived from tables 15, 16, and 17 using the assumptions discussed earlier. For instance, it was assumed that all of the turnings, grindings, and mixed melt shop scrap not being remelted are downgraded. In addition, it was assumed that half of the available solid scrap not being remelted or lost is downgraded. Responses to the survey supported these assumptions. Note that through the use of these assumptions, a simplified view of an extremely complex industry is presented. Therefore, while there are currently efforts underway to develop technology to recycle certain grindings, sludges, and so forth, the total of material recycled in this manner is currently small and will be neglected for the purpose of this study. 1 •-< /— \ o O O CN • 13 en u • • • CJ H rH •H U 0) •P O -p r ■M Q, to rH U e 3 cd o o VO o^ o o lO 13 (U O O T3 •H • • • O S' »^ C u CO rH IT) U r^ PLH -H 4J a> • pa " rH ^ o o O O o o O CO O U 13 a w cd d 5 Q) cd 1 -1 4J O (U 00 iH CX3 m rH r^ o «« •H m -u • • » • • M 4J CO ,o d- -^ vo (U CO O O H rH CN •H O CO ■ ' ■p 1 rn rn •H 4J a CO H Cd in tJ (0 S :3 ca «* CO 1^ « MH 13 0) CO S o r-« VO 1^ «;r O CO r^ (U • • » • • 13 T3 •s X iH rH rH rH CN 00 cu cd § •H 60 1 -• O (U vO CSJ . T3 >>4 e :i td • • • rH St O G 60 o ts •H CN 0\ lO r^ o rH 3 c ^< s u Cv) rH St C rH r-\ O ^ fl^ -H 4J •H « cu o • • M-l 1 0) ^ 00 Cd • ■M 1 0) ■u & " iH C^ o St r^ O CO t^ rH VO M H ;3 CO < » • • •H rH d) O 13 •H ^ CO IT) CVJ rH Csl in Cd Si- (a U G U r— CN > W Cfl . cd a U 3 S 2 00 >3- St O r^ o o • m rH rg CO a. CO • • (U ci C>4 -a • 1 • 4J o cu -H m rt cd > • ! >^ '. rH rH t^ • ^ . td • o CO o • o ' 'd • « O • P • p • CO •H > -H ' C! ' o rH • C ' cl o m c ! "^ • CO ' u rH > cd • 0) 00 CO • 1 ' rH • 1 • rH 4J > CO • •H • u 3 !>> td ' Cd • CO • o •• O o a CJ a 1 M (U ^ Cd « ua ti •H V ti CO cd a O 0) •H 1 1 CO 6 O 60 4J CU 4-1 s ■u O 4. +J ■p +J -l 1- CD -H H (U 13 CO ct m ct W) Cd 60 1 *. O P u s (U ^ 13 ►c 3 ^ 3 U V U CO a cd > c M c o o o Cd ct U Cd (U M « cJ td Cj >i o n . Exported (solids) 39.5 19.7 Total 317.4 83.2 180.3 580.9 •'•Does not include 26.6 million pounds of solid scrap purchased from outside alloy classes . Next, the finished product manufacturing cycle was examined. Through discussions with manufacturers and industry experts, it was determined that the overall average efficiency of utilization of primary product in the manu- facture of finished products was about 75 percent (38 percent of the raw materials melted). Thus, of the 330.8 million pounds of primary product of the six alloy classes studies, it was estimated that 247.6 million pounds was contained in finished products (heat exchangers, gas turbine engines, chemical process equipment) in 1976 and that 83.2 million pounds of prompt industrial scrap was generated. The form and disposition of this prompt industrial scrap are given in tables 31 and 32. Finally, discussions were held with end users, scrap dealers, and industry experts on the average life cycle and scrap practices for obsolete equipment. Based on these discussions, it was estimated that the average life cycle for 36 components made from cast nickel- and cobalt-base alloys was 5 years, compared with- 10 years for products made from the remaining four alloy classes . An estimate was then made of the quantity of obsolete scrap that would occur in 1976 based on primary production data from previous years. The amount of service wastage and the character, quantity, and disposition of obsolete scrap generated when obsolete equipment was removed from service in 1976 were then estimated. Thus, 180.3 million pounds of obsolete scrap of cast and wrought nickel-, cobalt-, and nickel-iron-base alloys and heat- and corrosion- resistant cast alloys was generated in 1976. Note this is lower than the 247.6 million pounds of finished products manufactured from these alloys in that year. The form and disposition of obsolete scrap generated in 1976 are given in tables 31 and 32. Regarding the overall recycling efficiency of these alloy producing and using industries, of the 580.9 million pounds of scrap generated from these six alloy classes in 1976, about 72 percent (416.8 million pounds) was remelted by the same alloy-producing industries, about 18 percent (104.9 million pounds) was downgraded into stainless steel and low-alloy steels, about 3 percent (19.7 million pounds) was exported, and about 7 percent (39.5 million pounds) was lost through landfill disposal. The lost material is primarily contaminated oxides which currently are unrecoverable. However, the 124.6 million pounds of scrap material estimated to be downgraded or exported in 1976 contained potentially recoverable critical strategic elements . The quantities of chromium, nickel, cobalt, iron, and other elements contained in scrap that is currently remelted, lost, downgraded, or exported are given in table 30. From this it can be shown that a significant amount of chromivim (22.1 million pounds) was downgraded or exported in 1976. Recov- ery of this chromium and other strategic metals would provide a significant quantity of the primary metals needs of these alloy-producing industries . CONCLUSIONS 1. A production model that defines the flow of materials from raw materials to obsolete scrap has been established for six related alloy classes produced by the superalloy and heat- and corrosion-resistant alloy casting industries. 2. Scrap has been identified according to quantity, alloy class, physi- cal form, grade or quality, origin, and destination. 3. The quantity and quality of scrap used for recycling and the proce- dures for using it are different for each alloy class. Generally, the requirements are most stringent for the high-nickel alloys, which use the purest and most costly form of primary chromium and the least amount of scrap. 4. The total quantity of scrap generated in the production and use of these alloys in 1976 was 580 million pounds containing 113.2 million pounds of chromium. Approximately 125 million pounds of scrap containing about 25 million pounds of chromium was downgraded or exported. About 40 million 37 pounds of scrap containing 7,4 million pounds of chromium was physically lost or considered as waste that was too contaminated to recover, 5. About 78 percent of the melt charge for heat- and corrosion-resistant alloy castings is scrap. This represents all of the available scrap of suit- able quality for that class; hence, there is little prospect for further improvement in recycling efficiency. 6. The current recycling efficiency for the other higher alloy classes is much lower (37 to 60 percent) owing to metallurgical constraints. Research aimed at improving recycling efficiency for these alloy classes would reduce the quantity of high-grade scrap now downgraded or exported. 7 . The model developed in this study could provide the basis for con- tinued surveillance of the field to develop a more comprehensive data base. 38 BIBLIOGRAPHY 1. Air Force Materials Laboratory, Metals and Ceramics Division. Summary- Report on Air Force Chromium Workshop. Air Force Systems Command, Wright-Patterson Air Force Base. May 1975, 138 pp. 2. Battelle-Columbus Laboratories (Columbus, Ohio). A Study To Identify Opportunities for Increased Solid Waste Utilization: Volume VI — Nickel and Stainless Steels (prepared for National Association of Secondary Material Industries, Inc.). June 1972, 113 pp. 3. Boyle, J. R. Manufacturing Methods for Strategic Materials Reclamation, Sixth Interim Technical Report. Pratt & Whitney Aircraft, Rept. AFML-IR-162-4-VI, AFML Contract F33615-74-C-5019, Sept. 30, 1975, 56 pp. 4. Cremisio, R. S. and L. M. Wasserman. Superalloy Scrap Processing and Trace Element Considerations. Proc. 1977 Vacuum Metallurgy Conf ., Pittsburgh, Pa., June 20-22, 1977. Science Press, Princeton, N.J., 1977, pp. 353-388. 5. Gordon, R. L., W. H. Lambo, and G. H. K. Schenck. Effective Systems of Scrap Utilization: Copper, Aluminum, and Nickel. BuMines OFR 18-72, 1972, 220 pp.; available for consultation at the Central Library, U.S. Department of the Interior, Washington, D.C. 6. Kusik, C. L., and C. B. Kenahan. Energy Use Patterns for Metal Recycling. BuMines IC 8781, 1978, 182 pp. 7. Kusik, C. L., H. V. Makar, and M. R. Mounier. Availability of Critical Scrap Metals Containing Chromium in the United States. Wrought Stainless Steels and Heat-resisting Alloys. BuMines IC 8822, 1980, 51 pp. 8. National Association of Recycling Industries. Recycling Nickel Alloys and Stainless Steel Scrap. June 1977, 20 pp. 9. U.S. Bureau of the Census. Current Industrial Reports. Iron and Steel Castings. M33A(78)-5, May 1978, 6 pp. 10. U.S. Bureau of Mines. Nickel. Mineral Industry Surveys, December 1958- December 1978. 39 APPENDIX A.— DEFINITION OF TERMS Aerospace Industry . — Manufacturers of airplanes, rockets, and attendant equipment . Air-Melt-Grade Scrap . — Mixed scrap of known alloy type, generally in solid form but may include turnings . Charge Materials (Melt Charge) . — Raw materials to be melted to provide an ingot or casting. Includes primary metals, purchased scrap, and home scrap . Continuous Casting . — A method of forming a bar or slab by continuously pouring molten metal through a nozzle into an open-ended mold. Solid metal is withdrawn continuously from the exit side of the mold. Corrosion-Resistant Alloy Castings . — Cast alloys used to resist corrosion by aqueous solutions at or near room temperature and hot gases at temperatures to 1,200® F. Includes those alloys defined as C-grades by the American Casting Institute. Downgraded Scrap . — A highly alloyed scrap metal used in the preparation of a less complex alloy (for example, a nickel-base alloy used as a component in a stainless steel charge) . Dust . — Fine, metal-containing particles formed during melting and working operations such as those collected in baghouses and electrostatic precipita- tors. These are usually fully oxidized and contain volatile impurities and nonmetallic elements. Equipment Life Cycle . — The average time period for which a particular part is expected to last in service prior to wearing away, corroding, or becoming inefficient. Exported Scrap . — Scrap metal that is generated in the United States and exported for sale outside the United States. Fabricator . — Organization that transforms a previously cast and/or wrought metal (primary product) into a finished product. Finished Product . — A completed part or structure that is ready for service. Grindings . — Scrap generated during the removal of metal by an abrasive wheel or belt. The waste includes particles of the metal being ground and the abrasive. Frequently they are contaminated with oil. Hardf acing . — Depositing metal on a surface by welding, spraying, or braze welding for the purpose of resisting abrasion, erosion, wear, corrosion, galling, or impact. 40 Heat-Res is tant Alloy Castings . — Cast alloys that are capable of sustained operation at temperatures in excess of 1,200° F. Includes those alloys desig- nated as H-grades by the American Casting Institute. Home Scrap . — Scrap generated by an alloy producer during the conversion of raw materials to primary product. Home scrap includes solids, turnings, grindings, skulls, slag, scale, and dust. Identified Scrap . — Scrap of known single-alloy designation. Generally only solids fall into this classification, and they are usually vacuvun grade. Intrinsic Metal Value . — The value of a quantity of scrap based on the current primary metal price of the individual alloying elements. Investment Casting . — Casting metal into a mold produced by surrounding an expendable pattern with a refractory slurry; the pattern is eventually removed by melting. Also known as precision casting and the lost wax process. Liquor . — Spent liquids from pickling, electroplating, and cleaning operations . Lost Scrap . — Dust, scale, slag, pickle sludge, electrochemical and electrodischarge machining wastes, and service wastage which are unsuitable for remelting or refining and are currently disposed of as landfill. In addition, this category includes lost solid scrap metal. Master Melt . — An alloy prepared for remelting by a foundry. Often pro- duced and sold by firms specializing in the business. Generally used as the melting stock for foundries making investment castings. Merchant Price . — Prices quoted by metal merchants or traders for primary metals and scrap. Prices vary according to market conditions and may be either higher or lower than producer price. Merchant prices for major primary metals are recorded on the commodity exchanges . Mixed Melt Shop Scrap . — Skulls and spills in which the solidified metal has trapped with it a significant amount (perhaps 10 percent) of refractory oxides, dust, or scales. These usually are not identified as to exact compo- sition, but are identified by alloy class. Near Net Shape Processing . — A process that produces an intermediate shape as close to final part dimensions as possible to minimize metal removal. Pow- der metallurgy and casting are examples. Obsolete Scrap . — Solids and grindings that occur when used equipment is overhauled or dismantled, and service wastage which occurs during the lifetime of the equipment. Primary Metal . — A raw material derived directly from ore that is used either by itself or with scrap to prepare a charge for melting. This category includes all new metals used during melting such as vacuum-grade chromium, ferrochromium, and electrolytic nickel. 41 Primary Product . — Cast or wrought, semifinished material prepared by an alloy producer. Includes master melt, sheet, plate, strip, bar, tubing, forging stock, welding products, powder, and rough castings. Producer ♦ — Organization that converts raw materials In the form of pri- mary metals, purchased scrap, and home scrap Into a cast or wrought form known as a primary product. Producer Price . — Price that a primary metal producer quotes for a product. Price statistics are usually published and recorded by publications such as American Metal Market. Production Efficiency . — A measure of output as compared to starting materials at any stage of the life cycle of a part. Production Model . — A mass balance model describing metals flow from raw materials through obsolete scrap. Prompt Industrial Scrap . — Scrap generated by a fabricator or manufac- turer during conversion of a primary product to a finished product at a location removed from the melting facility. This generally takes the form of clippings and punchlngs from sheet metal, turnings, and solids from heavier castings and wrought products and grlndlngs, sludges, and liquors from fin- ished operations. Purchased Scrap . — A raw material used for melting having an origin out- side the melt shop. This form of scrap may be purchased from another alloy producer, from a manufacturer, or as obsolete parts and can be obtained directly from these sources or through an Intermediary. Raw Materials . — The basic materials needed for melting an alloy; that Is, the metallic constituents. Including primary metals, home scrap, and purchased scrap. Recyclers .- — Organizations that collect, classify, and redistribute Industrial wastes and obsolete equipment for the purpose of recovering valu- able constituents. Recyclers Include scrap dealers and brokers, reprocessors, and secondary refiners. Refinery-Grade Scrap . — Mixed turnings and solids of unknown composition, oxides, grlndlngs, etc., that are generally unsuitable for remeltlng without refining. Remelted Scrap . — Solids, grlndlngs, and turnings that are used as part of the raw material charge for melting. Same-Alloy Scrap . — Homogeneous scrap of known composition that Is to be remelted Into a new alloy of the same designation. Little or no composition adjustment would be needed to meet alloy specification. 42 Scale . — Metallic oxides that form on the surface of metals during elevated-temperature exposure, generally produced during hot working or heat treating; they are of mixed composition and are often contaminated with oil. Secondary Metals . — Pure metals or master alloys prepared by a refiner from scrap. In some cases secondary metals may be metallurgically indis- tinguishable from primary metals. The distinction is further blurred by primary metal producers who introduce scrap metal into their refinery circuit. Service Wastage . — Generally unrecoverable loss of metal during service, caused by wear, spalling, oxidation, corrosion, etc. Also includes materials that are unrecoverable because of the nature of their service; that is, cer- tain military hardware, nuclear power system components, and general consumer items such as appliance heating elements and automotive parts. Skulls . — A layer of solidified metal on the walls of a furnace, ladle, tundish, or mold. This solid scrap usually has a significant amount of refractory oxide associated with it. Slag . — A mostly nonmetallic product resulting from the mutual dissolution of flux and nonmetallic impurities in smelting and refining operations. Slags often contain valuable metal dissolved as oxide or physically trapped as small metallic droplets . Sludge . — Scrap produced by electroplating, pickling, polishing, electro- chemical machining, and other industrial operations. Sludge generally has a low metal content and contains large quantities of chemical salt, oil, or water . Solids . — A classification for articles larger than about %-inch diameter. Includes casting scrap (misruns, gates, risers, imperfect castings), ingot hot tops, billet cropping, clippings, obsolete parts, etc. Spills . — Solidified drops and splashes of metal formed inadvertently during the pouring of molten metal. This solid scrap usually has a signifi- cant quantity of refractory oxide, dust, and scale trapped within it. Superalloy . — A general definition used for chromium-containing alloys based on nickel, cobalt, or iron developed for elevated temperature service where severe mechanical stressing is encountered and where surface stability is frequently required. Wrought heat-resisting stainless steels (>55 percent iron) are excluded from this classification. Trace Element . — Small quantity (<0.1 percent) of an element known to degrade the physical or mechanical properties of an alloy. Also commonly referred to as tramp and subversive elements. Many elements, including phosphorus, sulfur, lead, and tin, adversely affect the properties of nickel-base alloys. 43 Turnings . — A classification for scrap generated by machine tool opera- tions. Examples are turnings from lathes and chips from milling machines and shapers. All turnings may contain cutting oil and are usually cleaned, frag- mented, and compacted by recyclers. Underutilized . — Refers to scrap of a particular alloy class that is not remelted in that class, but for reasons of geography and/or economics and/or form is used to prepare a different class of alloy (downgraded) or is discarded. User . — An organization that uses a finished product until the product is retired from service owing to wear, corrosion, or inefficiency and/or is con- sidered to be obsolete. Includes aerospace, transportation, petrochemical, and energy conversion industries . Vacuum-Grade Scrap . — Scrap of the highest quality that is of known origin, identity, and composition. This form of scrap has not necessarily been previously vacuum-melted nor need it be used again in a vacuum furnace. Waste . — Materials generated during production and service that are not currently recovered. Includes dusts, floor sweepings, wear and corrosion products, and metals contaminated with salt, oil, or tramp elements or in a very dilute concentration such that they cannot now be economically recovered . 44 APPENDIX B. —DEVELOPMENT OF MATERIALS FLOW MODEL In the metals producing and using industries, it is possible to simplify an exceedingly complex system (number of alloys, production practices, and uses) by a materials flow diagram. The diagram shown in figure 1 represents a mass balance for these industries. This model has four discrete elements: raw materials, primary product, finished product, and scrap material. Each of these elements can be characterized in terms of the quantity and character of input and output materials. General Description of Model The following section summarizes how the production model was developed and used. Alloy classes were defined based on ranges of composition of Cr, Ni, Co, and Fe and distinct characteristics of the producing industries. Pro- duction practices, quantity of Products and scrap produced at each stage of production, and the character and disposition of scrap generated were all estimated, based on published information, Inco experience, and a selective industry survey. First, the quantity and average composition of primary production for 1976 were estimated. Second, the alloy producers provided an estimate of their efficiency of production and the relative quantity of primary metal, purchased scrap, and home scrap used to produce these primary products. The alloy producers also characterized and estimated the quantities of scrap gen- erated during their production cycle. From this information estimates were made of the quantity of home scrap that was recycled internally, downgraded, exported, or lost. Next, the finished-product manufacturing cycle was examined. Through discussions with manufacturers and industry experts, an estimate was made of the overall efficiency of utilization of primary product in manufacturing the finished product. From this, it was possible to calculate the quantity of finished product and quantity of scrap generated during the base year . These same sources were asked to characterize the scrap generated during the finished-product manufacturing cycle and to provide estimates of the relative quantities and disposition of this prompt industrial scrap. Finally, end users, scrap dealers, and industry experts provided esti- mates of the average life cycle, and indicated scrap practices for obsolete equipment. An estimate was made of the average life cycle of components made of alloys from each class, the amount of service wastage, and the character, quantity, and disposition of the obsolete scrap generated when the finished products were removed from service. This model was developed, for each of the six alloy classes covered in this study, by gathering data and information from many of the producers and users of the alloys and products. The model is applied to the wrought nickel- and cobalt-base alloy class in the following discussion for demonstration purposes . 45 Model Applied to Wrought Nickel and Cobalt Alloy Class Defining the Alloy Class The initial step in developing the production model is to define the alloy class. For the wrought nickel- and cobalt-base alloys, the ranges of Cr, Ni, Co, and Fe are as follows: 15 to 25 percent Cr, to 80 percent Ni, to 80 percent Co, and to 20 percent Fe. Compositions of typical alloys included in this class are given in table C-2. The production of these alloys is confined to a relatively small number of companies that have specialized facilities for melting and hot working. Quantity of Primary Product Experience has shown that the information that can be most accurately defined within a production circuit for a given year is the quantity of pri- mary product. This quantity was the starting point in developing quantitative data in the production model. Because there is no comprehensive reporting of production data for this class of alloys, an estimate based on a variety of data sources was made. For the wrought nickel- and cobalt-base alloy class, 1976 production was estimated at 90 million pounds. Further, estimates were made of the quantity of specific alloys produced within this alloy class (table 4). Combining the information in tables 4 and C-2, it was possible to calculate the average composition for the alloy class: 62.5 percent nickel, 18.2 percent chromium, 7.0 percent iron, 4.8 percent cobalt, and 7.5 percent other elements. This composition is representative of the raw materials that go into making up the melt charge and of the products and scrap generated throughout the production circuit. Constituents of the Raw Materials Charge The second step in developing quantitative data for the model was to estimate the quantity and makeup of the raw materials for melting. This could be done in one of two ways. First, detailed data on specific alloys and producers could be compiled to deteirmine total raw materials used. How- ever, it was found that this tjrpe of specific information was not available from many alloy producers and that available data are unreliable because raw materials inventories vary widely. An alternative approach, suggested by several alloy producers, was to estimate the average efficiency of production for each class of alloy. The figure for the wrought nickel- and cobalt-base alloy class derived from the survey was 50 percent. Thus, production of 90 million pounds of wrought nickel- and cobalt-base alloys in 1976 required melting and processing of 180 million pounds of raw materials. The alloy producers were asked to identify the types of raw materials used for melting. The responses showed that, on average, the raw materials charge consisted of 40 percent (72 million pounds) primary metal, 13 percent (23.4 million pounds) purchased scrap, and 47 percent (84.6 million pounds) home scrap. The purchased scrap was estimated to be 100 percent solids. 46 derived from prompt industrial and obsolete scrap. The industry currently recycles all of the solids and turnings generated as home scrap. Characterization of Home Scrap From the raw materials and primary product differential, it was estimated that 90 million pounds of home scrap was generated in producing 90 million pounds of wrought nickel- and cobalt-base alloy primary product in 1976. Based on the information provided by the alloy producers, it was estimated that home scrap consisted of 44 percent (79.2 million pounds) solids, 3 per- cent (5.4 million pounds) turnings, 1.5 percent (2.7 million pounds) grind- ings, 0.5 percent (1.0 million pounds) mixed skulls, spills, etc., and 1.0 percent (1.7 million pounds) waste. The alloy producers indicated that the solids and turnings were recycled within the melt shop, the waste material was disposed of in landfills, and the grindings and mixed scrap were sold to dealers or secondary refiners . Virtu- ally all of this material is believed to be downgraded, and much of the con- tained chromitmi and other metals is lost. Quantity of Finished Product Next, an estimate based on production efficiency was made of the quantity of finished product derived from the primary product. Based on various data sources (including direct inquiries) , it was determined that production efficiency at this stage is 54 percent. Thus 48.6 million pounds of finished product (heat exchanger, chemical process equipment, gas turbine, etc.) was produced in 1976. Character of Prompt Industrial Scrap Inquiries were made regarding the character of the scrap produced during finished-product manufacture. It was estimated that the 41.4 million pounds of prompt industrial scrap consisted of 46 percent (18.9 million pounds) turn- ings, 30 percent (12.6 million pounds) solids, 17 percent (7.2 million pounds) grindings, and 6.5 percent (2.7 million pounds) wastes. Regarding disposition of prompt industrial scrap, it was estimated that 5.4 million pounds of solids was recycled as purchased scrap by the wrought nickel- and cobalt-base alloy producers, either through direct sales or indirectly through dealers. The remaining usable prompt industrial scrap sold to scrap dealers and refiners was exported or downgraded. The 1.5 per- cent waste was disposed of in landfills. Character of Obsolete Scrap Manufacturers and scrap dealers were consulted to define the life cycle, service wastage, and decommissioning procedures for obsolete equipment con- taining wrought nickel- and cobalt-base alloys . From the responses to these inquiries, it was estimated that the average lifetime of these alloy compon- ents in such equipment (gas turbine components, heat exchangers, and chemical 47 and process heat equipment) is 10 years. Thus the 48.6 million pounds of finished product produced in 1976 will become a similar quantity of obsolete scrap in 1986. The obsolete scrap available for remelting in 1976 was esti- mated from 1966 primary production by assuming that production efficiencies were the same in both years. Therefore, the quantity of obsolete scrap in 1976 was 38.4 million pounds. Service wastage due to wear, corrosion, and misplacement accounted for a loss of material equal to 7.5 percent of the original manufactured product or 2.8 million pounds. The obsolete equipment yielded 33.5 million pounds (8.7 percent) of solids and 2.1 million pounds (5.5 percent) of grindings. Of the obsolete scrap, it was estimated that 14.2 million pounds of solids was recycled to the wrought nickel- and cobalt-base alloy producers, primarily through indirect sales. The remaining 19.2 million pounds of solids and 2.1 million pounds of grindings was sold for export or downgrading, The 2.8 million pounds of waste material was lost to the environment. 48 APPENDIX C— CHEMICAL COMPOSITIONS OF SPECIFIC ALLOYS This appendix presents the chemical compositions of some of the specific alloys that are considered to fall within the six broad alloy classes covered in this study. Hardfacing cast nickel-base and cobalt-base alloys were not included because of the many proprietary compositions which exist. An average cobalt-base composition and an average nickel-base composition are presented in table C-3. Frequent mention of specific alloys is made in this report. It will be readily seen that the six alloy classes surveyed are characterized by a large number of alloy compositions and designations, many of which are proprietary. Many companies apply a numerical system appended to a trade name for identi- fication of their alloys. In some cases, the numbers are dropped in popular usage and the trade names are applied to the most common alloys; for example, INCONEL alloy 600 is often simply referred to as INCONEL, even though this usage is discouraged by the producer. This report identifies alloys by cor- rect trade name designations when it is necessary for understanding the indus- try. In some cases, the alloys are produced by more than one company under license, but are still most often referred to by the trade name of the licen- sor. Use of these designations does not imply endorsement of the alloy or producer by either the Bureau of Mines , The International Nickel Co . , Inc . , or the authors of the report. The following list gives the owners of alloy trade names referred to in this report. ARMCO — Armco Steel Cojrp. HASTELLOY—Cabott Corp. INCOLOY — Huntington Alloys, Inc. INCONEL — Huntington Alloys, Inc. PYROMET — Carpenter Technology Corp. RA 330~Rolled Alloys, Inc. RENE — General Electric Co. RENE — Teledyne Allvac. UDIMET — Allegheny Ludlum Industries. WASPALOY — United Technologies, Inc. 49 TABLE C-1. - Compositions of cast nickel- and cobalt-base alloys Alloy designation Cr Ni Nominal compos Co ition, ^ weight- Fe Mo W percent Ta Cb Al Ti Hf Alloys 71 3C and 713LC B-1900+Hf RENE X-40 INCONEL alloy 738 INCONEL alloy 718 FSX-414 WI-52 12.3 8.0 14.6 25.5 16.0 19.0 29.0 21.0 74.6 65.0 58.6 10.5 61.8 52.9 10.0 NAe_ NAp 10.0 15.0 56.5 8.5 NAp 52.5 69.5 NAp NAp NAp NAp NAp 18.5 1.0 2.0 4.2 6.0 4.2 NAp 1.7 3.0 NAp NAp NAp NAp NAp 7.5 2.6 NAp 7.5 7.5 NAp 4.0 NAp NAp 1.7 NAp NAp nael 2.0 NAp NAp NAp .9 5.2 NAp NAp 6.1 6.0 4.3 NAp 3.4 .6 NAp NAp 0.8 1.0 3.3 NAp 3.4 .8 NAp NAp NAp 1.0 NAp NAp NAp NAp NAp NAp NAp Not applicable. ^Nickel- and cobalt-ba manganese, silicon. se alloys may also contain minor quantities of carbon, boron, zirconium, and other elements. TABLE C-2. - Compositions of wrought nickel- and cobalt-base alloys Alloy designation Cr Nominal composition,^ weight-percent Ni Co Fe Mo W Cb Al Ti INCONEL alloy 600 WASPALOY INCONEL alloy 718 INCONEL alloy 750 INCONEL alloy 751 INCONEL alloy 700 UDIMET 500 UDIMET 700 RENE 41 HASTELLOY alloy X HASTELLOY alloy C-2 76, RENE 95 ■ 15.5 19.5 19.0 15.5 15.5 15.5 18.0 15.0 19.0 22.0 15.5 14.0 76.5 58.4 53.0 73.3 72.5 46.3 53.7 52.0 55.4 48.4 57.2 Bal. NAp 13.5 NAp NAp NAp 29.0 18.5 18.5 11.0 1.5 2.0 8.0 8.0 NAp 18.5 7.0 7.0 NAp NAp 1.00 NAp 18.5 5.5 1.0 NAp 4.3 3.0 NAp NAp 3.8 4.0 5.0 10.0 9.0 16.0 3.5 NAp NAp NAp NAp NAp NAp NAp NAp NAp 0.6 3.8 3.5 NAp NAp 5.1 1.0 1.0 NAp NAp NAp NAp NAp NAp 3.5 NAp 1.3 .5 .7 1.2 3.3 2.9 4.2 1.5 NAp NAp 4.4 NAp 3.0 .9 2.5 2.5 2.6 2.9 3.5 3.1 NAp NAp 2.5 NAp Not applicable. %ickel- and cobalt-base alloys may also contain minor quantities of carbon, manganese, silicon, boron, and zirconium. Figures for Cb include Ta. 50 TABLE C-3. - Compositions of wrought nickel-iron-base alloys Alloy designation Cr Nominal composition, 1 weight-percent Ni Co Fe Mo W Cb Al Ti Mn Si INCOLOY alloy 800.. INCOLOY alloy 801 . . INCOLOY alloy 802.. INCOLOY alloy 825^. INCOLOY alloy 901.. INCOLOY alloy 903.. A-286 ARMCO 20-45-5 V-57 N-155 RA 330 PYROMET 860 21.0 20.5 21.0 21.5 12.5 15.0 20.0 14.8 21.0 19.0 12.6 32.5 32.0 32.5 42.0 42.5 38.0 26.0 45.0 27.0 20.0 35.0 43.0 NAp NAp NAp NAp NAp 15.0 NAp NAp NAp 20.0 NAp 4.0 44.4 44.5 46.0 30.0 36.1 Bal. 53.6 27.2 52.4 30.5 43.0 30.0 NAp NAp NAp 3.0 5.7 1.3 2.2 1.3 3.0 NAp 6.0 NAp NAp NAp NAp NAp NAp NAp NAp 2.5 NAp NAp NAp NAp. NAp NAp NAp 3.0 NAp .2 NAp 1.0 NAp NAp 0.4 NAp .6 .1 .2 .7 .2 NAp .3 NAp NAp 1.2 0.4 1.1 .8 .9 2.8 1.4 2.0 NAp 3.0 NAp NAp 3.0 0.8 .8 .8 .5 .1 1.4 4.0 .4 1.5 1.5 .1 0.5 .5 .4 .3 .1 .5 .4 .8 .5 1.2 .1 NAp Not applicable. %ickel-iron-base alloys may also contain minor and zirconium. ^Also contains 2.25 percent copper. quantities of carbon, boron. TABLE C-4. - Compositions of major heat- and corrosion-resistant alloy castings Alloy Nominal composition,! Alloy Nominal composition, 1 designation weight-percent designation weight-percent Cr Ni Cr Ni HK 26 26 20 12 HU 39 25 19 HH HN 20 HT 15 28 20 35 4 10 HL 30 20 28 20 HC HF 10 CF-8M^ HD 5 CF-8 20 10 CA-6NM 12 4 CA-15 12 1 CF-3M^ 20 10 CN-7M 20 26 CD-4MCu3 26 5 CB-30.... 20 2 CF-8C^ 20 10 HP 26 35 CA-40 12 1 (max) ■"■Heat- and corrosion-resistant alloy castings may also contain minor quanti- ties of carbon, manganese, and silicon. The balance of the composition is iron. ^Also contains 2.5 weight-percent Mo. ^Also contains 2 percent Cu. ^Also contains Cb; 8xC min, 1.0 percent max. 51 APPENDIX D. —COMPANIES AND ORGANIZATIONS CONTACTED DURING THIS STUDY Name Category^ Abex Corp , ^ ^p Air Force Materials Laboratory q^ EH AiResearch Manufacturing Co GTM. PM Alloy Engineering & Casting Co ^p ' CP Avco Lycoming Division qj^ Brown Boveri Turbomachinery , Inc qTM Cabot Corp ^ Cannon-Muskegon Corp ^p ^p Carondolet Foundry Co A.P CP Carpenter Technology ^ Certified Alloy Products , Inc AP , CP Chromalloy Corp ^ -p-^ Chyrsler Corp GTM, PM Detroit Diesel Allison Division GTM, PM Duraloy Blaw-Knox Inc AP CP Eaton Corp PM Electralloy Corp AP, SR Ferroalloys Producers Association PIA Ford Motor Co GTM, PM General Electric Co GTM, PM General Motors Corp GTM, PM Howmet Turbine Components Corp AP , CP Huntington Alloys , Inc AP Inco Metals Co . , Inc MP International Metals Reclamation Co . , Inc AP , SR International Nickel Co . , Inc MP Jet Shapes , Inc CP Kokomo Tube Co AP , CP Ladish Corp F Levin Metals Corp SD, SR Martin-Marietta Corp AP , PM National Aeronautics and Space Administration GA, EH National Association of Recycling Industries , Inc PIA Precision Castpar ts Co . , Inc AP , CP Prestige Metals Co SD, SR RSC Materials Technology Associates , Inc C Samuel Keywell, Inc SD, SR Samuel Zuckerman and Co SD , SR Shieldalloy, Inc AP, MP Solar Turbines International GTM Special Metals Co AP, CP Suissman and Blumenthal , Inc SD , SR Teledyne Allvac AP Teledyne Ohiocast AP, CP TRW, Inc AP, CP United Airlines , Inc EH U.S. Department of the Interior, Bureau of Mines GA United Technologies , Inc GTM, PM, Universal Cyclops Corp AP Westinghouse Electric Corp GTM, PM Williams Research Corp GTM. Wisconsin Centrifugal , Inc AP , CP Wyman-Gordon Co » ^ Private industrial association Product manufacturer Scrap dealer Scrap recycler INT.-BU.OF MINES, PGH., PA. 24692 II c; CmUFRHMFMT PRTMTTNC; nFFTrT ■ IqRtl - 325-970 lAP Alloy producer F: Forger PIA: C Consultant GA: Government agency PM: CP Castings producer GTM: Gas turbine manufacturer SD: EH End user MP: Metals producer SR: li^ ^'^ ^4.* o"".*. >, v' *l^Lr. Ou .V ^^. >.v V - 0' '"<(>.*•"• .'J) 'b V" \>' .. -^ •'" '^^ "^ 2- •' .1 .^■^ ^. -^^0^ .^-^^ ^ V A .0 ^^•^^. A^ A <^^ ^^ ^•i^. 0^ o"! "« *o O > aV .... -^^ .-o -V /?.* ,*^