. : : by .. . L ! - . I OFT ORNL P 3327 . . LA , EFEFEEEE . . . 엘엘에 ​의 ​01.25 1.4 1.6 MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS - 1963 .. ORNLP-3329 MASTER iki CESTI 520S C.$3.00 MN - 65 Conf.67053.3--5 POTENTIOSTATIC METALLOGRAPHIC ETCHING EXPERIMENTS* J. B. Buhr, T. M. Kegley, Jr., R. J. Gray RECEIVED BY DTIE OCT 2 1967 1 Oan • bls and Ceramics Division ge National Laboratory Oak Ridge, Tennessee • * • * v- . - .- - -- ABSTRACT ini... 11 . : 1. imia :. - . . . The potentiostat, which is an instrument for maintaining any desired electrical potential relative to a standard electrode, provides a means for maintaining a particular optimum potential at which a specific phase in the microstructure can be selectively etched electrolytically and dif- ferentiated from the remaining phases. The particular potential for op- timun selectivity must be found experimentally, and the potentiostat aids in this by allowing the potential to be varied as desired. ... .. - .. ... ... The purpose of the experiments described in this report was to obtain experience in the application of a potentiostat to the etching of metallo- graphic specimens and to acquaint ourselves with the possible use of poten- tiostatic etching for phase identification. . . . The experiments performed concerned (1) the etching of two-phase alloys of tin ard zinc in which little or no solid solubility is exhibited, (2) the etching of austenitic stainless steels which contained ferrite, and which were free of ferrite, and (3) the etching of heat treated type 310 stainless steel containing sigma phase. In the tin-zinc alloys, we observed the zinc phase to be selectively etched in IN NaOH at - 1.2 v vs saturated calomel electrode (SCE) and the tin phase to be selectively etched at -0.9 v (vs SCE). We observed the ferrite phase of cast 19.9 st preferentially in IN ESOat 1.35 v (vs SCE). When the cast 19-9 speci. . men was etched in I'N HCL we observed the ferrite, to, etch preferentially at • 0.42' v (vs SCE) and the austenite to etch preferentially at - 0.16 v (vs SCE). We were unable to preferentially etch the sigma phase of the type 310 stainless steel in either 1 N HNO, or 1 N HCl at any potential. We did observe . .. - - . -- *Research sponsored by the U. S. Atomic Energy Commission under contract, with Union Carbide Corporation. #J. B. Buhr, Summer Student Trainee, Oak Ridge Associated Universities. LEGAL NOTICE Thie report was prepared as an account of Government sponsored work. Neither the United ." - : States, por the Commission, nor any person acting on behalf of the Commission: A. Makes any warranty or representation, expressed or implied, with respect to the accu- - rioy, completeness, or usefulness of the information contained in this roport, or that the use of any information, apparatus, method, or process disclosed in this report may out infringe privately owned righto; or B. Assumes any liabilities with respect to the use of, or for damages resulting from the use of any information, apparatus, method, or process disclosed in this report. As used in the above, "person acting on behalf of the Commission" includes any om- ployee or contractor of the Commission, or employee of such contractor, to the extent that such employer or contractor of the Commission, or employee of such contractor prepares, dlaseminates, or provides access to any information pursuant to his employment or contract with the Commission, or his employment with such contractor. DISTRIBUTION OE THIS DOCUMENT IS UNUMITED marityisestavimas th that recrystallized austenite (formed in 25% cold worked type 320 stainless steel at 650°c) surrounding the sigma phase particles could be preferen- tially etched at 0.00 v (vs SCE) inl N HCL electrolyte which had been in use and contained dissolved metallic ions. AL .' INTRODUCTION Since the potential existing at an electrode largely determines the particular chemical reaction(s) which takes place at the electrode, im- portant information is obtained from controlled potential electrolyvis experiments. In a controlled potential electrolysis, & circuit for which · is shown in Fig. L, the potential of the working electrode relative to & reference electrode is maintained constant by varying the total applied voltage between the working electrode and an auxilliary counter electrode to compensate for changes in electrode potentials, overvoltages, and IR drop during the course of the electrolysis. Since manual adjustment of the applied voltage is tedious, control of the potential is usually by means of a potentiostat, which is an instrument for automatically maintaining: any desired potential between the working electi'ode and the reference elec- . trode. The potentiostat maintains the desired potential despite ele or chemical changes which may be occurring in the system. Controlled potential electrolysis tech with potentiostatic cor trol has been applied in analytical chemistry and in corrosion studies.<-* In metallography, potentiostiatic etching has been employed in the etching of metal specimens. In potentiostatic etching a particular optimum po- tential is maintained by means of a prtentiostat so that a specific phase in a specimen can be seleccively etched and thus identified. The experiments described in this report concern (1) the etchin two-phase alloys of tin and zinc in which little or no solid solubility is exhibited, (2) the etching of two different austenitic stainless steels, one with ferrite and the other without ferrite, and (3) the etching of type 310 stainless steel containing sigma phase. In these experiments an anodic polarization curve (potential-current diagram) was first determined, after which the specimen was repolished and etched potentiostatically at the poi tentials corresponding to the current maxima indicated by the polarization curve. APPARATUS The experimental setup depicted in Figs. 2 and 3 included a Duffers Model 600 potentiostat, two electrolytic cells (one containing a Beckman fiber junction saturated calomel reference electrode and one containing an auxilliary platinized platinum electrode plus the specimen working electrode), a 12 v automative storage battery, and a salt bridge (glass tubing with capillary ends) connecting the two cells. Electrolytes' used in the cells . 3 included 1 N Naon, IN EASO, IN HINO, and 1N ECI. In any given experiment, the same electrolyte was employed in both cells and in the salt bridge. The metallographic specimens, which were mounted in either epoxy resin or Bakelite, were prepared by grinding on silicon carbide papers, and me- chanically polishing, first on silk using Linde A abrasive and then on microcloth using Linde B abrasive. A stainless steel sheet metal screw driven into the mount to contact the specimen served as the electrical con- tact. : 1 ETCHING OF TWO-PHASE TIN-ZINC ALLOYS Tin-zinc alloys were selected for the initial es periment since these alloys could be made fairly easily, and Green et al.,'had previously shown that both tin and zinc phases in a binary alloy could be selectively etched through the application of a suitable electrical potential in a NaOH elec- trolyte. cependea was prepared by meating Alloy specimens of 0, 15, 50, 70 and 100 wt% zinc were prepared. The pure tin specimen was prepared simply by melting in & graphite crucible held over a Bunsen burner. The pure zinc specimen was prepared by melting at 500 C for 1 hr in a graphite crucible. suspended in & vertical furnace, stirring occasionally with a quartz rod. The tin-zinc allcys were prepared in a graphite crucible by melting the tin first and immersing the zinc in the molten tin; the tin-zinc alloys were then melted by heating 1 hr at 500°c. Anodic Polarization Curves . . . . Tae potential-current diagrams for pure zinc, pure tin, 15 wt% Zn- 85 wt% Sn alloy50 wt% Zn-50 wt% Sn alloy, and 75 wt% Zn-25 wt% Sn alloy are presented in Figs. 4 and 5. The current peaks corresponding to the dis- solution of zinc occurred between - 1.15 and -1.3 v, and most commonly at - 1.2 v. The current peaks corresponding to the etching of tin occurred at about - 0.9 v. . . . . . - . - - 1. The polarization curves we obtained for the tin-zinc alloys were rea- sonably reproducible. As Fig. 6 illustrates, our polarization curves were not in agreement with those of Steigerwald and Greene, particularly with regard to the location of the current maxima. The current maxina of Steiger- wald.and Greene's curves were located at slightly more negative potentials than we observed. The shape and form of our polarization curves were in general in agreement with theirs, however. Etched Microstructure We were able to selectively etch each of the airloy specimens so that at one potential the tin phase was etched and at a different potential the . 4. zinc phase was etched. As an example, Fig. 7 shows the 75 wt% Zn-25 wt% Sa specimen efter etching I min in 1 N NaOH at - 1.2 v, and Fig. 8 shows the same specimen after etching I min in 1 N NaOH at • 0.9 v. At - 1.2 v the zinc phase 18 etched, while at 0.9 v the tin phas0 18 otched. .... . ETCHING STAINLESS STEELS ..::::...... . .... Anodic polarization curves, shown in Fig. 9, were first determined for a cast 19-9 stainless steel containing ferrite and a type 347 stainless steel containing no ferrite.* AIN H2SO, solution was employed as the nd the range • 0.5 to + 1.7 V was covered. Two current peaks at - 0.25 and + 1.35 V were obtained for the cast 19-9 specimen, but only one small peak at - 0.25 v was obtained for the type 347 stainless steel specimen. * - :** Both the cast 19-9 specimen and the 347 specimen were then etched at the 1.35 v peak observed for the cast specimen. Figure 10 shows the etched microstructures which resuïted after etching the cast 19-9 specimen 2 min and after etching the 347 specimen 12 min. Although the grain boundaries were etched slightly, the ferrite phase in the cast specimen Was etched predominantly. Apparently the peak observed at 1.35 v for the cast 19-9 specimen is associated with the etching of the ferrite phase. . . omocionar The anodic polarization curve shown in Fig. ll was determined ior a type 304 stainless steel specimen* using ), 'N HCL electrolyte over a range of . 0.5 to + 1.7 v. After the curve was completed the 304 specimen exhibited deep pits and an etched grain structure, as shown in Fig. 12. The 304 spec- . imen was polished and etched at - 0.10 v and then polished again and etched at 0.20 v. Figure 13a shows the etched krain structure obtained at - 0.10 v with 1 'N HCl, while Fig. 130 shows the pitting obtained at + 0.20 v with 1 N : HCI. The region of negative potential of the anodic polarization curve shown in Fig. ll was examined more closely for the 304 specimen which contained no ferrite and for the cast 19-9 specimen which contained ferrite. The two anodic polarization curves which resulted are shown in Fig. 14. The greater height of the weak obtained with the 304 specimen as compared with that of the 19-9 cast specimen is partly due to the greater area of the 304 specimen. Even thougn the area of the 304 specimen was larger, a greater current was obtained from the cast 19-9 specimen at potentials less than • 0.26 v than was obtained from the 304 specimen. Since the 19-9 specimen contained ferrite; and the 304 specimen did not, we speculated that at some potential more nega- tive than - 0.26 v the ferrite phase of the 19-9 specimen would be etched preferentially. Indeed, we found that the ferrite phase was etched when the cast 1909 specimen was etched 5 min at • 0.42 v in HCl and the austenite was etched preferentially when the cast 19-9 specimen was etched 5 min at -0.16 v 1 - *The chemical composition of the cast 19-9 specimen and the nominal compositions of the types 347 and 304 stainless steel specimens are given in the Appendix.' ..5 in 11 HCl. Figure 152 shows the etched microstructure with the ferrite etched preferentially at - 0.42 v, while Fig. 156 shows the etched micro- structure with the aurtenite etched preferentially at - 0.16 v. ETCHING TYPE 310 STAINLESS STEEL CONTAINING SIGMA PHASE The three type 310 stainless steel* specimens which were to be etched potentiostatically were each heat treated 1980 hr at 650°C. Prior to this heat treatment, one was in the annealed condition, ** oue was cold worked 10%, and one was cold worked 25%. The amount of sigma formed during the 650 C beat treatment decended upon the amount of cold work in the specimen; the 25% cold worked specimen having the greatest amount of sigma. Tue me- tallographic identification of the signs and carbide phases was established essentially by the methods developed by Gilman. Figure 16 compares the microstructure of the 25% cold worked. specimen after etching with Vilella's etchant (95 m2 ethyl alcohol, 5 ml conc Hci, 1 g picric acia), after etch- ing electrolytically in conc NH,OR, and after etching electrolytically in 10 N KOH. Both sigma and carbide phases are revealed, Fig. 16a, after swabbing 60 sec with Vilella's etchant. Only carbides are revealed, Fig.160, after etching electrolytically at 1.5 v for 20 sec ia conc NH, OH, Only sigma phase is revealed., Fig. 16c, after etching electrolytically at 1.5 V for 2 sec in 10 N KOH. The distribution of the sigma in the 25% cold worked specimen is similar to that which Lena and Curryto observed for type 310 stainless steel which was 40% colå rolled and heat treated 300 hr at 1250 F C. According to their data the isolated areas of sigma represent regions in which strained austenite of one composition has recrystallized to form sigma, and unstrained austenite of another composition. Lena and Curry also noted the absence of caroide in the recrystallized austanite surrounding the sigma. . This absence they attributed to an increase in the solubility of carbon in the austenite associated with the formation of sigma. (b Anodic polarization curves obtained when each of the 650°c heat treated type 310 stainless steel specimens was placed in IN HINO, electrolyte are given in Fig. 17. All three of the specimens exhibited similar curves even though they had different amounts of cold work prior to the 650°C heat treatment. No current peaks were observed in the curves and so it was not possible to associate a particular potential with the preferential etching of a given phase. After the polarization curves were determined, the 10% cold worked and 25% cold worked specimens were repolished and etched poten- tiostatically at 1.05 v, then repolished and etched potentiostatically at: 1.35 V, and finally repolished and etched potentiostatically at 2.00 v.. Figures 18, 19 and 20 show the etched microstructures obtained at 1,05, 1.35, and 2.00 v in 1 N HNO3. There was no appreciable difference in etching behavior at the three potentials although, of course, the attack is more se- vere at the higher positive potentials, which can be compensated for by : decreasing the etching time. *Nominal composition of type 310 stainless steel is given in Appendix. **Quenched from 1900-1950°F. . .. ... . . : - 6. The potentiostatic etching behavior of type 310 stainless steel in. N HCl was quite different from that in 1 i HNO2. Figure 21 shows the anodic polarization curves obtained for each of the type 310 stainless steel speci- mens in IN HC). Only one peak was observed, which was at 0.00 v, for the 320 specimen which had been cold worked 25% prior to the 650°c heat treat. ment. After the polarization curves were completed the three type 310 stainless steel specimens vere repolished and etched potentiostatically at - 0,28 v, and then repolished and etched potentiostatically at 0.00 v in the IN HCL electrolyte, Figures 22 and 23 show the etched microstructures ob- tained at - 0.28 and 0.00 v in. N HCL. At neither potential was sigma concentrated were attacked mainly, while at 0.00 v recrystallized austenite surrounding the sigma particles was attacked mainly. meierein se on n ... o Using a fresh ln solution of HCl we tried to duplicate the results, shown in Fig. 23c, obtained at 0.00 v in obtained at 0.00 v in which the recrystallized austenite surrounding the sigma particles was attacked. But when freshly prepared IN HCL was used the recrystallize ustenite was attacked very little, as shown in Fig. 248. We again employed the same usedl N HCl solution and obtained the results showri in Fig. 246, which duplicates the earlier results. The attack of the recrystallized austenite would appear to be associated with a buildup of metallic ions in the electrolyte. We then employed as the electrolyte a synthetic.N solution of HCl containing 0.74 g/1 Nicla.6 H2O and 0.85 8/1 recl, 6 H20. With this synthetic solution we were then again able to etch the recrystallized austenite, as may be seen in Fig. 24c. Hemen en. w ...in CONCLUSIONS AND RECOMMENDATIONS .::. . These potentiostatic etching experiments yieided quite encouraging results as to the application of the potentiostat as a metallographic tool for the identification of microstnictural phases. The successful applica- tion of the potentiostat depended upon finding both a suitable electrolyte and the optimum electrical potential for selectively etching the particular phase to be identified. We successfully selectively etched the tin-rich and zinc-rich phases in the tin-zinc alloys and the ferrite phase in aus- tenitic stainless steel; but we were not entirely successful in selectively etching the sigma-containing type 310 stainless steel. ............ .... .... .. . Potentiostatic etching provides an alternate method to the usual chemical etching methods employed in metallography. The principal value of potentiostatic etching, however, is the selective etching and possible iden- ticular phases in the microstructure. To establish cri. teria for proper identification of microstructural phases by this method, potentiostatic etching should be used in conjunction with other methods of analysis, particularly analyses as performed with the electron microprobe and the microchisel. With this in mind, further investigation might include - 7. the combination of potentiostatic etching studies with 1. Electron microprobe analysis, 2. Use of the microchisel, as which 18 a mechanical device for extracting microstructural phases for either x-ray diffrac- tion or microchemical analysis. More specifically, the potentiostat may have an application in the selective etching and identification of phases in uranium systems of carbon and nitrogen, ::.... ACKNOWLEDGMENT : We wish to thank the Oak Ridge Associated Universities for providing James B. Buhr, who performed the experiments, the opportunity to work in its Summer Student Trainee Program : . . .... ..... APPENDIX Chemical Compositions of Stainless Steel Specimens Cast 19-9 (wt) Type 304 ss (wt %) Type 310 SS (wt %) Type 347 SS (wt of Carbon Manganese Silicon Chromium Nickel 0.05 0.86 0.98 0.08 max 2.00 max 1.00 max 18 to 20 8 to 12 0.25 max. 2.00 max 1.00 max 24 to 26 to 22 0.08 max 62.00 max 1.00 max 17 to 19 9 to 13 10 XC 19:08 8.72 Co-Ta 0.008 Phosphorus Sulfur 0.012 0.03.7 Aluminum REFERENCES 1. G. A. Rechnitz, Controlled-Potential Analysis, MacMillan Co., New York (1963). C. Edeleanu, Metallurgie 50, 113 (1954). 3. C. Edeleanu, J. Iron and Steel Inst. 188, 122 (1958). 4. N. D. Greene, Corrosion 15, 369 (1959). 5. C. Edeleanu, J. Iron and Steel Inst. 185, 482 (1957). 6. V. Cihal and M. Prazak, J. Iron and Steel Inst. 193, 360 (1959). . 7. N. D. Greene, P. S. Rudaw, L. Lee, Principles of Metallographic . Etching, Technical Report No. 2, Rensselaer Polytechnic Institute, Troy, New York, (June 1965). R. F. Steigerwald and N. D. Greene, J. Electrochem. Soc. 109 (11), 1.027 (1962). J. J. Gilman, Trans. Am. Soc. Metals 44, 566 (1952). A. J. Lena and W. E. Curry, Trans. Am. Soc. Metals 47, 193 (1955). 11. G., L. Kehl, H. Steinmetz and W. J. McGonnaga), Metallurgia 55 (329), 151 (1957) ... . FIGURE CAPTIONS Fig. 1. Manual Controlled Potential Electrolysis Fig. 2. Schematic Diagram of potentiostatic Etching Apparatus Y-73989 ORNL DWG 67-3228R Y-76716 ORNL DWG 67-3432 Fig. 3. Potentiostatic Etching Apparatus Fig. 4. Anodic Polarization Curves for Pure Zinc and Pure Tin. I N NaOH electrolyte. ORNL DWG 67-3431 Fig. 5. Anodic Polarization Curves for Tin-Zinc Alloys. I N NaOK electrolyte. ORNL DWG 67-6434 fig. 6. Comparison of 15 wt% Zn-85 wt% Sn Polarization Curve with Steigerwald and Greene's Curve for 15.9 wt% Zn Specimen. 1 N NaOH electrolyte. Y-73975 Fig. 7. Microstructure of 75 wt% Zn-25 wt% Sn Alloy After Etching 1 min at - 1.2 v (vs SCE) in I N NaOH. Zinc phase has been etched. 7-73974 Fig. 8. Microstructure of 75 wt% Zn-25 wt% Sn Alloy After Etching 1 min at - 0.9v (vs SCE) in 1 N NaOH. Tin phase has been etched. ORNL DWG 67-3229 Fig. 9. Anodic Polarization Curves for Cast 19-9 and Type 347 Stainless Steel. IN H2SO4 electrolyte. Y-73980 Y-73978 Fig. 10. Stainless Steel Etched Potentiostatically at 1.35 V (V8 SCE) in IN H2SO4 (a) Cast 19-9 stainless steel etched for 2 min. (b) Type 347 stainless steel etched for 12 min. ORNL DWG 67-3230 Fig. ll. Anodic Polarization Curve for Type 304 Stainless Steel. 1 N HCl electrolyte. Y-73975 Fig. 12. Surface of 304 Stainless Steel Specimen Afte. Completion of Polarization Curve for 1 N HCl Electrolyte. Y-73977 Y-73979 Fig. 13. Type 304 Stainless Steel Etched Potentiostatically in 1 N AC1. (a) Etched 2 min at - 0.10 v (vs SCE). (b) Etched 2 min' at 0.20 v (vs SCE). Fig. 1 ORNL DWG 67-3231 Anodic Polarization Curves for Type 304 and Cast 19-9 Stainless Steels. 1 N HCI electrolyte. Y-73982 .8-73981 Fig. 15. Cast 19-9 Stainless Steel Etched Potentiostatically in 1 N acl. (a) Etched for 5 min at - 0.42 v (vs SCE). Ferrite etched preferentially. (b) Etched for 5 min at - 0.16 v (vs SCE). Austenite etched" preferentially. Fig. 16 Y-75650 Y-75648 Y-75649 Microstructure of Type 310 Stainless Steel Cold Worked 25% and Heat Treated Subsequently at 650°C for 1980 Fr. (a) After swabbing 60 sec with Vilella's etchant (95 m2 ethyl alcohol, 5 ml conc HCl, 1 g picric acid). (b) After etching Electro- lytically at 1.5 v for 30 sec on conc NH,OH. (c) After etching electrolytically at 1.5 v for 2 sec in 10 N KOH. ORNL DWG 67-3232 Fig. 17. Anodic Polarization Curves for Type 310 Stainless Steel Specimens After 1980 Hr at 650°c. 1 N HNO3 electrolyte. í Y-74564 Y-74565 Fig. 18. Type 310 Stainless Steel Cold Worked and Heat Treated 1989 Er at 650°C. Polished and then etched potentiostatically at 1.05 v (vs SCE) for 10 min in 1 N HNO3, electrolyte. (a) 10% prior cold work. (b) 25% prior cold work. Fig. 19. Y-74567 Y-74568 Type 310 Stainless Steel Cold Worked and Heat Treated 1980 Hr at 650°C. Polished and then etched potentiostatically at 1.35 v (vs S.CE) for 10 sec in I N HNO, electrolyte. (a) 10% prior cold work. (6) 25% prior cold work. Y-74570 Y-74572 Fig. 20. Type 310 Stainless Steel Cold Worked and Heat Treated 1980 Ar at 650°C. Polished and then etched potentiostatically at 2.00 v (v8: SCE) for 2 sec in 1 N HNO, electrolyte. (a) 10% prior cold work. (b) 25% prior cold work. ORNL DWG 67-3233 Fig. 21. Anodic Polarization Curves for Type 310 Stainless Steel Specimens After 1980 Ar at 650°C. IN HCl electrolyte. Fig. 22 Y-74442 Y-74576 X-744173 Type 310 Stainless Steel After Heating 1980 Ar at 650°C. Polished and then etched potentiostatically at - 0.28 v (vs SCE) for 10 min in 1 N ici. (a) Prior condition - annealed. (b) Prior condition - cold worked 10%. (c) Prior condition - cold worked 25%. Y-74444 Y-74445 Y-74448 Fig. 23. Type 310 Stainless Steel After Heating 1980 Hr at 650°c. Polished and then etched potentiostatically at 0.00 v (vs SCE) for 1 min in I N HC1. (a) Prior condition - annealed. (b) Prior condition - cola worked 10%. (c) Prior condition - cold worked 25%. Y-75653 Y-75652 Y-75651 Fig. 24. Type 310 Stainless Steel Cold Worked 25%, Heat Trented 1980 Ar at Polished and then etched potentiostatically at 0.00 v (vs SCE) in IN HC1. (a) Etched i min in fresh 1 N HCL. (b) Etched i min in "used" 1 N HCL. (c) Etched 2 min in 1 N ACL containing 0.74 g/1 NiCl, i no and 0.85 g/1 FeCl2.6 H0. Y-79389 6 V D.C. SOURCE A = Ammeter for measuring current in working electrode - auxiliary electrode circuit M V=Voltmeter for measuring applied voltage A.E.-Auxiliary electrode S.C.E.- Saturated calomel electrode A.E. W.E. H.R.V. - High resistance voltmeter for measuring potential of working electrode vs saturated calomel electrode H.R.V. MANUAL CONTROLLED POTENTIAL ELECTROLYSIS 110 V-AC ORNL-DWG 67-3228R DUFFERS ASSOCIATES MODEL 600 POTENTIOSTAT _GALVANOMETER SERVING AS VOLT AND AMMETER 4V to o VOLTAGE ADJUSTMENT COARSE- FINE WORKING ELECTRODE (METALLOGRAPHIC SPECIMEN) 12-V AUTOMOTIVE BATTERY AUXILIARY ELECTRODE- SALT BRIDGE BE -SATURATED CALOMEL REFERENCE ELECTRODE . Potentiostatic Eiching Apparatus. انه مددة می : به : این . : له ادی : از اپ . . .. . . .. و ' h راه عد . . از بهترین نمونه :: 1 با م - 1 T و 1 ارد 1 دمتم . وید ! ما 1 . عمر من : . . ارد ، . . 2:32 , . - : مر ا ا ا : نا و کره ا : دی ۰ ۱۱: و ! | ترم " . 1 , . اامد " - . . . ا . . اما در بر . - . وید ه 1 1 ، ". . ,ا PM "، : نام * : " . . " ' ' - :: * مير * . . . . .. ,10 ". ا ، " " " 18 ا 1- ا 'و - : ) امام ا۔ ارد مه بی م کی ' مه : ) لا .3 ORNL-DWG 67-3432 ZINC C amo - --- - - - - 0-0-0-0-0-0-0- CURRENT (milliamperes) 4.0 -4.5 -4.0 -0.5 = 0 POTENTIAL VS S.C.E. (volts) Anodic Polarization Curves for Pure Zinc and Pure Tin. 1 N NAOH Electrolyte. ORNL DWG 67-3431 ô 120, ewy 00 g C 15 wt% ZINC ð r 50 wt% ZINC 75 wt% ZINC CURRENT (milliomperes) -.. - r o OE--- 101 o -1.5 -1.0 -0. 5 0 0.5 0 0.5 -1.5 -1.0 -0. 5 0 0.5 -1.5 -1.0 -0. 5 POTENTIAL VS S. C. E. (volts) Anodic Polarization Curves for Tin- Zinc Alloys. 1 N Na OH electrolyte. ORNL-DWG 67-6434 -- THIS EXPERIMENT STEIGERWALD AND GREEN'S CURVE ADJUSTED FOR 2 cm2 AREA CURRENT (milliamperes) - oco sogenambapo ambalo -1.0 -0.5 0 0.5 1.0 POTENTIAL VS S.C.E (volts) Comparison of 15 wt% Zn-85wt% Sn Polar- ization Curve with Steigerwald and Green's Curve for 15.9 wt% Zn Specimen. 9 N NaOH Electrolyte. است. . . م ... .رفتن بر روی وت م ۱۱: کرد ممممممممم.. سه .. . . .. . . . .. ده ; . - !! ! ا نا - و ۔ با : ORNL-DWG 67–3229 CAST 19-9 SS CONTAINING FERRITE CURRENT (milliamperes) 347 SS WITH NO FERRITE AU 5 -0. 0 0.5 1.0 1.5 POTENTIAL VS S.C.E. (volts) Anodic Polarization Curves for Cast 19-9 and Type 347 Stainless Steels. 1 N H, SO4 Electrolyte. E ) 2. • * . WH O . . clothes an : ; . . 47348.0 . . . Seperti . . et . . . . d . A w 4 . . . SUKI i + robe . . ..............com . I VS 11 wy: 1 , he D ST 12 I* . WA - 1 . . T! VE . T2 - 1 ,! 57?. til . 4. CA 773778 Nada TEL : 2 . Hotel i Lidi... . L # - ** . TWO ht St . 11 IT . . . SHES -- - . . LA C . 19. i ,, , Y WN . . 1..." 11 . Y TI . . - --- . ..,, .... * K ., . . . m . $ 2. 1. . 1 I Fig. 1e. Stainless Steel Etchent patentestaticoida at. 1.35 Volts (Us, S.c. 6.) I. IN H2 Sove(a) Cast 1919 stainless steel etched for a minia () Type 347 stainless steel.etched for 12 min.: 250X. ORNL-DWG 67-3230 CURRENT (milliamperes) • Anme OLO -0.50 -0.25 16-0-0-0-0-0 0.75 0 0.25 0.50 POTENTIAL VS S.C.E. (volis) Y Anodic Polarization Curve for Type 304. Stainless Steel. 4N HCI Electrolyie. ・・・ ….. . ……. ... りつろす ​ は ​しい ​こいつ ​● 巻き ​10 いいいい ​Sa 12 . . ' . 1 - - " Yas . 1 さい ​Tee " r 1本​、 ・ ●1 - NEPALI master bedre!" . " .. . ... . *.***. . . . . . ... ht: . . 7. * $ ? 1 in -. i n 1 .. - 304 Stainless Steei .!.:: Estance en main, this wiO, 10 s li jit *:!!!.. r . ; ORNL-DWG 67–3231 304 STAINLESS STEEL WITH NO FERRITE CURRENT (milliamperes) -CAST 19-9 STAINLESS STEEL CONTAINING FERRITE www 0 Owood 00g ba Oood co 0 0 0 od Oloo -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 POTENTIAL VS S.C.E. (volts). Anodic Polarization Curves for 304 and Cast 19-9 Stainless Steel IN HCI Electrolyte. . .. . 1 . - ?, AL LEXX ; . ; 17. ini . Y , , TT 0 1 SA . - ..4; 2 > . " . " * sed - 2. i. ) (1 3 1 * 1 2. 5 que u . Hi . . T1 ME a . . * S . AW L 3 - - . 1 . . 31: . ?. e f ? . i . . YOY . VP. ring sin. :) . ,i.. ( . . . * LA CI LI . .. . * 22 . 1 TV 1 . se ...? " . .... 3 . VID 2 ... ! ** . * 21 . 1 . . . . . . 14 Listing . . N . . . . . CY 02 1 :. :: PN . more ! I . - r 7 . . . . n 2. 1 mm ! 2 SO . .' . 11 -- . Prisi Cast !9-4 Stainless Steel Et1.09/ Pote istros tintes : ... nës! Didi Korona 5 praco.-0.42 MB ), tiesi'. tiene etter for breakin ibrage is b) Itality : 1 -:7 .. مسا.... . . . . . . نام و نام این ساختمان ها و نمونه متن . پر است این بهانه برای میهمان برنامه خنفور - . . . 7 . . 4 " . . . Route 10 22 Carbido com h ******** UL . i . *.*.. - ISTA Bolig B . MORE . .:. L 12 . . erit L , . V * . 1 . A " Sofia 19 S . . D 2 . . TUT + . e . 1. . . w 12 À C SU . . . of ... . A . - TUR ntents . TA 7 T - . 11: they . . . o re . . . S A . . . ? AU 1. . 4 . + y . . . 44 Å V . 521 1 . . 1 . . . . Com incs .. . PN. . . TA LE'. . A 1. 4. . . SMS . , 4 La7 TM > N 4 3 Ses > ht i 1 S 1 i i it. ti 1 2 73. Ylei475649. je 1975650 ..loosy (6) 475648 Fille messa e. Top 2 Heat 77... . peri66 (stl. Detta 3 - Erleri . mpa o ) pilarekin !!! i DS .. v (B) Hodin Pro : *** .ck Fra; 70:s so 1,51717 ales insti. ORNL-DWG 67-3232 ANNEALED - 10% COLD WORKED - 25% COLD WORKED CURRENT (milliamperes) Od -O A O -A- 0 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 POTENTIAL VS S.C.E. (volts) Anodic Polarization Curves for Type 310 Stainless Steel Specimens After 1980 hr at 650°C IN HNO3 Electrolyte. ** . . . .... ... . و . مه . الوزن - ۱ مر نم .. ! . | . . . . . .. .. .. ، دبی ، . م. تم نے دین یار و مد ! :/. . / . با ما . . . . . . . . . . . ، : ،اس ::: . . . . . . : : : : اسی : 11 ) س . .. ... " .. نے میر . . . . . . . . . . . * * * - بيا - کی ۱۲ ممه سسسسسسسسسممه.... بعد ... ه ا ا ' . ' خه - - - . ] t 11 . و |..- - و - - بهتر ----- --- مد - .. - و رول همه - CY . . . . ... = . . ا ه . 1( - . . م . . ما: من این رمان تمنا میری a / . : . 17 دی در میان این مردم با بود و باید به خه باتی خود را می بینه . . . انا .. . شد. به منه : . ها را . . مسعود کامل ( . . ... . . : : : : : . 1 . , , , | ... .......... .... ...... .... ....... .... : به ................. ا جا ۱ ....... اوه ... ..... او ر و ن کیا اور د ا * : : ... ا .. ... _ . ا ا م : . هم * دار او ا ..... .. م . م . ... . . . . ... بو نعیم نخاری ، لب هاته سه: م ج . . مندان ، دین یه تی و : ... : | | r .., . . (a); : - . . . . . . A 4 - AP1. OR NL-DWG 67-3233 8 8 ANNEALED - 10% COLD WORKED 25% COLD WORKED = 8 . ố ồ CURRENT (milliamperes) ồ ồ j o 6.6.0-6.0.0.O.C. to 0.3 -0.4 -0.3 -0.2 -0. 1 0 0.1 0.2 POTENTIAL VS S.C.E. (volts) Anodic Polarization Curves for Type 310 Stainless Steel Specimens. After 1980 hr at 650°C IN HCI Electrolyte. 19157.imarina mam; nr: V . Hatima ".. . *... nh : .;:, :,:!“..", " .. . .. ..''. '' 1 . C anfitra .. .. E TA AN . . . E . Y . HTI!.. orem L 11 ::! guien . 11 i 1 22 ?.. . . . 3 ' TH :,. . . ' .: . . 1 I I . . ... . ... ... ... . . . . . ....... ... .... ... . . . ... . .... .-- - . - 1 . * i . i 2 . 10 WC Imense STA - 1 - - - . . . & SE . ut -- L 3 ? 1 .1.1 C. 1, miem 1 . ... L . - 2 2 . . . - . 1. . IN the . st . 20 - . . . .. 6. LA . . . . i toim 1 ) 77444.5 escit 0.10 AR . * ! . 1 * " . . S . 2 11. 11 . C ir Timor Ii r i , . 1 im . 1 1 . 357 . " P e - 1 2 * . ini tentu MY . 1 . N . . L . " " i . . D . . 3 Honor 2 ..Boris i . eiii . ... 1 11 ... 1 2 . emil three . . . . " 1 .. 2 ID : titucemi . . p. 11 CA . | .. 1 . 11 • AS 1 X 1 . 12 *****--..-... m c -.-- PHY *** . END . . 7 DATE FILMED 11 / 7 / 67 .*, . -: i W ... '1" . 7 E. LT VG+ +