THE 'ETAL MIXER The easiest, simplest and most exact method of mixing iron by chemical analysis, with tables and ready made mixtures. Indispensable to Molders, Melters ^ per cent of C and 66-/3 per cent of A iron. As the A iron is composed of scrap iron and scrap steel, it means we are to use 33V3 per cent of each pig iron, scrap iron and steel. In checking off at these percentages we get the following results: Example — Pig iron Scrap iron Scrap steel A— Pig iron Scrap iron Scrap steel Silicon. 331/3% of 3.6% silicon equals 1 .200 % 331/3% of 2.2% silicon equals 0.733/ % 331/3% of 0.2% silicon equals 0.0662/^% Total silicon Loss in melting equals Silicon in casting Phosphorus. 33/3% of 0.55% phos., equals 33/3% of 0.60% phos., equals 33/3% of 0.05% phos., equals 2.000 0.2 % % Phosphorus does not lose or gain in melting 22 1.8 % 0.1833/ % 0.2000 0.01662/^ .4000 % B — Sulphur. Pig iron 33^37^ of 0.016% sulp., equals 0.00533/3% Scrap iron 33^3% of 0.07 % sulp., equals 0.02330/ Scrap steel 33/3% of 0.05 % sulp., equals 0.0166 V^ Gain in melting equals .03 C— Manganese. .07524|/4% Pig iron 33]/3% of 0.50% mang., equals 0.1662/^% Scrap iron 33/3% of 0.45 % mang., equals 0.150 Scrap steel 33^% of 0.50% mang., equals 0.1 66^/^ Loss in melting, equals Manganese from 80% ferro-mang., equals D — Total Carbon. Pig iron 33j/3% of 3.50% carbon, equals Scrap iron 33^% of 3.25% carbon, equals Scrap steel 33^3% of 0.08% carbon, equals E — Total carbon Pig iron 331/3% of 2000 lbs., equals Scrap iron 33!/^% of 2000 lbs., equals Scrap steel 33^%c of 2000 lbs., equals 0.483/3 0.100 0.383 0.367 0.750 % 1.16662/S%, 1.07431/3 0.02662/^ ^26762/^% 6662/^ lbs. 6662/i lbs. 6662/^ lbs. 2000 lbs. TABLE No. 21. This table shows that all the elements are nearly as we want them, except the manganese, which of course can be corrected to what we require with ferro-manganese. The 23 sulphur is slightly higher, but the high manganese will be liable to offset that much. As we desire 0.75 per cent manganese in our mixture and our irons have given us only 0.383 per cent, it is evident we must get 0.367 per cent from the ferro-manganese. To find the number of pounds of ferro-manganese to use, so as to get this 0.367 per cent manganese in the mix- ture, we will set the 80 per cent under C, the desired 0.367 under B, and figure out as in table 15 on correcting mix- tures or, using a shorter method which can always be done when figuring a one iron mixture like this, we will simply affix two ciphers to B, move the point two places to the right, then divide it by C. Example: — TABLE No. 22. TABLE No. 23 A. B. C. 80 0. .367 .80 -45^8 80)36.700(.457/8% 7q 320 4Q0 400 .3670% _=7/g 70 80 TABLE No. 24 2000 pounds .457/8 1750 10000 8000 9.1750 pounds 24 If you will look over Table 22, you will see we have accomplished the same results as we did in table 15, with :onsiderable less figuring. The figures show we are to use 45%% *^f ferro-manganese. Multiplying 80 per cent man- ganese by the .45%%, gives us our required 0.367%, as in :able 23, and to get the number of pounds of fero-manganese we are to use to get this percentage of manganese, we mul- tiply the full charge of 2000 pounds by the .45%%, which shows we are to use, 9.175 pounds of ferro-manganese as in table 24. By multiplying the 9.175 pounds by the 80%, A'ill give us the exact number of pounds of manganese, /ve will get from the fero-manganese which is 7.34 pounds. Now divide this 7.34 by 20, the number of 100 pounds in he mixture, will again give us our required per cent, 0.367 )f manganese, as in table 25. Example: — 9.175 80 20) 7.34000 (.367% manganese. 60 134 120 140 140 TABLE No. 25 Vlanganese from pig iron and scrap, equals 0.383% Vlanganese from 80% Ferro-Manganese, equals 0.367% Vlanganese in mixture 0.750% In shop practice the per cent of D and F in table No. Zl, and tables 22 and 24 is all we need figure. The other :ables are worked merely to prove the mixture. 25 MIXTURE FOR LARGE CYLINDER LINERS, ETC. Show Methods, if a Certain Per Cent of Some of the Irons Are to be Used We will make a mixture of 2000 pounds to contain 1 .0 per cent silicon. We must use 500 pounds of steel scrap containing 0.2 per cent silicon, and 500 pounds of liner scrap containing 1 .0 per cent silicon. We have besides some scrap containing 1.6 per cent silicon, and pig iron containing 2.2 per cent silicon. By adding the 0.2 per cent silicon to make up for loss in melting, our mixture will have to con- tain 1 .2 per cent silicon. The first thing to do when making a mixture with a given per cent of some of the irons is to find how many pounds of silicon the mixture must contain. Here we want 2000 pounds to contain 1 .2 per cent silicon, multiplying the 2000 by the 1 .2 per cent gives us 24 pounds of silicon. This is the amount we must get in this mixture. The next is to find how much the given irons will contribute to the 24 pounds, multiplying 500 pounds of steel by 0.2 per cent will give us 1 pound of silicon. The 500 pounds of liner scrap containing 1 .0 per cent will contribute 5 pounds more. This makes 6 pounds, leaving 1 8 pounds more for the other 1000 pounds of iron to bring in. Now, if we had some 1.8 per cent silicon iron, 1000 pounds of that would just make our mixture complete, by giving us the 18 pounds of silicon we require. And of course no more mixing would be necessary, but we have only 1 .6 per cent scrap, and the 2.2 per cent pig iron. So we must find how much of each of these we must use to complete the mixture. As we want 1000 pounds more iron, and 18 pounds of it must be silicon, that means it must contain 1 .8 per cent silicon, which of course is our desired silicon, and must be put under B, set- ting them down under their proper headings, they stand ready to be figured as in table 1. Example: — 26 A. 1.6 Tl B B. 1.8 1.6 26, C. 2.2 1 .8 Take B from C. Remainder .2 TABLE No. .4 2nd Remaindei Take A f IstR As we have shown in previous mixtures, when one remainder is as much again as the other, it means we are to take 33|/3% of the iron the smallest remainder represents, (which is C), and 66^% of the iron that the largest rep- resents — which is A. As we only want 1000 pounds more iron to complete the mixture this means we are to take 333|/3 pounds of pig iron, 666^ pounds of scrap iron. By taking the 500 pounds of steel, 500 pounds of liner scrap, 333J/3 pounds of pig iron, 666^ pounds of scrap iron, and multiply each one by the per cent of silicon it contains, will give us the 24 pounds of silicon we require in the mixture. Example: — Steel 500 pounds x 0.2% equals 1 lb. silicon Liner scrap 500 pounds x 1 .0% equals 5 lb. silicon Pig iron 333J/3 pounds x 2.2% equals 7!/3 lb. silicon Scrap 666^/3 pounds x 1 .6% equals 10^^ lb. silicon 20)24.0(1.2% sil. 20 40 40 TABLE No. 27. By dividing the 24 pounds by the number of 100 pounds in the mixture, (which is 20), gives us our required 1.2 per cent silicon. Here is another way to check it off, but as we were only figuring for half the mixture in table 26, we must take only half of each percentage thus obtained, mak- 27 ing it 162/^% of pig, or "C" iron, and 33^3% of the scrap, or "A" iron. Example: — Steel 25% of 0.2% silicon equals 0.050% silicon Liner scrap 25% of 1.0% silicon equals 0.250% silicon Pig iron \(iY3% of 2.2% silicon equals 0.3662/^ silicon Scrap 33^/3% of 1.6% silicon equals 0.533% silicon .200 %c silicon TABLE No. 28. By using this same percentage, the other elements if known, can be figured as in table No. 21. And the Man- ganese corrected as in tables 22, 23 and 24. Any number of different grades of iron can be mixed this way. Always leaving two irons, — ^one with lower and one with a higher silicon content than we desire to corect the mixture with. 28 WETHOD OF FIGURING WHEN A CERTAIN PER CENT OF STEEL MUST BE USED. This mixture would be suitable for heavy gas and lydraulic cylinders and other castings that require btrength md close grained enough to stand water pressure. We wish I 25 per cent steel mixture of 2000 lbs., to contain 1 .6 per :ent silicon, and 0.75 per cent manganese. We will use 12 )er cent manganese scrap steel to corect the manganese vith, we will use the following irons: Silicon Phos. Sulp. Mang. 'ig iron 3.007^ 0.5% 0.016% 0.5% 5crap iron 1.8 0.5 0.08 0.4 scrap steel 0.0 0.02 0.05 0.5 TABLE No. 29 By adding 0.2 per cent silicon, and 0.1 per cent man- ganese for loss while melting, will make our required silicon 1 .8 per cent, and the manganese 0.85 per cent. When mak- ng a mixture of this kind, I figure to get all the silicon from he iron, because of the small amount of silicon in the steel. 3n account of having to get all the silicon from the 1500 jounds of iron, that of course changes our desired silicon or the present, because the 1 500 pounds of iron will have :o carry enough silicon to give 1 .8 per cent to the full :harge of 2000 pounds of both iron and steel. To get this lew required per cent of silicon, we will divide the percent- age of silicon required in the whole charge, by the per cent jf the iron used, — which is 75 per cent. Please take note jf this rule. Example: — TABLE No. 30 TABLE No. 31 .75)1.800(2.4% A. B. C. 150 1.8 2.4 3.0 1.8 2.4 300 300 .6 .6 29 Table No. 30 shows our new required silicon must be 2.4 per cent, which means we are take enough of the pig iron and scrap to give us that amount and, according to table 31 we must use 50 per cent of each. As we only require 1500, that means we are to take 750 pounds of each A and C, together with the 500 pounds of steel and no more figuring is required, — except of course for the man- ganese. Example: — As we have 25 per cent steel, the other 75 per cent must be divided between A and C. Steel 25% of 0.0% silicon equals 0.0 % silicon Pig 37.5% of 3.0% silicon equals 1.125% silicon Scrap 37.5% of 1.8% silicon equals 0.675% silicon 1.800% silicon TABLE No. 32. Table 32 shows our figures are correct and is a much shorter method than table 27. We will now figure the man- ganese.^ Taking the same percentage as in table 32 we will see how much manganese the irons figured have already brought into the mixture. Example: — Steel 25% of 0.5% equals 0.125 % manganese Pig 37.5% of 0.5% equals 0.1875% manganese Scrap 37.5% of 0.4% equals 0.150 % manganese 0.4625% TABLE No. 33. Table 33 shows our mixture already has 0.4625 per cent manganese. As we desire 0.85 per cent we must get the other 0.3875 per cent from the 12 per cent manganese steel scrap. This 0.3875 per cent of course is what we desire, and must be put down under B. The 12 per cent man- ganese under C, and figured as in table 22. Example: — By using the figure 3 in table 34, we save a lot of figures and it does not affect the result. 30 A. B. C. 0. .3875 12 12)38.7500(3.23% 36 27 24 35 36 TABLE No. 34. Table 34 shows we are to take 3.23 per cent of C. To find how much steel scrap we are to use, we will multiply the full charge of 2000 pounds by 3.23 per cent, which gives us 64.6 pounds. Multiplying the 64.6 pounds by the per cent of manganese it contains, which is 12, — gives us the exact amount of manganese this 64.6 pounds adds, — which is 7.752 pounds. This again divided by 20, the number of 100 pounds in the mixture, will give us our required per cent of manganese. Multiplying the 12 by 3.23 per cent, will also give us our required per cent of manganese. Example: — 2000 20)7.7520 03.23 64.6000 lbs. .3876% man. 64.6 12 .12 03.23 7.7752 lbs. .3876% Manganese from mixture 0.4625 Manganese from 12% steel 0.3876 Total manganese equals 0.8501% 31 TABLE No. 35 Using the figure 3 in table 34, altered the result but slightly, and saved a lot of figures. To use this 64.6 lbs. of 12 per cent manganese steel, we would take out that amount from the 500 pounds of the common steel scrap. MuTHOD OF FIGURING THREE OR MORE ELEMENTS EXACT IN THE SAME MIXTURE We have shown in previous mixtures how to get the exact percentage of both silicon and manganese in the same mixture. The silicon is figured correct, and the manganese is corrected by the use of ferro-manganese. But now, sup- pose we have to get another element exact, — say phosphorus — to specification? The best way to do it is to make two mixtures, both to contain the same per cent of silicon we desire in the final mixture, but one mixture to contain a lower and the other to contain a higher per cent of phosphorus than we desire in our final mixture. We then take the phosphorus contained in each of these two mixtures to figure the exact percentage of phosphorus we desire in our final mixture. So you see, when we have two mixtures, each containing the same per cent of silicon, no matter how much we use of each one to get our desired per cent of phosphorus in the final, mix- ture, the silicon will not be changed. Example: — We wish to make a mixture of 2000 pounds to contain 2.3 per cent silicon, 0.65 per cent phosphorus, and 0.75 per cent manganese. As we lose from 0.10 to 0.15 per cent in melting, we will make our mixture to contain 0.9 per cent manganese. Silicon Phosphorus Sulphur Manganese 2.00% 3.00% 2.25% 2.75% 0.4% 0.7% 0.6% 0.9% 0.04% 0.02% 0.03% 0.01% 0.60% 0.75% 0.65% 1.00% 32 TABLE No. 37. When mixing for Phosphorus no allowance is made for gain or loss in melting. For silicon we will add the 0.2 per cent, making our desired silicon for the mixture 2.5 per cent. We will make our first mixture from the first two irons, and our second mixture from the next two. You will notice we have tried to select two irons that will give us a lower and two that will give us a higher per cent of phosphorus than we want in our final mixture. Setting the first two irons under their proper heading they stand re^dy to be figured. First Mixture Second Mixture Silicon Silicon A. B. C. A. B. C. 2.0 2.5 3.0 2.25 2.50 2.75 2.0 2.5 2.25 2.50 .5 .5 .25 .25 TABLE No. 38. In both of these mixtures we get even remainders, which shows we are to take 50 per cent of all the irons. In our first mixture we get the lowest phosphorus 0.55 per cent, as 50 per cent of 0.4 per cent equals 0.20 per cent and 50 per cent of 0.7 per cent equals 0.35 per cent, adding these two together we get 0.55 per cent phosphorus, which is lower then we desire in the final mixture, but we get our desired silicon 2.5 per cent. In the second mixture taking 50 per cent of 0.6 per cent phosphorus equals 0.3 per cent and 50 per cent of 0.9 per cent equals 0.45 per cent. Adding these together we get 0.75 per cent phosphorus which is higher than we require in the final mixture. But, we also have the same silicon (2.5 per cent) in both mixtures. Now we have two mixtures, both containing the same per cent silicon, but one has a higher and the other has a lower per cent of phosphorus than we 33 want in the final mixture. So we will take these two per cents of phosphorus with our desired per cent and set them under their proper heading and figure as in table No. 1 . Example : — A. B. C. Phosphorus .55 .65 .75 .55 .65 .10 .10 TABLE No. 39 As both remainders are the same again, it shows we are to take 50 per cent of each mixture, which will give us our required per cent of phosphorus and the required per cent of silicon in the final mixture. As we are to take 50 per cent of each of the first mix- tures, and each mixture contains two irons, it is apparent that we are to take 25 per cent of each iron. Example: 25% of 2.00% silicon equals 0.50 % 25% of 3.00% silicon equals 0.75 % 25% of 2.25% silicon equals 0.5625% 25% of 2.75% silicon equals 0.6875% 2.5000% )ilicon loss in melting 0.2 % Silicon in castings 2.3 % 25% of 0.4% phosphorus equals 0.100% 25% of 0.7% phosphorus equals 0.175% 25% of 0.6% phosphorus equals 0.150% 25% of 0.9% phosphorus equals 0.225% Total phosphorus 0.650% 25% of 0.6 % Manganese equals 0.150 % 25% of 0.75% Manganese equals 0.1875% 25% of 0.65% Manganese equals 0.1625% 25% of 1.00% Manganese equals 0.25 % 34 0.7500% TABLE No. 40 Our mixture gives us 0.75 per cent Manganese, leaving 0.15 per cent for the fero-manganese to bring in. As this 0.15 per cent is what we require, we will set it under B. The 80 per cent ferro-manganese under C and figure as in tables 22, 23, 24 and 25. A. B. C. 0.15 80 Affix two ciphers to B, move the decimal point two places to the right and divide by .80. Example: — 80) 15. 0000 (.1875% of C. Ferro-Manganese. 80 700 640 600 560 400 400 2000 lbs. 80 .001875 .001875 3.750000 lbs. Ferro-Mang. . 1 50000% TABLE No. 41 Our figures show we are to take 00.1875 per cent of C ferro-manganese, by multiplying the 80 per cent ferro- manganese, by the 00.1875 per cent will give us our required manganese. And by multiplying the 2000 lb. charge by the percentage of ferro-manganese 00.1875 we are to use, will give us the amount of fero-manganese in pounds we are to use. Manganese from mixture equals 0.75% Manganese from ferro-man. equals 0.15% 090^ Loss in melting < 0.15 Total manganese equals 0.75% ■35 FRENCH SPECIFICATIONS FOR SHELLS OF 122 TO 155 MILLIMETERS CALIBER TO BE CAST IN SAND By Edgar Alien Custer in "The Foundry" Silicon Phos. Sulphur Mang. C. Carb. G.Carb. 1.2% 0.15% 0.08% 0.70% 0.70% 2.40% The above analysis are for dry sand molds, if cast in green sand, the silicon should be about 1 .35 per cent. The total carbon and silicon must not exceed 4.7 per cent. If this limit is exceeded, the iron will lack toughness, at least 20 per cent of the total carbon must be combined to produce proper fragmentation. The percentage of dust increases as the combined carbon decreases. The charge should be as follows: Pig iron 40 per cent, scrap 40 per cent and steel 20 per cent. The term scrap is used to denote scrap melted, pigged and charged according to analysis. All the foundries in France engaged in this work have been mobi- lized on a common basis, and are using precisely the same methods of selection, analysis and general foundry procedure. This has not been done without enormous losses and vex- atious delays. There have been many cases where the loss of a total heat has been reported, and the loss of 40 per cent was not uncommon in the first stages. Team work, scientific methods and keeping everlastingly at it, have brought results. Today, September 1917, the output has reached staggering proportions, over 1 ,000,000 rounds per day are being made. This must certainly be interesting to every metal mixer, and should have a tendency to induce him to try his hand at making mixtures for shells, so as to be prepared, to some extent, for any emergency. We will make a mixture as near as possible to the French specifications, from some Iron Mountain pig iron which I recently had analyzed, and some scrap we will presume contains the following analysis after it has been melted and pigged. 36 Sil. Phos. Sul. Mang. C. C. G. C. Iron Mountain 1.4% 0.14 0.011 1.22 0.60 2.70 Selected scrap 2.0 0.40 0.080 0.55 0.40 3.00 Steel scrap 0.2 0.01 0.040 0.50 0.10 TABLE No. 42 In making this mixture we will use the silicon in the steel, although as a rule I leave it out when making a mixture to contain a certain percentage of steel. According to the specifications our mixture must contain 1 .2 per cent silicon, adding 0.2 per cent for loss in melting, will make our desired silicon 1 .4 per cent. As we are to use 20 per cent steel, we will get 0.04 per cent from it, leaving 1 .36 per cent for the pig iron and scrap to bring into the mixture. Now, as we only want 80 per cent more iron, and this 80 per cent will have to carry enough silicon to give us 1 .36 per cent for the whole mixture of 2000 pounds, that means we are to find a new temporary per cent of silicon to wor"k with. So by using the same rule as in table 30 — that is by dividing the actual per cent of silicon desired by the per- centage of iron used in the mixture, which in this case is 80 per cent, we get the new per cent of silicon, 1.7 to work with, — see the point. We must get 1 .7 per cent silicon in 80 per cent of the mixture to give us 1.36 per cent more silicon to the whole mixture. Example: — TABLE No. 43. TABLE No. 44 .80)1.360(1.7% silicon. A. B. C. 80 1.4 1.7 2.0 1.4 1.7 560 560 3 .3 The result of table 44 shows we are to use the same percentage of each pig iron and scrap, which in this case is 40 per cent, with 20 per cent of steel. So figuring all the elements on that basis, we will see how near our mix- ture is to the specifications. Example: — 37 Iron Mountain 40% of 1.4% silicon equals 0.560% Selected scrap 40% of 2.0% silicon equals 0.800% Steel scrap 20% of 0.2% silicon equals 0.040% Loss in melting Silicon in mixture 1.400% 0.2 % 1.2 % Phosphorus. Iron Mountain Selected scrap Steel scrap 40% of 0.14% phosphorus equals 40% of 0.40% phosphorus equals 20% of 0.01% phosphorus equals 0.056% 0.160% 0.002% Phosphorus in mixture 0.218% Sulphur. Iron Mountain Selected scrap Steel scrap 40% of 0.011% sulphur equals 40% of 0.080%, sulphur equals 20% of 0.040% sulphur equals 0.0044% 0.0320% 0.0080% 0.0444% Gain in melting 0.0350% Sulphur in mixture Manganese. 0.0794% Iron Mountain 40% of 1.22% manganese equals 0.488% Selected scrap 40% of 0.55% manganese equals 0.220% Steel scrap 20% of 0.50% manganese equals 0.100% Loss in Melting Manganese in mixture 0.808% 0.100% 0.708% 38 Iron Mountain Selected scrap Steel scrap Iron Mountain Selected scrap Steel scrap Combined Carbon 40% of 0.6% C. C. equals 40% of 0.4% C. C. equals 20% of 0.1% C. C. equals 0.240% 0.160% 0.020% 0.420%, Graphite Carbon 40% of 2.7% G. C. equals i.yjoyc 40% of 3.0% G. C. equals 1.20% 20% of 0.0% G. C. equals 0.00% 2.28% TABLE No. 45. These tables show that all the elements are very nearly what the specifications call for. Even though phosphorus is a little higher here, there is not the least doubt it would be lower in actual practice, even from this mixture. If is was not, we would use two grades of pig iron, and melt and pig two different grades of scrap, and get our phosphorus exact, by the same method as in table 38 and 39. The carbons we cannot tell very much about till after analysis has been made from the mixture, because it is a semi-steel mixture. But both carbons will be well within specifications, which says the combined should be at least 20 per cent of the total carbon. As this mixture shows over 15 per cent, it is bound to be higher in the casting on account of the low silicon, and high steel in the mixture. Successful mixtures of this kind are not accomplished with one trial. And like the French foundrymen, only sticking everlastingly at it, would we accomplish the desired results. 39 SIDE LIGHTS ON MIXTURES In making some mixtures you will find when dividing your first remainder, that to get the exact result, you would be compelled to carry it out to several decimal places. Now, if it will not finish with one decimal place, just raise the last decimal or figure in the quotient, one more. Although the divisor will not go that many times, still it will save a lot of figures, and will not affect the result any. But, be sure and do this with the first remainder only, then you will always have the full percentage of the element you are figuring for. Example: — Suppose we wish a mixture of 1500 pounds to contain 2.2 per cent silicon. We will make it from 1.8 per cent silicon scrap, and 50 per cent ferro-silicon. TABLE No. 46 A. B. C. 1.8 2.2 50.0 1.8 2.2 .4 47.8 47.8 48.2) 40.000 ( .83% of C iron 3856 99.17% of A iron 1440 1446 As there are two more decimal places in the dividend than in the divisor, we point off two decimal places in the quotient making it .83 hundredths per cent of C iron to be used, and 99.17 per cent of A iron to be used. A iron 1.8% silicon Take 99.1 7% of A iron 1.78506% silicon .4150 2.20006% silicon C iron Take 50% silicon .0083% of C iron .4150% silicon 40 You will notice, by using the figure 3 in table 46 did not make any material difference to the result. But saved carrying the quotient to several decimal places. We will try another from 3.25 per cent pig iron, instead of ferro-silicon. A. B. C. 1.8 2.2 3.25 1.8 2.2 .4 .05 .05 .45)40.00(28% of C iron. 290 72% of A iron. 1100 1160 A iron Take TABLE No. 47. 1 .8% silicon 72% of A iron 1.296 C iron Take 3.25% silicon 28% of C iron .9100 .296 2.2060%r silicon Even by having too much by 60 in table 47 only added 6 thousandths of one per cent to the silicon, but saved quite a lot of figures. By taking advantage of this idea when you are dividing your first remainder, if the figures are inclined to run to several decimal places, you will always get the full percent- age of silicon, or any other element you may be figuring for. Table 46 says we are to take. .83 hundredths of one per cent of the C iron and 99.17 per cent of A iron. 41 Example : — Charge 1500 pounds 00.83% of C iron 1 500 pounds 99.17% of A iron 4500 12000 1487.5500 lbs. of A iron 12.4500 12.4500 lbs. of C iron 1500.0000 pounds Table 47 says we are to take 28 per cent of C iron and 72 per cent of A iron. Example: — Charge 1500 pounds .28% of C iron 12000 3000 420.00 lbs. C of iron 1500 pounds .72% of A iron 3000 10500 1080.00 lbs. A iron 420.00 1500.00 pounds. 42 MISCELLANEOUS MIXTURES These mixtures are taken from my note books and was cast several years ago from the following irons. The cast- ings answered their purpose and finished up clean. You will notice the steel mixtures are made from irons low in sulphur and phosphorus with manganese from 0.75 per cent up. Piston Valve Liners 70% Carron No. 1 ; Tranverse 2800 per sq. inch. 30% steel scrap; Silicon 1.6 per cent in casting. Hammer Block 60%. Foundry scrap; Tranverse 3600. 40% Steel scrap; Silicon 1.16 per cent. Stamp Heads 68% Shop scrap; Tranverse 3900. 32% Steel scrap; Silicon 1.09 per cent. V Gear 8' 6" Dia. 9" Face, Hub Split. 74% cyl. Niagara; Silicon 1.2 per cent. 26% Steel scrap. Large Marine Cylinder. Net Weight 34,020 lbs. 30% Gun iron; Silicon 1.7 per cent in casting. 30% Cyl. Niagara. 30% Shop scrap. 10% Carron No. 1 . McCully Crusher No. 7 85% Texada No. 2; Test piece Chilled 2% deep. 15% Steel scrap; Silicon 0.85 per cent. 90-inch Snap and Bull Rings 67% Carron No. I ; Silicon 1 .6 per cent in casting. 33% Steel scrap. 43 Two Marine Cyl-Liners, 6927 and 7134 lbs. Net 56.25% Gun iron; Silicon estimated 1.2%. 25.00% Carron; 1st liner cast 1.07%. 18.75% Steel scrap; 2nd liner cast 0.97% silicon. 16.000 pounds. Good For Strong Castings and S( imi-St( 2el Brand — Sil. Phos . Sul. Mang. C.C. F.C. G.C. Carron 2.8 0.50 0.035 1.45 3.64 Texada No. 2 1.25 0.30 0.025 0.90 Cyl. Niagara 1 .80 0.50 0.044 0.75 Car Wheels 0.70 0.40 0.16 0.50 0.9 2.90 Gun iron i.25 0.31 0.070 0.60 Iron Mountain 1.40 0.14 0.011 1.22 0.6 2.70 Irondale 2.30 0.16 0.035 1.10 Niagara No. 2 2.20 0.40 0.04 0.60 3.58 Muirkirk 2.21 0.28 0.031 2.22 0.55 3.01 Good for Soft Iron Work Sloss No. 1 3.60 0.65 0.03 0.45 Crown No. 1 3.25 0.71 0.022 0.50 Clifton No. 1 3.50 0.50 0.015 1.40 0.3 3.30 Mississippi 3.34 0.294 0.022 0.90 Grading numbers will correspond closely to the follow- ing percentages of silicon and sulphur. No. I Pig No. 2. No. 3. No. 4. Silicon 2.75 to 3.50% 2.25 to 2.75 2.00 to 2.25 1.75 to 2.00 Sulphur 0.02 to 0.04% 0.01 to 0.03 0.0 1 to 0.03 0.01 to 0.03 No. 5. No. 6. No. 7. No. 8. Silicon 1 .50 to 1 .75% 1 .25 to 1 .50 1 .00 to 1 .25 0.75 to 1 .00 Sulphur 0.02 to 0.04% 0.02 to 0.04 0.03 to 0.04 0.03 to 0.05 The following analysis of a few of the most important castings, will give the young student some idea to work on while making mixtures. 44 If from five to ten per cent of steel is mixed in these mixtures, it will strengthen and improve the castings for this class of work. Silicon Phos. Sulp. Mang. Hydraulic Cylinders 1.5 .40 .08 .8 Amonia Cylinders 1.6 .60 .09 .7 Air Cylinders 1.3 .45 .09 .8 Steam Cylinders, Heavy 1.6 .40 .09 .8 Steam Cylinders, Small 1.9 .55 .08 .6 Gas Engine Cylinders 1.8 .50 .07 .7 Locomotive Cylinders 1.6 .55 .08 .6 Automobile Cylinders 2.2 .50 .08 .7 Propeller Wheels 1.4 .30 .09 .8 Bed Plates, Heavy 1.9 .55 .08 .6 Dynamo Frames A • . 1 r 2.5 • 1 • .80 .07 ■I .5 Approximate rule for weighing pig iron in piles: If piled in the usual way 7!/4 cubic feet will weigh one ton. If very closely piled 7 cubic feet will weigh one ton. 45 THE INFLUENCE DIFFERENT ELEMENTS HAVE UPON THE IRON. Silicon. Silicon will soften the iron up to 3.50 per cent. When iron contains more it begins to get hard, short and brittle. Silicon increases fluidity, decreases shrinkage, open the grain of the iron and helps to turn combined carbon into graphite carbon, which helps to reduce the strength of the iron. In melting we lose about 0.2 per cent of silicon, which amount must be taken into account when figuring for silicon. Phosphorus. Phosphorus helps to make iron fluid and weak, so for all kinds of castings except the very thinnest, it should not be over 0.7 per cent. But for light, thin castings where strength is of no importance, it can run as high as 1 .0 or 1 .25 per cent. In fact iron for stove plate and that line of work require that much. Phosphorous lowers the melting point of iron, and decreases the shrinkage. In melting it neither loses or gains very much. So no provision for loss or gain is required when making mixtures. Sulphur Sulphur if too high will make the iron hard. Increase the shrinkage and promote chill, and cause the iron to con- geal quickly. If very high it will cause blow holes, shrinkage cracks and dirty iron. In all machinery castings it should be kept below 0.9 per cent if possible. In melting it gains about 0.03 to 0.035 per cent, chiefly from the fuel. This gain must be taken into account when making mixtures. Manganese. Manganese is one of the best elements we have in iron. It is a regular scavenger. There is no element that will cleanse the iron, reduce the blow holes, reduce the sulphur, 46 increase the strength and improve the grain hke manganese. When siHcon is normal for the work being made, manganese from 0.5 to 0.8 per cent will be alright. In melting we lose from 0.10 to 0.15 per cent. Graphite Carbon. Graphite carbon is a softener. It opens the grain of the iron, makes it soft, weaker and reduces shrinkage and chill. Combined Carbon Combined carbon is a hardener. It closes the grain of the iron, increases the strength, shrinkage and chill. In melt- ing there is no gain or loss, only that one form will change to the other according to the rate of cooling, and influence of the other elements, especially silicon and manganese. In the common, soft foundry pig irons, combined carbon will run about 0.30 per cent to 0.50 per cent. Graphite carbon will run about 3.0 per cent to 3.5 per cent. But as the iron is made harder by mixing, the carbons will change. Graphite carbon getting lower in per cent and combined carbon in- creasing in percentage, according, of course, to the per cent of silicon put into the mixture. Graphite carbon will be high, when silicon is high, and combined carbon will increase as silicon is lowered. Approximate per cent of Silicon for Different Castings I have found castings containing the following percent- ages of silicon, were satisfactory, both in machining and use. For light castings from % to one-inch in section. From 2.25 to 1 .9 per cent silicon. Castings from 1 inch to 2 inches in section. From 1 .9 to 1 .6 per cent silicon. Castings from 2 inches to 3 inches in section, from 1 .6 to 1 .3 per cent silicon. These figures are given to give the reader an idea how to regulate the silicon for castings of different section, and if the other elements are kept normal by selecting irons suitable for the class of work being made, will be entirely satisfactory for all kinds 47 of general machinery castings when figuring for sihcon only. For pulleys the silicon should range from 2.3 per cent to 2.6 per cent, and the sulphur should be kept below 0.06 per cent if possible. For large Marine cylinders with brackets and flanges liable to crack through unequal sections, the silicon should run from 1.6 per cent to 1.8 per cent. Ihe castings of course, always have liners of much harder metal. Small and medium sized cylinders with no liners should run from 2.0 to 1.6 per cent silicon, with 10 to 15 per cent steel. For large gear wheels, blank or otherwise should contain, — after 20 to 25 per cent steel has been added, — about 1 .6 per cent silicon. Car wheels, from 10-inch mining wheels, up to regular passenger car wheels, from 1 .5 to 0.70 per cent silicon. From 5 to 10 per cent steel scrap always helps the chill and strength of the wheels. All car wheels should be annealed as soon as possible after casting, by putting into a pit altogether. When selecting pig iron for small and medium castings, try and get iron containing less than 0.03 per cent sulphur, phosphorus about 0.7 per cent. Manganese about 0.6 per cent or 0.8 per cent, with graphite carbon about 3.25 per cent and combined carbon 0.25 per cent or under. In the castings the sulphur will average about 0.08 per cent. The other ele- ments will not vary very much. In the heavier castings the sulphur should not exceed 0.095%, phosphorus should be kept down from 0.4 to 0.5%, manganese about 0.8 to 0.9 per cent. Graphite carbon will run from 2.50 per cent to 2.75 and combined about 0.75 per cent. Judging the percentage of silicon in Different Kinds of Scrap. As a general rule light machinery scrap will contain about 1 .9 per cent to 2.25 per cent silicon. But sometimes we run across heavy scrap that runs that high in silicon. In that case, as a rule, the fracture will show a dark rough sur- face, full of shining particles of graphite, whereas the low silicon heavy scrap, will show a lightish, slightly rough frac- ture. AS Heavy scrap from 1^2 inches to 3 inches in section, will run from 1 .8 per cent to 1 .25 per cent siHcon. Standard car wheels — silicon 0.7 per cent, phosphorus not over 0.4 per cent, manganese 0.4 to 0.5 per cent, sulphur not over 0.17 per cent, graphite carbon from 2.5 to 2.9 per cent, combined carbon not over 0.90 per cent. Steel plate scrap contains silicon about 0.2 per cent, phosphorus from 0.01 to 0.05 per cent, sulphur form 0.03 to 0.05 per cent, and manganese 0.5 per cent, with total carbon about 0.10 per cent. Stove plate scrap runs about 2.75 per cent silicon, phos- phorus about 1 .0 per cent. Although stove plate scrap is high in silicon, it is a quantity that cannot be depended upon, on account of its thin section, both the iron and the elements in it are burnt somewhat, especially so if melted under high blast. Use it with judgment. If light and heavy scrap are brought together, it will pay to sort, and give each its proper rating, which with a little experience can soon be learned. DECIMAL FRACTIONS In adding a few examples on decimal fractions and percentage, I thought would be an advantage to those who have allowed themselves to get rusty on decimals — to have under the same cover, — as a ready reference while working over the mixtures. Addition of Decimals The only respect in which addition of decimals differ from simple addition is, in placing the decimal point directly over one emother. Example: — 26.346 .263 26.609 49 Substraction of Decimals Substract as in whole numbers, but keep the decimal points directly under each other, as in addition. Example: — 80.312 79.200 1. 112 32.3 2.3 969 646 Multiplication of Decimals Multiply as in whole numbers, and point off in the product as many decimal places as there are decimal places in the two factors, and if the product has not so many, supply the defect by writing ciphers on the left hand. Example: — 1st— 2nd— .33 .2 .066 74.29 Note: In the first example there are three decimal places, so must make three decimal places in the product by adding one cipher to the left hand of it. Division of Decimals Divide as in simple numbers and point off as many decimal places in the quotient, as the number of decimal places in the dividend exceeds the number in the divisor. If necessary prefix ciphers to the quotient; or affix ciphers to the dividend. When both dividend and divisor contam the same number of decimal places, the quotient is a whole number, without or with a remainder as the case may be. 50 Example : No. 1 Divide 60 by 1.5. No. 2. Divide 34.75 by 2.5. Divisor Dividend Quotient 1.5 ) 60.0 ( 40 600 2.5)34.75(13.9 25 97 75 225 225 In the first example the divisor has one decimal place, but the dividend has none, so one must be affixed to it. As the dividend must have as many, if not more, decimal places as the divisor, with the added decimal place in the dividend makes the quotient a whole number. In the other example the dividend has one decimal place more than the divisor, so we point off one in the quotient. Example No. 3. Divide 30.5 by .9. Example No. 4. Divide 70 by II .2. .9)30.5(33-8/9 27 11.2)70.000(6.25 672 35 27 280 224 8 560 560 In the 3rd example we find we could not bring it to an end, so to save carrying it on to several decimal places, we have finished with a vulgar fraction, and as the dividend has the same number of decimal places as the devisor, the quotient is a whole number, with the fraction 8/9. In the 4th example we had to add three more ciphers 51 to the dividend, giving it two more decimal places than the divisor, so we point off two decimal places in the quotient. Percentage Percentage is the process of calculating by the hun- dreths. Thus 5 per cent of a quantity is 5 of every hun- dred, or 5 hundredths of the quantity. When multiplying for a percentage of a certain number, the multiplier is ex- pressed decimally. That is, if we are to take 5%, 25% and 12j/2% of a number, we would set them down to multiply like this: .05.25 and .125. The following table will show our meaning: PER CENT DECIMAL PER CENT DECIMAL PER CENT DECIMAL 1% .01 75% .75 1/2% .005 2% .02 100% 1.00 3/4% .0075 3.1% .031 150% 1.50 1/2% .015 10% .10 500% 5.00 8/3% .O8K3 50% .50 !4% .0025 12/2% .125 In the first place the base is the number on which the percentage is computed. Example: — Suppose we wish to take 6^ per cent of 12.7 per cent. The 12.7 is the base, and the 6Y4 is the rate, so multiplying the base by the rate decimally expressed we get the percentage of .79375. , Example: — 12.7 .0625 635 254 762 .79375% > As explained in the multiplication of decimals, vye must point off as many places in the product as there are in the multiplier, and the multiplicant, which is five. It will be noticed that although we called 12.7 a per cent, it became 52 a base as soon as we wished to take a percentage it. Examples. 2. Take 50% of 2.75%. 3. Take 30% of 3.25%. 4. Take 70% of 1.75%. 2.75 3.25 1.75 Base. 50 .30 .70 Rate from 1.3750% .9750% 1.2250% Percentage when two numbers are given and we wish to know the rate of each one, we add the two together, and divide each number, — after affixing two ciphers and moving the points two places to the right, by the sum of the two. Example: — What per cent of 1.50 is .45 and 1.05? .45 1.05 1.50)45.00(30% 4500 1.50)105.00(70% 10500 When multiplying for percentage with decimals, we must always point off two extra in the result for the whole numbers. Example: Suppose we wish to take .5625 per cent of 80 per cent 80 .005625 You notice we have added two .450000 ciphers, which represent the two whole numbers, and of course moves the decimal point two places to the left, so in pointing off the result, we count six decimal places. Of course in actual practice, we imagine the two whole numbers are there, and point off the result accordingly. Hoping these few suggestions will carry the point, we will not go any deeper on this subject. 53 CUPOLA PRACTICE Although it is not the purpose of this book to treat on cupola practice, I feel I could not conclude it without a word or two. We may make our mixtures as they should be made, still there is a possibility of them going wrong by im- proper handling and charging of the cupola. If every melter would take the trouble to find the proper height the coke bed should be for his particular cupola, then make all his charges of iron from first to last as near the same weight as possible, he will get a more uni- form grade and even flow of iron, with less coke consumption, than the man who crowds his coke bed to the limit with an extra heavy first charge of iron. The proper practice calls for the same weight of charge on the bed as every succeed- ing charge, and the weight of that charge is figured by the weight of coke it takes to fill four inches high in the cupola. Then use a ten to one ratio, that is if it takes 150 pounds of coke to fill four inches high in the cupola, the iron charges should be about 1500 pounds and so on. Experimenting foundry men have proved the melting zone averages from four to five inches in depth. And they have also found that amount of fairly good coke will melt 10 times its weight in iron and when that amount of iron is melted, the bed is then ready for another four inch layer of coke. Now, when I speak of a four inch layer of coke, I do not mean that we must put four inches all over the inside area of the cupola. That rule is only used as a stan- dard on which to figure our iron charges. It has been proved that the best results have been derived by putting all the coke in the center, and all the iron as close to the lining as possible, excepting of course, when making different mixtures wh'ch must be separated by coke. Bv this method of charging, the coke can be reduced and still have hot iron if the bed and first charge have been started right. When 54 the bed is the right height it is only the top four inches that does the real melting, so if the bed is higher than it should be the extra coke will be burnt and wasted until it lets the iron down to the real melting zone, which will vary from. i5 to 28 inches above the tuyers according to high or low blast, so the main point is to find the proper height of the bed for every cupola, and the best way to find it is by the time it takes the iron to drop lively after the blast is on. If it takes more than three minutes at the most the bed is too high, and the extra time will be taken up burning coke that is not required. Now then, it is generally upon high coke beds that extra heavy first charges of iron are put, because we are under the impression that so much coke on the bed ought to melt a much heavier charge than the rest of the charges. But it is a wrong impression. An- other reason for heavy first charges are, that most foundries have some special mixtures to make, different from their regular run of work, and if they happen to be heavier than their regular charges, the bed is considered the best place, so as to get them down, and out of the way of the regular mixtures. But, as we must put an heavier split of coke between two different mixtures, the bed is built up somewhat, the amount it has lost by having an extra heavy first charge to melt, and I believe, that one reason of having to put an heavier split of coke between two different mixtures, have saved many a coke bed from getting dangerously low with- out the melter being aware of it. Now here's the point: We know, if we wish to retard the melting between two different mixtures, we must put an heavy split of coke between them. By so doing we keep the iron high above the melting Zone, until a part of the coke is burnt away, when the top part or last four inches of the coke wil drop to a point where it can melt the iron above it. It is just the same with the high coke bed. It is only the last, or top four inches that does the real melting, and like the heavy split of coke, even that four inches will not melt iron until it drops to the real melting zone, and then it will only melt so much, so if burdened with an extra heavy 55 . first charge of iron, the bed proper is bound to suffer, and can only be built up again at the expense of irregular iron, and extra coke, which would not be, if all the charges had been made as near as possible what they should be, accord- ing to the size of the cupola. It is not very good cupola practice to let the iron soak too long in the cupola before starting the blast, as I believe the iron absorbs more or less sulphur from the fuel during that time. It is a fact, that "converter steel" men, if they have to make castings to strict specifications, will not use first charges for that class of work if they can help it. The reason, that sulphur always runs higher in first charges than in the following charges. Fairly good practice calls for the fire to be started about one hour before charging. As charging will take from three quarters to one hour, the blast should then be put on as soon as possible. If the bed is the right height, the iron will begin to drop within a minute or so, and will be droping quite fast within three minutes, as can be seen through tuyer glasses. Although I have mentioned that the melting zone will average about 20 inches above the tuyers, I do not mean that to be the height of the bed. We may have to make it 30 inches, or even more, because the bed will settle from 8 to 12 inches as soon as the first charge of iron is dumped on it — that point will have to be settled by the time it takes the iron to begin to drop after the blast is put on, the melting zone being located entirely by the force of the blast. If the blast is high and strong, so will the melting zone be located high, so make the coke bed rather high at first then reduce till you find proper height by above instructions. 56 LIBRARY OF CONGRESS 003 275 803 4