S77 METAL MIXER The easiest, simplest and most exact method of mixing iron by chemical analysis, with tables and ready made mixtures. Indispensable to Molders, Melters ^ and Foundry Men. W\ IV. ELLIS COPYRIGHT, 1919. OAKLAND, CALIF. - GIFT OF THE ZMETAL MIXER The easiest, simplest and most exact method of mixing iron by chemical analysis, with tables and ready made mixtures. Indispensable to Molders, Melters and Foundry Men. W. W. ELLIS COPYRIGHT, 1919. OAKLAND, CALIF. CONTENTS Introduction 5 Mixture for Medium Machinery Castings 9 Soft Mixture for Pulleys, Short Method 12 Four Iron Semi-Steel Mixtures for Rolls 15 Correcting Mixtures with Ferro-Silicon or Ferro-Manganese 1 8 Semi-Steel Mixture for Rings, Piston Valve Liners, Gears Etc., 21 Mixture for Marine Cylinders Liners 26 Mixing with a Certain Per Cent of Steel 29 Figuring Three or More Elements Exact 32 French Specifications for Semi-Steel Shells 36 Side Lights on Mixtures 40 Miscellaneous Mixtures 43 Analysis of Pig Irons 44 Approximate Grading Numbers 44 Approximate Analysis of Important Castings 45 The Influence Different Elements Have Upon the Iron 46 Percentage of Silicon for Different Castings 47 Judging Per Cent of Silicon in Different Kinds of Scrap 48 Decimal Fractions and Percentage 49 Cupola Practice 54 395059 3 INTRODUCTION, In presenting this book to molders and foundry foremen I do so, believing there is a real demand for a book, written in plain every day foundry language that anyone may understand, showing a simple and easy method of mix- ing iron by chemical analysis. I have endeavored to explain every mixture in a manner so simple, that the man who has never mixed iron, or understands anything whatever about foundry work, can, with a few minutes study, make any kind of a mixture, from any number of different grades of iron, by this easy method, almost as well as the more exper- ienced foundry man. We do not require a knowledge of chemistry to be able to mix by analysis. In fact, the aver- age foundry man or foreman has very little use or time for it. But what we must know is the composition of the iron we are mixing, and the percentage of the different elements it contains. The broker generally gives an approx- imate analysis. Drillings should be analyzed for the exact composition. In regard to the influence and relation the elements have to one another, and above all the percentage of the most important of these elements, castings designed for different kinds of work, should contain, I have endeavored to explain, and if followed, will give the reader a good work- ing knowledge of the characteristics of the different elements, which is a big help in making mixtures. Foundry iron contains several of these elements, or im- purities as they are sometimes called, but there are only five in which we are mostly interested in. They are silicon, phosphorus, sulphur, manganese and the carbons. Of these five, I think the carbons are the most important, because carbon is the element that gives the iron its character. Foundry iron contains carbon in two distinct forms, called graphite carbon 'and qoiAbi-ied carbon. And according to the percentage. , of each ^of , these carbons, so will the iron be hard or rof ; . Graphite,; or boft carbon, is always high in very soft open grained iron. Combined or hard carbon is always high in very hard, close grained iron. In making mixtures for the cupola it is a more difficult proposition to take hold of the carbons and figure their content than it is silicon or some other element, so, as a rule if we wish to reduce or change the carbons, we generally add some low carbon steel scrap, or change the carbons by using high or low silicon in the mixture, as the case may require. In making mixtures for the ordinary run of machinery castings, we do not trouble about the carbons because we find if silicon is high, graphite carbon will be high also, and if silicon is lowered, graphite carbon will be lower, and com- bined carbon will be higher, and the more we lower the silicon the more combined carbon we will get in our cast- ings. Chemists long ago proved, if we wish to regulate the carbons it can be done through the silicon, which at once proves that silicon is one of the most important, if not the most important element the founder has to work with. Not only does it influence the carbons, but the other elements also, to a certain extent. For we find if we get silicon normal for the class of work we are making, the other elements also will be normal, especially so, if we use the ordinary run of foundry irons. As the silicon can be raised or lowered as required, it is the first element that should be figured in mixing iron by chemical analysis. When iron contains more than 3.5 per cent silicon, it will begin to get hard. Not hard and strong like a low silicon close grained iron, but hard, short and brittle. So in making mixtures, we never go above 3.25 per cent silicon, and even that per- centage is very rarely used, except in fine stove plate, or work similar to it. There are special mixtures however, for acid proof castings, that call for a much higher percentage of silicon, but these are exceptional, and are not included in the ordinary run of foundry products. Silicon and mangan- ese are not affected by mineral and vegetable acids, like graphite carbon, sulphur and phosphorus are. So in making mixtures for this kind of work, the combined carbon, silicon and manganese should be high, especially the silicon, which of .course will make the casting very brittle. To make such mixtures takes considerable experimenting, even by the most experienced chemist and metallurgist. In arranging the different mixtures I have tried to make them as progres- sive as possible. The few mixtures from my note books, I thought would give the reader an idea of what has been done with steel mixing. These were made when pig iron was very much cheaper than now, as some were made as far back as 1904. The analysis of different pig irons will also give beginners a working idea of the composition of iron. The few remarks on the influence the different elements have upon the iron will all help the student how to use, and mix them to accomplish a certain purpose. In selecting and using scraps, of course is more or less guess work. But, by careful study and selection, and by getting a determination now and then, one will soon be able to judge the silicon content for all practical purposes. But if special work is to be made to specification, such as shells or other governmental work, all the scraps must be melted and pigged, and analysis taken of each cast. Only then can we say with confidence, just what is the composition of the scrap. In the mixtures showing the method of mixing three or more irons together, I have used a higher per cent of steel than I would advise to use without experience. Although I have made mixtures containing more than 25 per cent steel, still I am convinced by actual tests, that no improvement or benefit can be obtained by using more. This opinion seems to be general among other foundry men, who have had any experience with steel and iron mixtures. I have also found if using a higher per cent the best results was obtained when using all pig and steel scrap. Steel mixtures must be melted hot and handled quick when in the ladle. The few examples on decimals and percentage will help refresh our memories, and are handy to refer to while studying this method, as they deal directly with the work of the book. The last chapter deals with the cupola, which are chiefly personal experiences, and agrees closely with our leading foundry men. And if followed as near as possible together with other in- formation in the book, the young foundry man should have no trouble in handling the mixing and melting end of any shop, independent of the class of work being made. W. W. ELLIS. MIXTURE FOR MEDIUM MACHINERY CASTINGS. In this mixture we will figure for silicon only, and I would advise the student to work over this first mixture until you understand it. You will then be surprised how simple it is. You will then have the foundation for making any kind of a mixture from any number of different grades of iron. A mixture for medium machinery work should contain about 2 per cent silicon, with that percentage, castings from 54- inch in section should machine quite easy. As we lose about two tenths (0.2) of one per cent silicon in melting, we must add that much to our mixture before it goes into the cupola. On account of this loss we must figure our mixture to contain 2.2 per cent silicon. To make this we will use pig iron and scrap enough to make a mixture of 2000 pounds. The pig contains 3.25 per cent silicon, and the scrap 1.75 per cent. As we desire only 2.2 per cent, you will notice that I have selected one iron with a higher, and one with a lower per cent of silicon. We will now put the lowest silicon under A, the amount we desire under B, and the highest silicon under C. So placing them in that order they stand as follows: A. B. C. 1.75 2.20 3.25 RULE: By subtracting A from B we get .45 remain- der; substracing B from C we get 1.05. We now add both remainders together, getting 1.50. Taking the first remain- der .45 and after affixing two ciphers to it, and moving the decimal point two places to the right, and dividing it by the sum of the two remainders 1 .50, we get 30, the percentage of the C iron to be used in the mixture. Taking the second remainder 1.05, and after affixing two ciphers, and moving the point two places to the right, dividing it also by 1.50 we get the percentage of the A iron, which is 70, to be used in the mixture. Example Take A from B. 1st Remainder Add both remainders Sum of the two A. 1.75 rs B. 2.20 1.75 C. 3.25 2.20 .45 1.05 1.05 1 1.50 TABLE No. Take B from C. 2nd Remainder 1st remainder .45 representing C iron. Two ciphers affixed and point moved two places and divided by 1.50)45.00(30% of C iron to be used. 45.00 TABLE No. 2 2nd Remainder 1.05 representing A iron. With two ciphers affixed and point moved two places we divide by 1.50)1 05 .00( 70% of A iron to be used in the mixture. 10500 TABLE No. 3 Don't miss this one point of setting the different silicons under their proper heading. Always set the lowest silicon under A, what we desire under B and the highest under C. Then take A from B, and the first remainder will always represent the C iron. Then take B from C and the second remainder will always represent the A iron. As these remainders only represent the A and C irons, they do not tell us how much per cent of each one to take. To find a rate so we can figure what percentage of these two irons to use, we add these two remainders together, and after affixing two ciphers to each one, we divide each one by the base, or sum of the two. The result of this division is of course the percentage of the iron we are to use that each remainder represent, which is clearly shown in tables 2 and 3. When affixing the two ciphers to 10 each of the remainders, be sure and move the decimal point two places to the right even though it does point off ciphers as in this example. We will now check off our mixture. According to our figures we are to use 30 per cent of C iron, and 70 per cent of A iron. By multiplying the 3.25 per cent of silicon by the 30 per cent, we get .9750 per cent, and by multiplying the 1.75 per cent by the 70 per qent we get 1.2250 per cent. Adding these two per- centages together will give us our desired percentage of 2.2 per cent silicon. Example: Percentage of silicon in C iron 3.25 Percentage of C iron to be used .30 Per cent of silicon .9750 TABLE No. 4 Percentage of silicon in A iron 1.75 Percentage of A iron to be used .70 Per cent of silicon 1.2250 Percentage of silicon from C iron .9750 The required per cent amount of silicon 2.2000 TABLE No. 5 This method gives the percentage of silicon as well as the percentage of the iron. Example : 30 per cent of 2,000 Ibs. = 600 Ibs. of C. pig iron. 70 per cent of 2,000 Ibs. = 1400 Ibs. of A scrap iron. Mixture of 2000 Ibs. TABLE No. 6 In tables 2 and 3 the divisors and dividends has each two decimal places which make the quotients whole numbers, see decimals. 11 SOFT MIXTURES FOR PULLEYS We will make this another two iron mixture, and figure for silicon only, introducing shorter method with less figuring. In making mixtures for pulleys, we should try and keep the silicon three or four points higher than we would for castings in our first mixture. The metal will be softer and of course the shrinkage will be lower. Even with this percentage, all pulley hubs should be stripped and cores taken out. Suppose we want a mixture of 1500 pounds containing 2.4 per cent silicon in the castings. That means with the loss of silicon in melting our mixture must contain 2.6 per cent before going into the cupola. To make this mixture we will use some of the gates of our first mixture containing 2.0 per cent silicon, and No. 1 Sloss pig iron containing 3.6 per cent silicon. Putting the lowest silicon under A, our desired under B and the highest silicon under C. We then work out as in table No. 1 . By substracting A from B we get our first remainder .6, which represents the C iron to be used in the mixture. Sub- stracting B from C we get our second remainder, 1 .0 which rep- resents the A iron to be used in the mixture. After adding these two remainders together and getting 1 .6, we take the first remainder and after affixing two ciphers to it, we move the decimal point two places to the right, making 60.0. We now divide the 60.0 by the sum of the two re- mainders 1.6; which we find goes 37J/2 times. As this first remainder represents the C iron, it shows we are to take 37.5 per cent of C iron to use in our mixture. Now, if we are to use 37.5 per cent of C iron, it stands to reason we must use 62.5 per cent of A iron, as 37.5 and 62.5 equals 100. So that being the case, further figuring are unneces- sary. Example : 12 A. B. C. 2.0 2.6 3.6 Take A from B 2.0 2.6 Take B from C. 1 st remainder .6 1 .0 2nd remainder Add both remainders 1.0 Divide by 1 .6)60.00(37.5 % of C iron. 48 120 112 62.5 % of A iron. 80 80 TABLE No. 7. You will notice instead of making two separate tables as in our first mixture, we simply take the first remainder .6 put it to the right of the 1.6, add two ciphers to it, and move the point two places, then divide it by the 1.6. The result of this division completes all the figures required to get the percentage of the irons to be used in any mixture, so make yourself familiar with the first mixture, then you will be able to follow table 7 with ease. For table 7 is the form in which you will make all your mixtures in actual practice, except, of course, when correcting mixtures, or mixtures that have even number remainders, which will be explained in other mixtures following. Percentage of silicon in C iron 3.6 Percentage of C iron to be used 37.5 Per cent of silicon 1.3500 13 TABLE No. 8 Percentage of silicon in A iron 2. Percentage of A iron to be used 62.5 Per cent of silicon 1 .250 Silicon from C iron 1.350 The per cent amount of silicon required 2.600 TABLE No. 9 37.5 per cent of 1500 = 562.5 pounds of C pig iron. 62.5 per cent of 1500 937.5 pounds of A gate scrap. Charge of 1500.0 pounds TABLE No. 10. Note: In multiplying by the rate for percentage, you point off two for the whole numbers, and as many decimals as there are in the multiplier and multipliant, which makes four in table 8, and three in table 9. See decimals. In actual practice we would only require tables 7 and 10. Tables 8 and 9 are merely used to prove our figures. 14 MIXTURE FOR A ROLL SEMI-STEEL USING FOUR DIFFERENT KINDS OF IRON In this mixture we will explain a method whereby any number of different kinds of iron can be mixed together. When making a mixture to contain several different brands of iron, and not being particular how much of each, the best way is to segregate them, putting all the irons together that contain a lower silicon than we require in our mixture into one group, and all the irons that contain a higher per cent of silicon into another group. After getting the mean percentage of silicon from each of these groups, we have practically but two irons to figure on, and can be worked out as in table 7. Then, after we have found what percentage of each group we are to use, we must divide each percentage into as many parts as there are irons com- posing each group. Example: Suppose we wish a mixture of 4,000 pounds for a 20 inch dia-chilled roll, containing 0.6 per cent silicon, adding the usual 0.2 per cent for loss of silicon, would make our desired silicon 0.8 per cent before it goes into the cupola. To make this mixture we will use some of the following irons. Sil. Phos. Sul. Mang. T. C. Heavy scrap 1.50 0.40 0.08 0.60 Salisbury pig 1.29 0.30 0.045 0.40 3.85 Steel scrap 0.2 0.05 0.05 0.50 0.10 Cargo fleet-pig 0.79 1.52 0.027 0.23 3.12 TABLE No. 11. By putting the two lowest silicons together and dividing them by 2. we find their mean silicon content is 0.495 per cent, which must be put down under A. Putting the two highest silicons together and dividing them also by 2, we 15 find their mean silicon content is 1 .395 per cent, which must be put clown under C. The desired silicon of course must be put down under B. This gives us practically a two iron mixture, and they stand ready to be figured as in table No. 7. A. B. C. 0.495 0.800 1.395 Take A from B .495 .80 Take B from C. 1 st Remainder .305 .595 2nd Remainder. Add both .595 Divided by .900) 30.500 ( 33-8/9% of C iron 2700 66-1/9% of A iron 3500 2700 800 equals 8/9 900 TABLE No. 12. Table No. 12 shows we are to take 33-8/9 per cent of C iron. Then, of course we must take 66-1/9 per cent of A iron. As each of these percentages have to be divided into two equal parts, we will do away with the fractions, and call each one a whole number, which will save extra figuring and will not affect the result any. By making them whole numbers we have 34 per cent of C iron and 66 per cent of A iron. As the C iron is composed of heavy scrap and Salsbury pig, we must use 1 7 per cent of each, and of course 33 per cent of each of steel and Cargo Fleet. In checking them off at these rates, we find we have a shade more silicon than we desire, brought about of course by using all whole numbers instead of the fractions. 16 Example : 17% of 1.50% silicon in Heavy scrap, equals 0.2550% 17% of 1.25% silicon in Salisbury scrap, equals 0.2193% 33% of 0.20% silicon in Steel scrap, equals 0.0660% 33% of 0.79% silicon in Cargo Fleet-pig, equals 0.2607% 100 Total silicon equals 0.8010% Loss in melting 0.20 0.6010% TABLE No. 13 17% of 4000 pounds equals 680 pounds Heavy scrap. 1 7% of 4000 pounds equals 680 pounds Salisbury pig. 33% of 4000 pounds equals 1320 pounds Steel scrap. 33% of 4000 pounds equals 1320 pounds Cargo Fleet-pig. Charge of 4000 pounds TABLE No. 14 To multiply one percentage by another percentage, see percentage. In shop practice when this method is understood, we would require only tables 12 and 14, saving the figuring of table 13, which we know would be correct. The other elements can be figured the same way as silicon. The manganese which would be low for a casting of this kind, could be corrected with ferro-manganese, as explained in following mixtures. 17 METHOD FOR CORRECTING MIXTURES WITH FERRO- SILICON OR FERRO-MANGANESE. This method is useful when we wish to add more silicon or manganese, as the case may be, to a mixture already figured. We wish to make a mixture of 2000 pounds for medium floor work containing 2.2 per cent silicon. We have 1000 pounds of foundry scrap which we know contains 2 per cent silicon and 1000 pounds of heavy scrap containing 1.5 per cent silicon. As these two lots of iron are the amount we require in our mixture, we will see how much silicon they will bring into it. 50 per cent of 2 per cent silicon in foundry scrap gives us 1.0 per cent, and 50% of 1.5% silicon in heavy scrap gives us 0.75% more, making a totoal of 1.75 per cent silicon, leaving 0.45 per cent more to be supplied by the ferro-silicon to make our mixture contain 2.2 per cent. This 0.45 per cent is what we want, and must go down under B. The ferro-silicon containing 80 per cent silicon must be put down under C, and as we are working with one iron only, we will put a cipher under A. Setting them down in that order, they stand ready to be figured as in table 7. 18 Example : A. Take A from B 1 st Remainder Add both Divided by B. .45 C. 80.00 .45 Take B from C. .45 79.55 79.55 2nd Remainder. 80.)45.0000(.5625% of C Per. sil. 400 500 480 200 160 400 400 TABLE No. 15 2000 Pounds 00.5625 11.250000 Pounds TABLE No. 16 11.25 Pounds .80 20)9.0000(.45% 80 100 100 TABLE No. 1 7 19 80 00.5625 .450000% of silicon from Ferro Silicon 1 .75 % of silicon from scrap iron 2.20 Total silicon. TABLE No. 18 Table 15 shows we are to add 0.5625 per cent of ferro silicon to the mixture. To find the amount of ferro-silicon in pounds we are to use, we will multiply the 2000 pounds of iron by .5625% making it 11.25 Ibs. Multiply 11.25 pounds by the per cent of silicon it contains (which is 80,) and dividing the result by 20, the number of hundred pounds in the mixture will give us our required silicon 0.45 per cent. Or, multiply the 80 per cent ferro-silicon by the percentage we are to take, .5625, will also give us our required 0.45 per cent. See tables 16, 17 and 18 above. I have used 80 per cent ferro-silicon, it serves our purpose as well as 50% or any other per cent. 20 THREE IRON SEMI-STEEL MIXTURES WITH APPROXI- MATE FIGURING OF ALL THE ELEMENTS. This mixture if melted hot and under proper conditions would be suitable for marine piston rings, piston valve liners, cut and cast gears, etc. Although we are using high steel in this mixture it is advisable not to attempt high steel mixtures without previous experience. In making a mixture of this kind, there are always two elements we are sure of getting exact. These are silicon and manganese, which will be proved in this mixture. The other elements will be influenced by these two, and can be made normal for the mixture, es- pecially so, if we select irons suitable for the work in hand. Keep the sulphur and phosphorus low. If the sulphur is high, raise the manganese a point or two. We will make a mixture of 2000 pounds to contain Silicon Phos. Sulphur Mang. Total Carbon 1.8% 0.45% 0.07% 0.75% From the following irons: Buckeye 3.6% 0.55% 0.016% 0.50% 3.50% Scrap iron 2.2 0.60 0.070 0.45 3.25 Scrap steel 0.2 0.05 0.050 0.50 0.08 TABLE No. 19. As we are not particular what per cent of each iron we use, the best way is to put the two lowest silicon's together, and get their mean percentage. In this case we will put scrap iron and scrap steel together. So adding 2.2 and 0.2 together making 2.4 per cent silicon, and dividing by 2. will give us their mean per cent, 1.2. This gives us now, practically, but two irons to figure on. Putting them under their proper headings they stand ready to be figured as in table 7. Adding 0.2 for loss of silicon in melting will make our desired 2.0%. 21 Take A from B A. 1.2 1st] nder B. 2.0 1.2 .8 C. 3.6 2.0 Take B from C. 1 .6 2nd remainder TABLE No. 20 When one remainder is just twice as much as the other, it shows we are to take 33 Vz per cent of the C iron, and 66/ / 3 per cent of the A, and no more figuring are required. If both remainders should come the same it would mean 50 per cent of each A and C, and if one remainder should happen to come three times as much as the other, we would have to take 75 per cent of one, and 25 per cent of the other. In this case we are to take 33^ per cent of C and 66^ per cent of A iron. As the A iron is composed of scrap iron and scrap steel, it means we are to use 33 Vz per cent of each pig iron, scrap iron and steel. In checking off at these percentages we get the following results: Example Silicon. Pig iron 33J/3% of 3.6% silicon equals 1.200 % Scrap iron 33J/3% of 2.2% silicon equals 0.733/ % Scrap steel 33/ 3 % of 0.2% silicon equals 0.066^% A Total silicon 2.000 % Loss in melting equals 0.2 % Silicon in casting 1 .8 % Phosphorus. Pig iron 331/3% of 0.55% phos., equals 0.1833/3 % Scrap iron 33J/3% of 0.60% phos., equals 0.2000 Scrap steel 33/ 3 % of 0.05% phos., equals 0.01662/ Phosphorus does not lose or gain in melting 22 .4000 % B Pig iron Scrap iron Scrap steel Sulphur. 33J/ 3 % of 0.016% sulp., equals 0.00533 Vz% 33|/3% of 0.07 % sulp., equals 0.02330/3 33]/ 3 %of0.05 %sulp., equals 0.0166 ^ Gain in melting equals .045241/3 .03 C Manganese. Pig iron 33J/3% of 0.50% mang., equals Scrap iron 33]/3% of 0.45 % mang., equals Scrap steel 33^3% of 0.50% mang., equals Loss in melting, equals Manganese from 80% ferro-mang., equals D Total Carbon. Pig iron 33^3% of 3.50% carbon, equals Scrap iron 33 J/3% of 3.25% carbon, equals Scrap steel 33J/3% of 0.08% carbon, equals E Total carbon Pig iron 33|/ 3 % of 2000 Ibs., equals Scrap iron 33J/ 3 % of 2000 Ibs., equals Scrap steel 33J/3% of 2000 Ibs., equals .07524/3% 0'.150 OA662/3 0.483/3 0.100 0.383 0.367 0.750 % 1.16662^% 1.0743/3 2.26762^% 6662/3 Ibs. 6662/3 Ibs. 6662/3 Ibs. F 2000 Ibs. 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. w* TABLE No. 23 A. B. C.