The Iron Age 1940-04-18: Vol 45 Iss 16

H. VAN DEVENTER President and Editor BAUR Vice-President and General Manager WRIGHT Managing Editor MILLER wachimery Editor OLIVER ROWAN News Editor WINTERS Art Associate Editors PHAIR FINDLEY Rditor Emerttus Metallurgical Editor G. RICCIARDI Washington Editors JAMEs ELLIs Resident District Editors CAMPBELL Pittsburgh JAMES Cletelana ROBERT BINGHAM Chicago SHERMAN Detroit Editorial Correspondents TURNER, JR. Buffalo FRAZAR Boston Milwaukee McINTOSH Cincinnati Hamburg, Germany CHARLES Post San Francisco SANDERSON CLYDE ENNIS Toronto, Ontario ALLISON Newark, N. J A. H. DIX, Manager Birmingham Roy St. Louis Reader Service ADVERTISING STAFF Robert F. Blair Emerson Findley 621 Union Bldg., Cleveland B. L. Herman, Chilton Bldg., Phila. H. K. Hottenstein, 1012 Otis Bldg., Chicago H. E. Leonard, 239 W. 39th St., New York Peirce Lewis. ©, H, Ober Robinson Fitzgerald D,. C. Warren, P. O. Box 81, Don F. Harner, 1595 Pacific Beach, Cal. 7310 Woodward Ave., Detroit 239 W. 39th St., New York 428 Park Bldg., Pitts. Hartford, Conn. Avenue, Long Member, Audit Bureau of Circulations Associated Business Papers Indexed in the Industrial Arts Index. Member, Published every tion Price: United States $6.00; Can- sessions, Mexico, Cuba, Thursday. Subscrip- and Pos- ada, $8.50; Foreign, $12.00 a year. Single copy, 25 cents. ber $1.00. Annual Num- Cable Address, *‘Tronage, Owned and Published CHILTON COMPANY Publication Office Chestnut and 56th Sts., Philadelphia, Pa., U.8.A. (Incorporated) aoe Editorial and Executive Offices West 39th St., New York, N. Y., U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, GEORGE GRIFFITHS, EVERIT TERHUNE, VAN DEVENTER, BAUR, Vice-President Vice-President Vice-President Vice-President Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, CHARLES HEALE HARRY DUFFY Contents April 18. 1940 Birth Control Small Enterprises How Alloying Elements Affect High Alloy Steels Spot Welding Aluminum Hi-Wave Welder Production Control Grinding Hardened Gears What's New Polishing and Finishing Apparatus the Assembly Line Washington News THE NEWS BRIEF Statistics Metal Working Activity Weekly Ingot Operating Rates Rate Activity Capital Goods Plant Expansion and Equipment Buying Free Industrial Literature Products Advertised Index Advertisers Copyright, 1940, Chilton Company (Inc.) 106 114 120 150 | | R | | OS vole \ | | ALLEGHENY LUDLUM MAKES TOOL STEELS TAKE IT! There are four steels select from when tools parts must stand driving impact. SEMINOLE oil-hardening steel that develops remarkable combination hardness and toughness. LUDLUM 602, the type, which may oil water-hardened. PYTHON, which hardens water with hard case and tough core. And ATLAS 93, oil-hardening, non-deforming, developing great toughness. Each type has many applications. Allegheny Engineers will gladly help you select just the right type for the purpose you have mind. The newly published folder gives complete temperature ranges, tempering chart and helpful suggestions shop practice. sure get it. Allegheny Ludium Steel Corp. Tool Steel Division, Watervliet, Send folder A-4 entitled Steels for Fatigue Name Company Street ? 2 F F THE IRON AGE ... APRIL 18, 1940 ESTABLISHED 1855 Vol. 145, No. Birth Control Small Enterprises the pronouncements the New Deal armchair philosophers that business con- cerns and industrial corporations have become too large. These gentlemen think that there should more small concerns than there are and that the way make them the way that they the prison rock pile. Make little ones out big ones. The trouble with that philosophy that when you get through breaking the rock pile, you haven't any more total poundage rock than you had the start. fact, considerably less, because the waste and loss that unavoidable part any disruptive process. agree with the thought that would good thing had more little businesses springing this country, just had before the New Deal instituted its program in- dustrial and business birth control. But until the birth control abolished, are not going get this increasing proportion new enterprise that the hope our future, just the little trees today are the hope tomorrow's forests. The chief reason why present-day corporations are getting larger and larger and new small enterprises fewer and fewer that men with new ideas now find easier sell them strongly financed corporations than find individual financial backers who will start them business. This fact was strongly brought home few weeks ago the experiences related two men. One them was research engineer ability who had devised and developed product outstanding promise. The other was able merchandising expert who had developed ingenious plan for its sale. These two men wanted into business for themselves. They had the process, the product and the plan which would undoubtedly have resulted new and successful small enterprise, they could have found the capital. But that where the New Deal birth control stepped in. Ten years more ago, these men would have found dozen people with money who would have been willing underwrite their proposed company. Today, thanks the contra- ceptives manufactured Washington the form confiscatory taxation, obstacles rea- istration, discriminatory labor legislation, third term uncertainty, and threatened laws pen- alize efficiency, these men could not find any individual take the risk. they did what they were driven into doing the people who profess want foster small enterprises and new enterprises, but who actually are forcibly feeding and fattening the large companies. They sold out existing corporation and became minor executive employees it. will not encourage new enterprise this country until run out Washington the gang quack doctors whose own mass production monstrosities has destroyed the fertility private enterprise. 9 ok maz ~ ew. pr: *, | : 4 “lg Sheet Forming and Fabrication Costs Many manufacturers are cutting production costs. making finer and beating competition with Inland special sheets and strip. They get these results be- cause Inland metallurgists determine the kind sheets best suited their purpose —and, then work with the mill produce the exact sheet specified. Users Inland Sheets can defiinitely count superior forming qualities, constant uni- formity, and fewer rejects, from beginning end production runs. Inland metallurgists, with their perience, will also pleased help you developing tailor-made sheet strip that will lower costs and improve your fin- ished product. This Inland service yours for the asking—without cost obligation. SHEETS STRIP TIN PLATE BARS PLATES FLOOR PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS 4, 4 e Dearborn ‘Street, Chicago Sales Offices: Milwaukee, Detroit, St. Paul, St. Louis, Kansas City, author herein summar- izes very understand- able manner the effects which the various elements produce high alloy steels, and indi- cates how variations the properties these steels are controllable appreci- able degree. this, the first two sections, the functions alloy additions are de- scribed, and detailed data are given for manganese, nickel and cobalt steels. development alloy steels has been progress for more than years, but only recently has emerged from empirical stage. great deal owed the pioneers—Faraday, Berthier, Mushet, Hadfield, Taylor and White, Mathews, Brearley, Haynes, with whose names are associated the high alloy steels. The industry also PETER PAYSON Chief Metallurgist, Crucible Steel Co. America, Eastern Research Laboratory, Harrison, indebted least equally the scien- tists—Sorby, Osmond, Chatelier, Gibbs, Laue, Hull and others—whose discoveries associated fields helped haviors the alloy steels. Through- out the years, writers various parts the world have published facts and opinions which have gradually clarified knowledge, that today possible modify the high alloy steels more less will. The present paper attempts sum marize the effects which the various elements produce high alloy steels, and indicate how variations the properties these steels are control- lable appreciable degree. high alloy steel may arbitrarily defined one which contains about per cent more alloying ele- ment addition carbon, and the usual small amounts manganese and silicon. Besides the main alloying element high alloy steel there may also present smaller quantities other elements which modify the ef- fects the primary element, and pro- duce secondary effects which depend presence the primary element. Functions Alloy Additions \lloy additions steels are impor- tant several ways. the first place, they affect the formation austenite the steel elevated temperatures next, they affect the manner which the austenite transforms cools from elevated temperatures room temperature; the third place, they may form carbides, other com- pounds, which turn may affect the manner which the hardness the steel changes when the steel heated the temperature range between about 400 and 1800 deg. F.; and final- ly, they may give specific physical and chemical properties the steel. AUSTENITE: There are about elements which are alloyed with iron various combina- tions the very large number steels which are obtainable today. The equilibrium diagrams the binary alloys these elements with iron have different characteristics, and the ele- ments have been classified according THE IRON AGE, April 18, aN 4 =e ng ° ° ° 7 5 . 4 urs | 4 = « these types binary diagrams. The most important distinction among these diagrams the extent the gamma field, austenite region. Some elements permit iron form austenite elevated temperatures without re- striction; whereas other elements per- mit the formation austenite definite amount the element, and beyond this amount, austenite, but only ferrite, can exist. The elements the first type may those the second type, “ferrite form- The latter may also referred those which form austenite loop diagrams. Among the ferrite formers, there are differences the amount the element which the formation austenite limited, and these are shown Table The smaller the amount required limit the formation austenite, the more active the element ferrite former. There are also shown Table the compounds which these elements may form witli iron. When more than one element added iron, the effects are generally cumulative. is, austenite- former like carbon, nickel, nitrogen iron-chromium, the limit the austen- ite field extended larger percen- tages chromium. For example, alloys with very low carbon, austen- ite can formed when more than about per cent chromium present whereas, when the carbon high 2.0 per cent, appreciable amount austenite can formed even though the steel. the other hand, when active ferrite-former like titanium, alloy, the austenite field contracted. For example, per cent chromium steel with low carbon will entirely austenitic high tempera- tures; whereas, steel similar an- alysis, but containing only about 1.5 per cent aluminum will have very little austenite high temperature. Transformation Austenite \ustenite forms while the steel cool ing from its molten condition, and may course also formed when the steel reheated elevated tem- peratures. Since the steel nearly always used room temperature, close room temperature, the manner which the austenite, which formed the elevated temperature, changes cools room temperature, ex- treme importance establishing the usefulness the steel. Bain, Davenport, and others, have 32—THE IRON AGE, April 18, 1940 shown that the austenite plain car- bon steels may made transform any temperature below the critical, and that the product the transfor- mation austenite depends temperature which this transforma- tion takes place. the transforma- tion occurs high temperature, the product may pearlite, spheroidite, both which are relatively soft. the transformation occurs near room temperature, the product martensite which quite hard. Bain and Daven- port also showed that the rate which austenite transforms varies the temperature which the transforma- tion takes place; that austenite, car- bon steels, transforms very rapidly temperatures between about 1100 deg. and 900 deg. during cooling room temperature, but avoids transfor- mation this temperature range, will transform temperatures below about 300 deg. order that its transformation the higher temperature prevented, the austenite plain carbon steel must cooled very rapidly through this temperature region that may form martensite the lower tempera- ture. For this reason, plain carbon steels, hardened, are quenched water from temperatures above the critical; but the transformation the temperatures around 1100 deg. 900 deg. rapid some plain car- bon steels that even quench brine spray from temperature 1500 deg. will not cool the center diameter bar fast enough prevent this high temperature trans- formation. Consequently, only the out- side the bar transformed hard martensite, and the core consists the fine pearlite formed about 1000 deg. during cooling. When the austenite contains alloying elements addition carbon, the rate its transformation the higher temperatures slowed appreciably. This true all elements present fairly large amounts, with the excep- tion cobalt. When, for example, the austenite contains about 1.5 per cent manganese addition about 0.90 per cent carbon, becomes slow transform the higher temperatures that even the cooling the center round quenched oil from 1500 deg. fast enough avoid any high temperature transformation, and the center transforms only low tempera- tures, and therefore forms martensite, very similar structure. The addi- tion the alloy element has thus made the steel “oil hardening” slowing the rate austenite transformation the higher temperature region. The further addition alloying elements may retard the high tempera- ture transformation austenite such degree that even air cooling sufficiently rapid avoid the high temperature transformation. For ex- ample, the austenite contains about per cent chromium, and per cent molybdenum addition about per cent carbon, will take long transform high temperatures, that even the cooling rate the center round cooled air from 1800 deg. will fast enough miss the high temperature transformation, and the austenite will finally transform low temperatures martensite, similar structure. other words, the addition these alloying elements has made the steel “air hardening.” The time required for transforma- tion take place various tempera- tures clearly depicted the trans- formation temperature-time curves, in- troduced Bain and Davenport curves. Three types such curves are shown Fig. The dotted curve represents steel, and has the familiar shape, with very short reaction times the region between 1100 deg. and 900 deg. steel with such curve must quenched water order for any martensite form even the outside the bar. The dash curve (Fig. shows the transformation behavior This shows slow reaction rates high temperatures, and therefore un- necessary quench such steel water order avoid the formation soft products. However, this steel has fairly rapid transformation the temperature region around 900 deg. 700 deg. F., and medium size bars, say between and 5-in. diameter, when oil quenched, smaller when air cooled, will transform this intermediate temperature rather than martensite. full line curve (Fig. shows the reaction rates 18-4-1 high speed steel after heating deg. Here the reaction rates are slow both high temperatures and low temperatures, and steel with such curve may hardened martensite, similar structure, either oil quench, air cool, even large sizes, Austenite Retained most the steels which are oil hardening, air hardening, good deal austenite retained such room temperature, even though most transforms martensite. This retained austenite can changed martensite tempering the steel. of ~ > rs 4 | | : | ; te t the 1.0 per cent carbon, 1.5 per cent manganese oil hardening steel, the tempering the retained austenite martensite occurs about 350 deg. 450 deg. high speed steel, occurs about 1000 deg. 1100 deg. Ina chromium-nickel-silicon valve steel occurs about 1400 deg. 1600 deg. Further alloy additions may make the austenite sluggish that will not transform high temperature 1500 High speed SAE 4340 °F. 1400 Ternperature deg. fos] So Seconds chromium, per cent nickel steel with low carbon. Finally, there are austen- ites which will not transform even liquid air temperatures, but some these, like the well known per cent chromium, per cent nickel, steel may made transform room tem- perature they are severely cold worked. Thus, has been shown that alloy- ing elements have the very important Minutes Hours temperature-time curves three different steels. products even furnace cool, but will form only low temperature trans- formation products. Such steels, for example per cent nickel steel with 1.0 per cent carbon, have practical value because they are always marten- sitic room temperature, since they cannot annealed, and therefore can- not worked machined. Then, there are austenites which will not transform even room tempera- ture matter how they are cooled, but may made transform very low temperatures, say —100 deg. ion Transactions A.S.M., vol. 27, December, 1939, p. 837. ability Molybdenum Metals and Alloys, vol. January, 1940, Allen, “Intermediate Transformations Alloy Steels”, Metal Progress, August, 1939, p. 158. *E. Houdremont and H. Schrader, ‘“‘The Ef- fect Molybdenum Carbon Steel Com- parison with Other Carbide Forming Elements”, Techn. Mitt. Krupp, vol. No. 1939, 23. Bain, the Alloying Ele ments American Society for Metals, 1939. function altering the transformation behavior austenite. The knowledge the effects various elements the transformation austenite rap- idly increasing due the publication Parke and Griffiths, Pfeil and and and Schrader*. Continued work along these lines will make possible balance the compositions steels produce austenites which will transform ac- cording particular requirements. FORMATION Alloy- ing elements, because their ability form complex carbides, inter- metallic compounds, may cause steels resist softening tempering, actually increase hardness, be- cause the precipitation these compounds heating temperatures usually between 600 deg. and 1400 deg. but sometimes 1800 deg. The tendencies for elements form carbides, according are follows: The most active are titanium, columbium, vanadium, tungsten, molyb- denum, chromium, and manganese, in the order named; iron and cobalt are next; and nickel, silicon, and alumi- num are less active than iron. High temperatures are required get these carbides into solution austenite, and even when very high temperatures are used, some these carbides never completely into solu- tion. However, the martensite formed from austenite which has these ele- ments solution resistant soften- ing because the re-formation the alloy carbides the higher temper- ing temperatures. These carbide form- ing elements therefore are valuable about 1200 deg. F., since they add the strength, hardness, the steel these temperatures. There are commercial high alloy steels which are important because their ability hardened pre- cipitation intermetallic compounds, although many such steels have been patented. One commercial steel de- pends the formation the com- pound FeCr for its resistance soften- ing temperatures about 1600 deg. F., but this steel, will pointed out later, the compound forms means phase change, rather than precipitation out another phase which was dissolved, the case for all precipitation hardening alloys Properties: The specific properties such low thermal expan- sion, corrosion resistance, etc., which alloying elements confer upon steel, aside from the effects they have the formation, and transformation, austenite, and the formation com- pounds, are sometimes predictable, but frequently they are not. the vari- ous high alloy steels are discussed the following paragraphs, effort will made point out what may considered the functional effect the alloying element, that is, its effect the structure, and what may considered the specific effect, its unique effect the properties the steel quite distinct from the structure. Manganese, Nickel, Cobalt Steels One the oldest alloy steels the Hadfield manganese steel which con- tains about 1.0 1.4 per cent carbon, and 10.0 13.0 per cent manganese. When water quenched from about 1830 deg. 1940 deg. F., has structure which austenitic room temperature and relatively soft and tough and non-magnetic. However, when pressure applied this austen- THE IRON AGE, April 18, ts at at i a 1e | 3 500 300 WwW ; IG. Ni, Si, steel, air cooled from 2100 deg. 83. Ferric chloride etch, and 1000 diameters. itic steel, the austenite breaks down very rapidly hard, brittle martensite. Because this behavior, this steel has had wide use for wear resistant parts where pressure well abrasion rock crushers. Where abrasion occurs itself, sand blast nozzle, this steel has only poor wear resistance. this steel, the alloy additions car- bon and manganese are purely func- tional that they establish austen- ite the heat treating temperature which exremely sluggish, and which does not transform cooled room temperature. New Steel Developed Because the austenite the Had- field manganese steel broken down readily martensite pressure, this steel cannot machined the usual methods since the metal hardens under the pressure the tool. There are some parts electrical equipment which are desired non-magnetic. The Hadfield manganese stcel would and inexpensive, but not suitable because difficult machine. Not long ago steel was developed which contains about 0.40 per cent carbon, 12.0 per cent manganese, 7.0 per cent nickel and 0.20 per cent sulphur, which satisfactorily meets the requirement very low magnetic permeability, fairly good tensile strength and ductility, rea- 34—THE IRON AGE, April 18, 1940 sonably good machinability, tively low cast. Here the addition nickel had the functional effect “stabilizing” the austenite that would not break down readily under cold work, pressure; and the addi- tion sulphur improved the machin ability. High nickel steels the nickel between about and per cent, have commercial cause these amounts nickel cause the transformation the austenite retarded such manner that only martensite formed room tempera- ture, even though the steel cooled extremely slowly from above its critical. For this reason the steel cannot softened for machining. The higher nickel steels range can retained the non-mag- netic austenitic condition room tem- perature but this austenite broken down martensite either subjecting the steel very low tem- peratures, reheating for long times temperatures under the criti- cal. This behavior can also brought about substituting some other trans- formation retarder like molybdenum for part the nickel. Some entertaining results were ob- tained with low carbon steel contain- ing per cent nickel, per cent sili- con, and per cent air cooled from 2100 deg. F., the steel was non-magnetic and had hardness When this material was packed dry ice and left over- night, the steel hardened and magnetic. Another piece, which 3—Same steel above, air cooled from 2100 deg. F., and then cooled deg. dry ice; 40. Nital-picral etch, and diameters. W had been air cooled from 2100 deg. F., was heated 1400 deg. for about hr., and also became magnetic, and hardened 42. The structures for these three con- ditions are shown Figs. and The first represents austenite (with perhaps some cold working effects due perature transformation product which definitely resembles bainite; third tempered product with ag- glomerated carbides. The last two structures are approximately the same hardness. When the nickel steel raised amounts over about per cent, number surprising things are found. the first place, all these steels are permanently austenitic room temper- ature, that is, they have the face cen- tered cubic space lattice, but all these high nickel austenitic steels are mag- netic room temperature. Another thing that the room temperature co- efficient expansion these steels decreases with increasing nickel about per cent nickel, and then in- creases again with further increase the nickel content. Invar and Elinvar This interesting discovered Guillaume who gave the name Invar the per cent nickel steel. also found that addition TABLE Classification Steel Alloying Elements Ferrite Formers Austenite Formers clement Compounds Element Boron FeB Aluminum Carbon Arsenic Cobalt Chromium Copper Columbium Manganese Molybdenum Nickel Phosphorus Nitrogen Silicon Zirconium Titanium Tungsten Vanadium Percentage Limits Gamma Loop Compounds 0.8 1.8 FeAl; FeAls 1.0 1.5 FeAs; 0.5 1.0 2.0 4.0 0.3 0.5 FesP; 1.5 2.5 FeSi; 0.5 1.0 FesTi 1.0 2.0 FeV about per cent chromium the per cent nickel caused the steel have modulus elasticity which was not affected relatively small changes temperature. This material called which today has some- what modified analysis, very useful for springs accurate chronometers. The very high nickel steels also have 4—Same steel left, air cooled from 2100 deg. F., then reheated 1400 deg. for hr.; 42. Nital-picral etch, and diameters. appreciable resistance corrosion. although they rust ordinary, well marine, atmospheres. Cobalt austenite former like manganese and nickel, but does not retard the transformation austenite they do; the contrary, Houdre- mont has shown that cobalt large percentages increases the rate trans- formation austenite. Steels contain- ing from per cent cobalt have been used for permanent magnets be- cause their very high coercive force and high residual induction, but these have been replaced almost entirely dur- ing the last few years the cast iron- nickel-aluminum-cobalt alloys which have even better magnetic properties. Appreciable amounts cobalt are also used some high speed steels because cobalt strengthens the martensite. Co- balt additions have also been made the high nickel steels low coefficient expansion control the coefficients various temperatures. These nickel and cobalt steels serve illustrate the unpredictable specific effects alloy additions. The discovery and modification properties such corrosion resistance, low coefficient expansion, and high magnetic charac- teristics, will probably continue subject chance even though other properties steels become controllable through better understanding the functional effects the alloying ele- ments. Ed. Note: Next week the author con- cludes with discussions tungsten and molybdenum steels and chromium steels. THE IRON AGE, April 18, 1940—35 Ste ha 4 ies Latest innovations methods; new uses; cost data; and review prop- erties; both protective and decorative. ADOLPH BREGMAN Consulting Engineer, New York art. Although the first patent relating this process was issued 1841 England, did not come into widespread use until 1919, following the work this field Udy. Since then cadmium plat- ing has grown steadily, although its career has been marked consider- able technical controversy nomic fluctuation. Cadmium’s present importance industry can judged some extent the fact that the apparent consump- tion metallic cadmium rose from 616,000 Ib. 1925 5,652,500 Ib. 1937 (dropping back 4,204,800 Ib. 1938). While cadmium plating was not the only cause this rise, was, about 1934, the principal outlet for the metal. that time, however, was discovered that cadmium-nickel, cadmium-silver-copper and cadmium- silver made excellent bearings for in- ternal combustion engines. 1937 automobiles alone took quantity cadmium estimated about 1,000,000 causing the worst shortage metallic cadmium its history. Co- course, the price anodes skyrocketed from normal 70c. per $1.60 and over, 36—THE IRON AGE, April 18, 1940 the average for 1937 being has since reacted, going down 55c., only rise again the end last year. The reasons for the cline were the usual economic factors- over supply stimulated high prices, lessened demand, and many users turn- ing bright for plating much lower metal cost. Properties and Applications Cadmium plate has its primary use the protection other metals against corrosion, rather than decora- tion, although its appearance pleas- ing. Cadmium, like zinc, anodic electronegative iron, protecting preferential corrosion. slight- less effective than zinc this re- spect and does not protect wide exposed area iron. But cadmium has other useful attributes. For ex- ample, when used thicknesses about 0.0001 in., protect piano wire against corrosion, does not impair the tone. deposits rapidly and low temperatures, springs and deli- cately edged tools are not greatly em- brittled long periods the plating solution. Such articles can com- pletely freed from any such tendency heating for one hour 350 deg. Cadmium has pleasing white color with good lustre and retains its natural satiny sheen under proper conditions for long periods time. For this reason cadmium used the protective coating for any parts which require not only efficient pro- tection but good appearance. Inside radio parts are cadmium plated preferable have coating which does not become discolored sents unpleasant aspect the user who, occasion, finds necessary dig into the works his radio. wide variety small hardware, such padlocks, hinges, screws, fittings, etc., are cadmium plated their attractive appearance even after long display the retailers’ hands. The electrochemical equivalent amp. hr., compared with 1.219 for zinc. Thus, cadmium requires, theoretically, only 9.7 amp. hr. deposit 0.001 thickness for sq. ft., compared with 13.7 amp. hr. deposit the same solutions have good throwing power, covering irregularly well. general, therefore, cadmium easy metal plate, giving 7 4 0 € | | | | | | trouble and requiring less care than like work with cadmium. The baths are less critical, analyze and control; they plate faster, requiring less equipment floor space. Cadmium covers malleable iron nicely and also zinc base die castings, calling for much less care removing grease and oxides from the work. For these reasons, the use cad- mium plate, within short time after the development commer cially feasible process and its intro duction industry, became widespread casket hardware; structural steel parts which are imbedded automotive bolts, nuts, screws and washers; builders’ hardware; aircraft parts; the radio industry for hardware parts; chassis and marine hardware; general, malle- able fittings, electrical parts, wire screen, springs, tools, stampings and screw machine parts. Although cadmium not generally resistant chemicals, has some vantages this field. Because its resistance weak alkaline solutions, like washing soaps and powders, cad- mium plate has found wide use washing machine parts, floor clean- ing machines, mops and clothes wring- ers. also serves protect lavatory Soderberg, Monthly Review the OURTEENTH Series Articles the Technical and Economic Aspects Metal Cleaning and Finishing fittings which come with washing soaps. Low Contact Resistance The fact that cadmium plated sur- faces can readily soldered eliminates many problems the assembly electrical products, hardware, etc. The ductility cadmium makes prac- tical plate flat blanks and then form them the desired shape. Cadmium has low contact resistance and is, therefore, used extensively protective coat for electrical contact surfaces. Clean copper is, course, the best conductor, but its resistance rises rapidly due oxidation under heat and pressure. The resistance cadmium rises much less under similar circumstances. For that reason cad- mium has served excellently for bus bar joints subject intermittent heat- ing and cooling. Another important application cadmium plate products where dissimilar parts are contact with ture the galvanic currents set result corrosion, and the case radio sets, actual interference with re- ception. Plating the different parts with cadmium prevents this condition. one instance,’ cadmium plated rivets duralumin sheets resulted much less reduction strength and ductility the sheets after exposure, than did rivets made aluminum, annealed duralumin, tinned heat treated duralumin, 18-8 stainless steel, copper brass. Cadmium used prevent brass from corroding, the potential difference less between cadmium and brass than between zinc Cadmium also good protector for brass and steel parts contact with each other. Cadmium plate has been used good effect for machinery the pack- ing industry, parts contact with greases containing oleic acids. must applied with care such fields, however. cannot used contact with food products due 1936, pp. 33-37. each other. the presence mois Cadmium plate has field COST REQUIRED PRODUCE COMMERCIAL DEPOSITS* (Based Current Efficiency Per Cent) Electrechemical equivalent 0.5824 mg. per Coulomb 0.0733 per amp. hour. Specific Gravity 8.65. Weight per cu. in. 0.312 DEPOSIT COST TIME Per Sq. Ft. Surface Required Minutes for Deposits Various Current Densities Thickness, Weight, Metal Power Amp. Per Sq. Ft. 0.00010 0.072 $0.00450 $0.00045 6.6 3.28 2.19 1.64 1.31 1.09 0.93 0.00015 0.108 0.00675 0.00060 9.9 4.92 3.29 2.47 1.98 1.64 1.41 0.00020 0.144 0.00900 0.00090 13.11 6.56 4.38 3.28 2.62 2.19 1.88 0.00025 0.180 0.01125 0.00110 16.4 8.22 4.11 3.29 2.74 2.34 0.00030 0.216 0.01350 0.00135 19.7 9.83 6.61 4.96 3.98 3.28 2.81 0.00035 0.252 0.01575 0.00160 22.9 11.44 7.66 4.59 3.81 3.27 0.00040 0.288 0.01800 0.00180 26.7 13.22 8.81 6.60 4.44 3.81 0.00045 0.324 0.02025 0.00200 30.0 14.78 9.83 7.39 5.89 4.29 0.00050 0.360 0.02250 0.00225 33.3 16.44 10.91 8.20 6.56 5.56 0.00055 0.396 0.02475 0.00250 35.6 18.00 12.00 9.00 7.22 0.00060 0.432 0.02700 0.00270 38.9 19.67 13.11 9.83 7.89 6.48 5.56 0.00065 0.468 0.02925 0.00290 42.2 21.33 14.22 10.66 8.56 7.03 6.03 0.00070 0.504 0.03150 0.00315 46.7 23.33 15.56 11.22 9.33 7.78 6.67 0.00075 0.540 0.03375 0.00340 48.9 24.56 16.33 12.33 9.83 8.14 6.99 0.00080 0.576 0.03600 0.00360 63.3 26.67 17.78 13.33 10.67 8.89 7.62 0.00085 0.612 0.03825 0.00380 55.6 27.89 18.67 14.00 11.17 9.25 7.93 0.00090 0.648 0.04050 0.00405 58.9 29.44 19.67 14.78 11.78 9.81 8.41 0.00095 0.684 0.04275 0.00430 62.2 31.11 20.78 15.56 12.44 10.37 8.89 0.00100 0.720 0.04500 0.00450 65.6 32.78 22.00 16.44 13.11 10.92 9.37 THE IRON AGE, April i ] x Sha F ior ee | ABOVE parts, cadmium plated for reduced contact resistance. RIGHT RENCHES and pliers, plated with cadmium for protection. ings. used ordinary commer- cial thicknesses for cheap ball bearings, worm gears and ball joints. can produced smooth coats nesses 0.03 in. this con- nection interesting development proceeding the work the Udylite Corp. ductile cadmium coatings. According patent 2,107,806, deposits are produced with high duc tility thicknesses ranging from 0.0025 mm. (0.00085 in.) 0.75 mm. (0.0255 in.) more. stated that sheet steel coated with even 0.75 mm. (0.0255 in.) can bent repeatedly 180 deg. angle without any evidence cracking the cadmium coating. The plate obtained very similar tin plate except, course, for the higher melting point the cadmium. Tests diesel engine motor pistons have shown very promising results. Deposits this character are pro 38—THE IRON AGE, April 18, 1940 duced the use agents the plat- ing solution and the control pertinent factors the plating op- erations scribed the pat- ent just cited. Ductile deposits have been produced Cadalyte for some time. instance, cad- mium coatings ten-thou- sandths wire remain intact covering the wire even when drawn one-fifth its original diam- eter. Also, relatively thin cadmium coatings from Cadalyte sheets rolled out four times their original surface area. Corrosion Resistance already stated, the primary use metals from corrosion. the subject its the protection iron and steel, controversy raged for several years and has only down. Cadmium originally into the limelight because its ex- tremely favorable showing under the BELOW ACKS and wash- ers, cadmium plated for rust resistance. salt spray test. has shown, however, that the salt spray test far from infallible index and the results demonstrated that cadmium plate has decided limitations. Cadmium chloride, which formed the salt spray, has low solubility compared with zinc, for example. Since cadmium chloride formed corrosion marine atmos- mium should stand well under these conditions. That the results service tests did not equal those the salt spray tests proves that other com- pounds are also formed posure, with higher cadmium chloride, and for that reason corrosion proceeds faster. BELOW ISCELLANEOUS hardware coat- with cadmium, for protection and good appearance. All photos courtesy the Udylite Corp. ABOVE ADMIUM plate for screens. Good throwing power puts metal into the inter- stices. LEFT protected cadmium plate without loss tem- per. industrial where sulphates are among products, cadmium shows low resist- ance corrosion because the high solubility cadmium sulphate. How- ever, has been pointed out that the corrosion products cadmium not accumulate like those and sometimes necessary use cadmium order keep exposed mechanisms working Cadmium plate operates best ad- vantage indoor service air moderate low humidity. Where the humidity high, less effective, but according does well. Although cadmium may applied other methods, such spraying and Atmospheric Corrosion Resistance and Protective Value Metallic Clarke, paper read the London Con- Society, May 17, 1939. THE IRON AGE, April 18, 1940—39 i { perhaps even hot dipping, the meth- almost universal use electro- deposition still tanks barrels. The solutions are cyanides made with cadmium oxide sodium Many commercial solutions the pres- ent time are prepared from proprietary salts containing cadmium salts, cya- nides and brightening agents, such Cadalyte (E. Pont Nemours Co.), Cadux (Hanson-Van Winkle- Munning Co.) and Udylite (Udylite Corp.). typical bath for still plating Sodium cyanide .........6.5 oz. Cadmium cyanide .......5.5 oz. Sodium hydroxide ....... alternative bath contains: Cadmium oxide...... Sodium cyanide ......... oz. Temperatures may range from deg. 110 deg. F.; current densities from amp. per sq. ft.; voltage, 2%. Anodes should pure cad- mium, but many anodes are also used, the proportion three cadmium one steel. Arsenic, antimony, lead, silver and tin must kept out the solution avoid dark, rough and spongy deposits. Numerous addition agents are recom- mended brighteners, such gulac, molasses, gelatin, dextrine, grain ex- tract, and other organic compounds. Nickel minute quantities may also used. Many these agents are tary mixtures just tion agents act not only eners reducing the grain size the deposits, but also improve wear resist- ance because the increased hardness the deposits. According Soder- berg* the hardest plates are always found within the bright range the solution. The hardness also increased with decreasing cadmium; decreasing sodium cyanide (only the presence nickel); increasing grain extract content, particularly when cadmium low; increasing the nickel content, particularly when cadmium and sodium cyanide are low. Acid cadmium baths have been de- veloped for producing highly adhesive plates, which have been covered patent applications.’ They are intended primarily for flash coatings used prior coating from cyanide baths. 8“Principles Electroplating and Electro- forming,” Blum and Hogaboom. Cyanide Cadmium Plating Solution,” Gustaf Soderberg, paper presented the first International Electrodepositors’ Conference March 1937. Private Soderberg. 40—THE IRON AGE, April 18, 1940 Good adhesion can obtained stainless steel and certain aluminum place for thin acid cadmium coatings ordinary steel. Apparently there always some oxidation prior immersion the plating bath. This oxidation not removed cya- nide baths. Low baths provide the maximum adhesion. Work has also been the bright plating cadmium, which centered around the development methods purification baths which have become contaminated service. Recent developments bright cad- mium plating have included facilitating maintenance brightening agents with sodium cya- nide that the brightening agents are automatically added the large proportion the commer- cial cadmium plating done barrels. This type work may conducted under widely varying current densities and voltages, ranging from volts and from 175 500 amp. per barrel. Higher voltages are used with higher concentrations. difficult measure current densities barrels due the variation the effective cathode area; only part the load the barrel the circuit any given time. solutions used barrel work contain about the same metal and chemical content the still solutions. ASURING the thickness cadmium plate the Hull and Strausser method. Photo courtesy Hanson-Van Winkle-Munning Co. The equipment used for cadmium plating the conventional type used most plating operations. Tanks forced. lining needed although rubber may used. Lead should not used. For plating barrels, hard rubber (free from sulphur) recom- mended, although Formica, Bakelite and other synthetic compositions can used. Bus bars should large enough allow for amp. per gallon still solution and amp. per gallon for barrel plating sq. in. cross-sec- tion copper bus bars will carry about 1000 amp.). The solutions are gener- ally kept their proper operating cooling coils. One precaution important prac- tical operations. barrel plated work, the work dumped out the barrel before rins- ing it. Rinse the work only, never the barrel. Rinsing the increases the drag-out losses. Numerous tests are measuring the thickness cadmium plate, such microscopic, stripping, etc., but the one most general use the dropping test developed Hull and Strausser. given solution (110 grams ammonium nitrate and ce. concentrated nitric acid per liter rate (90 110 drops per min.) the test piece mounted deg. angle that the solution runs off quickly. The time required coating (usually determined with stop watch) gives direct measure the plate. estimating the cost cadmium may figured that Ib. cadmium will cover approximately 100 sq. ft. surface with average coating 0.0002 in. (This figure in- cludes average drag-out.) the pres- ent price cadmium, 80c. per the cost the metal is, therefore, about per sq. ft. The cost chemicals and electric current, including cleaning and pickling, runs something the order per cent the cost heavier cadmium coatings the percent- age decreases proportion, the cost cleaning and pickling chemicals fairly independent plate thickness. Labor costs, course, vary with every job. However, may mated that one man can handle much nine barrel loads per with the proper equipment. The accompanying table gives the cost and time required produce com- mercial deposits still tanks under specific conditions. 4 4 | | * ; i ; | 4 | | | | > | | » ; 5 | | | PROTECTIVE SUMMERS General Electric Co. Nela Park Engineering Department Cleveland ° ° sands complaints sabotage and espionage industrial Government contracts, and consequently every fense measure necessary protect such plants. Many the methods destruction require certain amount time prepare, and under cover darkness this may has received thou- more easily. Particularly vulnerable locations are along railway tracks, along highways, near woods heavy undergrowth which furnishes concealment, dead-end streets the property line, steep banks inside outside fence, entrances the property, around important buildings where entrance forced, and behind stacks material. serve all purposes, but proper lighting great help and the principle keep mind direct the light where will help the guard most from his point observation. high fence around the property line usually considered necessary. The fence should painted white light color that trespasser may readily seen silhouette against and lighted means floodlights local One the best methods lighting the fence line locate narrow beam floodlighting projector equipped with 1000-watt lamp each corner and place additional projectors in- tervals not exceeding 300 ft. between the corners, shown accompnaying mounted ft: high and there guard patrol all projectors should pointed the direction which the guard walks that the light does not shine into his eyes. the guard fixed post, the pro- jectors should point away tageous have the guard fixed platform the same height the pro- jectors, thus giving him structed view the entire area well lessen the danger stealthy at- tack. the fence the open type and easily seen through, may desir- able project the light outside the fence line that the edge the beam along the fence. guard patrol will then command wider area approach while remaining relative darkness second method consists local units equally spaced around the fence. There are many special types, which, properly installed, will excel- lent job. The most common are the RLM Dome and wide-angle refractor. They should mounted ft. high and spaced not more than ft. apart. Two-hundred 500-watt lamps should used depending the vul- nerability the location. only local units are used, there should supple- mentary floodlights strategic loca- tions which are controlled guards. This gives desirable flexibility that the unit may directed any point where emergency may require light hurry. Satisfactory protection may also obtained lighting the entire yard provided care taken locating the lighting equipment. open where there little obstruction, simple matter light the yards placing projectors the roofs and directing the ward the boundary line, being careful, course, not direct light toward the guards. For short distances about 200 ft. wide should used and for the longer dis- tances medium narrow beam equip- ment. contrasts are reasonably YARD LIGHTING GUARD HOUSE good, narrow beam projectors with 1000-watt lamps can used effec- tively 600 ft. and even beyond under favorable conditions. Where there are large piles ma- terial, small outlying buildings, other obstructions which may throw long shadows, great care must taken placing the projectors that there will shadows serve hiding places for trespassers. many cases shadows can eliminated directing the light toward the obstruction from two directions. other cases necessary place local light pole near the obstruction. Buildings near the fence line should receive particular attention serve obscure anyone scaling the fence the point unless special light- ing provided. The building and fence should most cer- tainly well lighted. Areas around freight cars the yard should also well lighted for these provide good hiding places from which small groups can operate. All entrances should well lighted that approaching persons can closely scrutinized the guard. also good practice provide lighting for appreciable area around en- trances that intruder succeeds getting past the guard will not immediately lost the veil dark- ness. Floodlighting projectors roofs nearby buildings furnish good sup- plementary lighting around entrances, provided they can properly located not too glaring the guard. FENCE LIGHTING THE IRON AGE, April 18, t i WES ‘ 7 fi ee ROOFS O a CURRENT WAVE FORM Current until very recently the electric spot welding heat treated aluminum alloys such used the construction airplanes has been accomplished with considerable culty. Frequent changing welding tips has been necessary due the 42—THE IRON AGE, April 18, 1940 faces, the finished welds have had tendency develop large cracks, and undesirable indentations produced the sheets. One the greatest drawbacks existing alumi- num spot welding equipment, however, has been the excessive kva. demand during weld. Table gives idea the newest machines for the spot welding alu- minum alloy sheets with low power input this Taylor Winfield Wave welder capable welding all the common- used gages. The model shown has throat and equipped with retractable stroke cylinder and dynamic pressure system incorpo- rating so-called air lock cushion. All the control equipment housed the cabinet the left. the magnitude this demand for vari- ous gages material throat mended for welding alclad with conventional equipment. There are several ways these difficulties may overcome. applied conventional single phase a.c. welding machines, the demand may very much reduced series capacitors which bring the load the line unity power factor and hence equivalent the kw. demand the welding machine. For large ma- chines, however, the required capacitor bank becomes quite expensive, and the load the line still phase intermittent one. Another method use motor-generator set, which uses its flywheel effect store energy between welds, and the actual line load becomes three phase, high power fac- tor load with minimum fluctuation. This equipment even more expen- sive than the equipment mentioned above, and considerable power lost overcoming the losses the motor- generator set. the other hand, neither these two systems offer any solution the problem weld qual- ity and tip pickup. third method storing energy the magnetic field inductance through direct current charge. This the method used the Sciaky ma- March 21, 33. Yet another method, and ciple used the design the Hi- Wave welder, recently developed the Taylor-Winfield Corp., Warren, Ohio, charge capacitor bank predetermined voltage direct cur- rent and then instantly discharge into the conventional welding machine 4 | | i | j | Time | | | | | | | ‘ | of ALUMINUM WELDER primary transformer pos sible arrange the circuit that the charging the capacitor may tak- ing place during the entire time inter- val between successive welds, thus reducing the power demand mini- mum. making use high voltages and all three phases the power line, small, low cost rectifier systems may used for charging the capacitor bank, resulting high power factor, and low kva., balanced load the line. Table gives the corresponding kva. demand Hi-Wave welder for the sa