The Iron Age 1945-11-08: Vol 156 Iss 19

DEVENTER President and Editorial Directer BAUR Vice-President General Meneger LEONARD Assistant General Manager HAYES Advertising Manager JOHNSON, Reader Service and Market Research BAUR, Production Manager Promotion Manager Executive Offices Chestnut and Séth Sts. Philadelphia 39, Pa., U.S.A. Editorial and Advertising 100 East 42nd St., New York 17, Regional Business New York New York 100 East 42nd St. East 42nd Cleveland Guardian Bidg. Park Bidg. Chicago 7310 Woodward Ave. Box RAYMOND KAY Los Angeles 2420 Cheremoya Ave. Owned and Published CHILTON COMPANY OFFICERS AND DIRECTORS MUSSELMAN, JOS. HILDRETH, President GEORGE GRIFFITHS EVERIT TERHUNE Vice-President VAN DEVENTER Vice-President BAUR Vice-President Vice-President JULIAN CHASE WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary BUZBY HARRY DUFFY THOMAS KANE CHARLES HEALE WILLIAM VALLAR, Asst. Treas. ° ° Chilton Editorial Board PAUL WOOTON Washington Representative Member, Audit Circulation Member, Business Nerth America, America and Vol. 156, No. AGE Editorial Blue Shirt Heaven Technical Articles Sodium Hydride Process for Descaling Steel Precision-Cast Copper Base Alloys (Part Selecting the Proper Heat-Resistant Steel Photo-Grid Technique for Measuring Distortion Transfax Simplifies Strain Analysis Studies Coined Grooves for Shaft Journals New Equipment Features News Front Assembly Line Washington West Coast Personals and Obituaries Dear Editor This Industrial Week News Industry News and Markets Machine Tool Developments Nonferrous Market News and Prices Iron and Steel Scrap News and Prices Finished and Semifinished Steel Prices Alloy Steel Fabricated Steel Products Prices Warehouse Steel and Pig Iron Prices Ferroalloy Prices Comparison Prices Week and Year Technical Advance Foundries Needed NAM Condemns Compulsory Patent Licensing Retain Key Advisory Committees Annual Wages and Guarantees Practicable Plate Edging Shear Aid Welding WPB Report Copper Control Army Ordnance Assn. Program Index Advertisers November 1945 122 124-5 126-7 128 129 130 131 132 133 134 138 140 142 146 148 156 237-8 PEIRCE LEWIS WARREN 104 ° ° ° master craftsmen. 54—THE For great machines, that really big jobs, Welded Steel frames provide the STRENGTH, LIGHTNESS and ECONOMY man- ufacturers these massive monsters industry. Appear- ance, too, enhanced the smooth finish produced addition vast fabricating and handling facilities, the Mahon organization maintains staff design engineers who are thoroughly prepared, through long experience, assist you adaptation problem. Address inquiries Steel Plate Division THE MAHON CO. Home Office and Plant, Detroit 11, Michigan Western Sales Office, Chicago Fabricators Machine Bases and Frames and Many IRON AGE, November 1945 aa \ | | } ESTABLISHED November 1945 VAN DEVENTER President and Editorial Director BAUR Vice-President and General Manager ° ° Editorial Staff News-Markets Editor CAMPBELL Machine Tool Editor...H. LINSLEY ° ° Associate Editors JACK HIGHT WINTERS ALBIN JOHN ANTHONY BARMASEL Editorial Assistants SCHIEN SPEAR Foreign Editors Canadian (Contrib.) Sanderson Regional News and Technical Editors LLOYD Pittsburgh 428 Park POST Chicago 1134 Otis EUGENE HARDY ANSBORO Washington National Press Bidg. LLOYD Cleveland 1016 Guardian BRAMS DETROIT 7310 Woodward Ave. OSGOOD MURDOCK WORTH HALE San Francisco 1355 Market St. Editorial Correspondents ROBERT McINTOSH Cincinnati DEAN Buffalo FRAZAR Boston HUGH SHARP Milwaukee RAYMOND KAY Los Angeles JOHN McCUNE ROY EDMONDS St. Louis JAMES DOUGLAS Seattle Blue Shirt Heaven HIS present labor-management controversy concerning which party shall get what share the postwar prosperity that still “around the corner” reminds story. Once upon time there was old prospector who had roamed the Rockies for years with burro for companion. Every often would manage come the nearest settlement mingle with people and enjoy human talk change from speaking burro language. such occasions, after sufficient priming with the liquid locally known “red eye” would invariably begin tell what was going “Here been, for forty years roaming the desert and climin’ the mountains along with jackass, huntin’ fer gold and once while striking nugget worth jest enough fetch some more beans and bacon. An’ all that time, never had blue shirt with stiff white collar. Boys, let tell you, got order now fer that blue linen shirt handed the minute reach the promised land.” Whereupon one his bar and boon companions who knew the old chap and his habits pretty well remarked: “Hold minute, Jack, you ain’t made the grade heaven yet. Mebbe where you are going asbestos shirt will suit you better.” Speculation what take-home pay can had our postwar promised land which yet almost unentirely surveyed something anticipatory Jack’s ordering his blue shirt advance knowing his actual destination. Our postwar economy remains yet built and arrived and continue approach the present crab fashion moving backwards, productively, may that will turn out paradise. Indeed, instead blue shirt even asbes- tos one, may find ourselves with shirts all. When your house burns down and you have insurance, you not expect have key handed you and deed larger and better dwelling. you want that you have got work for and work harder than ever make for what you have lost. have had insurance repay for our war losses, material otherwise. Yet that world holocaust have burned billions upon billions dollars’ worth values. have worn out machinery and equipment unheard scale, not make goods make richer but make things cause people, ourselves and our enemies, become poorer. have deprived ourselves some million automobiles, new homes, millions wanted and needed products every sort and description. true that have gained the largest navy the world, the atomic bomb and variegated and enormous pile munitions and the added expectation enormous tax load order maintain what shall keep these nonproductive items that man can eat, wear enjoy. Why then dispute among each other the fabled pot gold the end the rainbow? Why talk about shorter hours, more pay, more profits and more for all with less effort? The way these things want them lies more work, more effort; certainly not shutting down our plants argue about the division what may come from them when and decide settle down business. can’t bake more pie persist keeping the kitchen stove cold. | SCHIMKO | | More Flexible Now the wider ranges temper, chemical composition and other qualities offer limitless combinations solve the problems modern design nex With such flexibility, the operations cold forming, deep drawing, stamping, welding, etc., can often simplified and economies effected, when sheets carefully determined specifications are used. Inland specializes the production steel sheets that meet particular requirements and prepared offer you engineering cooperation and metallurgical assistance. This service rendered without obligation and may the means lowering your costs, increasing your output and bettering your product. Inland Steel Company, Dearborn St., Chicago Sales Offices: Cincinnati, Detroit, Indianapolis, Kansas City, Milwaukee, New York, St. Louis, St. Paul. Principal Products: Bars Structurals Plates Sheets Strip Tin Plate Floor Plate Piling Reinforcing Bars Rails Track Accessories i | | = i few } was Sto | nak ord | Nov. 1945 about close its DPC Buffalo plant and will move its Columbus, Ohio. This action prompted the terms offered for aircraft disposal. C-54's suitable for airline transport use are being offered $300,000 minus for reconversion cost. Offered lease basis for only $25,000 per year and with expectant life only three years for used planes, the cost drops down only $75,000 for new type tricycle landing gear for airline use under development Curtiss-Wright and expected ready for use yr. Automotive dealership profits which the past have run from pct pct more, are expected pared somewhat under current OPA policy. The agency considers that the scarcity used cars will reduce trade-in losses which have always reduced dealer margins appreciably. Treating alloy and stainless steels with sodium hydride fused caustic accomplishes descaling uniformly without hydrogen embrittlement loss metal and generally less time than other pickling methods. This process has been developed Pont, being enthusiastically used number plants, and being offered industry and basis. applying pattern fine grid lines metal surface photographic means, stretch and flow metal during former operations the testing coupons can readily observed distortion the grids. While additions silicon aluminum stainless steels increase corrosion resistance high temperatures, these elements fail produce passive film the surface the iron alloy room temperature and the presence moisture. This probably the result the tendency for the oxides silicon and form hydroxides that dissolve water. Marked progress has been made high-temperature resistant steels the few months, with research developing "synthetic metals" which resist the heat notably higher temperatures than heretofore possible. Indicative the difficulty producing such metal the fact that its selling price cur- rently ‘is upwards $2.00 lb. Safety blocks extruded magnesium are easier handle than the oak blocks commonly used additional safety precaution the die openings sheet metal form presses. These blocks are considerably stronger than oak and have been standardized three sizes types sections meet most nents. Research the first French jet-propelled airplane started secretly 1943, and carried clandestinely until the liberation that country. flying research laboratory for the Rateau turbine unit, and will called the 6,000. Flight tests the prototype two place craft scheduled for early next year are expected demonstrate speeds 600 The technique for making German hollow turbine blading for jet engines (internally cooled, superior and far cheaper than solid blading) devised prominent maker ordinary straight pins, the Prim Company, Stohlberg. costs, for pins, carefully guarded family secret, the Prim Company uses small battery automatic machines which cut wire size, cold head, and then less grind the points, the output being about 700 per min. But: brother, Connecticut manufacturer, has for decades used the same pin technique. Aluminum ingots and billets Germany were scalped very high speed ordinary planers equipped with flycutters. German development was the cutting gear teeth undersize, plating the teeth with copper and diffusing tin into the copper give bronze wearing velding, burning the presence so- dium metal characterize new pickling process developed Pont. Visually, there little else, except for these flames which lick the covers battery sodium hydride generators located one side dip tank, distinguish this process from ordinary pickling tank. The reduction metallic oxides, resulting from fabrication metals elevated temperatures accomplished the use sodium hydride formed burning bricks sodium hydrogen atmosphere and having the resulting hydride dissolve fused caustic bath. opera- tion, the scale reduced immers- ing the work the fused bath with- out use electric current. When the work removed from the bath the reduced scale still remains the surface the work but loosely adherent form. Upon quenching the work water, the adherent material blasted from the surface the generation steam and remains only brighten the surface few seconds dip acid. The scale hav- ing been removed, the article can now subjected such operations rolling drawing and various finishing treatments, fig. worth noting that hardly any the scale material left over sludge the bath, thereby contaminating and weakening it. underlying metal yellow flames hydrogen IRON AGE, November 1945 removed should the work left the bath longer than required. fig. shown the sequence opera- tions the sodium-hydride acid dip treatment. The first large scale installation this process has been the Rust- less Iron Steel Corp., Baltimore, where its operation has been con- tinuous one for the past four years. The process has also been carried number other plants, but its extension industry generally has been restricted due the diversion sodium for other war purposes, chief which was the manufacture tetraethyl lead. Now that sodium again available, expected that the process will find ready acceptance throughout the alloy industry. plain-carbon steels however, the proc- ess, while technically satisfactory, far not considered economic operation. considerable array metals are being descaled large fabricators who have had the Pont sodium hydride process operation long ascertain for themselves its Sequence operations Pont sodium hy- dride descaling process for commer- cial application. Hy- drogen source monia dissociator recommended most economical) not indicated. Acid dip treatment varies with alloy metal being brightened. ° economic feasibility. The Jessop Steel Co., Washington, Pa., installed the process about three years ago and are regularly descaling all types straight-chromium stainless steels well stainless-clad steel. the clad type, the process provides good white pickle finish the stainless without overpickling the SAE 1010 steel used backing Other metals descaled Jessop, without having experienced loss weight due dissolution metal, have been copper, high-speed tool steel, pure sil- ver, pure nickel, Inconnel, composite high-speed hack saw steel, high-car- bon high-chromium steel and Stellite. Inasmuch the bath can main- tained the proper operating condi- tion continually, has also been Jes- sop’s experience that sufficient weight must put through the process keep the cost per pickled economi- cally feasible. general, the process highly satisfactory with electric furnace quality materials, and lends itself handling sheets and plates. The method operations and precau- tions followed galvanizing dip in- stallations are applied the hydride process Jessop. The Solar Aircraft Co., San Diego, Calif., has had the process produc- tion the usual varieties itic stainless steels. has applied the procedure castings, forgings and complicated stampings and fabri- cated parts. This company uses the same acid for all austenitic stainless alloys which are free carbide pre- | Sodium 40% oe? ov”, sc the are the 1010 ther hout due been Jes- omi- ends ates. cau- in- lride plied abri- the nless pre- cipitation, but for other alloys special acids are sometimes required. After high pressure water spray, the finish attractive pearly gray. During the war, the process was operation 24-hr basis and now 10-hr basis. Considerable success has been experienced exhaust manifolds. The shorter time cycle which this process removes scale, particularly the case steels which had scale broken similarly treated be- fore pickling, has led the Allegheny Ludlum Steel Corp., Dunkirk, Y., after having used the process for the last three years, increase its hy- dride cleaning capacity the present time 200 pct. Other installations addition the companies already mentioned are Carpenter Steel Co., Reading, Pa., and Pittsburgh Steel Co., Monessen, Pa. The Universal Cyclops Steel Corp., Bridgeville, Pa., after having investi- gated processes connection with materials difficult pickle, such high-speed steel, stainless and heat- resisting steels and other grades con- taining high alloy contents that add pickling problems—has made plans to, install and put operation this process the near future. According the experience one large manufacturer, the process has been successfully employed for the past months the descaling all grades stainless steel sheets and plates the hot-rolled and an- nealed conditions; the stainless types that are being descaled include 301, 302, 304, 309, 316, 321, 347, 501, 502, 405, 410, 442 and 446. The advantages that this company realizes this process are—simplicity con- trol rapid test for sodium hy- dride, attack base metal result- ing metal saving and improved Fon Descaling Steel ALBIN Associate Editor, THE IRON AGE The most significant development pickling (descaling) decades the descaling alloy steels and particularly the stain- less steels through the use sodium hydride fused caustic bath. has been developed Pont, and offered industry the United States license-free and royalty-free basis. Descaling uniformly accomplished without hydrogen embrittlement metal, and generally less time than other pickling methods. This article discusses the development the Pont and includes practical data for large scale app gathered the writer the Rustless Steel Corp. surface, and the elimination re- treats since one trip through the sys- tem removes all the scale, thus in- creased production results. That metallic sodium powerful reducing agent has been well known but difficulties were experienced when attempts were first made employ reduce the oxide scale. Early dif- ficulty was experienced wetting the scale uniformly with the sodium. Where reaction did occur, the reduc- tion was accompanied the forma- tion sodium oxide, which was cor- rosive. Other difficulties were experi- enced removing excess sodium from the treated work and special tech- nique would have been required operate molten sodium bath elevated temperatures the pres- ence air. Solution sodium molten caus- tic was tried but was soon discarded because the accumulation sodium oxide the molten caustic. Such bath dissolves iron oxide and other ~ TANK constituents the scale but this con- taminates the bath and eventually deposits the dissolved scale sludge the bath excessive amounts. addition, solution sodium oxide caustic very corrosive the iron the tank walls. Sodium hydride, the other hand, was found dissolve molten caus- tic and such solutions were found reduce iron oxide metallic iron. The sodium hydride reacts with the scale form caustic soda—which the material comprising the bath itself— the following manner: Thus undesirable impurities are added the bath and the metal walls the tank are not attacked. The reduced material adherent form the work and carried off with it. The presence sodium hydride, was found later, decreases the corrosion iron fused caustic. Sodium hydride caustic reduces nickel and cobalt oxides the cor- responding metals. Chromium tri- oxide reduced lower oxide but not the metallic state. While the early laboratory investi- gations were carried out adding solid sodium hydride the bath, the material was not that time commercially available. Experiments were made determine the possibility forming the hydride direct- the bath from sodium and hydrogen. Sodium was placed THE IRON AGE, November — ln { | ~ > RINSE a AREA HYDROGEN the caustic beneath sodium the bell. The third hole was used introduce work treated into the fused caustic bath. this manner reg- ulating the sodium and hydrogen ad- ditions, hydride concentrations any 3—Sectional desired amount pct could The caustic bath had covered caustic bath through concentrations higher than bottom which hydride were employed, exces- sive fuming and loss hydride oc- curred open air. Concentrations without noticeable fuming although air did tend reduce the hydride test time. Considerable loss NaH occurs open bath because the attrac- tion NaH for oxygen but for working bath this loss economically vessel which contained fused caustic formed bell which layer Practical and can avoided meth- and had nitrogen atmosphere. The sodium was maintained removing sealing off the bath surface sodium melted and floated the sur- the cover and adding solid metal from when not use. face the caustic. Hydrogen gas time. hydrogen inlet pipe this bath samples carbon bubbled into the caustic layer. The was introduced through the second steels, alloy steels and stainless steels hydrogen reacted with the sodium the large pot cover and well such other metals nickel, when the sodium had disappeared the ranged discharge hydrogen into cobalt, and copper were descaled read- caustic contained equivalent the sodium added. This hydride bath acted scale identical- with the bath made dissolving solid sodium hydride fused caustic. apparatus was then developed for carrying this reaction continu- ously and was used subsequent lab- oratory work. iron pot for melt- ing caustic was fitted with cover which had three openings. Through one opening cylinder was suspended which was open the bottom and dipped about in. beneath the caustic surface. The cylinder was equipped with removable cover and thus SODIUM HYORIDE ABOVE 4—Stainless steel wire being descaled the sodium hydride bath that has been oper- ating, with the exception only mechanical improvements, for four Steel Corp. Pipes right feed hydrogen generators which metallic sodium burning. ° ° ° LEFT 5—About 3000 stain- less steel wire being lowered into the water quench immedi- ately upon removal from sodium hydride bath, left. Vigorous action generated steam re- moves reduced material which adherent form after the wire leaves the IRON AGE, November 1945 ini TANK caus | | ° 7—Replenish- ing the sodium supply the molten caustic bath done dropping sodium bricks into the gen- erator boxes in- tervals. 6—Descaled stainless steel wire shown coming out the brightening acid dip, after which rinsed. Material now ready for further processing. The purpose the acid dip remove any reduced metal still adhering the work after the water quench. Immersion time short duration; the case alloy steel from ily. was not found feasible re- move the oxide from aluminum and its alloys, nor treat zinc magne- sium cadmium and their alloys because reaction the metals with the bath. hydrogen embrittlement was ever found with steels. Tests made samples treated for long periods showed deterioration the physi- cal properties the steels. The work- ing temperature the bath 700°F, which well below steel’s transition temperature. sense the sodium hydride bath alkaline pickling bath which re- quires electric current. Further- more, the reduced scale remains the work and removed with the work without contaminating the bath. The sodium hydroxide content auto- matically renewed the course reducing scale. The sodium hydride descaling proc- ess covered Patent No. Nemours Co., Inc., Wilmington, Del., and available interested companies for laboratory commer- cial application, free from license royalty the United States. Developmental work and commer- cial applications the process has been under the direction Harvey Gilbert, supervisor, Sodium Cyanide Products Research, Electro- chemicals Dept., with laboratory as- sistance Clare. Cooperating with Dr. Gilbert the first large scale installation the process were Feild, director research. Rustless Iron Steel Corp. and Fred Emm, general superintendent. Large Scale Installations Based the laboratory data just described, apparatus was designed for generating hydride large caustic tank measuring in. Steel Corp. plant. Six hydride generators were con- structed and mounted brackets the caustic tank along one side. These generators are rectangular boxes ordinary welded steel open the bot- tom and having cover with two 5-in. diam feed holes also provided with removable caps. The bottoms the generators are in. below the aver- bath depth. gas inlet tube passes through the cover each box and delivers the hydrogen the generator near the bottom, fig. Hydrogen was obtained disso- ciating ammonia standard dis- sociator. After dehydrating the bath concentration 1.5 pet NaH was built the bath. steel water tank located about from the caustic tank was used for quenching the work. Fan ex- haustors built into the wall and locat- just above the water tank served ventilators. The descaling unit was installed corner the pickle room and additional equipment was required other than that used the usual pickle house. The present installation Rustless take care bars well other work, fig. This tank low- carbon steel and mounted brick setting with top approximately above the floor level. Automatic temperature controls maintain the bath 700°F. The installation has THE IRON AGE, November ugh : on — 7 Ts rac- Ja capacity for treating tons work per day and used for wire, rod, and bar stock the various grades stainless steel. The bath temperature not crit- ical far the reduction scale concerned. working temperature 700° 20° has been found the most practical. Higher tempera- tures cause excessive loss hydride. Lower temperatures cause difficulty forming frozen layer bath the cold work when first intro- duced and additional time required melt this frozen layer before the liquid bath can react the scale. Concentrations NaH low pet are effective but this small amount quickly reacted locally when contacts the scale. Hence, more practical carry from 1.5 pet 2.0 sodium hydride the bath all time. additional ad- vantage results from the use higher hydride concentration the open surface the bath loses hy- dride more readily reaction with The time required reduce scale varies from few seconds min depending the thicknesses and nature the scale and the condition under which was originally formed. The quench tank approximately the same dimensions the caustic tank and located adjacent the descaling tank. The work lowered slowly into the quench tank and then can removed once. The quench- ing operation produces steam and ventilation provided remove steam and caustic spray from the room. The tanks are arranged end end with least 4-ft space between them and overhead crane with re- mote control used convey the work the tank, fig. the case the stainless alloys, most the reduced metals and lower oxide chromium remain the work removed from the bath. The work which 700°F generates steam causing the loose material fall away from the surface. Reduced metal comes off the water large patches; other cases more finely divided. The surface the work after the water quench has matte appearance because some the re- duced material not removed. This material soft and does not harm tools and dies, the original scale does, but usually desirable eliminate entirely the reduced ma- terial. This readily done short acid dip, fig. The acid dip treatment will vary with the alloy. practice min min dip hot pct sulfuric 62—THE IRON AGE, November 1945 IS. 8—With simple gas evolution apparatus, the operator testing the sodium hy- dride contents the bath. The two-part steel mold (shown opened) dipped into the bath make pellets for the test. acid used remove the reduced metal still adhering the work. For pet nitric acid 160°F suffi- cient produce bright surface. Some the stainless steels require somewhat longer treatment the any case acid dip used brightener and passivator rather than pickling operation. After the bright- ening dip good wash with high pressure water hose will produce clean metal surface and the work then dried the usual way. source hydrogen, any dry gas mixture containing hydrogen which free from oxygen, and can used. Nitrogen and low percentages hydrocarbons are not objectionable. Rustless found eco- nomical source hydride that obtained the dissociation ammo- nia. Dissociators for this purpose can obtained standard equipment from number manufacturers. many plants such equipment already installed for use bright annealing. these cases may possible divert portion the gas for use the sodium hydride descaling process. meter capable measur- ing total 500 gas per “cracked gas,” corresponding 2.15 4.3 ammonia, are re- quired per ton descaled metal. For installations the use cylinder hydrogen practicable. the other two raw materials used this process addition that hydrogen, namely sodium and caustic soda, the former used are shipped steel barrels contain- sodium are used per ton de- scaled metal. Rustless, the smaller size sodium brick used. for the caustic soda, the initial bath made (calculated After the original installation, very little more required, caustic soda pro- duced byproduct the descaling reaction and the amount formed usually compensates for the amount lost the dragout. Setting-up Procedure step-by-step description for set- ting the bath and its maintenance for typical installation here follows: The tank loaded with solid caustic. Spaces are filled with caus- tic flake form. possible. Gradually bring 700°F. This heating period consumes | | . | | | | | ; | | hy- into steel wire and bars shown after quench. Bars are separated spacers order that all areas uniformly descaled. None the underlying metal removed this bath which effective carbon, alloy and stainless steels well such metals nickel cobalt, and copper. days. Care should taken avoid forcing, and observe any hot spots forming’ the tank wall. Next hold the bath 800°F for expel the water. Not all the will expelled this operation some will have combined with the caustic. Further elimination the water from the fused caustic can accom- plished with the use sodium bricks. First permit the tank drop back maintained during the next hr. pieces using knife blade and place the pieces top the bath. Begin place whole bricks the open surface where the sodium pieces and float and skim around patches due the evolution hydrogen from the water. The hydrogen burns with- out violence and only towards the end the dehydration period does the sodium show tendency burn. Any burning can readily stopped stirring the sodium patch with iron rod. When the bath completely dehydrated, striking color change occurs. The bath takes the appear- ance black oil. perfectly quiet and more hydrogen evolved. The feeding sodium bricks will, course, have stopped. During the de- hydration period ventilation the room desirable caustic spray formed due hydrogen generation. After the dehydration period the bath produces practically gas fumes and operated open bath with- out ventilation. Dehydration only required starting new bath and does not have done again even the bath remains idle for long periods. <4 Begin flush out the generator boxes with hydrogen (or cracked ammonia gas). Start this operation one end and continue doing the same for each generator down the line. After min flushing, ignite the hydrogen using for safety pur- poses long stick. maximum flow required for each generator box. (In normal operation slight excess hydrogen allowed burn from small vent hole the charging cover each generator. cracked am- monia used; 3.8 anhydrous ammonia will usually required per ton steel treated.) After the hydrogen has been burning for min begin introduce sodium bricks through the charge hole the generator box. Sodium in- troduced means tongs and dur- ing its introduction hydrogen allowed keep burning the charge hole (fig. 7). Normally, one brick added each generator every required per ton steel treated, depending the relative amount surface descaled. The sodium hydride content the bath tested after about sodium feeding the afore- going mentioned interval. The sodium hydride content maintained tween 1.5 pct and 2.0 pct, which determined simple gas test with gas evolution apparatus, fig. Using two-part steel mold which dipped into the bath, small cylin- drical pellets the bath material can made available for the test. the test shows low, the rate sodium feed increased. the test exceeds 2.0 pct, the rate feed decreased. When the bath satisfactory according the hydride content test, work may descaled placing steel rack which lowered into the fused caustic bath. Time im- mersion will depend number factors such the mass the work, character the scale, etc. For ex- ample, the time immersion for load 3000 stainless sheet wire will from min min. the bath permitted penetrate throughout the work, uniform de- scaling all surfaces will pro- duced, fig. All grades alloy steels can descaled this bath and dif- ferent grades can descaled inter- changeably using the same procedure. The bath may worked for each day. for any reason the bath permitted cool such may over the week-end, the fol- lowing procedure should followed. Using portable type gas oil heater, commence heat the surface the bath one spot and continue until the whole surface heated. Care should observed when the burners are avoid any forcing hot spots. 10. Sodium bricks can removed safely from the steel shipping barrel operator wearing asbestos gloves, and celluloid type face shield. Shirt sleeves should down and the arms dry any perspiration. 11. The most important precaution the avoidance any carryover water into the bath. The work should carefully inspected before immer- sion for adhering water. Any oil the work will usually volatilized the surface the bath. THE IRON AGE, November For nder rials and hich de- aller istic the nore pro- ling med set- ance mes Precision-Cast Copper-Base Alloys concluding this two- part article, experimental data precision cast leaded red brass, leaded yellow brass, manganese bronze and silicon brass are presented and the ef- fects such factors flask temperatures and pre- quench time intervals the physical properties and these castings are discussed. microstructure ° ° ° and ROSENTHAL Metallurgists, Frankford Arsenal Ord- Laboratory, ° ° IRON AGE, November 1945 Density, Hardness, 85-5-5-5 alloy ounce metal, listed composition Fed- eral Specification and also alloy ASTM Specification B145-44T. Gardner and have “Factors Affecting the Physical Proper- ties Cast Red Brass (85 Cu, Sn, Pb),” Proc. ASTM (1932), Part pp. 517-535. investigated the properties this alloy the Bureau Standards. the absence published data the properties the precision-cast alloy, comparison has been limited the Bureau Standards values obtained sand and iron molds. Experimental Data: Fig. indi- cates the effect flask temperature tensile strength, elongation, hard- ness and density. Other variables, such pouring temperature, deoxida- tion procedure and centrifuge speed EADED red brass, also known oO Rockwell Elongation, per cent lin. Tensile strength, psi per 1000 400 600 800 1000 1200 Flask were held constant. The arrangement specimens the tree shown fig. This arrangement was empiri- cal and was used with this alloy suc- cessfully. The tensile strength drops with in- flask temperature while the elongation tends increase with flask temperature. This relationship ap- parently correlated with the grain size and comparative coarseness the dendritic structure, which may seen fig. Gardner and Saeger’s data for vari- ous types sand-cast specimens show maximum tensile strength 36,000 psi. Their data for specimens ma- chined from chill-cast ingots poured iron molds show maximum tensile strength 42,000 psi. The tensile strength (fig. exhibited the pre- cision-cast specimens compares favor- ably with their results. Gardner and Saeger’s best density value 8.92 per was also ob- tained the chill-cast alloy. Their best value for the sand-cast alloy was 8.88 percc. These values are equaled bettered the precision- cast alloy (fig. 8). The size the lead particles dis- tributed through the metal shown fig. dependent upon the flask temperature, other things being equal. 400°F flask temperature, the par- ticles are small but become progres- sively larger with increasing flask temperature. 1200°F the lead agglomerated into relatively large masses. Conclusions: (1) The physical properties precision-cast leaded red brass com- pare favorably with properties ob- tained sand casting. (2) the flask temperature in- creases, elongation increases and tensile strength decreases. (3) Grain size, dendritic struc- ture, and lead particle size become coa.ser with increasing flask tem- perature. ° ° 8—Effect temperature tensile strength, elongation, hard- ness and density preci- Other variables, such temperature, de- oxidation procedure and centrifuge speed were held constant. | 9.00 + 400°F x 1000°F The Alloy: The leaded brass cov- ered this report listed compo- sition Federal Specification QQ- B-621 and composition ASTM Specification B146-44T. The ASTM Specification and the analysis are listed table The copper-zine constitutional dia- gram shows that the 60-40 alloy made both the alpha and beta phases room temperature. How- ever, short temperature range just below the solidus line, the alloy passes through single phase beta field. further cooling, the alpha plus beta field entered causing alpha separate from the primary beta. quenching from elevated temperatures, greater amounts beta are retained than with slow cool- ing. Through varying the ratio alpha beta, different properties may obtained. Tin, the order pct, slightly increases the hardness and strength. Lead added improve the machinability. small percentage aluminum, 0.1 0.2 gives the casting smooth lustrous surface and provides oxide skin the molten state which reduces the loss enn 600°F 1200°F Experimental Data: The possibility quenching casting water after the metal solidified not often taken advantage sand casting. There are practical difficulties which prevent this practice for sand casting. precision casting, however, there always the possibility quenching desired. Because the limited time which could devoted the investi- gation any given alloy, this quench- ing effect could not studied de- tail over the entire range flask tem- peratures from 400°F 1200°F. In- stead, the effect has been investigated with only the 1000°F flask tempera- ture. Fig. illustrates the tree design adopted for the 60-40 alloy. The de- sign shown fig. gave unsound castings when used with the 60-40 alloy. believed that the fig. design gives rise too much turbu- lence when the 60-40 alloy enters the mold thus causing entrapment sur- face dirt and oxides. shown fig. 10, the interval be- tween casting and quenching the 60- alloy has important influence the resulting microstructure. Pre- quench intervals 12, 18, 24, - TZ. os 800° ° ° preci- sion cast 85-5-5-5 alloy tensile specimens cross-section the center the gage length. Fiasks were held the indicated tem- perature during casting. The in- verse relation tensile strength and the direct relation elonga- tion flask temperature are ap- parently correlated with the grain size and comparative coarseness the dendritic structure. Etched dichromate solution, 75X. and min produce progressively lesser amounts beta. Fig. presents graphical form the data showing the influence the prequench interval tensile strength and elongation. Although the tensile strength declines steadily with in- creasing prequench interval, there maximum the elongation the 21-min interval. Because quenching exerts deci- sive influence, the effect flask temperature was studied only with reference the fast quench. shown table II, the properties for the vari- ous flask temperatures were found fairly narrow range. TABLE Physical Properties Quenched 60-40 Brass Tensile Specimens Cast Flask Temperatures Temperature Tensile Elongation 400 38.7 800 53,800 | 35.6 1000 | 55, 400 30.2 1200 33.0 The 400°F flask temperature pre- THE IRON AGE, November ant ize the ri- na- or- ~ o o is al. 7 ob- in- uc- 'm- i 66—THE IRON AGE, November 1945 ° ° preci- sion-cast, leaded 60-40 alloy tensile specimens cross-section the center the gage length. Specimens were quenched cold water various periods after cast- min and slow cooled. evident that the interval between casting and quenching the 60-40 alloy has important influence the resulting microstructure; longer prequench intervals pro- ducing progressively lesser amounts beta. Etched NH.OH H.0. and FeCls. ° vented fast quenching because the in- vestment breaks slowly the water quench compared the rapid decrepitation characteristic the quenched investment tempera- tures 600°F and above. This prob- ably explains the somewhat lower values obtained 400°F. 1200°F, was found that quenching min after casting did not permit complete solidification that another sec was necessary. Here again, this may account for the somewhat lower values obtained 1200°F. Density determinations were made (fig. 10) samples cut from the ten- sile specimen gage lengths. These samples were taken from heats cast into 1000°F flasks for the prequench interval study. The values all fall Hardness. Density, Density, Hardness Rockwell Elongation, per centin lin. Tensile strength, psi per 1000 LEFT properties preci- sion-cast leaded 60-40 alloy for flask temperature with vari- ous periods between casting and quenching. Although strength declines stead- ily with increasing pre- quench interval, there elongation the min interval. ° ° ° RIGHT 12—Physical properties preci- sion-cast silicon brass for various flask tem- peratures. ° ° Cold Period between casting and quenching, minutes into narrow range between 8.44 and 8.47. Theoretically, alloys containing greater amounts beta should somewhat denser since the beta con- stituent has higher density than the alpha. However, for alloy given composition, such 60-40 brass, the effect the order 0.01 per for comparison between quenched chill-cast specimen against equilibrium conditions. There appears significant trend the den- sity data shown fig. and the slight variations can attributed experimental error. Because the centrifuging action which takes place during casting, there possibility for segregation, the resulting casting, the ele- ments accordance with their spe- cific gravity. order investigate this possibility, series chemical analyses were made the copper, lead and tin. These analyses were made the gage length the ten- sile specimens cast into 1000°F flasks with various intervals before quench- ing. addition, the threaded ends the tensile specimens were analyzed for lead. Since lead low melting point constituent limited solubility the alloy and has high density, was probable that any segregation effects would most prominent the lead variation. Table III shows that both lead and tin appear higher percentages the tensile specimens than the orig- inal ingot material. However, the fluctuations the lead content the various parts the tensile specimens not appear significant any particular trend. Conclusions: (1) Quenching has greater in- fluence the physical properties the 60-40 alloy than the flask temperature. (2) quenching high propor- tion the beta constituent re- tained. The ratio alpha beta may controlled the prequench interval. (3) prequench inter- vals decrease hardness and tensile strength. The elongation reaches Hardness, Elongation, Tensile strength, x vo © a a 400 600 800 1000 1200 Flask maximum for prequench interval min with 1000°F flask tem- perature. (4) The hardness rapidly quenched specimens with 1000°F flask temperature was and slowly cooled specimens, Rb. (5) Density varied between 8.44 and 8.47 per Silicon Brass The Alloy: The silicon brass cov- ered this investigation listed ASTM Composition 12C having the designated chemical range and actual analysis listed table One the most important charac- teristics this alloy its low melt- ing point for which the silicon TABLE Chemical Analysis 60-40 Brass Tensile Specimens Cast Into Flasks With Various Intervals Between Casting and Quenching Copper, Gage Length Gate End www quench Gage Length Top End Lead, Tin, Pet Gage Length THE IRON AGE, November 8.25 | © in- the the ira- wer hat did so | | the Interval, } 3 62.54 1.19 1 0.96 ade 6 62.32 1.33 1 1.18 62.4 1.07 chiefly responsible. Seybolt and Gon- have reported freezing range High-Strength Silicon-Brass Diecast- ing Alloy,” Trans. AIME Metals (1940), 137, pp. 414-424. 1517°F 1546°F for the 80-15-5 copper-zinc-silicon alloy. Because the low melting point, low pouring temperatures can used thus obvi- ating the nuisance zinc flaring. The copper-zinc-silicon alloys were extensively investigated Density, per =] Hardness, Rockwell *E. Vaders, New Silicon-Zinc- Copper Alloy,” Jnl. (1930) 44, No. pp. 363 379. Gould and Ray, “The Effect Silicon the Properties Brass,” Metals Alloys, (1930) Vol. No. 11, pp. 502-507. Smith, “Constitution and Micro- structure Copper-Rich Silicon-Copper Alloys, “Trans. Inst. Metals (1940), 137, pp. 313 333 Anderson, “Alpha Solubil- ity Limit and the First Intermediate Phase the Copper-Silicon System,” Trans. Inst. Metals, (1940), 137, pp. 334-353. Metals gram may prove some assistance making in- telligent estimates what happens the ternary system copper corner. Experimental Data: Two series experiments were performed. the first, specimens were cast with flask temperature 400°, 600°, 800°, 1000° and 1200°F cooled. series, specimens were cast with temperature 1000°F but Elongation, cent lin. quenched cold water various intervals after casting. The effect quenching gated with only the 1000°F flask temperature, although the same effect could probably expected with other flask temperatures. The fig. tree design satisfactorily with this alloy. Tensile strength, psi per 1000 13—Physical properties precision-cast silicon brass for flask temperature with various periods between casting and quenching. limits the ternary alloy, finding that the pct copper-14 pct zinc-5pct silicon just beyond the solubility limit. The casting fluidity great. Machinability stated similar the alloys. Gould and state the corrosion resistance 85-15 alloys almost un- affected the addition silicon about The ternary constitutional diagram has yet not been worked out al- though and re- cent work the copper-silicon dia- 68—THE IRON AGE, November 1945 Cold Period between casting and quenching strength and elongation gether with the hardness and density data are plot- ted figs. and 13. Fig. shows the type microstructures obtained with the slow-cooled speci- mens cast with flask tem- peratures 400°F and 1200°F. Fig. illustrates the microstructures obtained quenching after with flask temperature 1000°F. Referring fig. 13, apparent that there notable increase both tensile strength and elongation when the quenching interval after casting increased from min min. Increasing intervals beyond min not appear cause any sig- nificant change properties. The hardness data also confirm this trend indicating that the material quenched with the min interval appreciably harder. The density figures show apparently random fluctuation within narrow range. interesting compare these properties with those other investi- gations. Table lists these values. The chill-cast tensile strength and elongation values all fall within narrow zone which the quenched precision-cast specimens also fall. Vader’s hot-extruded specimens ex- hibit higher tensile and elongation values which are similar the slow cooled precision-cast specimens. view the sensitivity quench- ing shown fig. 13, not surpris- ing that the lowest flask temperature the slow-cooled series fig. also shows the lowest elongation. From 1200°F flask temperature, the tensile strength the slow-cooled specimens decreases slowly although the elongation fairly constant. This effect may allied with increasing grain size the higher flask tempera- tures. Since there ternary copper- constitutional diagram available, the microstructural constit- uents shown figs. and cannot identified with certainty. From Vader’s work known that 80- 15-5 alloy just beyond the solid solution boundary within which these three elements are soluble each other. Smith’s paper the copper-silicon alloy indicates. that the banded constituent shown high magnification fig. consists alternate layers alpha and kap- pa. The matrix material presum- ably alpha. The phases produced quenching, and fig. 14, have apparent relation those produced slower and indicate that increasing amounts the banded alpha and kappa phases are with in- creased prequench intervals. (1) The effect quenching im- mediately after casting with the 1000°F flask temperature de- both tensile strength and elongation compared longer prequench intervals. With quench intervals min more, the properties are stable. (2) The best tensile strength properties the slow cooled speci- mens were obtained with 600°F flask temperature. (3) The density this precision- cast alloy average 8.20 per cc. (4) The hardness the slower j thin hese esti- lues. and ched fall. ex- ition slow This »per- ° ° cision-cast silicon brass tensile specimens cross-section the ‘rom center the gage length. Flask 80- temperature during casting was 1000°F. Quenched various in- tervals after casting: min; dary min; min; min, and are min. The phases produced jape relation those pro- cates duced slower cooling cate that increasing amounts the banded alpha and kap- phases are obtained sum- creased prequench intervals. Etched with NH,.OH H.0:; 100X. hing, arent ower eries and cooled specimens averages Rb; the hardness the most severely TABLE (5) The microstructure of this mparison o micon Grass — 1es om arious ources alloy complex and varies mark- edly with the prequench interval. de- The slow cooled and slower quench- and structures are characterized the presence the banded alpha Manganese Bronze The Alloy: The manganese bronze high-strength yellow brass which was investigated listed Class Specification and analysis are listed table THE AGE, November 100 oO Elongation, per Tensile strength, psi per 1000 400 600 800 1000 Flask temperature, °F. IRON AGE, November 1945 120 110 1200 ° ° ° pre- cision-cast silicon brass tensile specimens cross-section the center the gage length. Flask temperature during casting specimens left was 400°F; right 1200°F. Since there ternary tutional diagram available, the microstructural constituents shown here and fig. cannot identified with certainty. How- ever, the matrix material pre- sumably alpha. NH.OH Upper speci- mens 500X; lower ture the properties slow- cooled, precision-cast manganese bronze. Both tensile strength and elongation increase with rise flask temperature from 400°F preciable decrease tempera- ture although the elongation re- mains constant. 1.80 Density, 100 Hardness, Rockwell ° ° RIGHT 17—Physical properties preci- sion-cast manganese bronze for 800°F flask temperature with vari- ous periods between casting and quenching. Short prequench inter- vals produce the hard- est structure while slow cooling tends crease elongation. Elongation, per Tensile strength, psi per 1000 Period between casting and quenching, minutes “ i