The Iron Age 1943-05-13: Vol 151 Iss 19

ENGINEERING COMPANY, Inc. WARREN, SLITTER SIDE TRIMMER type) ELECTROLYTIC and BONDERIZING TIN PLATE EQUIPMENT Company KR SPE EC | SHELL and SLEEVE LATHE WILSON TUBE ANNEALING FURNACE Just the Boats are streamlined for speed carrying out their important war duties, Whiting Victory Cranes are § service the shortest possible time. Manag News 2 Technic North Ar Posse Single OFFICES CHICAGO, DETROIT, LOS ANGELES, YORK, PHILADELPHIA, PITTS BURGH, AND WASHINGTON, AGENTS OTHER PRINCIPAL CITIES. CANADIAN SUBSIDIARY: WHITING CORPORATION LTD., TORONTO AND MONTREAL. scores wat that might still that them eo = "4 MAY 13, 1943 VAN DEVENTER President and Editor BAUR Vice-President and General Manager fo] ° ° Managing Editor, LIPPERT Technical Editor, OLIVER Art Editor, WINTERS Associate Editors Editorial Assistants BUTTERS Regional News and Technical Editors Washington Pittsburgh Washington Chicago Cleveland Detroit OSGOOD MURDOCK San Francisco Editorial Correspondents Buffalo Cincinnati Boston Los Angeles HUGH SHARP JOHN McCUNE Milwaukee Birmingham Ontario St. Louis BACON Seattle DIX, Manager, Reader Service Regional Business Managers Robert Blair, 1016 Guardian Bldg., Cleveland Fitzgerald, 428 Park Pittsburgh Herman, Chilton Bidg., Philadelphia Hottenstein, Otis Bldg., Chicago Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, 100 East 42nd New York Warren, Box 81, Hartford, Conn. Johnson, Market Research Mgr. Hayes, Production Manager. Baur, Typography and Layout. ° ° ° Member, Audit Bureau Circulations Member, Associated Business Papers the Industrial Arts Index. Pub- every Thursday. Subscription Price North America, South America and $8; Foreign, $15 year. Single copy, cents, Annual Number, $2. Owned and Published CHILTON COMPANY Editorial and Advertising Offices 100 East 42nd St. New York, OFFICERS AND DIRECTORS MUSSELMAN, President HILDRETH, EORGE GRIFFITHS, ERIT TERHUNE, VAN DEVENTER, Vice-President BAUR, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, DUFFY CHARLES HEALE Executive Offices Chestnut and Sts. Pa. Vice-President Vice-President Vice-President This Week Editorial Features Washington West Coast Fatigue Cracks Dear Editor News Industry THE Want Stay Business? Technical Articles Centrifugal Castings—A Symposium Punch and Die Life Increased Spot Welder Converted Electro-Brazing Machining the Garand Rifle Comparable Arc Welding Electrodes Assembly Line News and Markets This Industrial Week Personals and Obituaries Machine Tool Activity Non-Ferrous Metals Scrap Markets Iron and Steel Scrap Prices Comparison Finished Steel Prices Index Advertisers 1943, Chilton Company | / — CCARCE TANTALUM ~ Ge SRA EWC & avi FOR STEEL CUTTING—These FIRTHITE Tungsten-Titanium Carbide grades stay sharp longer, cut faster, and make smoothest finish. They are described FIRTHITE Price List FE-105 or, FIRTHITE Engineer will gladly discuss them your plant. TITANIUM GRADES FIT “WAR” NEEDS (CONTAINS TANTALUM) FIRTHITE T-04—for coarse feeds, heavy and interrupted roughing cuts. Closest approach universal grade. ry | a PURPOSE (CONTAINS TANTALUM) FIRTHITE TA—for general-purpose cutting tools all types steel high-speed production. (CONTAINS TANTALUM) FIRTHITE T-16—for light, rapid finishing harder steel, shells, etc. (CONTAINS TANTALUM) FIRTHITE T-31—for lightest, fast- est, shallow cuts. Recommended for precision boring, etc. STEEL COMPANY McKEESPORT, PA.- NEW YORK HARTFORD PHILADELPHIA CLEVELAND DAYTON DETROIT CHICAGO LOS ANGELES y IRON AGE, May 13, 1943 — FIRTHITE q f = ae Want Stay Business answer this question will probably almost unanimous But there more needed than just wanting. You will have work for it. Somebody going run your business after the war. You hope that somebody will you. will be, all the you’s and who own manage the businesses this country get work and the biggest job that American industrialists have ever had set before them. It's even bigger job than the one that you have done are now doing connection with the war effort. the job maintaining production and employment level after the war that will just about half again high any that attained prior the beginning our defense and war programs. simple matter arithmetic. With seven eight million our best potential producers withdrawn from our labor supply and now war service, are still operating productivity rate per cent higher than ever before. keep those people who are now working industry busy and take care the reemployment our disbanded armed forces will require some very competent planning and action. Somebody going have provide employment for these people. Either private industry will have government will. And government has this scale, almost certain that will MAY 13, 1943 witness the burial the private enterprise system and the birth state socialism. The Committee for Economic Development, which headed Paul Hoffman and which was formed the suggestion Jesse Jones the nucleus organization which spreading every state the Union and which will endeavor enlist not merely the cooperation but the active effort every concern our country employing men more. addition case studies six typical industrial centers which are now being surveyed post-war employment possibilities, this committee seeks and needs action every American employer. The action needed survey post-war product and marketing possibilities for both old and new products determine closely possible the number workers that can expectably employed each plant and thus each community. ESTABLISHED 1855 Thus far the results have been remarkably encouraging. the Peoria district, for example, where present employment approximately 31,000, the expected post war employment shrinkage less than eight per cent. This job that you cannot George do.” done and the system private enterprise saved, you will have your part it. when you are approached your state local committee, for your own sake well that the rest us, give this task every- thing that you've got. | ] ] ¥ | the word used England for all identification, from machine truck the metal cut away machinists’ railroad car. Establish effective, but simple, ings, chips, shavings, etc. There, America, markings for machines, tote boxes, chip valuable because may contain crit- buggies, V-dump trailers, and salvage bins. ical alloys—alloys that cannot replaced un- Provide adequate supervision prevent care- less reclaimed, and they cannot reclaimed lessness, and mistakes new employees. from various types steel mixed. valuable stuff. When carefully seg- Review your methods segrega- regated, assures more production tion today. See that blueprints are more airplanes, guns, clearly marked for the type steel armor for the protection our used. Check your system fighting men. SHEETS STRIP TIN PLATE BARS PLATES FLOOR PLATE STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS INLAND STEEL CO. Dearborn Street Chicago Milwaukee Detroit St. Paul St. Kansas City New York 52—THE IRON AGE, May 13, 1943 Ins on. Centrifugal Casting RDNANCE and aircraft designers are finding centrifugal cast- ings the answer many difficult wartime material problems. Cen- trifugally cast steel literally being “rediscovered.” Its future holds much promise. Presented herewith are series timely, practical re- ports covering various types centrifugal castings. These reports touch upon theory, production techniques, design problems, and its advan- tages. bibliography will appear next week. This material has been abstracted from papers presented before recent meeting the Steel Founders’ Society America. The Development Centrifugal Casting ° ° BRIGGS Technical and Research Director, Steel Founders Society America ° the United States, elsewhere, the centrifugal casting steel still recent development with the major advances being made the last years. While there are number dif- ferent processes centrifugal cast- ing commercial operation today the broad principles outlined early British patent Eckhardt, dated 1809, are common all them. The Eckhardt patent included all possible constructions regarding the spindle arrangements and all subse- quent patents relate merely con- structional details special pur- poses. The fact that the centrifugal cast- ing steel has become established only the last years based technical and grounds. ° the earlier years the problem driv- ing the rapidly rotating molds was means simple and only the intro- duction the electric motor and its development permitted the solution centrifugal movement. Railway car wheels were probably one the first products the United States centrifugally cast cast steel. The first wheels produced were made the East St. Louis Works American Steel Foundries 1902 and centrifugal casting was carried until the year 1930. the early years the produc- tion wheels using the centrifugal pouring process, ground manganese was introduced into the first metal going into the mold. Centrifugal ac- tion caused this metal thrown Symposium into the outside the mold forming the rim and flange, while the plate and hub sections the mold were formed.of the milder steel. This was later superseded the casting one grade steel for the entire wheel. From 1920 1930 the Watertown Arsenal Watertown, Mass., was engaged the development the centrifugal casting guns. molybdenum-vanadium cast steel was cast cast iron mold rotated horizontally. The steel was melted induction furnaces and two guns were cast from the same machine each hour. Miscellaneous gear castings have been produced for the last years Sawbrook Steel Castings Co. These gears have been vertically cast sand molds. Street car wheels produced from cast steel have been centrifugally cast for the last years National Malleable and Steel Casting Co. These machines are also the verti- cal spindle type. About years ago development casting the high chromium-nickel steels centrifugally for pipe was un- dertaken Ohio Steel Foundry and Michigan Steel Casting Co. both cases these were cast with horizontal spindle machines. Steel Founders’ Society’s report producers September, 1942, cen- trifugally cast carbon and low alloy steel castings showed using verti- cal spindle units and eight using hori- zontal spindle units. number foundries also have experimental units. Reduced its simplest definition, centrifugal casting may described the casting metal under pres- THE IRON AGE, May 13, 1943—53 rat : Ry ag ; 7 sure the centrifugal force devel- oped through high rotative speeds specially prepared mold. The basic requirement for me- chanical equipment capable vari- ous speeds depending the charac- ter work done. Mold equip- ment varies widely depending upon the design construction the basic equipment and the type castings being produced. number different types processes for the production cen- trifugal steel castings are com- mercial operation. The process may conveniently divided into the fol- lowing three parts: (1) The method mold rotation; (2) the method pouring the mold; and (3) the con- struction and form the mold. Centrifugally produced steel cast- ings are made molds that are ro- tated both vertical and horizontal axis. the casting produced has depth length greater than zontally rotating mold. This does not mean necessarily that steel castings less than this length are produced the vertical spindle units. the steel casting produced entirely die without core inserts, will usu- ally rotated horizontally regard- less its length. Most steel castings sand molds core assemblies are ro- tated the vertical spindle. castings made sand molds core assemblies are produced molds ro- tated with horizontal axis. The fol- lowing examples are given: Long (1) Horizontal spindle with die molds: Guns produced Water- town Arsenal; corrosion and heat re- sistant steel tubes, pipes and liners produced Ohio Steel Foundry and Michigan Steel Casting Co.; cylinders and liners produced Ford Mo- tor Co., American Cast Iron Pipe Co. and Forging Casting Corp. (2) Horizontal spindle with sand molds core assemblies; flanged and grooved miscellaneous castings where rammed mold core insert nec- essary form protruding sections grooves the outside inside sur- faces the casting. Castings this type are produced American Cast Iron Pipe Co. and Ford Motor Co. (3) Vertical spindle with die molds; small gear blanks, cluster gears, bushings and liners duced Ford Moter Co. (4) Vertical spindle with die molds and core inserts; gear blanks, sheaves, casing heads and flanges and aero- nautical castings produced Ford Motor Co., American Cast Iron Pipe and Allegheny Ludlum Steel Corp. (5) Vertical spindle with molds and core inserts; sand cast tooth 54—THE IRON AGE, May 13, 1943 Pouring IG. types centrifugal casting methods. shows mold rotating hori- zontal axis; shows the arrangement for pressure castings. ° ° ° gears and blanks, unions, sheaves, valve bodies, gates and plugs and other such produced Maynard Elec- tric Steel Casting Co., Oklahoma Steel Casting Co., Sawbrook Steel Casting Co., Wehr Steel Na- tional Malleable Steel Casting Co. and Ford Motor Co. Molds which rotate horizontal axis are cast allowing the molten metal enter pouring box, the spout which extends into the ro- tating mold shown Fig. (A). This type arrangement mostly for large and long molds. For the smaller castings produced large quantities long lip pour shank ladle used. The lip constructed extend well inside the horizontal opening. Molds spun about vertical axis are cast pouring the steel through central opening. This opening usually made runner into the sand mold. Molds are usually poured from hand shanks, and some cases the molten steel weighed care- fully measured prior pouring. Some centrifugal castings rotated vertically are completely filled with steel before centrifuging. These molds are usually produced sand with core inserts and may rather com- plex character. found that filled with molten steel and then rotated. The die molds are made steel east iron. chromium-molybdenum steel often preferred. The inside surface the die slightly tapered facilitate casting removal. Most sand molds are core assem- mold blies. The cores are oven dried and are quite hard for handling purposes. Green sand, air dried sand oven- dried sand molds with core inserts are also used. vary depending the type steel casting shape concerned, the speed need only enough hold the steel against the mold wall. The higher the speed rotation the greater will the compacting and cleaning ac- tion due centrifugal force. the speed too great, defects the form hot tears will propagate. Rotation speeds 1200 r.p.m. are used centrifugally steel The range most normally used 150 300 r.p.m. The term centrifugal casting all-embracing one and refers any casting that has been rotated during the time solidifies. There are, how- ever, three general types centrifu- gal steel castings. These are: (1) True centrifugal castings; (2) semi- centrifugal profiled centrifugal castings; and (3) pressure castings. True centrifugal castings are ob- tained pouring steel rotating metal die. The steel solidifies from the die casting interface toward the center the casting. There are gates risers and yields approach- ing 100 per cent may obtained. The casting may may not have cylindrical hole through its center, de- pending whether not measured amount molten steel poured. The central region the casting usu- ally finished machining. Semi-centrifugal trifugal casting molds may either a n dies, sand core assembly molds where the inner surfaces the cast- ings are not formed centrifugal force alone but cores. The speeds employed are low. this case solidi- fication occurs different directions with the result that shrinkage cavi- ties may appear unless feed heads are provided. Some gates may serve the function feed head and others merely pouring basin. Pressure castings involve the use centrifugal action generating high pressure force the molten steel into the mold. This method used for asymmetrical castings which cannot spun about their own axis. The mold arranged shown Fig. (B), that steel poured into gate the center rotation. In-gates distribute the steel mold cavities arranged around the central down gate. The primary reasons for casting steel centrifugally are produce castings more economically cast part which can more satis- factorily cast centrifugally than stati- steel casting certain design, such wheel cylinder, when cast statically may result yield per cent. The same casting may centrifugally cast with yield per cent. The increased yield usually results reduced clean- ing room costs. tubular castings are ideal design for centrifugal casting. When these objects are made stati- there tendency for the de- velopment shrinkage cavities areas inaccessible feed heads. Centrifugal steel castings that sol- idify progressively from both outside and inside surfaces may also inferior quality unless precautions are taken feed the last portion the casting solidify. The metal solidifies from the out- side surface only the true type centrifugal castings and there possibility shrinkage cavities oc- curring. Slag and bits furnace ladle lining sand included the steel will largely eliminated because the weight differential and the rejec- tion tendency the bath due the centrifugal motion. has been stated from time time literature regarding centrifu- gal castings that these castings are better quality, denser and have me- chanical properties excess stati- cally poured castings. Looking from the point how this statement applies steel cast- ings may said that the state- ment does not tell the entire story. true centrifugal casting were being compared with poorly fed statically poured casting, then the statement correct since the latter would most probably contain shrink- age cavities areas center line weakness. Test specimens taken this zone would not exhibit the dens- ity the mechanical properties test specimens taken from the true centrifugal casting. However, well fed statically poured steel casting compared true centrifugal steel casting simi- lar design, there will difference the density the two castings. tensile specimens taken from the heat treatment castings similar locations, will found that near the die face higher mechanical prop- erties will recorded than can obtained from similar area statically poured sand mold casting. This due the finer structure ob- tained due the chilling action the metal die. well fed statically poured steel casting compared similarly designed profiled semi-centrifugal casting consisting sand mold and core inserts, there will differ- ence the density the mechanical properties since rates cooling and effect mass conditions are similar. has been stated the technical literature that when more cen- trifugal castings are required, the cost the buyer little more, any, than for statically produced castings. There are probably many excep- tions the above statement but will furnish clue least the general picture comparative costs. Centrifugal Casting with Vertical Spindle Machines POWER Maynard Electric Steel Casting Co. HIS discussion confined description the centrifugal casting machines and equipment used Maynard Electric Steel Casting Co., Milwaukee. The spinner tables are two sizes —36 in. and in. diameter with 37/16 in. diameter spindles mounted standard duty Shafer Con-Ca-Vex roller bearings and driven through six strand Tex-Rope drive. The motors are h.p., 312 r.p.m., 220 volt, cycle, with reduction- IG. 2—Sketch centrifugal casting machine with vertical spindle. ° geared heads and adjustable brakes, and mounted slides which give suf- ficient longitudinal adjustment per- mit speed changes from 450 the spindle, using pulleys various diameters. sketch the equipment shown Fig. Individual safety guards with cov- ers are provided for the 36-in. diame- ter machines. hole the cover provided for pouring the molds means hand shank bottom pour ladle. The centrifugal machines with 46- in. diameter tables are located common rectangular shaped enclosure which serves safety guard. general these machines rotate lower speed and individual. guards are not necessary. special mold equipment re- quired. Standard 20x20 in., 24x24 in., in. round and in. round flasks are used. The molds are assembled with ribbed tops and bottom plates, the top plate having 7-in. diameter hole located the center. Screw clamps complete the assembly. Each spinner table fabricated for the exact pin center dimensions the various flasks. Two pins are screwed THE IRON AGE, May 13, 1943—55 | q | | ql ° ° ° a ° | 1 A OSS = SS ¥ Sse > WwW => /b. Yield Weight= 3—Typical castings made Yield BELOW Fig. 4—Cluster type pattern, cores and mold. into the proper holes spinner table and the mold placed these pins. The weight the mold sufficient hold place during spinning and removal after pouring done quickly and easily placing the mold the centrifugal table. The length centering pins such that the slightest upward movement flask allows the pin clear the lugs the flask. Centering pins conform holes flasks and increase diameter with the size the flask. battery 36-in. diameter cen- trifugal machines, number, are the construction described above. The thirteenth machine different construction—a direct current type with speed changes from 600 r.p.m. Experimental work done this machine determine desirable speed for casting. Pulleys other machines can changed provide speed required. Similarly, battery 46-in. di- ameter are the type first described, while the thirteenth equipped with Reeves speed reducer which permits variation from 650 r.p.m. Experimental work can done flask sizes 38-in. diameter this machine. The main source supply for molten steel one ton acid electric furnace. Heats 3500 lb., the limit crane capacity, are available from any one three four-ton acid electric furnaces. The number molds produced per heat varies with the weight each casting and ranges from for heavy work more than 26—the number centrifugal machines. the type casting permits, number ma- chines are reloaded during the course heat, this number being limited the furnace capacity length time that the ladle can held. Castings which have been produced centrifugally vary weight from 500 and flask sizes range round. The types castings made success- fully include blank gears, with arms and with solid webs, sheaves, impeller hubs and impeller covers, double- flanged wheel hubs, plain and flanged rings, bevel and sprocket gears—plain and with teeth, tapered rollers, motor heads, break drums, sprockets, com- mutator sleeves and commutator rings. Drawings typical castings made centrifugally are shown Fig. number factors influence the yield, especially large castings, but the average approximately per cent. Whether the mold filled while spinning rotated after filling de- termined the character the cast- in, tri sil ty 56—THE IRON AGE, May 13, 1943 ing. All molds are poured directly through the center. Wire supports for holding center core place are avoided. The core nailed place, because the tendency burn off or, the case castings with rel- atively small hubs, too severe chill- ing effect critical point. Centrifugal Casting Vertical Machines Wehr Steel Co. ASTINGS produced centri- fugal machines Wehr Steel Co. are all made cores. The cen- trifugal machines are all vertical with Veri-pitch pulleys, Tex-rope drum, single-speed motor. Each unit has individual motor and starter. Fig. shows the pattern for cluster type molds where patterns are clustered around center group, and also cluster type mold. The cores any possibility breakout metal. The castings revolve around central sprue and each casting poured and fed from this sprue. the core assembly the cluster type, the cores are matched three markers prevent shifting. Cores are pasted ceiling ring provided for this purpose. The ceiling ring extra precaution for securing the core eliminate the spilling metal. Fig. shows the mold assembled. These castings are poured and fed through the sprue provided center core. This type casting lim- ited, depending the size the cen- ter core. The top section the casting cast permanent mold die which ° ° ° RIGHT 5—Cluster type mold as- sembled. ° ° ° serves permanent core and also chill eliminating extra feed for heavy sections top, which would necessary chill were not used. The mold jacket placed plate and the plate slipped onto tical shaft which driven pre- viously explained. The plate has tapered male dowel arrangement which seats the tub the plate. Fig. shows the placing the core the jacket. The core fits loosely within the diameter order secure firmly the core against side motion. cover with flange hole accept the runner core clamped into the assembly. The runner core wedged into the hole and all cores are com- pletely clamped with wedges the bottom the plate prevent rais- ing the cope. Fig. shows the pouring molds. The safety apron each mold, which adjustable for any height mold, can also seen. Cores are removed from LEFT molds. Note the safety apron each mold. THE IRON AGE, May 13, 1943—57 ° ° ° ° ° ° : | { : 7—Cope and drag view castings produced shown Fig. Top view the cope section, bottom view the drag. ° ° the jacker lifting the entire jacket and reversing it. Fig. gives cope and drag view the casting, shows gating and feed- ing arrangements. The flange the hub which shows permanent die and chill can also seen. The heavy has two connecting gates the sprue, while the lighter piece has only one. The average spinning speeds vary according the type casting from 150 250 r.p.m. The cost core molding, while considerably higher than green sand machine molding, offset the finished casting, better casting and higher yield. The aver- age yield for centrifugal casting 71.3 per cent. Punch and Die Life Increased has been found beneficial pre- treat piercers, punches, tools and dies used metal forming oper- ations with film graphite pro- duced with the aid Aquadag, dis- persion colloidal graphite dis- tilled water, made Acheson Col- loids Corp., Port Huron, Mich. Since this product supplied concen- trated form, having solids content ally diluted from times its weight with more distilled water clean condensate, mixing gredients into agglomerate-free solution. Metal surfaces should first prepared thoroughly degreasing them, preferably with solvent such trichlorethylene. the parts are sprayed, brushed, swabbed with the above solution they should evaporate the water rapidly and thus hasten drying the film and the 58—THE IRON AGE, May 13, 1943 same time more tenaciously bond the tiny particles graphite the metal. the parts are small enough ‘immersed, generally suggested that after the cleaning operation they heated 300 deg. and dipped rapidly several times the same mix- ture that the objects retain suffi- cient amount heat evaporate any excess moisture. Films graphite formed this manner have been found possess desirable low friction properties that will appreciably reduce wear, improve the finish the formed metal, and frequently eliminate subsequent ma- chining operations. Sometimes, found desirable nitride these metal surfaces prior the Aquadag treatment. Should any difficulty observed complete wetting the metal, small amounts brown sugar some liquid detergent added the aqueous graphite mixture have been Colloidal Graphite Lubricant graphoid film service many con- cerns engaged difficult metal form- ing operations use lubricant consist- ing the following ingredients: oildag concentrated graphite dispersion Type 1175 90% paraffine base oil having Uni- versal Saybolt viscosity 350 sec. and minimum flash deg. This particular formula has been developed for use swabbing mate- rial, manually applied. For the types machines that are equipped with automatic spraying device, lower viscosity oil should employed, pref- erably one having viscosity 200 sec. with relatively high flash point. Completely blended lubricants the above nature can secured from major oil companies. For those oper- ations where has been decided that water soluble lubricants containing colloidal graphite are preferred, they likewise are available com- pletely blended, ready-for-use form. Case lem use com crac evel can tory out cart iner whe ma) out and line que one con dan tair duc on situ whe the q JAMESON Works Metallurgist, International Harvester Co. replacement plain carbon steel for alloy steel the me- dium carbon grades is, case the carburizing grades, prob- lem hardenability, involving the use water quenching medium order offset the low hardenability the plain carbon steel, and ac- companied increased danger cracking and warpage hardening. suitable selection steel, how- ever, parts made from AISI 1045 can oil quenched sections 7/16 in. and under produce satisfac- tory surface hardness, although 7/16-in. section the maximum tensile properties are not developed through- out the section. Possibly they are section. slight increase the carbon content AISI 1050 does increase the hardenability point section can develop maximum tensile properties through- out the section after oil quenching, and give satisfactory surface hard- The problem where draw the line dividing water quenching from oil quenching has always been serious one. For example, section water quenched when the carbon content over 0.44 per cent, the danger cracking present; the other hand, certain heats steel con- taining this carbon content not pro- duce satisfactory surface hardness oil quenching. This results situation where heat steel ex- hibiting these characteristics cannot used for heat treated parts, which, say the least, embarrassing when the steel has been purchased for the particular application. Concluding his discussion the trend plain carbon steels for heat treated parts, the author investigates choices steels and treatments medium carbon grades. Last week discussed carburizing grades, their treatment and selection. Therefore, plain carbon steel must purchased under rather rigid speci- fications and with careful planning which requires knowledge the application, that is, the section the knowledge the heat treatment proposed give it. The type heat treat equipment also important consideration. For instance, atmos- phere controlled furnaces may pro- duce satisfactory product, whereas open furnace may not so. certain that where plain carbon steel extensively used, the metallurgist heat treater will have busy time. The specifying the proper carbon range previously stated based study the part and the method heat treatment the hardenability the steel related the carbon content. The AISI list carbon steels gives number steels within range 0.32 0.50 carbon which included the term “medium carbon grades.” They are shown Table The effect the carbon content the hardenability shown Fig. data for which were obtained from standard end quench specimens quenched from 1550 deg. Trans- lating this data Fig. tion based cooling rates, into terms cylindrical sections, found that TABLE Steels Included the Term Carbon Grades" Chemical Range Carbon Manganese 1942 Number Min. Max. Min 1035 0.32 0.38 0.60 1036 0.32 0.39 1.20 1038 0.35 0.42 0.50 1040 0.37 0.44 0.60 1041 0.36 0.44 1.20 1042 0.40 0.47 0.60 1043 0.40 0.47 0.70 1045 0.43 0.50 0.60 *Silicon range accordance with heat treating purposes. under Hot Rolled Carbon Section 15, Sheet 1—Nov. 1942. remarks lished last week THE IRON the necessity for silicon Steel Phosphorus Sulphur *Silicon Max Max. Min. Max. 0.04 0.05 0.15 0.30 0.04 0.05 0.15 0.30 0.04 0.05 0.15 0.30 0.04 0.05 0.15 0.30 0.04 0.05 0.30 0.04 0.05 0.15 0.30 0.04 0.05 0.15 0.30 0.04 0.05 0.15 0.30 under “Carburizing Grades,” pub- steels used for Wire Rods—Steel THE IRON AGE, May 13, 1943—59 ° ° | on- ‘m- ist- e een | ate- pes vith wer ref- 200 int. 90 99 80 rom 50 that red, ‘om- n. + + + | | | | | | | + + + QUENCHING TEMPERATURE b nN 24 20 60 COMPOSITION c RA% 556 270 DISTANCE FROM SURFACE ABOVE 2—Relation quenched hardness tensile proper- ties specimen tempered 900 deg. 3140 3-in. round, water quenched from 1550 deg. F., was used. LEFT effect carbon content the hardenability rating medium carbon steel specimens quenched from maximum surface hardness and maxi- mum tensile properties would ob- tained the sections shown Table II. used these calculations was assumed the lowest hardness which, after quenching the structure would least per cent mar- tensitic. From this condition the steel can tempered produce uniform sorbitic structure, the structure pres- ent within the hardness range usually 1045 steel, end quench test. CHEMICAL COMPOSITION AUSTENITIC GRAIN SIZE 60—THE IRON AGE, May 13, 1943 DISTANCE FROM END-SIXTEENTHS QUENCHING TEMPERATURE specified for these materials which well fairly good idea that Rock- well the quenched condition properties illustrated Fig. This figure was drawn from information obtained from quenching 3-in. round in. long made from 3140 steel, water from 1550 deg. The upper curve represents the cross-sectional hardness the quenched state, the hardenability COOLING PER SECOND 200 CHEMICAL COM POSITION 1550 deg. second curve the same cross-section after tempering 900 deg. the tempered condition, standard 0.5 ASTM test bars were machined from the locations indicated Fig. The tensile properties obtained are shown. will noted the tensile properties, while not good those for bars taken from the area which averaged Rockwell are still satisfactory when taken from the area which averaged Rockwell the quenched condition. 4—Effect chromium content the hardenability rating medium carbon steels, end quench tests. END QUENCH TESTS 100 NUMBER OF TESTS ness sizes tion, prop cons cond spec the cont caus dist crac carl miu har effe | | | | x | | | | r 3 | | DISTANCE FROM END-SIXTEENTHS INCH COMPOSITION HEATS effec port stee 5910 STEEL QUENCHING AUSTENITIC NO.OF INCH NO. TEMPERATURE GRAIN HEATS SIZE TESTED ‘tion dard ined ined nsile hose still area the « hardenability plain carbon and 3140, 4042 and 4140 steels; end quench tests, based LEFT From actual cross-sectional hard- tests made round bars, the sizes given Table under the cap- tion, “Size which maximum tensile properties are obtained,” and referred elsewhere the test, are quite conservative and represent minimum conditions hardenability with the ness specification range, for example, the case AISI 1040 carbon content per cent and man- ganese content 0.60 per cent. The question grain size also arises the medium carbon steels. coarse grain size has marked effect increasing the hardenability the steel, thus enabling large sec- tions hardened. This quite im- portant the case oil quenching. preferable have fine grained steel for all water quenched parts, be- cause fine grained steels show less distortion and are less subject cracking hardening. The effect grain size illustrated Fig. Taking the cooling rates Rockwell from Fig. and trans- lating this terms the hardening round bars, Table III, have increase the hardenable size shown Table II, which was for fine grained steel. previously referred under low carbon steel, slight amount chro- mium has effect improving the hardenability the medium carbon When 0.14 0.19 per cent present, has effect equal the effect changing from fine grain 5—Frequency distribution curve for heats 1045 steel, showing hardenability. The steel was fine grained, containing under 0.10 per cent chromium. coarse grain steel. This effect illus- trated Fig. The hardenability heats bon steels compared with three standard alloy steels Fig. will noted that the carbon AISI 1045 steel shown dis- tribution frequency curve Fig. The hardenability the plain car- steel containing 1.48 manganese, far hardenability concerned the lower end the alloy class, TABLE Hardenability Various Carbon Contents Terms Bar Size Maximum Size Which Least Rock- Size Which Maximum Tensile Properties well Obtained the Surface, In. Obtained, In. Oil Water Oil Water C 1045. TAs 33,4 TABLE 1045 Fine Grained Coarse after quenching oil. in. in. Size which tensile properties are obtained after oil quenching. in. in. TABLE Hardenability Terms Bar Size Carbon and Alloy Steels Maximum Size Which Least Rock- well Obtained the Surface, In. Size Which Maximum Tensile Properties are Obtained, In. Steel Number Water Oil Water THE IRON AGE, May 13, 50 6 52 48 zx r z 323 ° z 28m 24 20 ’ 12 4 y n = ~ 1 4 4 ATS | 5 i il 4 | | | END QUENCH TESTS COOLING PER SECOND WATER 415 444 240000 A.S.T.M TEST BARS 388 363 z 255 235 '60000 140000 RELATIONSHIP STEEL CHEMICAL QUENCHING AUSTENITIC 120000 NO. COMPOSITION GRAIN SIZE 7—Effect manganese content the hardenability BRINELL HARDNESS-CONVERTED rating medium carbon steel. 8—The relation tensile strength hardness water quenched carbon steel and oil quenched 3140, 4140 and 4150 steels. q equé TABLE Manufacturing, Hardness Specifications and Other Data for the Parts Shown Figs. and Material Austenitic Hardness Type Used, Grain Size Manufacturing Rockwell Heat Treatment Notes the No. Part AISI No. 1700 deg. Process Specified Nut 1940 Fine automatic screw machine 30-40 Quenched cold water from 1550 deg. and tempered Stud 1035 Fine automatic screw machine 23-31 925 deg. Gear 1040 Fine lathe 43-53 tempered 400 deg. Quenched cold water from 1550 deg. and Bolt 1035 Fine automatic screw machine 22-32 925 deg. Normalized 1650 deg. after forging. Quenched brine stre Wrench 1035 Fine drop forging 40-50 from 1550 deg. and tempered 400 deg. — = t > 1035 Fine cold headed 30-38 800 deg. tion Quenched warm water from 1500 deg. and tempered Clutch part 1040 Fine screw machine 30-35 800 deg. Quenched warm water from 1500 deg. and tempered fast Coupling part 1040 Fine screw machine 28-37 850 deg. cold water from 1525 deg. and tempered whi Pivot pin 1040 Fine hot headed 23-31 925 deg. Quenched water (95 deg. F.) from 1525 deg. and tempered Pivot pin 1040 Fine automatic screw machine 23-31 925 deg. the Quenched water 100 deg. from 1525 deg. and tempered Piston pin 1040 Fine automatic screw machine 30-40 800 deg. Quenched water (95 deg. F.) from 1550 deg. and tempered and Pin 1040 Fine automatic screw machine 30-37 800 deg. sec Quenched water from 1550 deg. and tempered Connecting 1035 Fine drop forging 15-25 1050 deg. Quenched water (90 deg. from 1525 deg. and 1040 Fine screw machine 22-32 950 deg. usal Quenched water from 1500 deg. and tempered Shaft 1040 Fine forging 23-31 925 deg. — = plai 62—THE IRON AGE, May 13, 1943 | o Ox! 302 I 3 4265 235 800 900 1000 1100 TEMPERING TEMPERATURE 700 800 900 1000 COMPOSITION GRAIN SIZE QUENCHING 9—The relationship hardness tempering temper- ature medium carbon steels, indicating that increase the carbon content the plain carbon steel increases the resistance softening tempering. equaling hardenability 4042 axle shafts subject torsional loads, hardened throughout, carbon steel molybdenum steel, which means that the maximum tensile properties, which maintains the same relationship analysis 1041) can hardened means approximately the same hard- hardness tensile strength does oil quenching fairly large the surface the alloy steel. also true that (Table IV). the part, are not necessary, only under the same hardening conditions well known that near surface is, service, subject the yield strength the same for the manganese content will increase maximum stress conditions. carbon steels for alloy the hardenability steel. Fig. illus- Fig. confirms the previous state- The ratio the yield strength trates the effect manganese the ment that where the section about per eent the tensile hardenability 0.40 carbon steel. Converting the data given Fig. terms bar sizes, gives values shown Table IV. TABLE The hardenability, which has now been covered some detail, will have Effect Agitation Tensile Properties brine strength which may obtained Ratio Carbon Tensile Elongation, Reduction Yield Point mpered the heat treatment various sec Content Yield Point, Strength, Per Cent Area, Tensile Hardness, Theoretically, all the commonly 0.50 111,500 16.5 54.8 0.82 used medium carbon steels, cooled 16.5 49.3 0.87 attainable ardness uenching, 0.46 119,300 13.5 which often resolves itself into terms 0.49 127,800 156 14.0 41.1 the same tensile strength for given 0.50 13.5 hardness. Average 48.4 15.4 0.82 31.4 ticable this maximum obtainable 20.2 56.6 0.71 According some authorities, espe- 0.50 94,700 17.5 45.5 0.70 cially the exponents the use 126,830 16.9 Average 49.3 plain molybdenum steels least for THE IRON AGE, May 13, 1943—63 477 TENSILE STRENGTH 1035. 1040.1045 CARBON STEELS-WATER QUENCHED-1050 & 1060 OIL QUENCHED ALLOY STEELS-OIL QUENCHED 260000 260000 240000 a ° 2 HARONESS RANGE OVER USUALLY CONFINED ALLOY STEEL L 72 220000 220000 200000 = 2 4 RANGE COMMONLY USED FOR ALLOY STEEL WHERE 0.40 PERCENT CARBON SPECIFIED 180000 160000 140000 - 140000 COMMONLY USED WHERE 0.40% PLAIN CARBON STEEL 120000 100000 100000 REDUCTION OF AREA-PERCENT AREA THE RIGHT THE VERTICAL LINES INDICATES SATISFACTORY REDUCTION AREA VALUES strength for fully hardened sections for both carbon and alloy steel after hardening and tempering within The advantage alloy steels main- lies the ability the alloy steels harden throughout larger sec- tions. Without entering into the the- oretical aspects, this accounted for the alloy steel’s capability at- taining given hardness slower cooling rates than the carbon steels. One other observed difference be- tween alloy and carbon steel that for given tempering temperature the alloy steel always harder. This due ‘to the greater resistance the alloy steel softening tem- pering. higher carbon content also has the same effect. These points are brought out Figs. and which show the relationship hardness the tempering temperature for plain and alloy steels. will noted Fig. that increase the carbon content the plain car- bon steel from 0.36 per cent 0.48 per cent increased the resistance softening tempering. This also illustrated comparing the 4140 alloy with the 4150 alloy steel. The various alloy compositions not exhibit the same effect, that is, the rate the decrease hardness 64—THE IRON AGE, May 13, 1943 LEFT The relationship tensile reduction for alloy and bon steels. BELOW Sketches parts which are being success- fully produced from car- bon steels. tempering not constant. For ex- ample, Fig. will noted that 9440 decreases hardness more rapidly than does 4340. Usually chro- mium-molybdenum combinations are more resistant softening higher temperatures. This property for this alloy composition utilized, for in- stance high temperature applica- tions for bolts, tubes, Carbon steels not well alloy steels these applications. Nickel, when added carbon steels has marked effect elongation and reduction area values, especially the higher hardness ranges. The effect increase these elongation and reduction area values for given tensile strength. Chromium and man- ganese have lower values than steels containing nickel, also combina- tions chromium and molybdenum and manganese and molybdenum, es- pecially the higher hardness ranges. However, they have improved re- sistance softening tempering. This effect desirable many appli- cations. NE TH ~24 NF 2 THD TAPS elong value resist ences from well not creas have steel This hard Rock parti wher requ whic from num can | 7 | x XXX | M xx! 6 I x 6 STEEL 1360 DRILL 9 ru R i ART = 16 \ ~ generally assumed that the elongation and reduction area values are measure the impact resistance steel. Actual test data showing the differ- ences between carbon and alloy steels are shown Fig. 11. evident from this figure that the lower hardness ranges the plain carbon, well alloy compositions which not contain nickel, are all satisfac- torily based value per cent reduction area. the hardness in- creases, the steels containing nickel have much higher value than steels which not contain nickel. This applies particularly the plain carbon steels over Rockwell hardness. The performance plain carbon steels hardness over Rockwell for many applications, particularly for gears, has been found not comparable with alloy steels where impact strength important requirement. Fig. shows sketches parts which are being successfully produced from plain carbon steel. fact number the parts whose can easily recognized have been Spot Welder MONG the special-purpose ma- chines converted from peace war production General Electric’s Schenectady works are spot welders and seam welding machines previously used for refrigerator unit *For detailed description these water-cooled brazing tongs and_ the electro-brazing process, see 67, March issue THE IRON manufacture and now used for in- candescent brazing. The spot welders were adapted for incandescent brazing the follow- ing three changes: switch was installed the controller box provide the continu- ous flow power necessary without the use the drive motor. The standard spot welding elec- trodes were replaced dummy cop- per electrodes drilled and tapped one end where copper blocks are at- tached for the water cooling supply and return. these copper blocks were at- tached large water-cooled leads (183,- 000 circular mills) and brazing tongs. The leads were made feet length that the working area would produced from plain carbon steel for many years. The process manufacture, the hardness ranges specified, well other information for the parts shown Figs. and 13, are shown Table will noted that the water temperature varied the heat treatment the parts. This effective means controlling the rate cooling the hardening plain carbon steel. increasing the tem- perature the water, cracking minimized and the opposite pro- cedure, that decreasing the tem- perature the water, the rate cooling may increased allowing more uniform surface hardening parts larger section. Figs. and not show any parts which are made from 1045, 1050 1060 oil quenched, but has been pointed out that small sec- tions, that in. and under, can oil quenched with satisfactory results both surface hardness and hard- ress penetration. this case, the degree agitation the oil very important factor hardening. not limited the table. Plier-type brazing tongs* can connected these leads and brazing operations performed within 10-ft. radius the table. This permits other jobs set while working one. The transformers were removed from the seam welding machines, pro- viding immediately adequate sup- ply that equipment for permanent installation elsewhere needed. These spot and seam welding transformers substituting dummy electrodes with water cooled leads attached, this spot welder has been converted into use for incandescent carbon brazing. The brazing tongs shown mounted the bench the left foreground. order produce satisfactory mechan- ical properties, agitation the oil necessary consideration parts with in. solid sections. The effect agitation evident the data shown Table VI, obtained from heats AISI 1050 steel. The 0.50 test bars were quenched oil from 1550 deg. F., specimens from ten heats being quenched placing wire basket with mild agitation the oil, and specimens from the same number heats quenched hand agitation the specimen the same mildly agitated oil. The specimens were all tempered 900 deg. will noted that there dis- tinct decrease the yield point and tensile strength values and, al- ways the case, where fully hardened structures are not obtained quench- ing, decrease the ratio the yield point the tensile strength. conclude, plain carbon steel can great many instances substituted for alloy steel. Closer supervision necessary for the pro- duction satisfactory parts. many cases the part must also designed for the use carbon steel. Converted for Electro-Brazing have range from 250 kva. capacity operating 550 volts a.c. primary and volts secondary, heat. This extra range secon- dary voltage permitted the use longer leads than would possible with the and 20-kva. brazing trans- formers ordinarily used, and were ideal for that reason. They are water cooled, minimizing the possibility burnouts from overloading. én THE IRON AGE, May 13, T Ss n he 1 \§ ‘ iff American soldier for great many years now, has car- ried the world’s greatest mili- tary rifle. Yesterday, Springfield, today, the Garand. While fully conscious the superiority the Springfield, the Ordnance Depart- ment the Army never re- laxed its efforts develop still better arm. The Garand, semi-auto- matic action, and with three times the fire power the Springfield, was the result. The Garand bolt action gun like the Springfield, but the bolt oper- ated rod which ends short ret (6-in.) gas cylinder, under the barrel and close the muzzle. small port, leading from the barrel the cyl- inder, allows the pressure generated the explosion the gunpowder snap the rod and bolt the rear, ejecting the empty cartridge case. the same time, spring compressed which immediately forces the bolt for- ward and fresh cartridge with it. The piece cocked and ready re- peat the cycle the instant the trigger pulled. The rapidity fire lim- ited only the speed with which person can press the trigger. The bolt and bolt action the views the receiver which the main unit the Garand rifle. Complete machining operations are listed Table LATCH CLIP SLOT REAR SIGHT- HOLES BARREL CARTRIDGE HOLE OPENING FOLLOWER PIN. HOLE REAR SIGHT HOLE OPERATING ROD SLOT LATCH CLIP CLEARANCE HOLE IRON AGE, May 13, 1943 CARTRIDGE OPENING FOLLOWER TRIGGER CLIP SUPPORTS BOLT LOCKING LUG CAM CUT, FRONT END BOLTWAY BARREL HOLE BOLT LOCKING LUG GROOVE ARM FOLLOWER PIN HOLE Garand are quite similar those the Springfield. However, place the familiar bolt handle the Spring- field, the Garand has operating lug. This lug nests cam recess the operating slide, and when the slide moves back, cams the lug and bolt through few degrees rota- tion. Prior this caming motion, the bolt locked, that is, the lug and one like the opposite side are secure recesses the receiver. slight rotation the bolt frees the lugs from these recesses, and th