The Iron Age 1943-01-14: Vol 151 Iss 2

rica- has ition have aiser the idus- netal mass the alone oduc- chool ndus- the writ- car- — Proceeding With Assigned Task” assigned task now give the armed forces what they need win this war. that job are devoting all our skill and experience manufacturing ENGINES, ELECTRIC MOTORS, PUMPS, and SCALES. 43 q { JANUARY 14, 1943 de- on, ral or- ith ave let i der. nere ’ ¥ Worm gear specifications frequently place Cleveland the preferred position because Cleveland has: Experience more than years devoted the manufacture Worm Gearing exclusively. Knowledge— gained long-continued Engineering Research into successful appli- cations throughout the heavy industries. Facilities—a plant built produce worm gearing volume precision methods— equipped with machines designed our own Engineers—expanded meet in- creasing demand. types cover every basic application complete range sizes and ratios. All are built Cleveland’s uniform standard excellence. The Cleveland Worm Gear Company, 3252 East 80th Street, Cleveland, Ohio. Affiliate: The Farval Corporation, Centralized Systems Lubrication Canada: PEACOCK BROTHERS LIMITED WORM GEA THE IRON AGE, published every Thursday the CHILTON co. (IN C.). Write “Cleveland Worm into specifications and you team your own demand for continuous operation with Clevelands’ proved ability keep your machines running hours day. You can bank Clevelands—for they never will let you down! Philadelphia under act March 1879. yearly North America and South America, Foreign $15. Vol. Entered second class matter November 1932, the Post Office No. is ‘ | Office JANUARY 14, 1943 VOL. 151, NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager ° ° Managing Editor, LIPPERT News Markets Editor, ROWAN Technical Editor, OLIVER Associote News Editor JAMES Associate Editors Art Editor, WINTERS Editorial Assistants BUTTERS Resident District Editors Washington Pittsburgh Washington Chicago Cleveland Detroit OSGOOD MURDOCK San Francisco Editorial Correspondents Buffalo Cincinnati FRAZAR RAYMOND KAY Boston Los Angeles HUGH SHARP JOHN McCUNE Milwaukee Birmingham SANDERSON ROY EDMONDS Toronto, Ontario St. Louis BACON Seattle ° DIX, Manager, Reader Service ° ° ° Advertising Robert Blair, 621 Union Cleveland Herman, Chilton Bldg., Philadelphia Hottenstein, 1012 Otis Bldg., Chicago Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit 100 East 42nd New York Robinson Johnson, Market Research Mgr. Hayes, Production Manager. Baur, Typography and Layout. ° Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price North America, South America and Possessions, $8; Foreign, year. Single copy, cents Cable Address Y." ° Owned and Published CHILTON COMPANY Executive Editorial and Offices Advertising Offices Chestnut and Séth Sts. East 42nd St. Philadelphia, Pa. New York, OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, GEORGE GRIFFITHS, EVERIT TERHUNE, VAN DEVENTER, Vice-President BAUR, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY CHARLES HEALE Vice-President Vice-President Vice-President This Week in... Editorial Wars Are Won the Battlefield ° ° ° ‘ Technical Articles Proper Grinding and Inspection Steel Sesci Steel for Steel Clad with Gilding Gun Welding With 150-Ft. Cast Armor Foundry ............. Segregated Production Scrap Cuts Alloy Thermal Shock Detects Flaws A.P. Shot Bonderized and Lacquered Steel Sheet New Equipment: Plant Service Apparatus Features Assembly Line Washington West Coast Fatigue Cracks Dear Editor News and Markets This Industrial Week News Industry Personals and Obituaries Machine Activity Non-Ferrous Metals Scrap Iron and Steel Scrap Prices Comparison Prices Finished Steel Prices Index Advertisers Copyright, 1943, by Chilton Company (Ine.) 4 i } | | | | 100 102 104 106 108 also, the life armature—or any other part that operates high speeds. Here, un- balance can short and painful whirl with vibration, noise, and excessive wear. The true static and dynamic balance which vital all high speed rotating parts, now more quickly and economi- cally through the use Gisholt Dynetric Balancing Machines, And done more accurately than ever before. MACHINE COMPANY 1215 East Washington Avenue Madison, Wisconsin GISHOLT DYNETRIC BALANCING employ the radio means amplification measure unbalance matter seconds. Their many war industries assures more efficient LOOK AHEAD and long life hundreds vital rotating parts. With Gisholt Improvements ture request. The Army-Navy and the Treas- ury Flag fly side side TURRET LATHES AUTOMATIC LATHES BALANCING MACHINES | locate Their parts. AGE | | e JANUARY 14, 1943 ESTABLISHED 1855 Wars Are Won the TRANGE, it, how some people take issue with axioms? spite the universal experience that fatal fly the face one. there ever was sound and substantial axiom that wars are won lost, the long run, the battlefield. Regardless the truth the saying about the importance the men behind the men behind the guns, amount production ever won war until was put use the fighting men the front. They are responsible for the final decision. Some are now overlooking that fact. Some seem think that this war will won the White House, the Lend-Lease Administration, industry American labor. All them, well all our civilians can help win this war. But none them nor all them can win it. The winning will done our soldiers and sailors. After the rest have given them what takes. Our men the fighting fronts and the embattled oceans what takes. They know what they need better than do. They know where bombers and fighting planes are needed and what kind and how many. They know the kind tanks and tank destroyers that will the trick given location against given enemy and what sort guns they should have it. They know from bitter experience whenever meet and overcome superior weapon initiated the enemy. These men the front transmit their knowledge their needs; and constantly changing knowledge, through the most direct channels communication possible. They not write the President about it, nor petition Harry Hopkins and his charming young bride help them ask Congress give them what they need. They their superiors the Army and Navy general staffs, who decide what, how much and when. And these gentlemen, turn, the WPB and Mr. Nelson then puts the finger the plants make it. think that you will agree that this sensible procedure and that would hard better it. The only trouble with that non-political and does not provide opportunity for run the war abroad and home. And some them want just that. They want take these things out the hands the Army and Navy and the WPB and fight this war the Senate and the House. Representative Tolan, fact has introduced bill (H.R. 7742) just that. American industry would not favor that nor think the rest our people would. They want see men kept charge things who have record winning battles, not merely debates re-elections. 4 | | | | | | | | ° iy | } A, 4 | | | | | | | a | | | Inland Reports First Year War MERICAN INDUSTRY all-out for performed production feats that would have seemed impossible before Pearl Harbor. But all know that the real accomplishments—ones that make ours are those our men the fighting fronts. therefore humbly, and with full realization this, that report what have done— putting every ounce skill and energy into backing the men who fight-for us! 1942 OUTPUT 102% CAPACITY. Inland main- tained its production “fighting steel” about 102% rated capacity during 1942, despite lack adequate supply suitable scrap and the loss hundreds skilled workmen entering the armed services. BREAK OVER PRODUCTION RECORDS. than Inland production records have fallen since Pearl Harbor! Open Hearth steelmakers March had their best month history. The Blast Furnace Department hit its all-time produc- tion peak the month December. Near the end July the 76-in. mill finished enough ship plate one 24-hour period for the hulls two Liberty ships. All our mills rolling ship plate turned out enough July for half the number sent down the ways that month. —And other departments throughout the mills. Inland steelmakers are determined that our fighting men will not suffer for lack steel they can supply. Inland mines and quarries produced far more iron coal and limestone than ever before. Lake freighters the Inland fleet broke their own cargo records, not once but several times 1942. EXPAND AND MODERNIZE FACILITIES. Not only has top production steel with installed facilities been main- tained, but completed major expansion and mod- ernization projects get even greater tonnage. Inland’s new No. blast furnace, first one built the Chicago area since Pearl Harbor, was blown Nov. and now pouring out 1200 tons pig iron day. soon will complete construction and begin oper- ating two more blast furnaces for the Defense Plant Corp. INLAND new electrolytic tin plate plant will soon oper- ation conserve our precious stock tin. New ore mining expansion assures larger supply iron ore. HELP TRANSPORTATION WAR GOODS. Reduced customer unloading costs packaging saved 10% space—increased weights carloading lowered car detention time 20%. GETS THE SCRAP. contributed heavily the American Industries scrap campaign, conducted its own extensive scrap advertising campaign, and Inland sales- men are participating actively the steel companies’ in- dustrial scrap drive. EMPLOYEES ALL-OUT FOR VICTORY. More than In- land workers have entered the armed services. medals were awarded workers war industries for effort “above and beyond duty,” many men Inland would qualify receive them. Women are helping carry the plant, too—doing variety jobs the mills help relieve the manpower shortage and maintain capacity output steel. The entire Chicago Heights plant and many depart- ments Indiana Harbor already are over the top the current drive put 10% total pay into war bonds. Inland girls have their own Red Cross group—making thousands bandages. Nutrition groups are endeavoring improve the general health workers and fit them contribute more the war effort. Many Inland employees are the plants’ own well- trained Catastrophe Organization, ready meet any war- time emergency. Others are busy civilian defense work, war group benefits, etc., and are sharing their cars, do- nating their blood and tightening their belts what- ever else necessary win this war. LOOKING AHEAD. the coming year, Inland and its men will continue push the production “fighting steel” top speed. Rather than make predictions, prefer let production records speak for themselves. know that can pledge the whole-hearted support every worker all-out effort Victory won! STEEL COMPANY DEARBORN ST. CHICAGO, ILL. 22—THE IRON AGE, January 14, 1943 | In- for and ywer the king well- war- vork, do- vhat- its hting ort j 4 f ° ° ° EDGAR BROOKER and LOREN ELLIOT Ordnance Engineers, Tank and Combat Vehicle Department, Ordnance Depart- ment, Army ° ° automotive combat vehicle de- pends the optimum combin- ation armor, armament and mo- bility. The object this study describe the relative merits welding compared riveting homogeneous rolled armor for the hull armored tank. The weld- hull shown outline Fig. designed light tank propor- tions but not based any hull now being made for the Army nor far known not coinci- dent with that any foreign army. estimated weigh not more than 15,000 which lighter than some production designs the Same relative cubical content, and hence meets the test mobility. The question armament out- side the scope this paper. The probability enemy fire against armored hull greatest against the front, hence the armor this hull sloped upward above the front main drive housing. The rear this hull also has high probability hits, hence sloping plate shown here also. the vulnerability side doors, this hull does not contain them, but entered from the top the tur- (casting not illustrated) from escape door the bottom. Ballistic Requirements Riveted joints for armored struc- tures are not quite bad the newspapers have indicated, because riveted tanks have given very Welding Armor Plate ombat Tanks Proving ground ballistic tests have verified the supe- riority welded over riveted construction. The saving welding compared riveting estimated $291 per light tank hull theoretical design. The authors re- ceived $250 award for this paper the recent $200,000 Industrial award program the James Lincoln Arc Welding Foundation. good account themselves. The efficiency the riveted joints used fighting tanks approximately per cent calculated for static tests, but working stresses armored hull are consequence, since sections are very heavy for the operating stresses imposed. In- stead, the integrity protective hull lies resistance ballistic penetration armor piercing pro- jectiles and resistance shock from overmatching projectiles that not necessarily penetrate because high obliquity impacts. mm. shot striking deg. can deliver shock 188 ft.-tons fighting range. joint armor can only ex- pected possess greater pene- tration resistance armor ing projectiles than the armor plate joints are made with the armor plates tightly butt- ing together. Hence, except for the cracks, all anti-tank projectiles impacting the joints are opposed armor. rivets not shear, the penetration resistance the joint practically good the virgin plate. Butt straps provide extra thickness against penetra- tion. Ball ammunition impacting against tight crevice between armor plates becomes liquid and will splash several inches before being stopped unless lead trap installed. The lining riveted tanks takes care this hazard, lead splash concern except around openings the hull where lead traps are installed. Shock Resistance Compared Low shock resistance the chief weakness riveted joints. This measured the use soft de- forming projectiles which have in- ferior penetrating power. Though such projectiles are not used combat, they serve useful purpose gaging the shock resistance joints armor. The method con- sists determining the critical de- structional velocity virgin plate, following which are selected for shocking jointed plates. Fig. shows hot riveted plate test assembly made with in. high THE IRON AGE, January | f ed the les- ! q 7 | tensile steel rivets in. pitch and in. butt strap. This plate was struck with one 75- mm. slug striking velocity 906 ft. per sec. addition the damage this photograph, total five rivet heads were thrown from the back side. Fig. shows with that Fig. The striking velocity for the one slug was 1246 ft. per sec., which resulted com- plete separation one-half the 24—THE IRON AGE, January 1943 plate. For comparison Fig. shows similar plate welded with the Lincoln Electric electrode. The cross bar the was welded last produce locked-up stress condition. ‘These slugs were fired this plate with striking velocities 1115, and 1216 ft. per sec. order firing. Round No. struck 1115 ft. per sec. and in. center distance from the vertical leg weld, hence did not stress the weld sufficiently LEFT IG. for light tank theoretical de- sign which riveted con- struction compared with arc welding. BELOW IG. 2—Effect 75-mm. steel slug fired 906 ft. per sec. hot riveted test plate. Rivets are in. high tensile steel in. pitch, with in. butt straps. prove anything. This one impact against riveted plate would have broken least two parts. Rounds and struck highly stressed area and cracking oc- curred the front back sides the joints. Such shocks will fre- quently break unwelded plate. interesting note the re- sults shooting second welded plate the same armor and welded under the same conditions except that Lincoln Stainweld electrode was used. Two slugs 957 and 970 ft. per sec. caused in. cracking the welds this plate. This not exact comparison the low and the high alloy weld metal but, shown numerous test data, the Armorweld electrode has given superior results those obtained with the better established Stainweld type. The data above are summarized Table wherein ballistic impacts are given terms kinetic energy impact, and damage given length joint broken. Resistance Welded Joints A.P. Shot Welds armor should possess re- sistance projectile penetration equal that the plate, but stain- less steel weld metal lower penetration resistance than armor plate. This deficiency does not exist welded joints when butt straps are used when weld reinforce- ments are not removed. The ar- rangement welded joints the hull Fig. such that rare lucky hits only would hit them. The armor and welds this vehicle are sufficiently thick that any projectile smaller than the mm. size can- not penetrate battle range. Fur- thermore, mm. heavier anti- tank projectiles are larger di- ameter than the width and root gap any the welds used; hence such impacts should occur these joints, the projectile would op- posed plate well weld metal. Penetration test data fre- quently show that the penetration limits the welded joints with normal reinforcements are 100 per cent that specified for the plate. The low penetration resistance stainless weld metal does not cause points weakness hull. The use 3-ft. square welded ballistic test plates Fig. have not been considered representative stress conditions welded arm- ored hulls those who appreciate the internal contractual and tensile stresses that occur welded joints. ij i] | \ ~ 8 | \ \ 5 16 = zed cts re- mor xist ar- the The ctile can- Fur- anti- gap Op- weld fre- ation with per plate. cause have tative eciate joints. — Before any ballistic shock pene- tration tests were performed welded hull, was prophesied that extensive failure could expected points widely separated from projectile impacts. was assumed that great internal stresses would exist and that severe shock one side the structure would cause wholesale failure. The qualification welding procedure with test plates shown Fig. was also criticized because when tested this manner the weld metal was thrown compression the face side and put tension the back side occurs the bending simple beam. With few excep- tions the welded joints tank hull are located that projectile impacts primarily place the weld metal compression. When became possible con- duct ballistic shock and penetration tests welded hull, the use plates for testing and developing weld quality was justified. Fifteen mm. slugs impacted against one side welded hull caused only local failures adjacent the points impact. cracks occurred else- where that could explained shock wave propagation ex- cessive internal stresses. Just shock impacts located more than in. center center distance from the welds plates caused damage, the welded structure, ballistic damage occurred only with- small area surrounding the de- pression caused the projectile. The hazards internal stresses were not evident. order judge the ballistic shock resistance riv- eted joints for comparison with the welded joints, the riveted and weld- were made. However, the con- struction riveted tank hulls the most common joints are angle butts which the plate edges are placed close contact. The arrangement plates such that hits from the side, front and rear not fail unsupported plates with few ex- ceptions plates supported only butt strap inside. The plate, therefore, represents abnormal test for riveted joints. Design Welded Joints Fig. illustrates the welded joints the homogeneous armor the hull shown Fig. will noted that simple fillet welds are avoided for joining outside plates except those the bottom. welds the inside transverse, front stiffener joining the curved plate 3—Same tes IG. 4—A welded test plate that was struck with three 75-mm. slugs 1115, 1112 and 1216 ft. per sec. impact. None the welds cracked. plate shown Fig. but struck with 75-mm. slug 1246 ft. per sec. impact velocity. ° ° ° THE IRON AGE, January 1943—25 t S. TABLE Summary Ballistic Tests Riveted and Welded Armor Plate Fig. No. Construction Test Plate butt strap above but cold riveted Manually arc welded with Armor weld, deg. incl. angle, double bevel, with root spacer bar the floor plate are far enough aft that ballistic impact con- cern, Root gap openings shown the details Fig. have been found experience permit complete penetration root passes. The most difficult part making sound weld with stainless steel elec- trodes armor the deposition sound root passes with complete penetration. The plate edge prepa- ration for this vehicle requires deg. bevels and these bevels are made such way that the cutting machine will not have ride guided upon the cross- section any plate. For example, detail Fig. could made with flame cut bevel the thicker plate angle deg. from the cross-sectional plane. The amount flame cutting decreas- Energy, Impact Kinetic Damage cross bar 181 in. joint breken, rivets sheared 463 cracking welds requiring all preparation the thinner mating plate. Welds self-hardening steels such armor result hard heat affected zone. The Knoop hardness shows the maximum hardness approximately 450 the plate im- mediately adjacent the weld met- al. Thus reasoned that layer low ductility adjoins the stain- less steel weld armor unless post heating used. This operation not necessary practicable for rapid production. The deg. bev- els details and 10, for example, are therefore justified because this brittle zone increased surface area over that which would result smaller included angle were used. Simple butt welded joints with beveling have been made and have given fair results ballis- tic shock. Such joints use mini- TABLE Comparative Weights Single Riveted and Arc Welded Joints Per Linear Foot Corres. Riveted Constr. Joint Rivet Butt Strap Fig. In. In. angle angle angle 14-15 Weight Weight Rivet Heads Rein- and forcements Butt Straps and Fillets Lb. Lb. Type Joint 10.5 0.33 deg. butt 8.2 0.15 deg. butt 12.1 deg. butt 10.7 0.32 deg. butt 0.98 deg. butt 4.1 0.21 deg. butt 9.7 0.20 deg. butt 9.6 0.18 135 deg. butt 10.5 1.51 butt 26—THE IRON AGE, January 14, 1943 mum amount weld metal which advantage for reducing the consumption critical alloys and minimizing welding hours, but are not favored for high shock strength. plates have been made with in- cluded angles the welds deg., and deg. with view ballistic shock strength, but the ballistic test not quantitative enough make such distinctions. interesting note that the most successful tank welding contractors today are using and deg. beveling. Out- standing welded plates have been made with “broken backed” edge preparation shown Fig. Table illustrates the great sav- ing weight which results from the use welding armored structures. These data were ob- tained detailing riveted joints take the place each the welded cated previously the static joint effi- ciency these riveted joints ap- proximately per cent. they were made with sufficient rivets and butt straps angles provide the customary per cent efficiency structural riveted joints, the result- ing weights would excessive and the comparisons would still more favor welding. The efficiencies the angle butt welded joints have not been calculated estimated be- cause the stresses ballistic im- pact are unknown. However, ballis- tic tests plates frequently illustrate plate failure equal fail- ure weld metal fusion zone, hence the ballistic efficiency weld- joints must almost 100 per cent. Production Advantages Welding Other than the ballistic perform- ance illustrated Figs. and welded construction offers nu- merous advantages from produc- tion standpoint. Plate preparation for riveting requires almost per- fectly flat plates give good fits against butt straps and faying an- gles plates. Flattening armor cannot performed stretcher leveling entirely, and hence brake presses and considerable manual labor are necessary for flattening plates that are riveted. Armor factory degree stretcher level- ling. flatness tolerance in. ft. acceptable for manually welded construction. root gap variation 1/16 in. taken care depositing more less weld metal. Plate edges for welded construc- | j | i | | | | | | | 4 | | | | | | | ore ies ave be- im- lis- ail- yne, ald- per rm- and nu- tion per- fits an- cher rake nual ning ‘mor atis- evel- in. ually gap care weld truc- tion can flame cut everywhere except bolted joints which hold machined parts components the hull. Main drive housings are bolted form the front some tank hulls. The hull shown Fig. has such joints, the bow being completely welded, and the main through the turret opening. This opening need not finished after flame cutting because the turret supported and guided machin- lower base ring. Flame cutting armor need not followed flame softening but welds can made directly the flame cut sur- face provided all heavy scale re- moved touch-up grinding. The hardness the weld affected zone armor not decreased previous flame softening. Riveting would require drilling approximately 1000 holes the hull illustrated Fig. These holes must reamed before driv- ing the rivets. The following tabu- lation illustrates the man-hours re- quired for these operations. Welded construction requires drilling only those holes which removable parts the hull are fast- ened bolts. The operations planing plate edges and drilling rivet holes takes valuable ma- chine tools which are needed badly this emergency for the manufac- ture other war materiel. Flame cutting equipment less critical supply than planers, shapers drills. Field Repair Tanks battle will inevitably be- come penetrated will come back field shops with bent plates. the joints are made riveting, will difficult repair them, and best the repair will heavy for the protection provides. Holes armor made penetrating projec- tiles can filled welding inserting repair plugs without increase weight. Bent plates welded hull will concern unless cracks occur, and these can easily filled welding, while riveted construction, cover plates would have riveted over the Openings prevent the entrance small arms projectiles lead splash. Conclusions Welded construction for arm- ored tank hull offers the following advantages over riveting: Welded joints shock and penetration resistance DETAIL DETAIL DETAILS 5-17 DETAIL DETAIL 14-15 REAR STIFFENER FRONT STIFFENER IG. 5—Details the various welds the light tank hull out- lined Fig. The detail numbers correspond the locations num- bered Fig. RIGHT 6—On the welded plate impact tests, double angle back" edge preparation showed well. The heat affected zone less critical from the point view ballistic shock. against enemy fire equal that af- forded armor plate, but riveted joints are very much weaker than welded joints and weaker than un- welded plate. Unless the rivets riv- eted hulls are seal welded, riveted joints offer added hazard flying Manually are welded fabrication the armor plate hull requires only per cent the man-hours needed for riveted fabrication. one man-hour worth $1, this amounts $291 per hull. Manual welding pro- vides per cent increase rate rivets. Welded joints this armored hull effect 9-10 per cent 1553 Machine tools needed badly for other war materials are released the use welding compared riv- eting. saving weight represented the rivet heads and butt straps riv- eted hull. Man-Hr. Man-Hr. Operation Riveted Hull Operation Welded Hull Drilling butt straps 104 Flame cutting plates and Drilling armor 184 Reaming holes, fit and Assembly and fit 104 Saving man-hours effected welding. 291 THE IRON AGE, January 14, MK 1. DETAILS 1-2-3-6-8 st Af, Af ce i Yi DETAILS 9-10 DETAIL q AA Uf Yj 3 \\ W\\\\ \ \ \\\ \AAAA\\ | ERB Schenectady Works Laboratory, volve such essential mate- General Electric Co. rial tool steel difficult under- stand, especially since this metal becoming increasingly scarce. HAT improper grinding and faulty inspection should in- Yet both practices are means the presented not newly discovered information, but review familiar but often disregarded facts, helpful alike conserving this val- uable metal and necessary accidents. Improper grinding the primary cause cracks, both visible and invisible, tool steel. When visible, these cracks are easily recognizable. That is, the direction the prin- cipal cracks always perpendicular the direction the grinding. Also, they are generally connected smaller secondary cracks. This | uncommon. Too, equally dif- ficult understand why the simple precautions necessary for the safe handling tools made this steel are often neglected. Merely fundamental knowledge the prop- erties and limitations tool steel would prevent much suffering and save many lost man-hours annually. Consequently, felt that the following, which like the case previous article tool steel “<p ractical Suggestions Concerning the Heat Treatment Tool Steels,” Ace, Oct. 1942, page 47. IG. used the General Electric Works Laboratory for magnetic crack detection. From left right are seen the demagnetizing coil used upon completion the examination; some tools tested; the link-type electromagnet use; and, the hands the man, the spraying equipment for applying the iron oxide powder suspended kerosene. 28—THE IRON AGE, January 1943 Proper Grinding and produces kind appear- ance the steel. Magnetic Test Method Suspected but invisible cracks produced grinding should sought for the mag- netic test method. this method, the tool steel inspected placed link magnet with the flux longitudinal (Fig. 1), that will intercept any possible cracks right angles. While thus mag- netized, the steel sprayed with kerosene which has suspension finely divided particles magnetic iron oxide. Cracks the metal set mag- netic poles, which turn attract and hold the iron-oxide particles, thereby outlining crack invisible the naked eve, Fig. Hardening Quenching Cracks Hardening quenching cracks, Fig. are distinguished from grinding cracks that they are usually larger and fewer number. Also, the main they are sym- metrically disposed, following holes, weaker portions the tool. The cause the cracks this die, which incidently example poor design, was follows: The upper, lighter portion cooled faster and reached the temperature the quenching oil first, remaining con- stant volume. The centra! and lower portions, cooling more slowly, continued contract, thus putting tension the weaker section be- tween the rectangular holes and the upper edge. Consequently, the die cracked. The remedy obvious. These rectangular holes should have been placed permit more metal between their upper corners and the top edge the die. Also, there should have been more metal be- tween the lower corner and the larger impression. addition, the cooling could have been more near- equalized drilling dummy holes the middle and lower sec- tions the die. Tool steel, must remem- > g 3 Inspection Tool Steels bered, will tolerate all kinds com- pression, but weak tension, particularly the tensile stresses are localized some edge, nick, corner, tool mark. The harden- ing cracks high speed cutting tools are due partly improper quenching, and surface imper- fections not removed prior hard- ening. Softening Together with causing cracks, improper grinding may also dam- age tools other ways, such cross-section set carbon tool steel test pieces which were soft- ened, but not cracked, improper grinding. facilitate the test, these square pieces carbon tool steel were first hardened, then broken across the middle. Next, the frac- tured surface was ground, then etched acid. The dark shaded outer portion represents the hard “case” shell (Rockwell C67), the light areas the center represent the case (Rockwell C45), while the light streaks bands show the areas softened grinding 2—Cracks aid the conservation critical materials, this article reviews briefly the familiar but often disregarded precautions taken the safe and proper handling tool steel. (Rockwell C55). contrast, Fig. shows the same specimens properly ground. Hardening uniform and there absence bands. Hardening also possible grind an- nealed high-carbon steels dras- tically that they harden. That is, the surface the metal raised momentarily red-heat and then instantly chilled, after the grinding wheel passes, the mass cold metal beneath, the flushing the grinding coolant, Fig. The resulting hard spots frequently cause trouble machining. Cracks are almost invariably associated with this kind grinding. Since tool steels can create haz- ards according their composition and according the methods turning tools located iron- powder test. loading applied, failure recognize their especial properties and limita- tions when handling them can re- sult certain dangers. For in- stance, highly dangerous strike piece hard tool steel steel hammer. Many persons have lost their sight this manner. guide, tool steels may divided into “hard” and “tough” steels follows: Hard steels: All steels contain- ing over 0.55 per cent carbon, which are capable being hardened over Rockwell Higher carbon steels, even when their hardness duced less than Rock- well are still held the hard steel class. Tough steels: Those contain- ing less than 0.55 per cent car- THE IRON AGE, January 1943—29 1S ° ° ° | es, ble ks, er. les, or his ster ing etal here nem- bon, and tempered that the hardness does not exceed Rockwell Strength and Toughness Test Figures Too, since potentially all tool steel weak and brittle, advisable not misguided strength and toughness test figures. These tests generally are made carefully prepared specimens, uniform section, loaded that the stresses are equally distributed. Consequently, high strength and toughness when ob- tained this manner may mis- 3—Quenching cracks die. The poor design the die resulted cases without taking into considera- uneven cooling. 4—Cross-sections set carbon tool steel test pieces which were softened, but not cracked, improper grinding. RIGHT IG. 5—Cross-sec- carbon tool steel test pieces, proper- ground. tion tions. For instance, much has been said and printed about fatigue strength, LEFT and the effect notches, sharp cor- ing high car- kinds lowering fatigue strength. bon steel, this true low and medium using water carbon steels, obviously many prevent the very composition which cracking. (high carbon) “stress-raiser.” Now known that square piece hard tool steel strength bending than round piece, due simply the stress-rais- ing effect the corners the square pieces. piece soft { | | i | > | } | | a | | b | © i & ta- th, or- th. ool ich are ess ind the Characteristics Steel analysis, per cent carbon Remarks Note The head was not spalled. The ball was flattened down and split because was hardened only one side. The other side was dead soft. 0.65 0.61 64-65 60-61 66-67 Spalled See Note Spalled | 0.54 0.89 0.64 64-66 68-70 55-58 Note Not spalled, but one corner was entirely knocked off heavy, shearing blow. Hardened case was very shallow. properly hardened, this probably would not have occurred. Fig. 7—View showing spalled corners six ball-peen hammer heads. steel, this effect would hardly noticed. Likewise, the surface finish bridge member has little effect the strength, whereas the direction and kind grinding applied delicate cutting edge has much with its strength. So, also, have grinding cracks Defective Impact Tools Defective impact tools also are highly dangerous. Shown Fig. are six defective machinist’s ham- mers collected some time ago General Electric’s tool and gage service department vated their request the com- pany’s Schenectady works labora- tory. During the characteristics listed the table and notes under Fig. were made. condition which may occur when impact tools are too soft. The nine figures are number stamps after test set. the upper right hand corner shown the head stamp which has been badly “mushroomed.” Obviously, this con- dition dangerous, since piece the split metal likely fly off the next time the tool struck. Tools this type should ground bevel the head, shown the next two stamps the right. Better still, they should returned the stock room for proper dispo- sition. Note how the degree decreases with the increase hard- ness the head, shown the Fig. 8—Number stamps after test set. All stamps softer the body than Rockwell were bent. THE IRON AGE, January 14, e S- following table, reading from left right the pictures: HARDNESS— ROCKWELL Stamp No. Point Body Head should also taken into con- sideration that stamps which the body too soft also create haz- ardous condition. stamps softer the body than Rockwell were bent. This may cause the stamp fly out the hands when struck. Tough Tool Steel Under Bending Tough tool steel when exposed steady bending load may more dangerous than the hard variety. This because its natural resilience. For example, conducting bend strength tests steel, the spe- cimen set simple beam, supported both ends and loaded the middle. When the specimen the halves the tough steel will usu- ally fly with terrific force, while the halves the harder and more brittle steel are not likely fly. Consequently, because these and other related experiences, the following general conclusions the dangers associated with tool steels have been arrived at: impact, the hard steels are especially dangerous. Small parti- cles spalled the corners and edges are most likely cause injury. Tough tool steel, the other hand, probably the safest mate- rial available for use impact. The danger associated with this steel, however, its “springiness” re- silience. Although tough tool steel will stand considerable deformation before breaking, enormous elastic forces are built that when does let go, these forces are released and large pieces may fly off with terrific force. Hard steels are classified those containing over 0.55 per cent carbon, over Rockwell hard- ness. Finally, since scale has been known cause serious eye injuries, all surfaces subject impact should ground remove scale and projections, and round off bevel all corners. Sesci Steel for Castings IMING the utilization the maximum amount its own scrap its internal metallurgical processes, the London, Midland Scottish Railway Co. its locomo- tive works Crewe installed 1932 two five-ton pulverized-coal- fired rotary furnaces, according Lemon and Hugh O’Neill article for the Iron and Steel In- stitute, London. Since was claimed for this type furnace that the high working tem- perature available would give very fluid metal, heat from exothermic bath reactions due the oxidation pig iron could dispensed with. Besides the reduced consumption pig iron, the advantage the Sesci furnace over the Tropenas converter, which had hitherto been employed for the manufacture steel castings, lies the better con- trol the steel-making process and the avoidance any metal loss projection. Adjustment the pul- verized-coal distributor positive air blower should produce either oxidizing reducing flames required, while temperature and composition control much more 32—THE IRON AGE, January 14, 1943 flexible than the converter. disadvantage that owing the absence side doors, the Sesci bath can observed only stopping the flame and sliding back the exhaust head. Great difficulties were encountered securing good life from the refractory lin- ings. With intermittent working, this has been raised from begin- ning heats per lining average 125, with record value 226. daily patching technique which enables the lengthening refractory lining life has been de- veloped. The most useful lining found one with adequate refrac- toriness and low after-expansion, but, above all, facility for forming durable ceramic bond with the patch repair. The furnace charge consists 99.5 per cent railway and tire scrap with not more than 1.5 per cent pig iron and introduced into the fur- nace horizontally from boxes standard type ground charging machine. some heats, small amount anthracite added with the steel scrap which together with little pig iron, provides carbon induce boil. After very many early trials, has been found that produce boil and work down the charge simpler and produces better steel than attempt direct fusion process without boiling. Ore additions are seldom required. Ad- ditions limestone are made the slag after the first carbon sam- ple has been taken. analysis ingot and slag showed the absence F:0:, which remarkable view the rather low temperature which this fur- nace operated. Carbon content analysis was 0.17 per cent; sili- con, per cent; manganese 0.81 per cent, sulphur, 0.048 per cent, and phosphorus, 0.042 per cent. Re- sults physical tests forged sample after normalizing were above average. Longi- tudinal Traverse Yield point, tons Max. stress, tons Elongation in., per cent... 33.5 30.0 Reduction area, per cent. 61.0 46.4 Izod value, 100, 75,66 30, 35, j i| | | | | J | ces ect PEACETIME cladding process developed Superior Steel Corp., Pitts- burgh, several years ago, has gone war for the United Nations and annually saving hundreds thousands tons strategic cop- per. Originally designed method for producing composite steel with ordinary carbon core and stainless steel surface, the process now being utilized produce composite metal, per cent which ordinary steel, and the balance per cent gilding metal (90 per cent copper and per cent Long before the United States Government adopted the Superior method for producing material utilized the production and cal. bullet jackets, Great Britain, Canada, the Soviet Union and China had already been using this compos- ite metal. Recently, however, the small arms division the Ord- nance Department decided upon the Superior process and.at present turning out millions bullet jack- ets the use this clad metal. The orders from the United States Government, however, were exceptionally large that the Superior Steel Corp. alone could not fulfill the total demands. order facilitate this particular type war production and fulfill the needs the United States, well that the United Nations, the Superior Steel Corp. offered the use its process without royalties for the duration the war and dur- ing period six months there- after. This contribution the war effort received the support and commendation the Ordnance De- partment and subsequently steel companies were granted permission Superior use its process for making gilding metal Steel Clad ith Gilding Metal CAMPBELL Pittsburgh Editor, AGE strip for the fabrication bullet jackets. addition agreeing discontinue the use this process six months the termination the war, these com- panies have also granted Su- perior Steel the right use any improvements made them the Superior process. The potential uses for the Su- perior cladding process during peacetime appear sizable, since the composite metal not limited steel and gilding metal alone, but can also utilize stainless steel, silver, copper and other metals, depending upon the end use for the strip. said that large new field for special products after the war will undoubtedly open and the process will great value for the manufacture cook- cladding steel strip with gilding metal and its conversion into bullet jacket cups. The drawings indicate the proper facings with the steel center. this particular case the top and bottom facings, shown black, are referred per cent total per cent gilding metal. COLD ROLLED AND ANNEALED SHEARED STRIP — Caliber Scrap from unsheared strip 30 Caliber Scrap from sheared strip WEBBING SCRAP LEFT AFTER BLANKING AND CUPPING Various types of cups as furnished to the Arsenals Unfinished bullet jackets— ready for filling and finishing THE IRON AGE, January 14, el, nt ° ° eS, ale off FINISHED COLD ROLLED STRIP—BEFORE SHEARING \d- ILLUSTRATING TWO METHODS OF SHEARING OFF EDGES OF STRIP lag ich ing utensil store front material, radiator material, and numerous other uses. time being, however, total output involving the gilding metal process direct war requirements. Many the steel companies which have been granted permis- sion use the Superior process are production and others ex- pected produce substantial ton- nages early date. While only and cal. bullet jackets are be- ing made from this composite metal the present time, experi- ments have indicated that larger shell cases can drawn from this material. Whether not the use the cladding process will ex- tend larger components yet undetermined but least the possibility there. Such move would further expand mendous saving copper which the present time represents one the tightest raw material prob- lems. Briefly, the process making gilding metal clad steel strip con- sists starting out with special rolled several steel companies. The steel section with the gilding metal facing given special treat- ment for keeping the metals to- gether. The steel section with its gilding metal facing secured place then placed furnace for proper heating. After proper heating, the material down several passes into hot rolled gilding metal clad steel strip. The latter then annealed, pickled, cold rolled and sheared. The gilding metal clad steel strip then securely packed coils and shipped fabricating com- panies which punch out the disks and make the cups which later are drawn into the bullet the case Superior Steel, the cups are returned from the fabricator their mill where the surfaces are properly cleaned tumbling and where the cups are properly an- nealed prior being shipped locations where bullet jackets are drawn. Accompanying photograph shows the gilding metal clad steel strip and its conversion bullet jacket cups. Practices are being developed recover’ the copper and zinc, well steel, from the punching operations. Interesting from the standpoint Superior Steel the fact that recently the company had made substantial expansion its finish- ing mill processes including the installation new rolling furnaces. The company was ad- mirably situated immediately begin the production the gilding metal clad steel strip since all the facilities which previously had been utilized for non-essential steel production were available. also thought that the company has already found other uses for its process besides the making material for small caliber bullet jackets, but for the time being least this lies within the realm censorable material. Gun Welding With 150-Ft. Leads PPLICATION welders far 150 ft. away from the source power possible with the new Thomson Power Pack, developed Thomson- Gibb Electric Welding Co., Lynn, Mass. The scope and efficiency resistance welding increased taking three phase standard volt- age a.c. and delivering low voltage d.c. the welding gun. This ar- rangement especially useful for welding guns multiple. For spot and projection welding, the Thom- son Power Pack finds many appli- cations. Because the unit furnishes d.c. for the welding, there problem cable reactance and much less power required transmit the useful welding current the point the weld. The power factor two three times better than would with single phase a.c. Use the regular three phase power source permits better balanced load- ing. Approximately 200 kva. dis- tributed over three phase equal 500 kva. the ordinary single phase a.c. gun welder. The Power Pack houses three phase transformer and three phase 34—THE IRON AGE, January 14, 1943 copper oxide rectifier with connect- ing bus bars, air blowers for indi- vidual cooling each unit, igni- tron type contactors, timing control and voltage regulators. The pack capable furnishing current for welding aluminum 0.040 in. thick for welding steel mild steel 0.064 in. thick. ° ° ° new Thomson Power Pack. The voltage regulators permit adjustments out- put d.c. voltage. Timer calibrated cycle steps from 300 cycles. distributor for connecting each several welding guns individual- and successively the current source may mounted the top the unit. Distributors may provided with stations. All guns can receive current within sec. desired. The control circuit, operating with pushbutton switch each gun, fires the gun when the push- button held down until the dis- tributor station operates connect the gun the Power Pack during the weld cycle. Two guns cannot fire once and any given gun fires only when its individual switch closed. Multiple guns, however, must working team, for receives the same current and welding time for any given set-up. The cables connecting the guns the Power Pack are flexible and easy handle. The smaller unit employs cables 500,000 circular mil cross section; the larger uses 1,000,000 circular mil cables. The guns are usually the manually cperated type with 300-lb. weld- ing pressure. Light heavy, air, hydraulic manual guns may | | 7 ach ent top All ing ach dis- ires ver, for and up. runs and unit ular uses The lally air, RIGHT ETTING tank turret core new cast armor foundry. Large arbors are baked into the core, which attached the cross arm visible the photo. The arm clamped the flask. This huge one piece core baked special oven which permits lowering the core directly into the oven from above. This plant devoted solely the pro- duction cast armor parts. BELOW MOLDING bay cast armor plant, show- ing open turret molds the foreground and molds for smaller pieces the background. the upper center sandslinger used for ramming large molds. BELOW RIGHT OURING tank turret mold with bottom pour ladle. Note the extensive clamping devices. WOR THE IRON AGE, January 1943—35 — | Segregated Production the war production program gains momentum alloy steel production scrap from turn- ings, borings, and also flashings, clippings and crop ends, becom- ing potential source alloying elements that the first magni- tude. WPB scrap segregation or- der, M-24-c, last June tak- ing renewed importance. This ruling will without doubt become more and more helpful the kinks the war production program are smoothed out. Already, two Bethlehem plants, one-third two-thirds all alloy- ing elements used are now being Other articles the reclamation and conservation metals appeared THE IRON AGE, Jan. 29, March 26,