The Iron Age 1934-08-23: Vol 134 Iss 8

Editor Managing Editor Consulting Editor News Editor Machinery Pittsburgh Detroit Boston Cleveland Chicago Editor Emeritus Washington Cincinnati Contents CODE Special Equipment for Machining Large Guns Creep Properties Oil-Still Tubes Open-Truss Steel Joist, Its Genesis and Future Power Requirements for Cold-Strip Rolling Investigates Performance Bearing Metals Personals and Obituaries Washington News Automotive Industry Markets Construction and Equipment Buying Products Advertised Index Advertisers 108 THE IRON AGE PUBLISHING COMPANY FRANK, President GRIFFITHS, Secretary BAUR, General Advertising PUBLICATION OFFICE: Corner Chestnut and Sts., EXECUTIVE OFFICES: 239 West 39th St., New York, Y., ADVERTISING STAFF Member, Audit Bureau Circulations Findley, 311 Union Bldg., Cleveland Member, Associated Business Papers Herman, 675 Delaware Ave., Buffalo, Hottenstein, 802 Otis Bldg., Chicago Published every Thursday. Subscription Price: Peirce Lewis, 7310 Woodward Ave., Detroit United States and Possessions, Mexico, Cuba, Charles Lundberg, Chilton Chestnut 56th Sts., Philadelphia, Pa. Cc. H. Ober, 239 W. 39th St., New York W. B. Robinson, 428 Park Bidg., Pittsburgh Sweetser, 239 West 39th St., New York Warren, Box 81, Hartford, Conn. EIGHTIETH YEAR SERVICE THE METAL WORKING INDUSTRY $6.00; Canada, $8.50, including duty; Foreign $12.00 a year. Single Copy 25 Cents Cable Address, ‘‘Ironage, for shaft, scan con- re- umps nged peed 10ve- ntly, ap- are IPM ined, ntrol the dard tons only ured ress, ving win- ress hy- nber fea- low sion the Page ESTABL tri medi: RYCASE indus and ment Willi dustr excef came Should You Using One These Newer Steels Rycase, comparatively new steel, was developed particularly for case hardening jobs where time, cost, and results all must considered. has its particular field usefulness. Other steels have theirs. New steels are constantly supplanting the old. most Does one these newer steels offer you better working qualities—tougher, stronger material—better finish—or lower costs? The Ryerson Special Steel Divisions will glad check for you. Experienced men will study your particular problem, furnish practical operating data and make suggestions that may lead economy and improvement. them for suggestions. Write for the Ryerson Steel Book, guide the most complete stocks, ready for immediate shipment. JOSEPH RYERSON SON, Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City the THE IRON AUGUST 23, 1934 4 | 7 7 7 arri CASE AUGUST 23, 1934 ESTABLISHED 1855 Vol. 134, No. Detroit Labor Revolts Against “Carpet matter history that the ink was not yet dry the President’s signature the National Indus- trial Recovery Act before the American Federation Labor set out its unionization campaign. im- mediately invaded communities such Pittsburgh and Detroit which had lived for years atmosphere industrial peace, saying the workers the steel plants and the automobile factories that the federal govern- ment, through Section the Recovery Act, was de- sirous having all labor organized. “Carpet baggers” was the name which Detroit applied these invaders. And carpet baggers they were, for William Collins, leader the motor car in- dustry, and his lieutenants, had real interest Detroit except might enhance their personal fortunes. They came southern Michigan overnight, established head- quarters and started function champions the workingman. These men, through their oratory and personal solici- tation, brought thousands workers into the Federation fold. The country had just gone through perhaps the most critical days its history. All things temporarily had lost their values. ‘Wages necessarily had sunk dis- tressingly low. Millions couldn’t get work any kind. The nation’s banks had failed the hundreds. Men seeing everything being stripped from them were bitter and became easy prey emotional appeals. play upon deep passions enabled these skilled union organizers have their inning. But every the time finally arrives when sound reasoning itself and the senses give way the logic the mind. one may judge rightly what occurring the ranks the Detroit, that time has for automobile workers. has remained for union men prominent the United Automobile Workers Federal Union, automo- tive affiliate the L., discover what out- siders has been apparent from the beginning. Arthur Greer, who has led the Hudson Motor local union out the Federation, quoted saying that Hudson work- ers objected the excessively high dues which they forced pay the Federation and the fact that thirty-five cents out every dollar dues went the national organization and was spent whatever way the national officers pleased. Over the protests Mr. Greer and his associates the direct the policies the federal automobile local unions. This council permitted discuss only matters brought before the chairman, who the personal repre- sentative President William Green. Says Mr. Greer, “This council controlled Federation clique that has grown more autocratic than democratic.” The executive council asked President Roosevelt re- cently remove Richard Byrd, labor representative the Automobile Labor Board. Mr. Greer and his fol- lowers think Mr. Byrd has been doing good job. appears that Mr. Byrd has the foolish notion that labor and management should and can work together amicably and governing his actions with that end view. This notion, course, hardly affords comfort organi- zation which thrives most when stirring class against class. uncertain language Mr. Greer states the funda- mental issue stake. reported have said, “We want the fair thing the Hudson manage- ment, and know they want fair us. But feel that the company does not want deal with persons not connected with the business and don’t blame them. want elect our own repre- sentatives from among our men and delegate them bargain with our employers. Outsiders, mat- ter how deeply they have their interests heart, cannot deal effectively with our employers ourselves can.” From the lips union worker comes the above acknowledgment the rightness principle for which management has contended since the troublesome Section came into being. BURNHAM FINNEY Detroit Editor, THE IRON AGE 3 2 Special Equipment Employed McCALL large caliber heavy machine tool equipment special design re- quired. machine efficiently guns These guns are built-up type, and are constructed shrinking sev- eral concentric layers hoops over central inner tube. The tube ex- tends the entire length the gun and the bore and the powder chamber. The long hoop that shrunk over the breech end the tube and extends well forward toward 10—The Iron Age, August 23, 1934 the muzzle called the jacket. Hoops shorter length are shrunk over the jacket, and other hoops over these jacket hoops, the number layers increasing toward the breech end the gun. Built-up guns are constructed the principle tensions.” The initial tension and compression set the different parts shrinkage causes them work together re- sist the pressure from the explosion, many these initial forces must entirely overcome before any stress resulting from the explosion pro- duced the parts the gun. The different parts the gun are forged from large ingots. Forgings EWSPAPER comment during the recent visit the com- bined fleets the United States Navy New York and other ports emphasized the impressiveness the large guns and other equip- Quite impressive, though un- sung newspaper columns, the mammoth machinery employed building these gigantic weapons defense. One the lathes de- scribed this article, for example, handles guns having outside di- ameter in. and length ft. The machine ft. long ‘ ip dri f p ‘ We large-scale and precise manufacturing operations—in steel mill and ma- chine shop—lie behind these awe-inspiring weapons defense. Beneath those the view opposite page stand President Franklin Roosevelt, Secretary the Navy Claude Swanson, and former Secretary the Navy Josephus Daniels. The occa sion was the recent review the combined United States fleets. The ship the USS. Indianapolis. (Wide World Photos. for the tubes are solid, but when the the carriage and rotating nut ring and weighs more than 420 tons; size the hole large enough, the fixed leadscrew. Independent om- alone, jackets and hoops are hollow forged. rapid power traverse provided ates driven 100-hp. motor, weighed The special machine tool equipment 5-hp. motor each carriage. This tons the rough. addition required for the rough and has maximum length machine tools for roughing and turning and boring ft. in. between centers and swings finishing the gun tubes, jackets jackets and hoops, and also for rifling in. over the carriages. sels and hoops large guns, Mr. the finished bore. the background Fig. may un- McCall describes equipment em- The machine the right fore- Bement center-driven double- the ployed for the important opera- ground Fig. Bement boring machine employed for tion rifling. Machining armor heavy roughing lathe for rough turn- rough boring large caliber gun tubes plate, related subject, ing operations large caliber gun from the solid. The forging de- was described the same author, driven motor clamped center driving head who has been identified with both and has four carriages, two the rotated 75-hp. motor. di- the design and manufacture front shears the bed and two ends the forgings are sup- such equipment, our issue the rear. carriage has inde- ported rotating steadyrests which long June page 23. pendent feed from the headstock are adjustable along the bed suit means spline shaft, change gears the length the forging. The ma- The Iron Age, August 23, Machining Large Caliber Guns . 4 Fig. 3—Hollow forgings for hoops and jackets are rough bored this special boring 12—The Iron Age, August 23, 1934 carr and max! Driv move move supp hung the The the bein; —Forgings for gun tubes are rough 1am and ig. 2—Hoop and jacket forgi orgings are rough turned 120 7 chine equipped with two 12-in. non- rotating boring bars bore simul- taneously from each end the forg- ing. Each bar will bore distance 37% ft. forging ft. long. addition, one the bars sufficient length bore 75-ft. hole from one end. The boring bars are held supports along the bed. They are clamped the rear supports prevent their rotation, and also provide feed and traverse when the support moved means nut screw the bed. Each screw driven 20-hp. feed and traverse motor. The opening the center driving head in. diameter, and the overall length the machine 204 ft. in. Machining Jacket and Hoop Forgings Fig. shows Bement 120-in. extra-heavy rough turning lathe for jacket and hoop forgings. has two carriages with front and back rests, and driven 100-hp. motor. The maximum distance between centers ft. and the swing over the car- riages The carriages are in- ing fed traversed 15-hp. motor mounted the carriage, which turns rotating nut fixed leadscrew. Fig. shown Bement 120-in. hollow-forging rough boring machine for boring large hoops with internal diameters 80.in., and jackets and hoops ft. length which are hollow forged with holes not less than in. diameter. The forg- ings are held the faceplate jaws and the steadyrest, the faceplate being driven 50-hp. motor. Bor- ing heads with different capacities are mounted 15-in. non-rotating bar which supported the spindle and the rear two sliding heads. The front head supports and clamp; ‘the bar, while the rear head carries the mechanism for feeding and trav- ersing the boring head along the bar. Driven 20-hp. motor, this mech- anism turns rotating nut fixed screw. The front end the screw fastened the boring head and moves along the bar the screw moves through the rotating nut. Roller Supports are provided for the over- hung portion the feed screw when the boring head moved the rear. The sliding heads are traversed along the bed 30-hp. motor, each head being provided with split nut engage screw the bed. Close-Limit Machining Required Before Assembling The three Bement 102-in. lathes pictured Fig. are for finish turn- and boring guns and their —— Th a turning and boring operations guns and their com- ponent parts are done these three 102-in. finishing lathes. This & & view component parts before and after each shrinkage operation. These ma- chines must capable very ac- curate work the parts are finished close limits before assembling. They have capacity for machining guns with bore in. and length ft. in. (55 calibers). The faceplate these lathes driven 75-hp. motor. The two which are identical, slide the shears the bed. Carriage feed gears are driven long square shaft which transmits also shows the rifling the feed from the headstock. Longi- tudinal feed along the bed obtained rotating nut fixed lead- screw parallel the square feed shaft. Transverse feed the cross- slide and feed the tool-holders for any angular position the tool-slide are also provided. Swing arms and change gears are furnished for cut- ting large number tapers. Lon- gitudinal and transverse feeds are used simultaneously obtain the tapers. Change gears are also pro- vided for thread chasing. Rapid The Age, August 23, 1934—13 - 5—This 120-in. finish turning and boring lathe has capacity for 20-in. has length 212 ft. The faceplate alone weighed tons the rough. power traverse for all carriage move- ments obtained from 15-hp. mo- tor, mounted the carriage which interlocking with and through the feed mechanism. The tailstock removed during boring operations. Steadyrests are used support the work. boring bench mounted the two rear bed shears. feed and traverse box attached the for- ward this bench and extends over the front bed shear. Boring bar feeds are obtained from the square feed shaft and suitable feed change gears the box which turn screw the top the boring bench. nut the boring-bar drive box the rear gives the necessary motion the boring bar. The front boring bar support stationary the bench while the others move varying speeds and maintain support for the bar equal distances. Boring Bar Has Power Traverse Rapid power traverse for the boring bar provided 20-hp. motor mounted the boring-bench feed box, which interlocking with and operates through the feed mechanism. This motor also turns rotating nut the fixed leadscrew and thereby provides rapid movement the en- tire boring bench along the bed. 25-hp. motor, mounted the boring-bar drive box, drives the spin- dle the box which line with the boring bar. Clutch teeth are cut this spindle for attaching and driving the boring bars. Several sets bushings for the boring bar sup- ports are provided for boring bars Iron Age, August 23, 1934 different diameter. The boring bar supports have angular caps which are hinged and counterweighted. When the gun bore calipered with star gage, the boring bar trav- ersed from the gun, the caps are opened, and after the bar un- fastened from its driving spindle, rolled out the way the flanges the bushings which roll tracks The star gage long, hollow brass tube with head the for- ward end having three radial points tempered steel which can moved and out longitudinal movement rod the tube. Movement the radial points actuated wedge the rod, and the longitudinal move- ment the rod swings pointer the rear the brass tube which in- dicates the diameter. 7 tha 2 — bor era Fi g gur ft. bed wid mal sho mo\ erec 7 | leac eac mac UN long The E ti ng The boring bar may clamped that does not rotate during the boring operation; may ro- tated obtain proper relative speed for boring the same time the spin- dle being rotated speed suit- able for turning operations. Lathe With Capacity for Guns Having 20-In. Bore After the gun has been completely this type and finish bored and cham- bered. bushing, sometimes made hard wood, turned the diameter the finished bore mounted the tool-holder directly behind the boring tools and forms moving sup- port for the front end the boring bar. Bement lathe the same gen- eral design, but larger, shown Fig. This lathe will machine gun with bore in., outside ft. has swing 120 in. over the bed, overall length 212 ft. and weighs 842,000 The bed 205 ft. in. long and made seven sec- tions, four which are ft. in. wide with three shears, and the re- maining three are ft. in. wide with two shears. Fig. does not show the entire length the machine the rear bed section had been re- moved clear railroad track the erecting shop. The fixed leadscrew the bed in. diameter, pitch, 3-in. lead. 114 ft. length and made two sections and bolted to- gether. The boring bench 101 ft. long and was cast three sections. The boring bar not shown this illustration. Each carriage weighs tons, com- plete, and the rough steel casting for the faceplate weighed tons. The faceplate rotated 100-hp. motor. When the assembled gun has been finish bored, set the bed rifling machine with the muzzle toward the rifling bar. Rifling system spiral grooves cut into the surface the finished bore the gun, the purpose which im- part spinning motion the projec- tile and prevent its end over Equipment for Rifling shown Fig. the cutter head with the grooving tools mounted the front end the rifling bar, and provides moving support for the bar the bore the gun. These cutter heads are made with provision for collapsing the tools after the cut- ting stroke clear the work during the return stroke. They also have mi- crometer adjustment for setting the tools the depth the grooves. the rifling bar moved through the bore also rotated the proper amount that the combined motions translation and rotation will give 7—Liner positioned for assembly over the shrinkage pits the required twist the grooves. some guns the rifling has constant pitch uniform twist, while others has gradually increasing twist the muzzle approached. the upper right-hand part Fig. may seen Bement rifling machine for guns 16-in. bore. The rifling bar position the bar bed, the left which the former bench with the former bar place. The cutter head and rifling bar are driven through the gun 35-hp. motor which rotates screw extending the length the bar bed. The bar moved its rear support which nut attached. The front 4 = a? 4 ii, support stationary and the inter- mediate supports are moved vary- ing speeds maintain supports for the bar equal distances moves forward. long arm extends from the rear support over the serving housing for sliding rack. The former bar set (Concluded Page 68) The Iron Age, August 23, 1934—15 nen av- are un- ges low ished oil-still tubes rather than from bar stock simi- lar composition, Howard Cross, metallurgist, Battelle Memorial In- Columbus, Ohio, and Johnson, assistant chief metallurgical engineer, Republic Steel Corpn., Mas- sillon, Ohio, recently made ex- tended investigation creep proper- ties. They contributed the results their tests the American Society for Testing Materials, and their paper large part was follows: Tubes Made from Two Heats Steel The steels used were the per cent chromium, 0.50 per cent molybdenum type and two differ- ent carbon contents. The analyses the other alloying elements were duplicated closely possible. Two heats were melted the plant the Republic Steel Corpn., using 6-ton electric furnace and normal melting practice. The melts were cast 20-in. round Gathmann type ingot molds. The ingots weighed ap- proximately 4750 each. The ingots were rolled into blooms and then 5%-in. rounds. The bars were sent tube manufacturer and fabricated into still tubes in. O.D. and in. wall thickness. normal practice the tube manufacturer an- neals the still tubes, but this case the tubes were returned Republic without annealing permit varia- tions heat treatment. Numerous chemical analyses the two materials gave the results here tabulated. COMPOSITION THE STILL MATERIAL Steel Steel Carbon, per cent..... 0.139 0.181 Manganese, per cent.. 0.38 0.40 Sulphur, per cent...... 0.015 0.014 Phosphorus, per cent... 0.017 0.015 Silicon, per .... 0.35 0.35 Nickel, per cent........ 0.23 0.26 Chromium, per cent. 4.63 4.96 Molybdenum, per ce nt. 0.54 0.49 Blanks for preparation longi- tudinal and transverse test specimens were cut from the finished tubes. SERS oil still tubes, the per cent chromium and per cent molybdenum class steel, and for that matter the whole the growing numbers steel buyers interested the be- havior steels elevated tem- peratures, were given quantitative information the meeting the American Society for Testing Ma- terials Metallurgist Cross, the Battelle Memorial Metallurgical Engineer Johnson, the Republic Steel Corpn. Creep resistance was found in- creased materially increase the carbon content. Better creep properties were obtained from slow cooling in’ the heat treatment than from normalizing, other things being equal. The findings the main are reported the accompanying extended re- view the ioint paper these investigators. obtain the short lengths were cut from the still tube, slit lengthwise, heated about 1700 deg. and flattened, admittedly introducing further deformation but not very severe deformation compared that involved making the Five Different Heat Treatments The major portion the test data was obtained the steels given the normal annealing treatment. The controlled cooling rate from 1500 deg. 1300 deg. was for the purpose duplicating the small blanks the cooling rate normally at- tained cooling large mass, such still tube. The other heat treat- ments used were evaluate the ef- fects various annealing tempera- tures, rates cooling, grain size, and structure upon the creep and other mechanical properties determined. The heat treatments used were follows: C—Normal annealing treatment. 1550 deg. F., hr.; furnace cool 1500 deg. F.; then deg. per hr. 1300 deg. F.; then furnace cool 1000 deg. F.; then air cool. 1425 deg. F. for 6 hr., then furnace cool. B—1550 deg. F., hr.; air cool; reheat 1425 deg. for hr.; then furnace cool, D—2100 deg. F., hr.; air cool; reheat 1425 deg. for hr.; then furnace cool. E—2100 deg. F., hr.; furnace cool 1500 deg. F.; then deg. per hr. 1300 deg. F.; then furnace cool 1090 deg. F.; then air cool. The annealing treatment differs from the reheating for hr. 1425 deg, The reheating 1425 deg. was required the normal- ized samples reduce the hardness Fig. 100 diameters, reproduced two-thirds original size; etchant, per cent nital Steel 11D: Normalized from 2100 deg. and reheated hr. 1425 deg. 16—The Iron Age, August 23, 1934 Steel Slow cooled from 1550 deg. 2100 deg. Steel IE: Slow cooled from Steel Slow cooled from 2100 deg. ment teris with Thes ferer struc and Thes indic coole treat the from deg. porti ture slow temp 4 paris paris struc test In per Still Tubes comparable values with the slow- cooled samples without changing the grain size resulting from the initial treatment. For comparison this re- heating treatment was also added the treatment. The annealing treatment differs from the initial heating tempera- ture 2100 deg. instead 1550 deg. This treatment afforded op- portunity study the effect struc- ture and grain size resulting from slow cooling from the higher initial temperature, The and treatments are nor- malizing treatments affording com- parison with slow cooling treatments and from the same initial tem- peratures. They also permit com- parison the effect the different structures and increased grain size resulting from the two initial tem- peratures. The identification the various test specimens shows the steel num- ber II, the heat treatment test specimen the still tube (longi- tudinal transverse and the specimen number etc. Thus indicates that specimen from steel No. (higher carbon heat), given the heat treatment, was transverse specimen, and was the fourth specimen its series. the examination specimens for microstructure the etchant was per cent nital. Fig. are shown photomicrographs steel IIC with the normal annealing treatment and steel IID with normalizing treat- ment. These structures are charac- teristic treatments and and and respectively. Fig. are also shown photo- micrographs steels and IIE with slow cooling from 2100 deg. These structures are decidedly dif- ferent from those obtained any the other four heat treatments. The Structure decidedly non-uniform, and large pearlitic areas are present. These are more clearly shown the higher magnifications Fig. Steel IIC clearly shows shading, indicating properties. Fig. 2—Photomicrographs 500 diameters, reproduced two- thirds original size; etchant, per cent nital 45 Steel Steel Slow cooled from 1550 deg. Steel Steel Slow cooled from 1550 deg. and reheated hr. 1425 deg. Steel Slow cooled from 2100 deg. Fig. 3—Photomicrographs 100 diameters, reproduced two- thirds original size; etchant, per cent nital Steel Steel Normalized from 1550 LASS: fi ‘ v — Steel Steel Normalized from 2100 deg. The Iron Age, August 23, 1934—17 3 - - ol. 7 Steel eat 7 ace Paes, ished oil-still tubes rather than material from bar stock simi- lar composition, Howard Cross, metallurgist, Battelle Memorial In- stitute, Columbus, Ohio, and Johnson, assistant chief metallurgical engineer, Republic Steel Corpn., Mas- sillon, Ohio, recently made ex- tended investigation creep proper- ties. They contributed the results their tests the American Society for Testing Materials, and their paper large part was follows: Tubes Made from Two Heats Steel The steels used were the per cent chromium, 0.50 per cent molybdenum type and two differ- ent carbon contents. The analyses the other alloying elements were duplicated closely possible. Two heats were melted the plant the Republic Steel Corpn., using 6-ton electric furnace and normal melting practice. The melts were cast 20-in. round Gathmann type ingot molds. The ingots weighed ap- proximately 4750 lb. each. The ingots were rolled into blooms and then 5%-in. rounds. The bars were sent tube manufacturer and fabricated into still tubes in. O.D. and in. wall thickness. normal practice the tube manufacturer an- neals the still tubes, but this case the tubes were returned Republic without annealing permit varia- tions heat treatment. Numerous chemical analyses the two materials gave the results here tabulated. material taken from fin- TERIAL Steel Steel No. Carbon, per cent..... 0.139 0.181 Manganese, per cent.. 0.38 0.40 Sulphur, per cent...... 0.015 0.014 Phosphorus, per cent... 0.017 0.015 Silicon, per cent.. 0.35 0.35 Nickel, per cent........ 0.23 0.26 Chromium, per cent.... 4.63 4.96 Molybdenum, per cent. 0.54 0.49 Blanks for preparation longi- tudinal and transverse test specimens were cut from the finished tubes. Creep Properties Oil- SERS oil still tubes, the per cent chromium and per cent molybdenum class and for that matter the whole the growing numbers steel buyers interested the be- havior steels elevated tem- peratures, were given quantitative information the meeting the American Society for Testing Ma- terials Metallurgist Cross, the Battelle Memorial Metallurgical Engineer Johnson, the Republic Steel Corpn. Creep resistance was found in- creased materially increase the carbon content. Better creep properties were obtained from slow cooling heat treatment than from normalizing, other things being equal. The findings the main are reported the accompanying extended re- view the paper these investigators. obtain the short lengths were cut from the still tube, slit lengthwise, heated about 700 deg. and flattened, admittedly introducing further deformation but not very severe deformation compared that involved making the Five Different Heat Treatments The major portion the test data was obtained the steels given the normal annealing treatment. The controlled cooling rate from 1500 deg. 1300 deg. was for the purpose duplicating the small blanks the cooling rate normally at- tained cooling large mass, such still tube. The other heat treat- ments used were evaluate the ef- fects various annealing tempera- tures, rates cooling, grain size, and structure upon the creep and other mechanical properties determined. The heat treatments used were follows: C—Normal annealing treatment. 1550 deg. F., hr.; furnace cool 1500 deg. F.; then deg. per hr. 1300 deg. F.; then furnace cool 1000 deg. F.; then air cool. 1425 deg. for hr., then furnace cool. B—1550 deg. F., hr.; air cool; reheat 1425 deg. for hr.; then furnace D—2100 deg. F., hr.; air cool; reheat 1425 deg. for hr.; then furnace cool. E—2100 deg. F., hr.; furnace cool 1500 deg. F.; then deg. per hr. 1300 deg. F.; then furnace cool 1090 deg. F.; then air cool. The annealing treatment differs from the reheating for hr. 1425 deg, The reheating 1425 deg. was required the normal- ized samples reduce the hardness Fig. 100 diameters, reproduced two-thirds original size; etchant, per cent nital Steel Normalized from 2100 deg. and reheated hr. 1425 deg. Iron Age, August 23, 1934 Steel 11C: Slow cooled from 1550 deg. 2100 deg. Steel IE: Slow cooled from Steel Slow cooled from deg. coole grail treat the from ture sti ment with Thes feren the struc and highe Ste indic deg. porti ture slow temp paris paris struc test q hes : test tudir J from heat) was 7 7 the 4 Still Tubes comparable values with the slow- cooled samples without changing the grain size resulting from the initial treatment. For comparison this re- heating treatment was also added the treatment. The annealing treatment differs from the initial heating tempera- ture 2100 deg. instead 1550 deg. This treatment afforded op- portunity study the effect struc- ture and grain size resulting from slow cooling from the higher initial temperature. The and treatments are nor- malizing treatments affording com- parison with slow cooling treatments and from the same initial tem- peratures. They also permit com- parison the effect the different structures and increased grain size resulting from the two initial tem- peratures. The identification the various test specimens shows the steel num- ber II, the heat treatment test specimen the still tube (longi- tudinal transverse and the IIC-T4 indicates that specimen from steel No. (higher carbon heat), given the heat treatment, was transverse specimen, and was the fourth specimen its series. the examination specimens for microstructure the etchant was per cent nital. Fig. are shown steel IIC with the normal annealing treatment and steel IID with normalizing treat- ment. These structures are charac- teristic treatments and and and respectively. Fig. are also shown photo- micrographs steels and IIE with slow cooling from 2100 deg. These structures are decidedly dif- ferent from those obtained any the other four heat treatments. The Structure decidedly non-uniform, and large pearlitic areas are present. These are more clearly shown the higher magnifications Fig. Steel IIC clearly shows shading, indicating properties. Fig. 2—Photomicrographs 500 diameters, reproduced two- thirds original size; etchant, per cent nital be ae Vowel hy ag Steel Steel Slow cooled from 1550 deg. Steel Steel Slow cooled from 1550 deg. and reheated hr. 1425 deg. Steel Slow cooled from 2100 deg. Fig. 3—Photomicrographs 100 diameters, reproduced two- thirds original size; etchant, per cent nital Steel Steel Normalized from 1550 deg. Steel Normalized from 2100 deg. The Iron Age, August 23, 1934—17 — pat ace 7 q THREAD 2.063" Otherwise the structure quite uni- form and the grains well defined. Steel IID (Fig. shows non- uniform structure due the local softening the hard areas when re- heated 1425 deg. Steels and IIC show well de- fined grain, and the difference amount carbide the two steels apparent. Steels and IIA show little, any, effect due the additional hr. heating 1425 deg. subsequent treatment exactly the same and Fig. are shown photomicro- graphs 500X the steels both 1000 LBS PER STRENGTH ULTIMATE STRENGTH BREAKING STRENGTH LBS. PER carbon contents with normalizing treatments followed reheating 1425 deg. The non-uniformity structure steels and IIB com- pared with steels and IIA clearly shown. Steels and IIB were normalized from 1550 deg. F., while steels and IIA were slow cooled from 1550 deg. F., and both were reheated 1425 deg. for hr. Steels and IID normal- ized from 2100 deg. also show non-uniform structure, but with much larger grain size than for and IIB normalized from 1500 deg. The structures shown Fig. indicate the possibility ELONGATION IN. REDUCTION AREA PER CENT TEMPERATURE DEGREES 5—What the tensile tests show room temperature and temperatures 1000, 1100 and 1200 deg. F., for the per cent chromium and 0.50 per cent molybdenum steel tube; steel having 0.139 per cent carbon and steel 0.181 per cent carbon; slow cooled from 1550 deg.; longitudinal specimens tube material and transverse specimens. Iron Age, August 23, 1934 a 4—Test specimen used the short-time tensile tests elevated temper- atures and the creep tests. structural changes taking place with- the grains due either the nor- malizing treatment during the re- heating 1425 deg. Test Specimen for Short Time Tests standard 0.505 in. diameter test specimen was used the room tem- perature tensile tests. The yield point was determined the drop the beam. few room-temperature tensile tests and all the short-time tensile tests elevated temperatures, well the creep tests, were made section. Fig. shows the details the test specimen used. This type test specimen was chosen because was desired test representative sec- tion tube wall. The tube wall thickness was the direction the 0.51 in. dimension, beginning with tube 0.625 in. wall thickness, about 0.055 in. has been machined off each side obtain the finished test specimen with 0.2 sq. in. section. The short-time tensile tests bars, with rectangular section were made Amsler hydraulic testing ma- chine 72,000 lb. capacity. The pull-adapters were fitted with spheri- cal seats assist obtaining axial loading. The heating furnace used the short-time tests in. long, gap wound, and provided with taps per- mit regulation the current vari- ous sections the winding obtain the desired temperature uni- formity along the gage length the test specimen. temperature survey the furnace was made according the methods recommended the A.S.T.M. tentative method test, E21-33T. The thermocouples the outside the gage length were at- tached spot welding. Data Creep Tests The time-deformation curves for the creep tests 1100 and 1200 deg. were deg. the The mens was tion were | loads difficu The curves the total 10,000 tained deforn ter pend elongat rates the carbe terial 5 ” ‘ o ~! TABLE Treat \ | ‘ | \ B. Ss. 7, NS Z| 60 EL. for deg. 10. The majority the creep tests were made 1100 deg.; tests 1200 deg. were made the steels with the treatment one load only. The omission the points the time-deformation curves mens IIC-L6 and IIC-T4 Fig. was due trouble with the tion measuring equipment. The tests were continued, the temperatures and loads maintained meanwhile, and the corrected. curves signifies the inside surface the still tubes. Fig. are shown data for the total deformations calculated re- sult from the various stresses 10,000 hr. These values were ob- deformation curves the same rate elongation existed over the lat- ter part the test period. This method gives lower stress than the TABLE I—Stresses for Per Cent Deforma- tion 10,000 Hr. for Steels Given Annealing Treatment and Tested 1100 Deg. Secondary Rate Total Steel Elongation Deformation 4200 4100 Ic-T 3850 5800 5170 5100 1IC-T 4850° 1850 stress producing secondary elonga- tion rate the same magnitude, since the values for total deformation de- pend the magnitude the initial elongation well the secondary rates elongation. However, the stresses for per cent 10,000 hr. LBS. a & Fic. 7—Creep tests 1100 deg. for the 0.181 per cent carbon still-tube ma- terial, slow cooled from 1550 deg. DEFORMATION PER CENT SO IN 10000 LB Ic-t3 FOR 10000 HOURS DEFORMATION PER CENT s. $Q.! Ic-T3 3250 LBS. 800 1000 1200 1400 TIME HOURS Fig. 6—Creep tests 1100 deg. for the 0.139 per cent carbon still-tube material, slow cooled from 1550 deg. are nearly the same, using both methods shown Table (Table VII original paper). Fig. and Table show that steel with 0.181 per cent carbon showed superior creep resistance, with only one exception compared with steel with the slightly lower carbon con- tent 0.139 per cent. There difference creep resistance about 800 1000 per sq. in. between the two steels. load 3000 per sq. in. occurred the only instance which steel (treatment showed lower rate elongation than steel II. The tests showed that the longi- tudinal specimens possessed better resistance transverse specimens, given the same heat treat- ment. The difference properties was small, however, and shown Table the stresses for per cent 10,000 hr. varied only 300 per sq. in. less than per cent. For comparing the effects the various heat treatments, creep tests were run one load only, estimated produce deformations per cent 10,000 hr. For steel the tests were run 5250 lb. per sq. in. and for steel 6060 per sq. in. Table and Fig. show the total 1000 1200 1400 HOURS The Iron Age, August 23, st ” | | | er- } » | | | | | | | | 200 sts est m- eld est est the off test ars, ma- eri- gap DEFORMATION PER CENT FOR 200 400 600 800 1000 1200 HOURS 8—Creep tests 1100 deg. the still-tube material for both carbons, the heat treatment these cases being normalizing from 2100 deg. and reheating for hr. 1425 deg., comparing behavior the longitudinal and transverse specimens; the shift the zero displace the curves noted. TABLE Per Cent Total Deformation 10,000 Hr. 1100 Deg. per sq. in.—Steel I.... 4.31 5.31 0.39 5.53 Stress—6060 Ib. per sq. 2.61 0.59 4.51 DEFORMATION PER CENT 200 400 600 800 1000 1200 deformation estimated result 10,000 hr. The creep resistance the speci- mens given the and treatments seem about equal. Apparently the reheating 1425 deg. hr. the treatment has had little effect creep properties. This particu- lar interest, for indicates that service short periods overheating would cause little effect the creep properties materials given the treatment. This was expected, since the photomicrographs showed little difference between the two treatments, The specimen given the treat- ment (normalized from 1550 deg. F., hr. 1425 deg. F.) showed the poorest creep resistance. This indicates slow cooling rather than fast cooling preferred obtain best creep properties the per cent chromium, 0.50 per cent molybdenum steel. The specimen given the treatment (normalized from 2100 deg. F., re- heated hr. 1425 deg. F.) showed better creep resistance than treatment normalized from the lower tem- perature. However, its sistance was not equal that given the normal anneal Since the large grain resulting from treatment gave better creep re- sistance than treatment was thought advisable determine the creep resistance several specimens slow cooled from 2100 deg. with the thought that better creep re- sistance might obtained than from treatment due the higher heat- ing temperature. This has proved the case, for the time-deformation curves shown Fig. and the data 9—These creep curves make com- parison heat treatment (slow cooling from 1550 deg. and reheating for hr. 1425), heat treatment ing from 1550 deg. and reheating hr. 1425) and heat treatment (slow cooling from 2100 deg.) treati four that super The better deg. coolin perat would impac that were struct Physi Phe creep mens IIC-T loade tre tend Since testec < 7 HOURS 20—The Iron Age, August 23, 1934 These curves show the creep test results 1200 deg. with the specimens slow cool- from 1550 deg. DEFORMATION PER CENT Table indicate lower rate -elongation for specimens given the treatment than for any the other four treatments. However, should kept mind that this treatment produced very low impact resistance which would prohibit its use regardless its superior creep resistance. These data suggest that possibly better creep resistance than produced treatment (slow cool from 1550 deg. F.) could secured slow cooling from somewhat higher tem- perature than 1550 deg. F., which would not the same time affect the impact resistance the material ap- preciably. should borne mind that the excessively high temperatures were used only produce maximum structural differences that good comparisons could made. Physical Properties After Creep Test Photomicrographs were made after creep test the structure speci- mens IC-T3 (1346 hr. 1100 deg. loaded 3250 Ib. per sq. in.) and (1596 hr. 1100 deg. loaded 4800 lb. per sq. in.) There was detectable change the mi- crostructure from that shown Figs. and for the two steels with the treatment before test. This was expected, since slow cooling should tend produce stable structure. Since differences were noted, the Photomicrographs are not shown. Short-time tensile tests were made four longitudinal specimens the Same temperature which they were tested for creep. There were only small reductions yield and ultimate TIME HOURS strengths and ductility values. These data further indicate the stability the two steels given the treatment. Izod impact tests using both key- hole and “V” notches were made specimens all treatments after creep test. The “V” notch seemed more selective, that indicated greater differences than the key-hole notch. Loss impact resistance was less than per cent for longitudinal and transverse specimens both steels with treatment tested with key-hole notch after creep test 1100 deg. larger reduction was noted when using the notch, but the material still showed good ductility. For trans- verse specimens, whose initial impact resistance was lower than for longi- tudinal specimens, for steel the drop was from ft.-lb. and for steel For treatment steel dropped from 104 83, and steel from 101 ft.-lb. after creep test 1100 deg. After creep test 1200 deg. both steels showed impact resist- ance about ft.-lb. compared with original values 71-76 ft.-lb. Specimens both steels given the treatments show practically (Concluded Page 68) TOTAL will the per cent chromium and 0.50 per cent still-tube the heat treatment given it, letters explained the text. PER CENT 10000 HOURS The Age, August 23, ents the ie A ting tain 200 400 600 800 1000 1200 1400 nent was the nens with dto data creep com- from naliz- 1425) IRST utilizing sheets basic material (and early 1855), metal joists—signifying that term substitute for wooden beams—did not really get under way until about ten years And this later development, the em- phasis has been placed form construction that does not much seek displace wood aimed satisfy demand that does not require primarily the weights and strengths existing shapes. the growth succeeding, the product the sheet mill has part given way the product the bar mill, and this because small mea- sure electric welding was being turned into constructing tool unusual flexibility. The open-truss joist steel bars assembled with the help welding believed have expanding future even the purely construction wood undoubtedly account for the first use the primitive forms steel joist, and tracing the de- velopments shall see how the mod- ern, approved type resulted. Historically, the first known use metal joist construction was the five-story Bank the State New York Building, formerly located William Street near Wall Street, New York. James Renwick was architect this building, which was erected 1855 and taken down 1903. The metal joists were made wrought iron and the floor design was shown Fig. When the building was demolished the sections were ex- cellent condition, and photographs plainly show the original shop marks. For complete report, see the Engi- neering News, Sept. 10, 1903. From 1885 1895 various other sections were designed, shown ‘in Fig. and Fig. These were all made from sheet steel and, therefore, limited short spans. the case the Chicago joists, the angles were bolted back back and there were lower flanges. angles were bolted along the web. Corrugated steel sheets were fastened top the joist means nails driven into the joint between the webs. Concrete was laid top the corrugated sheets and metal ceil- ing carry plaster was hung from the joist. This construction was used August 23, 1934 Steel A\nd known the Renwick joist was used the Bank the State New York building erected 1855 William Street and Exchange Place, New York, and razed 1903. Wood IG. 2—The St. Louis joist, made from No. gage sheets, was used number buildings St. Louis, particularly partitions, from 1887 1890 20-Gage Sheets 3—The Chicago joist, patented and manu- factured Chicago from 1887 1893, used stiffening angles prevent buckling the web and help take diagonal stresses Riveted Riveted Spot Welded Spot Welded Junior Beam Fig. 4—The forms strip steel joists, leading the development the junior rolled steel beam | Ny ay Ng « | | Wood and Plastered Ceiling Plate i ‘tt aN Fig J Vil F he: Joist, Its Genesis Future WARREN TRUSS TYPE PRATT TRUSS TYPE 6 Fig. 5—-The design the open-truss joist follows along the lines long used for built-up structural steel trusses Fig. used various designs open-truss uses plain round bar throughout top chord has two angles but other members are plain round bars top and bottom chords are angles and the web plain round bars uses special twin tee section top and bottom, with round bars for the web uses tee section for top and bottom chord and plain round bars for the web uses special for the top chord, pressed metal bottom chord section and plain round bars for the web Clearance | te ~ p Overall Length 7—The expanded |-beam, made + and then opening the slits, typified the Kalman > GEORGE PINGER General Superintendent, Concrete Steel New York quite extensively Chicago between 1901 and 1905. Attempts market these various sections were only local, and because short lengths sheets available, little progress was made. Increased production facilities for the manufac- ture sheet metal and improved equipment for working this material caused the Berger Mfg. Co., Canton, Ohio, start the making sheet steel joist 1908. The Berger joist was designed shown Fig. 4-A, and was made entirely from Nos. and gage sheet steel brake (bending machine). Sections over ft. long had spliced, which was expensive operation and gave period from 1908 1917 some im- provements were made toward in- creasing the unspliced lengths ft. About 1915 the roll forming method making the sheet steel joist plus the coming widened strip steel accelerated its production. further interesting follow the development sheet steel joist reference paper read before the American Iron and Steel Institute “Sheet Lumber.” One paragraph will show the tendency that date and also that the steel mills were begin- ning recognize the growing de- mand for this product. “Steel Lum- ber consists light structural members the form I-beams and channels approximately one-third the weight standard sections equal depth and primarily designed fulfill the function wooden joists and studs.” The sections shown Fig. made from strip steel formed shape and either riveted spot welded together when used joist floor construc- tion, reduced the dead weight the floor construction lb. com- types fireproof construction. Build- ings light floor load design were built various parts the country using the sheet metal joist, was labeled one The -extensive use the “metal lumber” led the perfection rolling mill for the production “Junior Beams,” Fig. 4-E, which the thickness flanges and web was less than and the weight per foot approximately the The Iron Age, August 23, 1934—23 same the built-up sheet metal From this see the recog- nized demand for light weight steel section which could produced either fabricating strip steel direct rolling the steel mills. Meanwhile the solid I-beam type steel joist met with restrictions building codes that did not allow until very assembled from standard rolled bars, angles and sections which can readily produced bar mills. The products these mills are fabricated shops especially arranged pro- duce “steel joist.” The design the open truss joist follows along the same lines used structural engineers used for floor filling between the main supporting girders, beams walls.” There are about dozen fabricators steel joist now operating, and all the members the Institute make their product conform the In- stitute specifications, that archi- tects and engineers have dependable data for use design, much similar Properties and Allowable Total Loads Pounds per Linear Foot accordance with Simplified Practice American Institute Construction Stresses. Steel Joist Institute Designation Depth Inches Resisting Moment Inch Pounds Maximum End Re- action Pounds 178 214 145 130 116 139 187 137 164 213 STEEL JOIST INSTITUTE STANDARD Open Web Steel Joists Adopted Steel Joist Institute Aug. 20, 1929. 260 240 236 184 170 212 288 174 215 236 127 158 196 241 215 116 145 179 221 197 recently steel for structural use less than 6/16 in. thick. “About 1923,” says Rudolph Miller, the Quarterly for October, 1931, the National Fire Protection Association, “the Massillon Bar Co. (later, the Macomber Steel Co.) abandoned the manufacture the strip joist and introduced the open-truss joist, which has since be- come the generally accepted type.” For the past years, following the general acceptance architects and engineers the joist,” there has taken place notable development its manufacture and use. This product sometimes called “bar joist” for the reason that 24—The Iron Age, August 23, 1934 structural steel trusses, except that the connections for the various mem- bers are held together either the electric pressure weld arc-weld process, place using gusset plates and riveted joints. Fig. 1928 various companies manu- facturing steel joist organized the Steel Joist Institute, with headquar- ters Detroit, and Feb. 1929, the Steel Joist Institute issued its standard specification for steel joist which was prepared Frank Bur- ton after months study. The term steel joist (as defined the Institute specifications) means “any steel beam truss-shaped steel member suitable