The Iron Age 1941-04-03: Vol 147 Iss 14

2 CANTON, APRIL 1941 APp Fuse Setter Reduced Hour the Frankfort Arsenal Philadelphia, machining fuse setter for shells for three-inch anti-aircraft gun was formerly eight-hour opera- tion. new Warner Swasey Turret Lathe cut the time one hour. Stepping production 700% and holding close tolerances timely example how Warner Swasey Turret Lathes and Tools are contributing the program national defense. you face turning problems defense work, Warner Swasey engineers can offer valuable suggestions. Write You CAN TuRN BETTER. FASTER. FOR LESS...WITH WARNER SWASEY a a 4 f = j 4 @ e**ee Editorial Technical Articles Heat Treatment with Salt Plymouth Improves Handling Small Three Phase Process Spot Welding Report Tool Engineers’ Convention ................ Features News and Market Reports oO News Industry Machine Tool Activity Personals Non-Ferrous Market 117 Scrap Market and Prices 118 VOL. 147, NO. The Industrial 110 Warehouse Prices 128 District Market Reports 112 Sales Possibilities 130 BAUR Vice-President and General Manager Copyright, 1941, Chilton Company Managing Editor News Editor Technical Editor Machine Tool Associate Editor Editor WINTERS DIX, Manager Reader Owned and Published Art Editor CHILTON COMPANY Washington Editors ncorporated) Advertising Staff MOFFETT JAMES ELLIS Publication Emerson Findley Editorial and ice Robert F. Blair } 21 Union Bldg., Cleveland Executive Offices Chestnut CAMPBELL HERMAN KLEIN Pittsburgh Chicago Cleveland Detroit Editorial Correspondents Buffalo Cincinnati FRAZAR CHARLES POST Boston San Francisco HUGH SHARP Milwaukee SANDERSON Toronto, Ontario JOHN McCUNE Birmingham ROY EDMONDS St. Louis LEROY ALLISON Newark, Herman, Chilton Bldg., Philadelphia Hottenstein, 1012 Otis Bldg., Chicago Leonard, 100 East 42nd St., New York Peirce Lewis, 7310 Woodward Detroit Ober, 100 East 42nd St., New York \428 Park Pittsburgh Don Harner, Pacific Avenue, Long Beach, Cal. Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price: United States and Possessions, Mexico, Cuba, $6.00; Canada, $8.50; Foreign, Single copy, cents. 100 East 42nd St. Philadelphia, Pa. New York, U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, Vice-President GEORGE GRIFFITHS, Vice-President EVERIT TERHUNE, Vice-President VAN DEVENTER, Vice-President BAUR, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY CHARLES HEALE we ’ a Jil - | 4 takes SKILL and EXPERIENCE produce Machine Bases like these Welded Steel Machine Bases, produced Mahon, pos- sess that sturdy strength and smooth, finished appearance which adds greatly the sales value the machines for which they serve foundation. The reason lies the skill the men who make them and the excellence the equipment with which they work. Mahon craftsmen have knowledge steel plate fabrication which comes only from long experience. you want Machine Bases with that greater ACCURACY and finer APPEARANCE which matches the machines they support, get touch with Mahon engineers. Send blueprints for quotations. THE MAHON COMPANY Detroit, Michigan Manufacturers Machine Bases and Many Other Steel Products These reproductions from un- retouched twe entirely different types welded Machine Bases produced Mahon give you some idea the smooth, clean-cut appearance and ac- curacy detail that pos- sible, when expert 28—THE IRON AGE, April a = = ‘ y ESTABLISHED 1855 The “All Out” UST few days ago, the President the United States appealed his countrymen unite effort mobilize the resources this country for national defense and aid the democracies. few days later, William Knudsen, senior-half head the OPM, made this appeal even more specific asking for per cent increase the industrial productivity rate. Books have been written about words and phrases, particularly the modern “slogan” expressions that are designed inspire action. The authors these books have clearly shown that the same word phrase may have entirely different meanings different individuals. think safe say that this very modern phrase “all out” inter- preted least per cent our American citizens mean just one thing. And that that every one us, matter what our position life, must exert every effort forward the program that has been set for through majority mandate. That must buckle down business, forgetting the normal ambitions for personal gain and advancement and make every minute count for production. “Time,” Mr. Knudsen tells us, what have work with and there may not enough it.” Unfortunately, there minority this country that has accepted the mandate its old fashioned and not its modern sense. For “all has been the strike slogan and command this country labor circles for many years. And, ironically enough, being interpreted today the new school union labor which seriously sabotaging our defense efforts and arrogantly defying both the Government and public will. must gratifying Herr Hitler know that this rallying cry which was turn America into united and powerful defender Democracy being put this opposite purpose. And must indeed disillusion- ing the Administration, and particularly Senator Wagner, observe that those for whom they have done much have now turned against them this hour need. Before many days have passed outraged public, which will include our great remaining army free labor, will demand drastic action change this battle cry from “all out” “all in”. + | ( the day Inland made its first steel, emphasis has always been placed use the most modern equipment available, the most and men special training and great skill—the combination which assures highest uniform quality steel mill products. Because this tradition most Inland’s steel- making and finishing equipment has been replaced within the past few years. Typical recent improve- ments are: modern blast furnaces; new open hearth furnaces; blooming mill exceptional speed and flexibility; new 44-in. and continuous sheet and strip mills; latest types cold reduction mills, completely rebuilt galvanizing department; new tin mills for production tin plate the modern and Skilled Men CARRY THE INLAND TRADITION FOR QUALITY cold reduction method; and, new furnace and mill control devices that automatically guard quality and uniformity. The Inland steel mill modern any the world. Operating the Inland mills are steel makers and metallurgists who know and produce uniform, high quality They are men who have added the science steel processing, and they can counted for important advancements meet the needs the future. Many users steel profit the Inland tradition for high uniform quality. saves them time and money. Let Inland’s modern mills and skilled men work for you. SHEETS STRIP TIN PLATE BARS PLATES FLOOR PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS 5 weer LLOYD RAYMOND Fairfield, Conn. author herein correlates data acquired over several years and informa- tion available from several published articles and several unpublished sources. This very important subject today. possible that some cases not sufficiently complete data are available but what issue may taken with the conclusions arrived at. None the less, this paper will endeavor de- velop the following: The effect bath upon the core, the effect the cyanide content the bath, and the effect the cyanate content the bath—in the following paragraphs; the effect temperature and time, the effect the steel being treated, and the effect the April issue; hardening and tempering salt baths, the cyanide reheat, and equipment general use—in the April issue. learned that some pow- dered cyanide hot low-carbon steel and water quenched while the steel was still hot, would have “file hard” surface. this practice surface carburizing continued, and years ago small tin box cya- nide toolmaker’s chest was considered essential tool, some bright young man conceived the idea heating quantity molten cyanide the hardening temperature and immersing the steel until had become car- burized the desired depth. This was the beginning the use the liquid bath for carburizing, which process has become very widely used today. Notwithstanding the extensive ‘Transactions, A.S.M., Vol. VI, No. August, 1924. Transactions, A.S.M., Vol. No. December, 1926 use sodium cyanide industry today, the process more less incompletely understood users. The statement Tour’ years ago the effect that “much the data available the public the subject salt baths the present time, the nature sales propaganda and such teeming with mis- leading statements, intentional ex- aggerations and even with un- truths,” may still applied limited extent the information available regarding liquid carbu- rizing baths. None the less, much factual matter can obtained from most the suppliers. Effect Bath Core There are misapprehensions con- cerning the effect the cyanide bath upon the core the steel being treated. One person will state that cyanide causes the core the steel become embrittled, while another may consider that the treatment the bath tough- ens the core. That they might have some actual data the pos- sible effect the bath upon the core low carbon steel, Messrs. Hillman and conducted exhaustive series tests. They treated several tensile specimens tne cyanide bath 1500 deg. F., removed the case and tested them. These results were com- pared with those obtained pull- ing several specimens the same material that had been heated the same temperature open furnace and quenched the same manner. alteration the properties the core could found from the cyanide treatment. further check the possible effect cyanide bath the core low carbon steel, four 12- in. lengths were cut from one bar steel and two were treated the sodium cyanide bath and two THE IRON AGE, April y | | } | | | | | | } y 7 | | | | | | } | | Ss / = Torque, Torque, Cores Cyanide Hardened Bars Tested Torsion and Compared With Cores Angle Twist, Deg. 0.5 1.5 2.5 Tests and were the cores cyanide hardened pieces. pack carburized pieces. All four pieces were carburized deg. and quenched from the car- Angle twist, deg. Angle twist ,deg. Torque, Torque, TABLE Pack Carburized and Hardened Bars Torque In.-Lb. 105 150 160 135 240 245 250 290 315 325 385 385 395 420 435 440 470 470 475 500 495 500 515 510 525 540 535 565 550 545 600 560 555 625 580 570 630 600 575 645 600 580 660 Angle burizing temperature into oil. All samples were machined from the same bar. NaCN, Per Cent 5.3* 9.3* 14.5* 19.5* 31.0 30.0* 37.8 60.0* Data reported Carbon Penetration (Per Cent) 0.002 In. 0.05 0.12 0.21 0.20 0.57 0.31 0.42 0.31 0.52 TABLE Effect Cyanide Content the Bath Depth, Depth 0.006 0.010 0.014 0.002 0.006 0.010 In. In. In. In. In. In. 0.04 0.00 0.00 0.76 0.16 0.02 0.07 0.02 0.00 0.85 0.28 0.05 0.12 0.00 0.00 0.99 0.21 0.04 0.11 0.06 0.00 0.98 0.42 0.11 0.29 0.16 0.05 0.62 0.21 0.08 0.22 0.12 0.02 1.06 0.49 0.11 0.27 0.12 0.05 0.82 0.40 0.10 0.25 0.09 0.00 1.08 0.46 0.07 0.41 0.20 0.00 1.06 0.02 100 165 250 320 390 430 460 480 500 520 560 580 590 600 605 Tests and were the cores Nitrogen Penetration (Per Cent) 0.014 In. the result independent investigations conducted others. 32—THE IRON AGE, April 194! cores bars cyanided and pack carburized and oil quenched. Vertical ordinates— torque inch-pounds; horizon- tal ordinates—angle twist degrees. Test cyanided 1550 deg. for oil quenched and case ground off. Test cyanided 1550 deg. for oil quenched and case ground off. Test carburized hr. after reaching temperature 1550 deg. F.; oil quenched and case ground off. Test carburized hr. after reaching 1550 deg. F.; oil quenched and case ground off. pack carburized the same depth case and quenched from the box. All four specimens were car- burized 1550 deg. and oil quenched. The case was ground from all four bars and the size all pieces held variation not more than 0.0003 in. The bars were then tested torsion Professor Colton, then Yale University, with the results shown Table and the graphs Fig. These results clearly sustain those obtained Hillman and Clark their investigations, and definitely disprove the more less prevalent beliefs regarding the core cyanide treated steels. The core will tough brittle depending upon the steel treated and the temperature from which was quenched. Figs. and show the cores two different steels which have been treated cyanide bath and oil quenched. These were from relatively thin sections. The core the type shown Fig. will relatively tough much ferrite was not transformed austenite upon heating and some the austenite had time revert fine pearlite during the quenching. such shown Fig. although 700 Angle twist, deg 100 600 300 300 100 3.5 harder backing for the case relatively brittle entirely martensitic. Effect Cyanide Content The amount sodium cyanide present the liquid bath fluences the chemical composition the case, the depth penetra- tion and the hardness the case obtained. Table lists several types cases that have been re- ported from several sources and personal observation the author. study data this table will indicate that low cyan- ide concentrations produce cases that are low carbon, relatively high nitrogen and quite shal- low. the cyanide content the bath increased, the carbon content increases and the hard- ness the underlying comes increased. The samples shown Table were obtained heating for hr. the bath and being permitted cool slowly while surrounded small quantity the bath, that they might machinable. The percentage carbon shown the table the increment over the composition the core. The point which the percentage shown was obtained follows: cut 0.004 in. deep was taken the radius the bar and analyzed. was assumed that the average would point one-half the depth the cut and that the analysis was the composition that point. all cases, the samples were immersed the bath for hr. The temperatures were 1500 deg. and 1525 deg. Effect Cyanate Content operating sodium cyanide bath over period years which the NaCN content was care- fully controlled chemical an- alysis between per cent and per cent, was found that er- ratic results were obtained the most unexpected intervals. These had several undesirable manifes- tations, such (1) shallow depth hardness although microscopic examination showed that the pene- tration was normal depth, (2) high surface hardness and shal- low penetration, and (3) complete failure carburize. analysis the bath that stopped carburiz- ing showed that although the cyanide content was the correct composition, there was but trace 2—Core free machining steel (SAE treated 1.5 hr. cyanide bath 1500 deg. and oil quenched. 500 diameters. sodium cyanate present the bath. This led study the effect the cyanate content. This study has shown that the lower cyanate content baths not carburize with the effective- ness that the baths higher cyanate content do. Although the apparent depth penetration under the microscope may seem practically the same, will found that the analysis the case will show considerably less total hardening units carbon 3—Core free machining steel (SAE treated 1.5 hr. cyanide bath 1500 deg. and oil quenched. 500 diameters. THE IRON AGE, April TABLE The Effect the Cyanate Content the Bath the Penetration NaCN, 0.0015 Steel PerCent Per Cent In. S.A.E. 5150 4.77 54.11 0.34 5150 1.61 51.93 0.12 6150 5.28 55.35 0.28 6150 1.40 52.65 0.07 X1020 5.2 33.5 0.50 X1020 3.8 30.8 0.41 X1020 29.9 0.42 Carbon Penetration Depth 0.0045 0.0075 0.0115 0.0145 In. In. In. In. 0.23 0.09 0.03 0.00 0.02 0.01 0.00 0.00 0.29 0.13 0.05 0.02 0.07 0.02 0.00 0.48 0.31 0.08 0.03 0.32 0.13 0.07 0.00 0.37 0.18 0.04 0.00 Nitrogen Penetration Depth 0.0015 0.0045 0.0075 0.0115 In. In. In. In. 0.75 0.10 0.05 0.05 0.34 0.05 0.05 0.04 0.65 0.12 0.04 0.05 0.26 0.05 0.04 0.02 0.52 0.25 0.13 0.02 0.56 0.19 0.05 0.02 0.51 0.21 0.07 0.04 and nitrogen, the cyanate con- tent the carburizing bath has been permitted drop low concentration. Table III shows the case analyses three steels treated baths dissimilar contents. The samples Table III were obtained heating the bath and being permitted cool slowly, surrounded small quantity the bath which they had been Notes face-hardened armor plate, general, superior homogeneous plate, according Horace Alter, writing the March-April issue Army Ord- nance magazine. Homogeneous plate, uniformly hard throughout, shows tendencies throw buttons, spall and shatter when subjected bursts machine gun fire, due the vibration which set the internal molecules the plate. Carburized plate, the other hand, shows little crack, spall throw buttons off the rear the plate when hit projectiles. For aircraft use, how- ever, armor plate not subjected concentrated bursts fire. The speed the plane relatively high, even when compared with bullet speed and, therefore, the dis- persion hits such that two shots are usually closer than in. Hence homogeneous plate safe and preferred for aircraft pro- tection since can formed contours, has simple heat treat- 34—THE IRON AGE, April 1941 heated order that they might machinable. The percentage carbon shown the table the increment over the composition the core. The point which the percentage shown was taken follows: cut 0.003 in. deep was taken the radius the bar and analyzed. was assumed that the average would point one half the depth the cut and that the analysis was the composition that point. The times and temperatures the runs were follows: 5150, hr. 1500 deg. F.; 6150, min. 1525 deg. F.; and S.A.E. X1020, hr. 1600 deg. Note:—Next week attention will directed effect temperature and time, effect steel being treated, activators, ete. Aircraft Armor ment, less and general easier fabri- cate. Present combat ranges for air- planes are approximately 100 yd. more. that range, homogene- ous face hardened plate in. thick will stop complete penetration caliber 0.50 armor piercing bullet when the angle obliquity, that the angle the flight path the bullet and line normal perpendicular the plate deg, more. Armor plate in. thick will stop armor piercing 0.50 caliber bullets deg. the normal. Good plate either type shatters the projectile without appreciable signs cracking shattering itself. Most the armor piercing cores break into small fragments upon striking the plate. comparison, bullet proof glass in. thick will stop 0.50 caliber bullets, and bullet proof glass in. thick will stop penetration 0.30 caliber bullets normal impact. the design armor plate for aircraft use, advantage taken the fact that penetration under glancing impact resisted thin- ner plate than under normal im- pacts. For armor installed the upper surface the wing, for ex- ample, where the angles impact are low, the plate can thin, while for section plate the rear the fuselage, the plate will thick because the preponderance attacks are most likely occur from the rear angles normal nearly normal the plate. other words, weight comparison made between thin plates installed critical angles and thick plate installed angles normal the general line fire. centralizing vital mechanisms and personnel specific areas, they may pro- tected one piece armor. Aux- iliary equipment may also in- stalled serve additional pro- tection and baffles for tumbling the bullet, thus allowing thinner plate installed. The effect tum- bling turning the bullet in- crease the angle impact. small parts skid boxes has been developed Plymouth Detroit reduce the number skid boxes use, reduce floor space taken partly filled boxes and greatly improve the steady flow material assembly plants. The method releases for other service great many skid boxes which here- tofore have been tied with par- tial loads and eliminates the neces- sity having several loaded partly loaded skid boxes always the point use and frequently cluttering aisleways, and work revolving fork truck, specially designed for this work, for Plymouth the Yale Towne Mfg. Co. The truck similar those used paper mills for upend- ing paper rolls lifting the roll the truck fork and then revolv- ing the fork about approximate- horizontal axis. method The special design for this truck was worked out Plymouth engi- neers and the Detroit representa- tive the manufacturer. opera- tion the fork the truck slid under the skid box platform the usual manner. Above the box this position welded plate hop- per with flanges inside the hopper above the top edge the box. The fork, loaded skid box and hopper are inverted the operator dump the load where desired. The cover the hopper opens automatically when the hopper inverted, being actuated dog which hits the spring-loaded latch the hopper nears down position. After the truck had proved itself successful tool emptying par- tially filled skid boxes into other partially filled skid boxes, Plymouth engineers then installed large stock hoppers which would hold the con- tents several skid boxes. These have inclined flooring and hop- per-type feed which leads directly the point where the assembly worker stationed. This has re- sulted saving additional floor space and further conservation skid boxes. The practice now eliminate the parking skid boxes near assembly points. The truck merely moves into position with the loaded box, dumps into the hop- per, then returns the skid box the shipping platform parts pro- duction for further use. Since the hopper holds the contents several skid boxes, frequent refilling un- necessary. Plymouth Improves Handling Small Parts skid box the Plymouth plant with new Yale Towne revolv- ing fork truck. THE IRON AGE, April 1941—35 ° ° ° OURING small parts into the stock hopper designed Plymouth. —Continuation series lessons enable beginners master the fundamentals bare and welding techniques. study the deposition beads weld metal the down hand position. Apparatus used Westinghouse Flex Arc welding machine, chisel, hammer and wire scratch brush. Material used steel plate in. heavier, and 5/32 in. diameter Crucible Weld “DH” welding electrodes. INSTRUCTIONS: The student has already mastered the art strik- ing and holding the arc and depositing beads weld metal with bare type electrodes. will not necessary, therefore, cover these elementary details again this lesson. The flux coating shielded- arc type electrode aids striking and maintaining the are and making more uniform weld de- posit. The flux coating also pro- duces slag deposit the weld which must properly controlled satisfactory beads are made. When welding with flux coated electrode the down hand position care must taken adjust the welding current and speed ad- vance that the slag covering the weld does not run ahead the the slag does run ahead ESSON No. 22: Object 36—THE IRON AGE, April the arc there danger obtain- ing poor fusion and irregular shaped deposit. The beginner will have some difficulty distinguish- ing between the slag and the molten metal. little experience, however, will make possible distinguish between the two because their slight difference color and their action and flowing characteristics. The molten weld metal has ten- dency sweat onto the fused parent metal while molten slag tends curl the edges the manner water oily surface. The recommended practice for welding with flux coated electrodes point the electrode toward the shown Fig. 41. The exact angle the electrode may varied under certain conditions but should not pointed away from the deposit unless arc blow other conditions make such procedure absolutely necessary. The arc length recommended for down hand welding with flux coated electrodes greater than that recommended for bare type electrodes. Too short arc will cause the coating the elec- trode drag the deposit and too long will cause the metal transferred.in large drops and produce rough irregular beads and excessive spatter. With little practice the beginner will soon able determine the proper arc length the sound the are and the way the deposit forms. When welding with flux coated electrode will noted that deep crater not formed. order necessary pause for short time over the crater and draw the out slowly until breaks. not attempt fill crater shorten- ing the arc discussed for bare type electrodes. When restriking the are con- tinue bead deposit, the slag should first removed from the end the previous deposit. This procedure not always necessary but highly recommended for the beginner order insure complete fusion. wide bead may made with flux coated electrodes weaving. The maximum width weave will depend upon the design the joint being welded and the diameter and type electrode. the weave too wide irregular deposit may obtained and trouble from the slag running ahead the deposit ] i H q q | may experienced. Recommended weaving procedures are similar types and discussed Lesson No. PROCEDURE: Set the polarity re- versing switch straight polarity, adjust the welding current 150- 160 amp. and place the plate welded flat the welding table. (1) Deposit string beads all directions until smooth uniform beads may made. (2) Practice stopping and con- tinuing beads deposited all direc- tions. Chip out the starts ex- amine for complete fusion. (3) Practice filling craters slowly lengthening the are. Try fill crater shorting out the arc, discussed Lesson No. for bare type electrodes, and note what happens. (4) Practice depositing bead weaving. Try small and wide weave. Note the difference the appearance the deposit and the action the slag when the weave becomes too wide. (5) After the above exercises have been completed, make test piece shown Fig. 42. ESSON No. 23: Object make single vee butt weld between plates using flux coated electrodes. Apparatus used Westinghouse Flex Arc welding machine, chisel, hammer and wire scratch brush. Material used 30-deg. bevel along one end each plate and 5/32-in. and 3/16-in. diameter Crucible Weld “DH” elec- trodes. INSTRUCTIONS: order reduce the amount deposited metal re- quired fill joint, common practice use joint design with narrow included angle and in- crease the diameter the electrode the joint nears completion. Also, the metal deposited with flux coated electrodes generally more fluid and molten for longer length time than metal deposited with bare type electrode, consequently joints with steeper kerf surfaces are often used. This lesson employs the use two diameters electrodes and intended acquaint the student with the characteristics flux coated electrodes when used groove. Special care must taken obtain fusion the kerf sur- faces and prevent the slag from being entrapped the weld. The slag should removed from each layer before depositing the next layer. string bead will found satis- factory for the first pass the bot- tom the joint. the joint be- ommended practice for welding with flux coated elec- trodes. wider will found necessary weave the electrode. The width weave should ad- justed that each pass will the full width the joint. The proper weave will result slightly con- cave weld deposit without any un- dercut. the weave too narrow, entrapped slag and poor fusion will present the sides the joint. amount the parent metal will melted and undercut will result. PROCEDURE: Set the polarity re- versing switch straight polarity and adjust the welding current for the diameter electrode used (5/32 in. diameter—160 amp., 3/16 in. diameter—190 amp.). Tack weld the plates together with Fig. 43, and place them hori- table. Weld the plates together us- ing three passes, shown Fig. 43. Clean the slag and spatter from each layer before depositing the next layer. careful obtain complete fusion all times. In- spect each layer for uniformity comes crater 42—Prepare this type test piece for depositing horizontal beads with down hand type elec- trodes. appearance and flaws. Try im- prove the appearance and quality the weld progresses. After the joint completed have the instructor inspect for appear-- ance. Following the instructor’s in- spection make nicked groove the top layer the center the weld and fracture the specimen. The exposed fracture should show sound uniform weld metal free from gas pockets, slag inclusions, poor fusion and incomplete pene- tration. Repeat this exercise until satis- factory butt weld this design can made. ESSON No. 24: Object make single bevel butt weld between in. thick plates using flux coated electrodes. Apparatus used Westinghouse Flex Arc welding machines, chisel, hammer and wire scratch brush. Material used are two in. steel plates with deg. bevel along one end one plate and 3/16-in. and 14-in. diameter Crucible Weld electrodes. INSTRUCTIONS: The single bevel butt joint often used cases elec.) 43—Method follow make single vee butt weld between plates using flux coated electrodes. where desirable bevel only one plate and cases where desired restrict the amount deposited metal minimum with- out resorting double vee type joint. The welding proce- dure used similar that out- lined Lesson for single vee butt joints. The use larger elec- trodes with consequently faster this lesson because thicker test plates are used. When welding single bevel joint must remembered that one the kerf surfaces right- angles the plate surface. Be- THE IRON AGE, April ' ! Joint cause this vertical surface, spe- cial care must taken the weld- ing operator insure complete fusion and prevent undercut. PROCEDURE: Set the polarity re- versing switch straight polarity and adjust the welding current for the diameter electrode used (3/16 in. diameter electrodes —185 amp., in. diameter elec- trodes—285 amp.). Tack weld the plates together with in. free space the bottom, shown Fig. 44, and place them hori- 44—Method follow make single bevel butt weld between plates using flux coated electrodes. zontal position the welding table. Weld the plates together using four passes, shown Fig. 44. Passes and should made with 3/16 in. diameter electrodes, and passes and should made with in. diameter electrodes. Clean the slag and spatter from each layer before depositing the next layer. careful obtain com- plete fusion all times. Inspect each layer for uniformity ap- pearance. Try improve the ap- pearance quality the weld progresses. After the joint completed, have the instructor inspect for ap- pearance. Following the instruc- tor’s inspection, make nicked groove the top layer the center the weld and fracture the speci- men. The exposed fracture should show sound uniform weld metal free from gas pockets, slag inclu- sions, poor fusion and incomplete penetration. Repeat this exercise until satis- factory butt weld this design can made. ESSON No. 25: Object make double vee butt weld between thick plates using 38—THE IRON AGE, April flux coated electrodes. Apparatus used Westinghouse Flex welding machine, chisel, hammer and wire scratch brush. Material plates with 30-deg. double vee one end each plate and 3/16 in. and in. diameter Crucible Weld electrodes. INSTRUCTIONS: The double bevel butt joint generally employed heavier plates in. above) order hold the amount de- posited metal minimum. order weld double vee joint necessary that both sides the plate accessible. This require- ment often limits the use this type joint. The welding procedure used similar that outlined the two previous lessons. After depositing the weld one side the joint essential that the back side chipped out sound metal before depositing metal that side. the root the weld not chipped out, inclusions and poor fusion will obtained. order prevent the plates from warping excessively often desirable deposit metal each side the joint alternately rather than complete one side before starting weld the second side. This type procedure will used this lesson. PROCEDURE: Set the polarity re- versing switch straight polarity and adjust the welding current for the diameter electrode used (3/16 in. 185 amp., in. diameter electrodes —285 amp.). Tack weld the plates together with free space, shown Fig. 45, and place them horizontal position the weld- ing table. Weld the plates together using six passes, shown Fig. 45; the sequence welding should shown the numbers layers. Layers and should made with 3/16 in. diameter elec- trodes and layers and should made with in. diameter elec- trodes. After depositing the first two layers, chip the reverse side the joint sound metal before de- positing the third layer. careful obtain complete fu- sion all times. Inspect each IS. 45—Method follow make double vee butt weld between plates using flux coated electrodes. electrodes layer for uniformity appearance. Remove all slag and spatter from each layer before depositing the next. After the joint completed, have the instructor inspect for ap- pearance. Following inspection, make nicked groove the top layer the cen- ter the weld and fracture the specimen. The exposed fracture should show sound uniform metal free from gas pockets, slag inclu- sions, poor fusion and incomplete penetration. Repeat this exercise until satis- factory butt weld this design can made. No. 26: Object tee joint with flux coated electrodes positioning the joint simulate butt weld. Apparatus used Westinghouse Flex welding machine, chisel, hammer and wire scratch brush. Material used two in. diameter Crucible Weld “DH” electrodes. INSTRUCTIONS: signed especially for down hand welding generally have very fluid slag which makes difficult de- posit the weld metal that one side will fuse vertical surface. horizontal fillet weld has one leg the vertical plane and down hand type electrode used make it, considerable trouble will probably experienced from un- the vertical surface, excessive roll, improper shape the weld and slag pits the weld surface. result, fillet weld made with down hand type electrodes recommended that the parts positioned angle deg., thereby simulating the welding conditions butt weld. The welding procedure such case identical that discussed for down hand type butt welds. PROCEDURE: Set the polarity re- versing switch straight polarity and adjust the welding current 185 amp. Tack weld two plates to- gether, shown Fig. 46, and position them the welding table Weld the plates together with fillet weld using two layers, shown Fig. 46. Make the first pass relatively rapid rate speed that not more than fillet will produced. De- posit the second layer weaving from side side insure complete fusion. Adjust the rate advance that the weld will not larger than in. The finished weld slightly concave and smooth and entirely free from undercut the edges. Fracture the finished weld and inspect for soundness and com- plete penetration. Repeat this ex- ercise until satisfactory weld can made. ESSON No. 27: Object study the deposition beads weld metal the down hand LEFT IG. mak- ing fillet weld tee joint with flux coated electrodes positioning the joint simulate butt weld. RIGHT study the deposition beads weld metal the down hand position. position. Apparatus used West- inghouse Flex welding ma- chine, chisel, hammer scratch brush. Material used steel plate in. heavier, and 5/32 in. diameter Crucible Weld welding electrodes. INSTRUCTIONS: Flux coated elec- trodes designed for welding all positions have somewhat different characteristics than those designed for down hand welding. The prop- shorter than for down hand electrodes. There also less weld- ing slag and this slag less fluid and solidifies more rapidly. These characteristics the welding slag make the operation this type electrode somewhat similar that bare type electrodes and conse- quently produce welds with surface ripples. little practice with this type electrode will make easily possible distinguish between the molten metal and slag, impor- tant factor controlling the de- posited metal and producing high quality welds the vertical and overhead positions. The fact that position type flux coated electrode does not pro- duce very fluid deposit makes the case with down hand type elec- trodes. String beads are generally used all cases except when weld- ing vertical surfaces. PROCEDURE: Set the polarity re- versing switch reverse polarity, adjust the welding current about 160 amp. and place the practice plate flat the welding table. (1) Deposit string beads all directions. Take special care have the rate advance uniform this important making smooth uniform beads. (2) Practice stopping and start- ing the weld. Try make smooth junction the starts. (4) Practice small weave and note how the deposited metal flows and quickly solidifies. (4) After reasonable skill has been obtained depositing beads make test plate shown Fig. 47. THE IRON AGE, April 1941—39 “ High Steel —Continuation data presented last week recent English production research. attention directed high speed steel tool failures and metallurgical aspects machining. Speed Herein, Metallurgist, William Jessop Sons, Ltd. Sheffield, IGH SPEED STEEL TOOL FAIL- URES: The failures high speed steel tools either the hardening operations ser- vice must necessarily lead very substantial losses time and out- put. is, therefore, the utmost importance that the causes such failures are fuily understood, because modifications heat treatment cycle may sug- gest themselves the design tool changed the results into premature failure. the majority instances, therefore, little care neces- sary the investigation tool steel failures. Nor this surpris- ing when realized that many post mortem examinations are car- ried out tools the failure which there was witness say whether there had been measure foul play, lack normal pre- cautions handling the tool. fact the evidence concerning fail- ure often second third hand when received the investigator, and even originally reasonably complete, some vital link the ac- count often unwittingly omitted, the account the conditions existing the time failure 40—THE IRON AGE, April written described distorted fashion. crack during hardening because the path the crack found rather rare variety, minor car- bide segregate well removed from the origin the defect. When such reasons account for failure are given, they very often serve indicate that the investigator has failed find any really positive evidence which would satisfactorily explain the formation the crack; consequently any slightly unusual characteristic the material seized upon explain the failure. HIGH SPEED TOOL FAILURES: the following brief review useful distinguish between the following cases classified broadly follows: (1) Inherent steel defects lead- ing subsequent failure. (2) Heat treatment failures (and failures arising there- from). (3) initiated during finishing the tools for ser- vice, and from abnormal conditions during service. failures under the first heading are usually found where considerable machining has been done the surface bar, where the case cutter hob made from blank, the cen- tral portion has been bored out. Should defects brought the operation and they persist after local machining very near the finished size, the tool scrapped. The danger arises, however, from the fact that after visual inspec- tion the defects often appear have been cleared, where point fact trace the trouble re- mains. Such deception more likely bored holes, but where there doubt, magnetic crack de- tection will invariably give clear answer. the other hand, elongated segregate internal crack may just come the surface tool after machining but prior heat treatment, and these cases may pass unnoticed. When either the above defects occur might thought that such defects would invariably open heat treat- ment, but this not always the case, especially when treatment under strict control. Two examples illustrating the above possibilities from number which have come the author’s notice are given below. The first relates two very complex cutters which had bored and keyed central holes in. long, and which be- ing put into service failed prema- turely. examination showed that both tools had failed similarly and that fractures had progressed from original defect the bore. The cutters had been treated and the original surfaces the defects were almost perfect- preserved. These defects which had smooth appearance resulting from rubbing during forging were almost certainly the remains some slight unsoundness which had extended during hot working, and had not been completely removed during machining. The other example concerns broach which defect, was ap- parently partially machining, and which was passed forward sound for heat treat- ment. The broach was successfully hardened and tempered, but final grinding established the presence extensive seam which persist- for length approximately in. After breaking the broach across the defect, one portion was used for exposing the surfaces the seam, which proved bright and crystalline. From the other half micro section was prepared which after polishing and etching showed that the seam had arisen from the elongation segregate. both the above examples, mag- inspection methods would have revealed the presence the defects before heat treatment. Dealing with failures classified under (2), should noted that heat treatment troubles are usual- most frequent where the plant antiquated, the fundamental principles heat treatment are not fully understood. well or- ganized shops minor defects pres- ent tools often persist during heat treatment without extension, which indicates that under control- led conditions heat treatment fail- ures should negligible. Never- theless, all too numerous cases heat treatment failures continue occur. Sometimes the troubles are traceable decarburization result- ing soft skin, and other times the softness due over- tempering. the one case the atmosphere was incorrect for given hardening temperature, and the other case the temperature control was fault. the other hand, numbers cracked tools often arise result ignoring normal precautions be- tween hardening and tempering. This proved the absence evidence disclosing inherent steel j troubles, overheated struc- ture when the tools have been tempered air tempering bath, blueing invariably develops the surfaces defects. temper- ing carried out salt bath trace salt invariably found the exposed surfaces the de- fect. Such cracks are due pro- longed delay between hardening and tempering alternatively, result putting tools having considerable changes section in- the tempering bath when the latter too hot. After hardening, tools should tempered immedi- ately they are hand warm (for ex- ample 104 deg. F.). They should temperature between 212 deg. and 302 deg. and allowed equalize, and then raised steadily the tempering temperature. Raising the temperature too quick- shaped tools having tions, because 842 deg. high speed steel expands suddenly. Thus. quick rise the tempering tem- perature causes the outside zones expand suddenly while the in- side portions the tool are rigid. Further examples heading are provided connection with snipped and fractured tools. many instances there always tendency blame the slightest evidence heterogenity the steel for such failures. has been the author’s experience that such failures are bound with the condition the LEFT fail- ure associated with the fracture which per- sists the result double hardening treatment, the tool after heat treatment, mal conditions under the tools functioned. number instances this type failure has been found associated with finely crystalline dry type frac- ture and high hardness, both which pointed unnecessarily long soak the hardening temper- tempering. This treatment had re- sulted putting the tools into brittle condition. Occasionally this type failure associated with the fracture which per- sists the result double hard- ening treatment, the result high finishing forging roll- ing temperature the blank bar, from which the tool was made. Fig. photograph showing this type fracture. Should such grain persist finished tool, failure will invariably shock stresses encoun- tered service. Under classification (3) failures initiated during finishing tool for service are usually associated with cracks which developed result faulty grinding, slight machin- ing errors, such the retention unnecessarily sharp changes section, the weakening the cutting edge employing large rake clearance angles. Failures connected with grinding cracks have been more frequent than would expected view the advances made this field, and would appear that the development such cracks results more often result high fin- ishing forging rolling temperature. Impact value ft- ° ° ° RIGHT Change impact value over tempering range 392 deg. deg. 300 400 500 Tempering temperature, 932 Tempering fahr. THE IRON AGE, April from the demand get job through the minimum time, rather than from ignorance the precautions which should taken. Regarding slight machining errors improper design which result the persistence sharp changes section, undercut radii, such defects often lead failure the initiation fatigue flaws, which comparatively brit- tle materials extend rapidly. Un- necessarily large top rake angles often cause fracture shear across the end turning tool, while large clearance duce the strength the cutting edge that more readily over- heated. should not taken for granted, therefore, that all tool steel failures are related, the quality the steel its heat treatment. Almost many tools fail service result faulty herent steel defects inefficient heat treatment. Metallurgical Aspects Machining order produce the most ef- ficient cutting tools necessary have clear idea the suc- cessive stages which govern the re- moval metal machining. The fundamental principles machining are the same whether the tools are milling, turning, hobbing; therefore the operation turning may taken ex- ample. When turning tool first engaged with the work, high compressive stresses tween the cutting edge the tool and the work, which first result the metal flowing over the tool face. the work moves against the tool, however, the peak com- pressive stresses fall slightly be- cause rupture occurs the surface the work shear, but simul- taneously with the fall the com- pressive stresses the wear effect the chip formed becomes ap- parent escapes over the built edge the tool the tool face. According Ernst there are three main types chip, (1) the discontinuous chip, (2) the con- tinuous type chip, and (3) the continuous type chip forming built-up edge adjacent the tool face. (3) far the most damag- ing, and more likely form when machining tough steels. (2) the ideal chip giving good finish for maximum amount wear and low power consump- tion. (1) Produces effects which com- promise between (2) and The above facts, therefore, sug- gest that the following properties are desirable high speed steel cutting tools. high hardness with measure toughness the cutting tem- perature; good heat conduc- tivity possible and high resist- ance wear the working tem- perature. number typical tool steels properties high degree, but the full benefits are only likely derived from such steels cutting tools they have received the op- timum heat treatment. has been established that the highest cut- ting efficiency obtained only when tool has been hardened from the highest temperature above which partial fusion and ex- cessive grain growth would occur, and subsequently tempered develop the maximum second- ary hardness. Invariably single tempering treatment insufficient develop the maximum secondary hardness even straight per cent tungsten steel, and many cases, such the cobalt steels, many two three distinct tem- pering treatments are necessary. This due change the properties high speed steel dur- ing cooling after tempering. Such changes have been detected mag- netic analysis, and although this effect has been investigated the TABLE Analysis Typical Tool Steels Tungsten type 0.78 0.30 0.25 4.2 0.5 Tungsten-cobalt type ............ 0.79 0.30 0.25 19.0 4.5 1.4 5.0 18.0 Molybdenum-tungsten type ....... 0.75 0.30 0.25 2.5 4.2 0.9 8.5 Molybdenum-tungsten-cobalt type 0.75 0.30 0.25 2.5 4.2 1.0 8.5 5.0 Molybdenum-vanadium type ...... 1.20 0.37 0.35 2.5 8.5 42—THE IRON AGE, April 1941 author, has not confirmed that purely further transforma- tion from austenite martensite suggested some investigators. doubt this change has im- portant bearing the cutting properties high speed steel, and only very highly controlled cooling procedure could the trans- formation fully effected single tempering treatment. thus more convenient temper number times order com- plete the transformation. However, not always advisable use tool this condition, because after having been heat treated give such hardness probably comparatively brittle condi- tion. Thus, when tool has used under conditions where higher degree shock resistance than normal desirable, such for example heavy intermittent cutting, will necessary heat treat that finer grain size obtained, and temper the range which will give the optimum tough- ness. Fig. shows the change impact value over tempering range 392 deg. 1112 deg. F., from which can seen that tempering 842 deg. will pro- duce tougher steel. Until recently, that before the advent controlled atmosphere furnaces, was not easy control the grain size hardened high speed steel tools. This was due some measure the self heating effect the atmosphere containing excessive quantities gas, which surrounded the tool the hardening temperatures. Now, when the composition the at- mosphere can the grain size the tool can much more easily controlled. addition, accurate pyrometric con- trol the heat treatment opera- tions has become more firmly es- tablished. apparent from the forego- ing remarks, therefore, that the properties obtainable high speed steel tools can usefully varied according the type being machined, the type ma- chining operation being carried out, and the conditions under which the machine tool functions. For example, play the bearing ab- normal vibration might result the premature failure cutting tool. consideration these and similarly related factors, will largely determine what proper- ties are developed