The Iron Age 1938-09-22: Vol 142 Iss 12

of ized t. art- date let ples, dis- nue, chi- and eral part pout roj- bids 330 rlec- ron- ools con- and aAnc- eral Co.. one- near new dis- Air bids alve gas- ock- and alve ions ight in- bout inis- reet, eral Ar- igan ent. and ther nits, Fi- 1 OLIVER FRITZ FRANK President VAN DEVENTER Editor Managing Editor News Editor Machinery Editor Art Editor Associate Editors PHAIR JURASCHEK Consulting Zditor Washington Editor Resident District Editors CAMPBELL ROBERT BINGHAM Pittsburgh Chicago Cleveland Detroit Editorial Correspondents London, England Cincinnati FRAZAR FIDRMUC Boston Hamburg, Germany MEYER Milwaukee SANDERSON CHARLES San Francisco ASA ROUNTREE, JR. Toronto, Ontario Birmingham LEROY ALLISON Roy EDMONDS Newark, N. J. St. Louis TURNER, JR. Buffalo Owned and Published CHILTON COMPANY (Incorporated) Publication Office Editorial and Chestnut and 56th Sts., Executive Offices Philadelphia, Pa. 239 West 39th St., New York, OFFICERS AND DIRECTORS C. A. MUSSELMAN, President FRITZ J. FRANK, Executive Vice-President FREDERIC STEVENS, Vice-President JOSEPH HILDRETH, GEORGE GRIFFITHS, EVERIT TERHUNE, WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JOHN VAN DEVENTER JULIAN CHASE THOMAS KANE CHARLES BAUR CARROLL BUZBY BAUR, General Advertising Manager DIX, Manager Reader Service Member, Audit Bureau of Circulations Member, Associated Business Papers Indexed in the Industrial Arts Index. Published every Thursday. Subscrip- tion Price: United States and Pos- sessions, Mexico, Cuba, $6.00; Can- ada, $8.50; Foreign, $12.00 a year. Single copy, 25 cents. Cable Address, “Tronage, ADVERTISING STAFF Emerson Findley, 621 Union Bldg., Cleveland B. L. Herman, Chilton Bldg., Chestnut & 56th Sts., Philadelphia, Pa. H. K. Hottenstein, 802 Otis Bidg., Chicago H. E. Leonard, 239 W. 39th St., New York Peirce Lewis. 7310 Woodward Ave., Detroit C. H. Ober, 239 W. 39th St., New York W. B. Robinson, 428 Park Bidg., Pittsburgh D. C. Warren, P. 0. Box 81, Hartford, Conn. Editor Emeritus Metallurgical Editor RICCIARDI McINTOSH Cont SEPTEMBER 22, 1938 Old Masters and New Ones Italian Plant Features High-Frequency Furnaces Utilizing Waste Pickling Supporting Assemblies Electric-Furnace Brazing More Space for Clipper Ships Cleveland Welcome and Steel Engineers Development Chrysler's Superfinish the Assembly Line Washington News THE NEWS BRIEF Weekly Ingot Operating Rate Rate Activity Capital Goods Plant Expansion and Equipment Buying Products Advertised Just Between Two Index Advertisers Copyright 1938 Chilton Company 108 121 123 148 The uniformity Bethlehem cold-rolled sheets bettering production records deep-drawing jobs. This high degree uniformity due part exclusive steel-making control process, part rigid inspections and careful workmanship. 38—THE IRON AGE, September 22, 1938 ‘ ESTABLISHED THE IRON SEPTEMBER 22, 1938 Vol. 142, No. Old Masters and New Ones lieves that man's achievements are hardly worth mentioning unless the man has been dead and buried for several centuries. FRIEND mine great admirer the past. one those chaps who be- The other day this friend was talking about the old masters. Michelangelo, Rubens, Van Dyck and others. can you find the equal these men asked. our time can begin their did they work asked, wnereupon friend waxed indignant. worked for themselves and for said. themselves through the joy artistic creation and expression and for posterity through the appreciation their very replied. that did not benefit many their own generation. Posterity, far their own times were concerned was non-existent. The fact the matter that these old masters worked for themselves and for some rich patron and his select circle friends. matter reality the patron was the master these cases and the so-called master’ labor2r who worked for his daily said this not depreciate the work the great artists the past but get this friend mine appreciate the work the comes around the corner, will not think any more the V-8 than the Model And will not flock art galleries reproductions either one them. Per- doubt whether Henry Ford automobile maker gives damn for posterity. But has furnished reliable and improved transportation good many millions his that, said you are tempted decry the modern age mass production. The old masters served best just few patrons who had money enough buy most anything that they wanted, including the works old masters. The new masters today, the men who have built and are operating mass production in- dustries, are serving millions people millions possess, enjoy and profit things that they could not have had These new masters not live the past, nor the future. They believe that pos- terity will well served posterity. But they know that posterity cannot serve those now living. | | ltalian Plant Features Hig Frequency Furnaces ° ° ° DR.-ING. KAUCHTSCHISCHWILI ° works the Cogne com- pany, Aosta, Italy, which large, new high-frequency fur- nace plants have been set up, are lo- cated about miles from Torino and miles from the highest Alpine tained from company Thuile, located 6340 ft. above sea level, and ore from deposits over Cogne village, altitude 8850 ft. Thanks the large quantities water coming down from Montblanc mountain, the local industries have available cheap electrical energy for metallurgical purposes. tinguished, above all, the fact that electrical energy being used all stages iron making. Thus, pig iron produced not only blast furnaces, but also in.a novel electric low-shaft furnace. After the construction additional electrical furnace units, expected that they will completely supersede present con- ventional blast furnaces. The pig iron first transferred into mixed, also heated electrical energy, and later on, into converter which blown. Thereupon, the largest part the steel transferred into electric arc furnaces con- are furnace for pig iron production rated 12,000 Kva., and the steel melting elec- tric furnaces for the duplexing have capacities tons each. 40—THE IRON AGE, September 22, 1938 ° ° verted high grade steel the du- plex process.’ The new high-frequency furnace plant consists four furnace units, having capacities tons, tons, 1760 and 330 This plant groups fed each case from gen- erator aggregate and condenser bat- tery. Within each the two groups, the two furnaces operate alternately that one furnace stands ready, com- pletely relined used with- out interrupting operations event that the other furnace crucible should need repair. The sec- ond furnace the larger furnace group has capacity tons work chiefly the hot charge from the electric arc furnaces available, enable the handling larger solid charges single melting operation. The and 8-ton furnaces belong the largest ones their type hitherto built the world. This true both regard the capacity and the gen- erator output, the latter being 1750 Kw. the motor and 1600 1650 Kw. the generators. The two fur- naces were built Siemens Halske Department for Electrochemis- try, accordance with Ajax-North- rup patents and Siemens side Germany, six similar units re- cently have been furnished for well known steel makers. This the best indication the rapid development the high-frequency furnace regard increased output and furnace ca- pacity. The high-frequency furnaces the Cogne works are primarily destined for the production special steels such tool steels, high speed steels, alloy steels. The raw materials used are chiefly scrap accruing the plant itself the form crop ends, turn- ings, For the time being, the crucibles are made acid material. However, the intention change the basic linings the near future; the latter have proved highly satisfactory the smaller furnace units, having capaci- ties 1760 and 330 and conse- quently will used similar man- ner the large furnaces. Among the many advantages af- forded the use high frequency furnaces, their special suitability for yielding absolutely pure, high grade products paramount importance further, their almost instant readiness for operation, the convenient regula- tion the output, ease operation, cleanliness and orderliness use and also the high degree economy are likewise favorable characteristics. This holds good not only for the oper- ating cost proper which from arc furnaces, view the absence electrodes, the simplicity opera- e & tion and inexpensiveness the but also regard the valuable charging material which lat- ter suffers practically loss metal due burning. The accempanying two tables show data two complete crucible cam- paigns obtained under practical op- erating conditions. Table relates the 6-ton high- frequency furnace and the operating period from Dec. 26, 1937, Jan. 1938. During this time, were made, Nos. 34,653 34,700. possibility did not exist with Table covering operating data for the 8-ton furnace; only the total energy consumed shown. com- pare the two furnaces, the energy consumption has been calculated per ton, total consumption with di- vision into melting and refining. tables have been assembled show the carbon content for each heat. However, inasmuch the steels melted were all cases special steels containing various ele- ments such chromium, nickel, tung- vanadium, the carbon con- tents afford only approximate clues for estimation the melting point. Inasmuch the author not author- ized give further details the heats, the indication the carbon content will have tional operating data for the furnaces are shown Table III. When calculating the average en- ergy consumption per -ton steel melted, both cases, the values re- lating the first two charges were left out consideration view the necessary heating-up the fur- nace; the average values, Table cover only heats instead heats, and Table heats in- stead heats. both cases, the energy consumption values per ton the same order; more specifically they are 670 Kw-hr. per ton with the 6-ton furnace and 679.5 Kw-hr. per ton with the 8-ton furnace. Taking into consideration that the average heat lasts hr. min. with the 6-ton furnace, and min. with the 8-ton furnace, one hour longer than with the 6-ton furnace, the re- sult must regarded narily satisfactory. spite the fact that the duration the 8-ton furnace heat per cent higher, the energy consumption figures have practically constant that has only per cent. Generally speaking, could ex- pected that the energy consumption new 8-ton high frequency furnace the Cogne works, Aosta, one the largest units this type the world. Currently acid lined, this furnace will soon changed basic lining. would lower with larger furnace. natural preliminary condition, this case, the energy input corre- spondingly higher with the larger fur- nace. the case hand, however, both furnaces are alternately operated from the same generator aggregate. The maximum input naces, both cases, was 1500 Kw. has already been stated, spite the considerably longer duration the heat the 8-ton furnace, the en- ergy consumption compared with that the 6-ton furnace, being 679.5 Kw-hr. per ton has dividual heats was low 575 Kw-hr. Several heats required 605 Kw-hr. per ton; the maximum energy consumption was 745 Kw-hr. per ton, the two first heats are not taken into consideration. With the 6-ton furnace (Table the average energy consumption 670 Kw-hr. per ton; one case, the consumption dropped 575 per ton, while the maximum energy consumption was 780 Kw-hr. per ton. The data the operation the plant given here relate the initial period after its erection. expected that after the work- men have acquired more experience, and after some important conditions such high “filling factor” the charge, thorough covering-up the heat, suitable wall thickness the furnace crucible which turn gov- erns the “magnetic coupling” and hence, the power input, are more closely observed, will further lower the energy consump- tion. the same time, the melting the furnace will in- creased. The following data are give idea the furnace loads and the generator voltage with the and 8-ton furnaces: the duration the heats, with the 8-ton furnace, reduced prevailing conditions, about hours, necessary increase the The average input, with normal heats and adjusted initial input 1500 Kw., related the total duration Kw., corresponding utilization factor the peak output about 0.75 0.80. Accordingly, the furnace in- put should raised about 2000 Kw. giving the plant the necessary dimensions. Such plant equipped with generator set which comprises generator approxi- THE IRON AGE, September 22, e r e | Heat No. 34653 34654 34655 34656 34657 34658 34659 34660 34662 34663 34664 34665 34666 34667 34668 34669 34670 34672 34673 34674 34675 34676 34677 34678 34679 34680 34682 34683 34684 34685 34686 34687 34688 34689 34690 34692 34693 34694 34695 34696 34697 34698 34699 34700 AVERAGE Heat No. 34487 3488 3489 3490 3492 3493 3494 3495 3496 3497 34503 34504 34505 34506 34507 34508 34509 34510 34511 34512 34513 1.03 0.50 1.00 0.70 0.70 0.70 0.40 0.50 0.70 0.80 Type Steel, Per Cent 0.30 0.70 0.10 0.50 0.60 0.30 0.70 0.30 0.70 1.00 0.50 1.00 0.50 0.70 1.00 0.30 0.09 0.30 1.02 0.80 0.30 0.37 1.10 1.10 0.80 0.37 0.70 1.00 4.30 1.00 1.00 1.00 0.50 0.52 0.50 0.50 Type Steel, Per Cent 3.50 1.00 1.00 1.00 0.75 0.50 1.00 0.50 0.10 0.75 1.00 1.00 0.70 0.75 0.46 1.00 1.00 0.50 0.50 1.00 1.00 1.00 TABLE OPERATING CHARACTERISTICS 6-TON HIGH-FREQUENCY FURNACE FROM DEC. 25, 1937, JAN. 1938 Weight Charge, Lb. 15,400 14,370 14,400 15,400 15,400 15,180 15,400 16,060 15,400 15,400 15,730 16,060 16,600 15,840 15,840 15,840 15,400 15,840 15,840 15,840 Melting Weight Time Charge, Lb. Hr./Min. 11,000 8/30 11,000 3/50 11,000 3/50 12,100 3/45 11,000 4/0 12,100 3/10 12,100 4/45 11,300 3/40 11,000 3/50 11,440 3/35 12,100 3/30 11,000 3/25 11,440 3/55 12,450 11,440 4/0 11,440 3/10 12,860 3/25 11,000 4/05 12,960 3/45 12,100 3/45 13,200 3/40 12,200 3/40 12,200 3/20 12,370 3/20 12,320 3/10 13,150 4/05 12,540 3/20 12,540 3/55 12,540 3/55 12,540 3/35 12,540 4/20 13,850 3/40 12,615 3/40 12,540 3/40 12,505 3/20 12,100 3/15 14,100 3/20 12,430 3/15 14,000 3/10 12,920 3/30 12,810 3/15 12,700 3/25 12,540 3/10 12,540 3/25 12,760 3/40 12,740 3/0 12,760 3/30 12,870 3/10 12,370 3/36 hr. Cha-ging Tine, 1/05 TABLE OPERATING CHARACTERISTICS FOR 8-TON HIGH-FREQUENCY FURNACE Power Melt Down, kw.-hr. 3400 3400 3000 3300 3300 3600 3400 3000 3100 2600 3400 3200 3200 3500 3100 3800 3500 3000 3400 3500 3100 3400 3300 3200 3609 3600 3600 3700 3300 3700 3590 3400 3500 3100 3300 3700 3200 3300 3700 3500 3300 3400 3400 3100 3400 3500 FROM NOV. DEC. 1937 Total Tine, Hr./M 12/55 5/15 4/50 4/40 4/40 5/50 4/50 4/15 5/40 5/50 4/55 5/45 4/05 4/30 5/40 5/40 5/30 4/45 4/40 5/0 4/15 5/15 Charging Time, Hr./Min. Finish, kw.-h r. 500 400 400 500 400 100 400 300 400 400 900 500 500 500 400 400 200 300 500 600 500 500 400 300 400 200 400 500 200 500 300 200 400 400 600 300 400 300 400 400 400 300 300 500 400 500 400 Power Total Power, 4600 3800 3800 3500 3700 3400 4000 3700 3400 3500 3500 3900 3700 3700 3900 3500 4000 3800 3500 4000 4000 3600 3800 3600 3600 3800 4000 4100 3900 3800 4000 3700 3800 3900 3700 3600 4100 3700 3600 3700 3900 3600 3700 3900 3500 3900 3900 Total Power 6200 5000 4900 4700 4400 5100 5100 4800 5100 4900 5200 5200 4400 4400 5200 5300 4500 5200 5100 5300 5500 4900 Total Power Per 2000 835 690 690 585 675 565 665 655 620 620 580 710 645 590 680 615 625 625 535 665 605 590 625 580 580 575 635 655 620 610 635 540 605 625 595 595 580 600 515 575 575 615 575 590 610 555 615 610 610 Total Power Per 2000 805 695 680 655 575 675 630 675 615 675 675 560 550 630 670 570 660 655 670 630 620 42—THE IRON AGE, September 22, 1/15 1.05 1/15 ir. TABLE Total Me'ting Charging Type Steel, Weight Time, Time, Total Power Heat No. Per Cent Charge, Lb. Hr./Min. kw-hr. 34514 0.50 16,700 4/50 4700 34515 1.00 15,840 4/30 4900 34516 0.50 16,500 4/05 4300 34517 0.50 15,400 3/55 3200 34518 1.00 15,840 4/40 5000 34519 0.50 15,620 4/05 4900 34520 1.00 15,840 4/30 4800 34521 0.75 16,700 4/25 4600 34522 0.50 16,280 3/55 1/25 5000 34523 0.50 15,620 3/45 4700 34524 1.00 15,840 5/05 5100 34525 3.00 15,620 4/45 4800 34526 0.50 16,060 4/30 5200 34530 0.50 16,280 3/55 5100 34531 0.50 15,840 4/15 5000 34532 0.50 15,620 5000 34533 0.50 15,840 4/0 1/15 4700 34535 1.00 15,890 4/30 5100 34536 1.00 15,820 4/10 4800 34537 0.50 16,080 4/20 4800 34538 17,600 4/30 4700 34539 0.50 16,280 3/40 4600 34540 1.00 15,840 3/50 4700 34541 0.40 15,690 4/20 1/10 5000 34542 1.00 15,840 4/25 5100 34543 0.40 15,380 4/35 5200 34544 1.00 17,690 5/05 5800 34545 1.00 16,060 4/30 5100 34546 0.50 15,840 4/30 1/20 5100 AVERAGE 15,860 4/37 TABLE OPERATING CHARACTERISTICS FOR AND 8-TON HIGH FREQUENCY FURNACES Total Power Power Per Weight Charge, Consumed, 2000 Time, Generator, Heat No. Type Steel Hr./Min. kw. 8-TON FURNACE 34215 16,590 0.93 5300 645 5/00 1500 5/30 1100 6/10 500 6/40 1400 8/55 800 9/50 TAPPED TIME MELT DOWN: Hr. TIME, START MELT TAP: 34216 16,500 0.93 5000 605 10/40 1500 11/00 1300 11/30 800 12/00 1300 2/10 800 3/5 TAPPED TIME MELT DOWN: TIME, START MELT TAP: TON FURNACE 34275** 11,000 1.20 3200 580 5/20 800 1100 6/10 1300 7/05 600 TIME MELT DOWN: 9/05 TAPPED TIME, START MELT TAP: Hr. Hr. 34248 9850 0.10 3500 710 4/00 1500 4/20 1000 5/00 800 5/20 1000 7/10 800 8/10 TAPPED TIME MELT DOWN: TIME START MELT TAP: Stainless 34253 9900 0.09 3200 645 4/45 1500 5/05 1000 5/30 800 6/00 1000 8/05 800 8/20 300 8/55 TAPPED TIME MELT DOWN: TIME, START MELT TAP: *Input capacity has not been fully utilized. After patching, furnace was heated carefully. THE IRON AGE, September 22, 1938—43 Total Power Per 2000 Ibs., kw-hr. 565 620 525 418 630 630 610 550 615 605 645 615 645 630 635 640 590 640 610 595 535 565 590 635 645 680 655 630 640 679 Generator, Volts 3000 3000 2000* 3000 2500 Min. Min. 3000 3000 2500* 3000 2500 Min. Min. 2300* 3000 3000 2000 Min. Min. 3000 3000 2800* 3000 2500 Min. Min. 3000 3000 2800* 3000 2500 1800 Min. Min. wer 7 mately 2000 Kw. and motor 2300 Kw. Considering the present status high frequency electrical engineer- ing, their construction will counter any difficulties. will then heat from hr. about hr. and increase the number heats The furnace throughout may then brought from tons about further improvement the util- ization factor the high frequency apparatus possible parallel oper- ation two more high frequency furnaces that the input the re- spective units adjusted that the total the power input constitutes the maximum possible with the con- cent. Such plants have been op- eration for two years, Germany, the Dorrenberg steel works Run- deroth, and thus tested under condi- tions practice. the case just mentioned, two 1320 furnaces are operated parallel manner with 250 Kw. generator. Some time ago, large new plant the Hochfrequenz- was put operation which consists two 4-ton and two 2-ton furnaces operating parallel manner and being fed 1600 Kw. generator. further development proved construction principles, correct op- erating procedure and rangement, the path which will the generally accepted one lead further improvement the utilization factor and economy general. was the intention author submit the American public some typical cases from European, chiefly Italian operating practice, and give outline the possibilities fu- ture development. view the present stage development high- frequency electrical engineering, assumed that the creation ton high frequency furnaces will possible the near future. Acknowledgment conclusion, the author wishes express his indebtedness Dr. Coli the Cogne works for his kindness supplying some operating data. The author also indebted Prof. Sil- vestri, president Steel Works, Aosta, Italy, who has been re- sponsible for the erection the new and large high-frequency plants the works Aosta, for per- mitting him submit the Amer- ican public the foregoing article con- taining some new data. UGE cast iron centrif- ugal pump casing weighing 45,000 longing one four 72-in. double-suction sewage pumps now under construc- tion the shops Allis- Chalmers Mfg. Co. for the Sanitary District Chicago. Each complete motor driven pumping unit will weigh 000 Ib. and will capable pumping 375 cu. ft. per sec. raw sewage and storm drainage speed 138.4 feet. __| 44—THE IRON AGE, September 22, 1938 ISPOSING waste pickling acid from steel mills has been the object much scientific and practical research for many years. patent treatment process was taken out 1880 and from that time until about 1920 there were numerous ideas patented, most these methods producing ferrous sulphate, what commonly known copperas. While very few patents have been taken out the last years, one im- provement was made, provide that very minimum ferrous sulphate crystallized out and certain amount through the pickle tanks. Not many years ago there was sizeable market for copperas the water treatment processes vogue, and the were able sell tonnages the prod- cost price. The production costs these plants ranged from about per ton. Unfortunately for these plants, however, the past decade has Witnessed copperas the filtration plants being supplanted alum and various other chemicals. possible produce sulphuric acid from ferrous sulphate, but there are objections this possible solution the waste acid problem, the most serious being that acid produced Chemical storage and mixing tanks Precipitating tanks WASTE would cost more than that made from sulphur. considerable promise new process which appears furnish answer this perplexing problem. Covered patents the Allied Development Corp., Cleveland, the waste pickle liquor converted into building material with insulat- ing properties. The material thus made, which has been given the name iron hydroxide and calcium sulphate. Sharon Steel Corp. present constructing such disposal plant Sharon, Pa., and the first steel company tackle the problem waste acid disposal this manner. this process, the spent liquor collected storage tanks. then transported through pipe precipi- tating tanks, where the batches free sulphuric acid and iron salts re- steel company now building plant handle waste pickle liquor this new manner. Pickle liquor mixed with other chemicals, the solids being pressed into building material, the only waste being clear, comparatively pure water which may re-used the mill. Filter main for about one hour and are neu- tralized with either lime, other alkaline calcium salts, and then pre- cipitated. The operating temperature closely held the neighborhood 150 deg., the tanks being heated with steam. The precipitate then sent through pipes filter presses. Clear, unpol- luted water discharged into streams sewers re-used the mill, and the matter remaining Ferron its plastic form. This Ferron then run through plug mill and de-aired. Taken from the plug mill cake form, the material then sent oven for drying. obvious that the entire process relatively simple and inexpensive. the plastic state, Ferron can molded into any desired shape which later sets into hard, rigid mass through the combined process dry- ing and oxidation. The product homogeneous, solid appearing mate- rial, tan color. has advantages over wood, plaster and brick, being fireproof, termite proof, non-warpable, able stand high temperatures with- out losing its strength. lighter than brick and can sawed and machined. While the product porous, ap- plications where absorption (CONCLUDED PAGE 81) Presses effluent dryer THE IRON AGE, September 22, 1938—45 ill ‘SS il- ‘e- COMMON method holding and 30. Here tapered pins are driven through small levers pressed shaft order prevent movement handling during brazing. This scheme though subject the objec- tions outlined for pinning levers, commonly employed for in- dexing certain sub-assemblies furnace-brazed for cash registers and business machines. Wedging Parts Together are frequently used lock members into assemblies. Fig. shows two methods wedging tung- milling cutters preparatory furnace brazing. shows use tapered pins for this purpose, while shows mica porcelain wedges pressed into the slots. addition assuring intimate contact between the surfaces desired bonded, these methods have an- other virtue that they prevent the carbide bits from becoming brazed the opposite walls the slots. Other- Wise, upon cooling and contraction the rim, the carbide would put IRON AGE, September 22, 1938 WEBBER Industrial Department, General Electric Co., Schenectady, tension and some the bits might become cracked. With the arrange- ment shown only one face the bit furnace brazed, and tension de- velops the bond while cooling. Be- cause the intimate contact, strong bonds are produced which result firm anchoring the bits into the cutters. Holding Parts Together With Screws One manufacturer punch holders, the large sizes, for die sets for punch construction that the shank, which simply cut with ends square from standard drilled and screwed the holder which cut which the assembly put together shown the sketch. cams The punch holders which are now were former- made steel castings. was lathe, face off the holder, and turn down the shank. The castings fre- quently had blow holes them which reduced their strength and sometimes Such breakage the often caused serious damage ex- pensive dies injured the operators. However, the hundreds copper- brazed punch holders which have been made reported that not one has ever failed from breakage the cop- per-brazed joint. This result the great strength the bond and the addition, the cost the furnace- that the finished steel castings. Winding Fins Tubes heat transfer tubing wind edgewise fin the tube and furnace- braze position, shown Fig. The copper wire can either applied the same time the fin wound, afterward. When the fins are fairly close together, gen- erally not necessary take precau- tions keep the wire adjacent the fin, The wire must tied the ends order keep from unwinding the furnace. ciple found the manufacture ABOVE cams hold their index while Tapere porcelain being furnace brazed common pins edges practice. LEFT 29—This cash register sub- assembly illustrates how pinning used lock the parts together. IS IG. methods wedging tungsten-car- bide bits into slots milling cutters prepara- tory furnace brazing. ~. ¥ Pj Shaft evers a 4 a q ° ° ° : now was turn fre- vhich times Iders pper- been has cop- the steel, half -Céar- ara- finned Calrod heating elements shown the lower view Fig. 33, brazed joint gives permanency thermal conductivity and tin which unapproached any other construction. Overlapping the Members There are several methods over- lapping members assembly which prove quite effective for use the furnace-brazing process. shows few these methods. frigerator evaporator formed steel, then copper brazed, porcelain enameled. the best bond where corrugated outer plate touches the smooth inner plate, the with the corrugations horizontal that the copper can pud- dle down into the joints. Putting cop- per clips over the upper edge in- dicated ingenious way supply- ing brazing metal joint which rather inaccessible. The clips need ectric-Furnace ETHODS commonly em- ployed for holding as- semblies together for furnace brazing are further described this article, continued from THE IRON AGE Sept. 15, page 30. tures, both for maintaining proper relationship the components assembly brazed and for support- ing the assemblies trays conveyors, also are dis- cussed. since the cepper will melt and creep into the joints and will drawn along the joints capillary attraction, overlapping, sometimes used hollow containers. copper wire cannot resort putting the copper inside the joint, apply copper-powder paste along the outside the seam indicated. copper-brazed, double-walled steel tub- which made laterally rolling copper-plated steel strip into the form shown. This tubing widely used for automobile gas lines, oil lines, hy- draulic brake lines, and gage lines, and used also refrigerating ma- chines. has proved very success- ful due its great strength, high resistance vibration, and low cost. ductile and can easily formed. The ends can expanded hold fit- tings. Although the copper plating the strip only about in. thick, the walls are solidly welded to- gether, and tubing has uniform copper coloring the inside and out- side after brazing. avoid electric-furnace brazing that shown Fig. 36, particularly with long straight seams. almost impossible retain contact the BELOW 33—Winding fins tubes and furnace braz- ing them gives good heat transfer. G-E finned heating units are made this way. Fins Copper wire ABOVE 32—Screws are com- monly employed for holding parts together for brazing. The assembly shown punch holder. LA 4 THE IRON AGE, September 22, the 1ace- r be fins gen- ends | | lain | oOo | surfaces within such joints, because warpage when the the heat, particularly the diameter relatively great, say in. more. The result opened-up bulged joints which will leak. Interlocked Joints Interlocked joints such shown Fig. are frequently used form- ing assemblies brazing. shown cross sec- tion steel tubing with the edges rolled and interlocked prevent open- ing while passing through the fur- nace. can supplied using either very thin copper plating threading wire through the tubes and having the joint the bottom. interesting observe that sufficient time allowed, the cooper will creep the inner sides the tube from the bottom and braze the joint even the seam the top. shows interlocked joint some- times used making tubing, hollow containers. has the advantage giving secure locking effect with very little possibility opening the heat. Auxiliary Fixtures All the foregoing methods holding assemblies together are com- monly used for electric-furnace braz- ing, the choice any method de- pending upon the characteristics each individual product. But some cases, found impracticable use any the suggested methods, and then necessary resort auxiliary 48—THE IRON AGE, September 22, 1938 paste Copper electroplate LEFT 1G. 34—Copper-brazed finned Calrod units are used this form for forced-con- vection air heating. fixtures properly locate the mem- bers with respect one another while being furnace brazed. These fixtures sometimes take the form graphite blocks, cast ports, clamps. tying the as- semblies together with heat-resisting alloy wire resorted to. Auxiliary fixtures have several dis- advantages. the first place, they present additional mass which must heated up, they slow down produc- tion the furnace because the extra mass heated, they are subject warpage which might make them unusable, and they present extra item maintenance expense. However, two examples where aux- iliary fixtures have been used ad- vantage are follows: Graphite Blocks contacts for automobile-ignition systems are supported graphite blocks shown Fig. and 39, while being copper brazed electric furnaces. The pur- pose the blocks center the tungsten disks the heads the Copper Copper plate wire 37—Types interlocked joints suitable for use elec- tric-furnace brazing. Copper-powder LEFT 35—Types over- lapping for use electric-furnace brazing. The section shows the Bundyweld cop- per-brazed steel tubing. BELOW 36—Overlapping joints type difficult make tight and keep tight furnace brazing. Avoid straight overlapping keep joint from opening steel shanks, there being copper shims between the disks and shanks sup- ply the brazing metal. slight clear- ance must left around the head the shank that the shank can settle down the copper melts. in- teresting observe that the manufac- ture tungsten contacts was the first commercial application furnace brazing large-scale produc- tion, and that the method brazing the contacts graphite heat-resist- ing alloy blocks shown essen- tially the same now was Graphite slabs are sometimes em- oyed trays bottom supports for assemblies because their ability remain flat and straight, thus giving even bearing surface which results minimum distortion assemblies which are otherwise subject distor- tion. supporting steel parts graphite some diffusion carbon into the steel expected. fact, the time the heat critical some cases, because the diffusion rapid that high concentrations carbon can built and cause sufficient depres- sion the melting point the steel result melting the surfaces the steel members contacting the graphite. This carburizing action gen- erally can prevented covering the upper surface the graphite with thin sheet asbestos paper. Graphite blocks slabs can ob- tained from such vendors the Na- tional Carbon Co., Inc., Cleveland. The vendor named makes grade “AGR” graphite which been used successfully for this application. Copper clip = a & Co er as ~ > TUN hims sup- lear- in- first zing em- for ving sults stor- steel that res- the hite ob- Na- ind. ade een ion. Copper shims Tungsten IGS. and 39— Graphite blocks are sometimes used for supporting semblies. Tungsten contacts for auto- mobile ignition coils holding the tung- sten disks and steel shanks recesses graphite slabs. available from list standard sizes special sizes. Clamps. Fig. shows method holding the members tungsten- carbide-alloy knife while being elec- tric-furnace brazed. Clamps made heat-resisting alloy bolts and bar-stock are improvised lock the carbide bits the steel shanks, there being sev- eral these clamps used the length Brazing metal the form copper strip can placed near the joint shown, copper paste can used. mica asbestos in- sert sometimes employed keep the carbide bit from becoming brazed the cross bar. The mica insert may not needed between the steel shank and cross bar some jobs, such the right Fig. 40, because the dis- tance from the brazed joint the bar sufficiently great that the copper will not creep that far the allotted brazing time. should also kept mind that the clamps expand they heat up, and they may not always hold assem- blies together tightly copper-braz- ing temperatures even though they are drawn tight when cold. Free-fitting threads should used assist tak- ing the nuts off after going through Copper strip alloy the furnace. Otherwise, might stick and require scrapping the bolts. Supporting Fixtures Sometimes Used addition using auxiliary fix- tures for maintaining proper relation- ship the members assemblies brazed, auxiliary fixtures are also sometimes used support the as- semblies trays conveyors, simply for the purpose (1) keeping the assemblies the best position for proper flow brazing metal, (2) keeping the assemblies from tipping rolling off the conveyor, (3) keeping them from touching and be- coming brazed one another. Three typical examples such fixtures are illustrated Figs. 41, and 43. Fig. shows how cylindrical support made heat-resisting alloy strip which tack welded the seam. shown holds refrigerator float place the belt that will not roll. Fig. shows heat-resisting cast- alloy support which holds two re- frigerator assemblies the RIGHT sheet alloy supports are used floats position the mesh-belt con- veyor the furnace. Chromium-iron alloy bolts and bars LEFT 40—Though last re- sort, alloy-steel clamps are occasionally employed hold parts together. The assembly shown knife with tungsten- carbide cutting edge. most desirable position for furnace brazing. When the assemblies are this position, the brazing metal, the form copper-wire rings joints, has opportunity flow downward into the joints. Fig. shows supporting fixture made heat-resisting alloy wire, which holds refrigerator piston the upright position that the flow copper will influenced gravity the best advantage. The supports made strip and wire usually consist alloys containing per cent nickel, per cent chromium, while the cast support illustrated made alloy containing per cent nickel, per cent chromium, per cent iron. Other alloys also are, course, commonly used. Assemblies Placed Directly Conveyor When heat-resisting-alloy conveyors trays are employed, which generally develop protective film chromium oxide use, usually satisfactory rest the assemblies directly upon them because there very little Graphite ° ° ° IRON AGE, September 22, 1938—49 4 valuable for supporting assemblies upright position obtain proper flow copper into the joints. chance the assemblies becoming brazed these alloy members. When the alloys have been service long time, however, some sticking likely noticed. Particular care should taken see that fluxes are not allowed come contact with the alloy parts because the result will quick destruction the alloys due the continuous removal the pro- tective oxides which form. Fig. shows typical refrigera- tor sub-assembly resting directly 43—Wire fixtures made heat- resisting alloy are effective for sup- porting assemblies upright position permit brazing meta! flow downward into joints. belt conveyor. The joint brazed the very botton, adjacent the conveyor. The brazing metal comes actual contact with the conveyor but bond made with it, and the assemblies are easily removed from the conveyor the discharge end the furnace. Sometimes trays made steel are employed, which case desirable cover them with sheets thin asbestos paper order prevent the assemblies from being brazed the 50—THE IRON AGE, September 22, 1938 44—Assemblies while being fur- nace brazed can rest directly the alloy mesh-belt conveyor charging trays used the furnace. trays. Some shops carry asbestos paper several thicknesses because handy for use spacers shims setting objects irregular shapes. vendors heat-insulating materials. Small alundum-compound blocks, ob- tainable turers, also are quite handy. Mica good material for separating where desired keep members from becoming brazed together. (TO CONTINUED) HIS shows the the Holland- America Line's ship, Nieuw Amsterdam, which has doors made Enduro stainless steel, product Re- public Steel Corp. This metal was used kitchens and else- where the vessel. 4 More Space for Clipper Ships and Flying Fortresses the new plant No. this 300 450-ft. modern factory building Seattle, the Boeing Model transports for TWA and Pan American Air- ways will assembled. The first unit the building, 200 300-ft. assembly section, en- tirely without obstruction, was built less than two years ago the Austin Co. Recently the same builders have completed two 125 300-ft. bays, increasing the clear rom working space nearly 5,000,000 cu. ft. the building, are apparent overhead Crane bridges, staggered along the runways, can seen the right. ; THE IRON AGE, September 22, Coiled Silicon Strip coiled silicon strip steel and its widespread electri- cal manufacturers making lamina- tions for motors, transformers, and other electrical apparatus has been one the most significant advancements the perfection electrical steels. Every year since was introduced 1930, the production coiled sili- con strip has increased over the pre- ceding year, total production 1937 being almost times greater than was five years ago. Possessing all the properties corresponding grades sheets, yet without any the shortcomings “coil set,” silicon steel the form coils results less scrap, reduces han- dling costs, and increases die life. Until the develop- ment coiled silicon strip, lamina- tions used electrical manufactur- ers were, course, punched sheared from flat steel sheets. Today, coils in. wide are being pro- 52—THE IRON AGE, Septernber 22, 1938 duced, and many are predicting that coils will eventually completely. sup- plant sheets this field. Silicon steels used electrical ap- paratus contain from 0.2 4.0 per cent silicon, depending upon the ap- plication, and minimum amount carbon and other metalloids. The qualities which determine the success silicon steel for this purpose are: (1) High permeability, (2) low core loss, (3) freedom from loose scale, (4) close gage and width tolerances, (5) minimum brittleness, (6) good punching properties, and (7) ability stack flat after punching. obtain these qualities, every step the manufacturing process must course subjected the closest metallurgical Until the development coiled sili- con strip there had been radical change the methods production electrical silicon steel for some years. important improve- ments the process were constantly |—Heat treating silicon strip Warren, Ohio, plant ing through rol- ler hearth furnaces, produce uct that will have required electrical properties lie flat coiled. ° ° ° BURTON LONGWELL Republic Steel Corp. ° ° made during that period. The mate- rial, say ten years ago, was far bet- ter quality than was ten years before that. But the basic mill operations for producing remained the same. recent revolutionary development the steel industry however intro- duced vital new elements that pic- ture. New mills which made the roll- ing sheets continuous process and made possible the production steel the form coils strip, were de- signed and built for the rolling car- bon steels. Some the sweeping im- provements incorporated these new continuous mills for the rolling carbon steels, seemed obvious, might very well applied the manufac- ture electrical silicon steels. least two important new prob- lems which the manufacturers car- bon steels did not have face, how- ever, had solved the makers silicon strip. new annealing process had developed that the product ‘would stay flat when un- ~ silicon arren, pull. urnaces, will bet- efore tor ntro- roll- and steel de- im- new car- 10W- that un- coiled, and some effective method had found restoring the steel the desired electrical properties which were destroyed the cold strip roll- ing process. Without solution these prob- lems, coiled silicon strip would have commercial value. Neither “coil set” nor “cross could tolerated. Not only would mechani- cal difficulties encountered the punching strip containing set,” but (and this prime objec- tion) the resulting laminations, not being flat, would not stack properly. Ordinarily, silicon sheets are an- nealed the conventional box an- tons sheets are placed large sealed container and subjected relatively high temperature for period from hr. But such annealing practice would not satisfactory the case coiled strip because the steel was heated and then allowed cool coil form would have pronounced “coil set.” The second problem was also very serious one. Silicon steel generally used thicknesses from 0.025 in. (24 Standard gage) 0.014 in. (29 gage). This considerably lighter than the thicknesses that can rolled directly continuous hot strip mill. the cold working the steel which therefore made necessary order get down the desired finish gage, however, the highly strained steel loses its electrical properties. very satisfactory solution both these problems was found the development entirely new tech- nique for the heat treatment silicon strip. This new technique consists pulling the ribbons strip exact, predetermined speed and tem- perature through atmosphere con- trolled roller hearth furnaces. The strip temporarily welded together make the process continuous one. The steel coiled some distance from the discharge end the furnace after has had chance cool room temperature, resulting product that will lie flat when uncoiled the punch press. addition removing “coil this type furnace gives excep- tionally uniform anneal and very satis- factorily removes the destructive ef- caused the cold reduction process. Further, mechanical control fur- nace operations very accurate that the heat treatment imparted uniformly every square inch strip. yet very important feature this new annealing techni- que the fact that the type mill scale oxide produced silicon strip different nature from the characteristic silicon sheets. This due primarily the atmosphere con- trol features the furnace. Silicon steels used electrical ap- paratus require continuous coating some form insulation, such mill scale, order reduce eddy cur- rent losses. the utmost im- portance that the mill scale tena- cious, otherwise becomes loose and breaks off fabrication. Loose scale also materially reduces die life. The oxide silicon strip made the new furnaces not only very tenacious, precluding rupture the scale while being punched, but also extremely light. Thus offers less abrasion resistance the punch- ing dies and consequently results longer die life. While apparent that the many mill operations and processes neces- sary for the production coiled sili- con strip entail more expense than that incurred the making flat silicon sheets, the same time the increasing demand for this product has reached such point that possible fur- nish coiled silicon strip only slightly higher price than that charged for silicon sheets the same gage, width and grade. The differential price gen- erally readily assimilated, moreover, the realization least three im- portant economies: saving scrap, reduced handling cost and increased die life. The saving scrap affected the use coiled silicon strip very considerable item. Individual flat sili- con sheets are seldom more than 124 in. long. Due limitations mill practice, exact sheet mill lengths cannot obtained without the pay- ment extra charge. The user therefore has his hands the end each slit sheet, scrap material either half-punched laminations un- used sheet. Silicon strip, the other hand, comes lengths from 700 1700 lineal feet, depending upon the gage ordered. With such long coils, scrap the end encountered much obvious saving. The fact that silicon steel now avail- able coiled form has also materially increased the use scrapless dies punching operations. The second important economy, that reduced handling cost both la- bor and time saving factor. This especially true the case the narrow widths, say in. stock such used electric shaver motors, which are extremely difficult han- dle. Full weight coils silicon strip weigh approximately per in. width, coil strip in. wide, for example, weighing 375 Ib. This the standard weight found most economical and convenient the ma- jority shops. Silicon coils this weight stand- ard are easily unloaded from trucks cars when received the final destina- tion. They are convenient stock and are readily mounted reels the punch press. Since the coils are delivered already slit the desired width the slitting operation the user eliminated. This means the (CONTINUED PAGE 82) 2—Testing silicon strip verify its high permeability, low core loss, and uniform temper. ° a ° Technical Papers Convention ments and operating costs greater interest this year than ever before steel and its in- dustries, more than 5000 steel execu- tives and plant operators will gather Sept. 27-30 Cleveland hear presented the Association Iron and Steel Engineers’ convention. Probably the most comprehensive program yet presented has been arranged for technical sessions which will he'd the Cleveland Public Auditorium conjunction with the and Steel Exposition. addition have been arranged Steel Corp.’s hot and cold strip mill, and General Body plant Cleveland. Many the technical deal with processing and manufacture wide strip steel, while will paper “Modern Blooming president, Mesta Machine Co., Pitts- burgh. Leading steel mill engineering au- thorities will me- chanical, metallurgical, combustion, lubrication and welding engineering, applied the steel industry whole. Seamless Mill Model Ready More than 100 manufacturers steel mill equipment will exhibit their latest designs and products annual Iron and Steel Exposition. Outstanding will animated model new tube mill 54—THE IRON AGE, September 22, 1938 Association and Steel En- gineers well superintendent the mechanical department, Bethlehem Steel Co., Sparrows Point, Md. recently designed and built Aetna- Standard Engineering Co., Youngs- town, for Youngstown Sheet Tube Co., Youngstown. The will actually roll lead pipe from lead billets and replica the first large seamless tube mill built this country over seven years. All social events will held the Hotel Statler, Cleve'and, tech- nical sessions and exhibitions will held under one the Cleveland Public Auditorium. Tom Girdler, board chairman, Republic Steel Corp., Cleve'and, will address the members and guests the Association Iron and Steel Engineers the formal banquet, Sept. 29. Said Coffin, superintendent, mechanical department, Bethlehem Steel Co., Sparrows Point, Md., and president the association “As the annual Iron and Steel Ex- position opens Cleveland Sept. and the Association Iron and Steel Engineers presents its technical program connection with this meet- ing, the importance these events the steel industry will twofold. Men and Machines “In the first place the exposition itself will display the latest designs more than one hundred manufac- turers steel mill equipment, occu- pying 25,000 sq. ft. exhibit space. the best balanced and most authorita- tive yet presented the association. Active operating men designers and discuss many the date developments steel mill engi- neering. Not only will marvelous advances fully described, but inspection the mills will serve impress these ad- vances more fully. “There another manner which this exposition and meeting should have its effect the steel industry, full purpose. Equipment are only the tools. The men who man and maintain these tools must keep pace with them; must understand and master them, their full usefulness obtained and further ad- vances are made. these tools become more refined and complicated, must the training men for these jobs become and more thorough. Operating vice departments require new and widely extended grams are achieve the fullest capacity and quality from each our new mi'ls. “If this meeting impresses more clearly the far-reaching scope these technical changes and thereby makes more conscious human problems involved and causes modify, improve, and accelerate our methods training men main- tain and operate these mills, will have served well indeed. Inspiration Hoped For “Managements and their operators and engineers can well afford par- ticipate full extent the activi- ties Cleveland the end that interchange thoughts and ; 2 é Vital Topics Await and Steel Engineers ideas, and renewed inspiration m