The Iron Age 1945-03-22: Vol 155 Iss 12

Editorial and Advertising Offices President and Editorial Director Vice-President General Manager Assistant General Manager Advertising Manager Service and Market Research CLEARY, Technical Research and Promotion Manager New York New York 100 East 42nd St. 100 East 42nd. Chilton Bidg. 1134 Otis PEIRCE LEWIS WARREN 87 be. 7310 Woodward Ave. P.O. Box 2420 Cheremoya Ave. Owned and Published CHILTON COMPANY (Incorporated) Executive Offices Chestnut and 5éth Philadelphia 39, Pa., U.S.A. OFFICERS AND DIRECTORS | $142.50 EVERIT TERHUNE Vice-President VAN DEVENTER BAUR Vice-President FAHRENDORF Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary Vice-President CHASE HARRY DUFFY CHARLES HEALE WILLIAM VALLAR, Asst. Treas. Member Audit Circulation mn, is, ith is, the Industrial Arts Pub- lished every Thursday. Subscription North America, South America and ad, Possessions, Foreign, $15 year. al- Copyright 1945, Chilten Company IRON AGE Vol. 155, No. Editorial United Stand Technical Articles History Induction Automatic Arc Welding Aluminum Structures Metal Cleaning Before Silver Heat Treating Steels From Rolling Temperatures Bessemer Steel Production and Conveyor Degreaser Made Fire-Safe............ Phosphate Coating Aids Steel Wire New Equipment Features News Front Assembly Line Washington Personals and Obituaries This Industrial News Industry ............. News and Markets Production and Financial Reports: Youngstown Sheet Tube Basic Refractories, Inc. Alan Wood Steel Rustless Iron Steel United Engineering Foundry Continental Steel American Brake Shoe Co............... Powder Metallurgy Machine Tool Market Developments. Nonferrous Metals News and Iron and Steel Scrap News and Comparison Prices Week and Year Warehouse, Semi-Finished, Steel Prices Steel Pipe, Tubing, Wire Products, Pig Iron and Coke Stainless Steel and Ferroalloy Prices Index Advertisers March 22, 1945 144 128-129 130-131 134-135 136-138 ° ° 108 108 140-141- 142-143 ° ° ° 42—THE IRON AGE, March 22, 1945 Steel tock! No!—buyers don’t run the Ryerson Steel- Service Plants buy steel, they cig- arette counter when the sign but sometimes have almost much difficulty keeping with demand. Every week thousands orders speed steel from Ryerson war plants and essential industries throughout the country. reasons are simple and basic. Ryerson plants stock more than 10,000 kinds, intelligent and helpful Equipment and how” are hand cut and otherwise prepare steel the way you want Deliveries are quick. But most important Ryerson dependability, demonstrated 102 years steel service, and the determination deliver you, humanly possible, the steel you want when you want it. Ask your Purchasing Executive let you see the Ryerson Stock List. realize what mean 10,000 kinds, shapes and sizes steel. your Purchasing Executive without the Ryerson Book sure gets one from our nearest plant. RYERSON Son, INc. Steel-Service Plants: Chicago, Milwaukee, Detroit, St. Louis, Cincinnati, Cleveland, Pittsburgh, Philadelphia, Buffalo, New York, Boston. ESTABLISHED 1855 ° ° March 22, 1945 ° VAN DEVENTER President and Director BAUR Vice-President and General Manager ° Editorial Staff Technical Editor ......... OLIVER ° ° Associate Editors WINTERS JACK HIGHT ALBIN JOHN ANTHONY BARMASEL Editorial Assistants SCHIEN HANSEN DAVIS News and Technical Editors LLOYD Pittsburgh 428 Park POST Chicago 1134 Otis DONALD BROWNE EUGENE HARDY Washington National Press Bldg. LLOYD Cleveland 1016 Guardian Bldg. BRAMS Detroit 7310 Woodward Ave. OSGOOD MURDOCK San Francisco 1355 Market St. Editorial Correspondents ROBERT Cincinnati DEAN Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ont. RAYMOND KAY Los Angeles JOHN McCUNE Birmingham ROY EDMONDS St. Louis JAMES DOUGLAS Seattle United Stand NITED have stood and only united effort can remain standing. think this axiom that most people will accept. the vital matter planning for postwar employment, this truth indisputable. not one man job, one class job one community job. does not start and stop with government, em- ployers, whether manufacturing distribution products, with employers transportation and service occupations. not task for steel plants machine shops alone for makers baby carriages and the other tens thousands products that are made, bought and sold, but permeates back the counter the smallest retail store, into the offices doctors, lawyers, architects and real-estate brokers and beyond these the hopes and fears for and the future that involve every man, woman and child our country. All-Amer- ican problem that requires the best from All-American team. The building efficient mechanism for postwar employment like the building any new machine requires the making detailed work- ing drawings parts and sections which finally, after design changes, will come together complete functioning assembly. That takes lots able work many able people. are fortunate indeed having the general specifications for our postwar employment machine laid down the Committee for Eco- nomic Development. Under its direction and guidance, thousands our ablest doers and thinkers throughout every state the Union have been organized effectuate its purpose, which make postwar jobs the American way. Probably more minds and more effort are being devoted this single purpose than any other except that doing our part helping win the war. But this job not done, nor will done, until its aims are known, understood and appreciated not only those now engaged but every intelligent person this country. And particularly should its purpose and how that being sought interpreted and understood our wage earners and the general public. The man the mill the man the lathe the clerk behind the counter, the engineer the locomotive throttle, the public servant, the doctor, farmer and housewife have much stake this great enterprise, not more, than has the largest employer this country. And she also can help making success. Many you who read this page are doubtless already actively en- gaged this work are least conversant with it. not, you owe yourself, your company, your industry and your country become informed about it. For the perfecting this great mechanism into efficient operating machine will need the active cooperation every man and woman good will and good mind. More than 600 business publications our country, covering almost all lines constructive effort have now been banded together assist conveying information you the developing activities this organization and assist spreading your employees, your fellow workers and your customers. This publication one them. will glad indeed have you write for information you prefer you can address, directly, the Committee for Economic Develop- ment, 285 Madison Avenue, New York 17, 4 MUNZER O'CONNOR lant. rvice 4-Way Traction matter what angle foot wheel contacts Inland 4-Way Plate, meets projection which safely grip, forward, backward, left, rig t—4-Way Safety Traction. The special Inland 4-Way pattern permits sweeping and drainage whatever direction most convenient, clean floors contribute safe- Inland Floor Plate made high quality open hearth steel. has the tensile, compression and bend strength structural steel plates. Its wear resisting qualities are far greater than other floor coverings. ty, and Inland 4-Way Floor Plate makes shop 4-Way The Inland pattern the same all four direc- tions. Plates can matched end end, side side, side end, provide continuous and appearance. Pieces, even small ones, can matched and used with practically waste. News March 20, 1945 Lockheed's fighter, which now combat action outpaces the best aircraft. When performance details the American fighter are released, the mprovement gas turbine engine design and efficiency will one the war's Weatest engineering achievements. Still superior jet craft are design boards and a'building. The and rationalization going the Army regarding certain items, particularly tanks, doesn't seem impress the soldiers fighting the equipment. Smugness tank design reminiscent severe cutbacks and operations tank plants over year ago when the talk was that tank had lost its effectiveness. The Army and Navy have set production goals for WPB that for size and speed surpass anything since Pearl Harbor. The military are deadly afraid that the American people will soft the war once Germany defeated. Already there growing talk isolating and leaving her relatively impotent but undefeated. And, many spokesman will field day about possessions other countries the Pacific being American lives. The Navy considers these lines thought inevitable that all plans are being put military action the final phase before widespread weakness spirit serious. WPB getting little worried about the civilian economy, primarily regards transportation. Repair parts are scarce and the battery and tire situation serious. Corrective actions are prospect. Although Allied airforces have been wrecking German industries, there concerted effort knock out power plants. This surprising view the captured parts the there still electrical power readily England, grandiose plans for postwar temporary steel housing seem dying quick death. The idea and the sample houses never created much enthusiasm among people who were going live the houses. Meanwhile: The British Government considering the utilization foamed blast slags for some house construction. production over one-half Million tons being aimed at; about tons will needed for medium house. Heavy pressure the aluminum production resurgence being placed the Co. Canada, operating completely without use coal for power, out for the possible coal shortage here. News dispatches describing Japanese robot bombs use Iwo "clumsy and are reminiscent the debunking artistically done the Army shen similar weapons were first used Germany. Airlines operators are disturbed the announcement the Air Transport that regular revenue operations for civilians will conducted, "to aid operators over the war end transitional period," while the Army continues draft airlines personnel. Foundries supplying General Motors lack sufficient process control, company engineers told foundrymen. characteristic applicable many foundries disregard for doing very much about quality content production, the standards and inspection personnel said outlining its viewpoint the sought its equipment. That this lack control proved expensive was illustrated two castings the rough GM's Detroit Diesel Division. The scrap these two $128,207 one year, while further scrapping these during machining, foundry defects were uncovered, represented additional $627,442. WPB and ODT have proposed that the steel industry, its suppliers raw materials mid the nonferrous smelting industry granted draft deferments greater than the per cent the group now generally being applied other industries. | | | Cc | = on — | INDUCTION HEATING History Its Development IGH frequency electric fur- naces are used universally almost all branches the in- dustry. Induction heating has emerged far from the developmental stage and has overcome the objection that expensive way heat. ex- pensive and limited thereby some applications; its progress has stemmed from the fact that its use new and better products have been made which could not have been made other methods. Despite high first economies speed and mass produc- tion permit induction furnaces show real savings fields where, only short time ago, its use from the com- petitive standpoint seemed imprac- ticable. the melting field, substantially all the “fussy,” exact analysis al- loys are melted high frequency. Nickel-chromium alnico and other magnet steels, gun steels, stainless alloys, tool steels and carbides, copper-lead airplane bearing metals, certain naval and airplane bronzes, gold, silver and platinum, are representative metals wholly, ad- vantageously, melted this method. Furnaces range size tons capacity, and are many types, in- cluding units capable melting and that there are nearly 200,000 kw. high frequency melting furnaces use, with small experimental size units every metallurgical labora- tory importance the world. High frequency heating used widely for forging, upsetting, spin- ning and other hot forming opera- tions. Some 60,000 kw. energy has been installed comparatively recent years for this purpose. the pres- ent time, most the production for war use—shells, bombs, cylinders, gun barrels and the like. About 40,000 kw. induction heat- ing equipment use for surface hardening and hardening applications, including such operations the sur- face hardening crankshaft and camshaft bearings, the surface har- dening the internal and external surfaces bearings and bearing race- 46—THE IRON AGE, March 22, 1945 the initial work done Dr. Edwin Northrup 1916 lies the basis for all future development induction heating. Contrary popular misconceptions the first high frequency converters were spark gap oscillators. Motor-generator sets did not into commercial use until almost years later; vacuum tube oscillators somewhere between. The growth applications the pioneer company the field traced and future possibilities pointed out the author commemorating the company's 25th anniversary ways, the harden- ing rolling mill rolls, the harden- ing the points piercing shells, the hardening the internal walls engine cylinders, and hundreds like uses. Most the remaining applications high heating include heating for soldering, brazing ing operations; the sintering car- bides; high temperature work, includ- ing the reduction ores, the graphi- tization carbon, and the like; the numerous low fre- quency current; the drying surface coatings; and the allied but separate field ultra high frequency dielectric heating. The total installed capacity for these latter operations small comparison with the melting, forging and hardening applications due largely the fact that power require- ments for some the operations are relatively low. Stage Set The electric furnace art was very meager about 1910, although the arc furnace was use. The ring type induction furnace was being used some extent but the undesirable pinch effect phenomenon and the shape the bath were Dr. Gillett, now Battelle Memorial Institute, and his associates were about begin active research the indirect rocking are furnace the Bureau Mines field station Cornell. Submerged resistor and high frequency induction furnaces had been built, was very much later found out, but the experiments had been Frank Chesnut failures and the Secretary, Ajax Electrothermic Corp., Trenton, doned. was about this time that Dr. Guilliam Cla- mer, president the Ajax Metal Co., was working new metallurgical problem for which believed elec- tric furnace was the answer. Dr. Carl Hering approached him with idea for electric furnace involving the principle his lately discovered pinch effect. Dr. Hering’s idea was that, with two solid electrodes embedded the bottom furnace hearth and liquid resistors immediately above, electric current passed through the electrodes and the bath would heat the metal and the pinch effect force would cause circulate. believed that the head metal over the elec- trodes was sufficiently great, the liquid conductors would not disrupted the pinch effect force. The Hering furnace idea was tried with water cooled electrodes and di- rect current. Although the results were sufficiently encouraging keep the work going for long time, the water was continuous source worry and potential danger. Because this, Dr. Clamer suggested that the electrodes eliminated and that the tests continued using submerged loop liquid metal, inductively ex- cited, but still depending upon pinch effort for circulation. Dr. Hering considered such construction im- practical and continued with his original theories but finally abandoned the project failure. After the Hering tests were discon- tinued, Dr. Clamer and James Wyatt; assistant who had been the Hering binatic diate Metal The was Bridg all alysis win ulty cepti Clan prob el and nor ven Hering tests, did make closed loop submerged resistor furnace and the Ajax-Wyatt furnace, the new com- bination was called, became imme- diate success. division the Ajax Metal Co. was formed exploit it. The first commercial Wyatt furnace was installed the plant the Bridgeport Brass Co. 1916. was universally adopted the brass in- dustry and today well over per cent all the wrought brass the world melted this type furnace. New Method Sought work out the mathematical an- alysis and theory the new Wyatt furnace, Dr. Clamer called Dr. Ed- win Northrup, co-founder Leeds Northrup Co., and then the fac- ulty Princeton University. ex- ceptional was his work that Dr. Clamer assigned him the following problem: “Has any basic principle for developing heat electrical en- been overlooked the art electric heating, and so, has such basic principle promise commercial application?” This was the early part 1916, and certain neither Dr. Clamer nor Dr. Northrup had any idea that they were actually calling for the in- vention and development the high frequency furnace. Dr. Clamer had mind the development furnace this, Dr. North- Princeton University, heating was 1916. DWIN NORTHRUP proved that over 50" are not through. graph, had invented, and was rapidly develop- ing, his high frequency furnace. which would have most the good characteristics the Wyatt furnace, but which would more flex- ible its operation—a furnace which would melt all metals, and which would poured clean after each melt, away with the necessity maintaining so-called holdover charge during non-production periods. Dr. Northrup reported that the only method which appeared have promise was the method heating high frequency induced currents. though was later learned that 1892 Colby had the idea using high frequency currents for melting platinum, and that 4 q 4 # j q * Italian named Jacoviello and Frenchman named Schneider had toyed with the idea before him, their experiments had failed and their work abandoned. Had Dr. Northrup Dr. Clamer known these failures, neither perhaps would have been will- ing spend the time and money neces- sary carry the work. Fortu- nately, the knowledge that persons THE IRON AGE, March 22, 1945—47 rary tors out the ban- bout Cla- Co., lec- Jarl dea the nch nat, ABOVE CLAMER without whose foresight and pa- tient guidance the high frequency furnace would unknown. RIGHT HIS, one the earli- est commercial high frequency furnace equipments, industry. previously had tried and abandoned high frequency heating did not come until several years after the new high frequency furnace had been proved successful. 1916 radio was its infancy. There was voice radio during those years, but the dot and dash spark sig- nals were used the high seas and the regular commercial channels. The vacuum tube oscillator was not yet wide use. Dr. Northrup had made experiments 48—THE IRON AGE, March 22, 1945 equipment produce high fre- quency current and the losses cables carrying such current. knew that these losses were could made large. chose the problem trying increase the so-called: “losses” the point where they would the useful energy, and the radi- ated energy would turn become the loss energy. First High Frequency Unit illustrate his idea, used modified Tesla circuit for developing high frequency oscillating current, similar the spark gap wireless transmitter the day—the main dif- ference being the oscillation coil connections. Where radio the ends this coil were connected respective- aerial and ground and the ‘ ° ° RIGHT ACUUM tube con- verters were used early date for in- duction heating. This first equipments built for such use. energy was radiated, Dr. Northrup eliminated the aerial and ground con- nections and induced the energy into charge within the oscillation coil. The early spark gap converter proved that energy could concen- trated effectively heat metallic charge piece, but when application for patent was made, was rejected describing inoperable mechan- ism. Argument could not convince the examiner that the device was work- able but consented witness demonstration Princeton Univer- sity, where tests were being made. earthenware pot melting under the effect few hundred watts high frequency energy induced into several turns ordinary lamp cord, turned the patent attorney said, “Well, Mr. Jackson, what you want?” The very broadest patent claims were granted since the office had not been able find any prior art. The “Ajax-Northrup” furnace, was called, became the glamor in- vention the day. was called the “Fireless-Wireless” furnace news- men and advertisers. near magic presentations the public, eggs were ~ re q cl hrup con- into erter ation acted the iver- the high cord, and you office fried iron skillet, apparently resting cake ice. One could put his hand the new furnace, and unless wore ring, feel heat— but this same furnace would quickly melt charge steel. Dental alloys soon were melted “radio.” Development Stages There was large gap bridge be- fore this new method heating could considered practicable. The radio art was beginning shift from spark gap devices vacuum and the capacitors, better spark gaps and the like, was turning away from the cir- cuits best suited for inducting heating. Independent work had done along these lines. Because the surface conduction high frequency current, one the first advances was making the induc- tor coil out hollow tubing and cool- ing with water. the art pro- gressed the point where power dealt with became larger and larger, not only the inductors, but the bus bars, main switches, and even some the generators were water cooled. The first capacitors were hand made, with sheets brass and photographic glass plates alter- nately stacked and immersed oil bath. The capacity the units necessarily was low, and the dielectric poor that breakdown was the rule. furnace would operate for period from seconds half hour, when the capacitors would fail. Dr. Northrup finally appealed the General Electric Co. make him high frequency power capacitor. The early cooperation General Co., especially respect these capacitors, made induction heat- ing possible from practical stand- point. Although good capacitors are now being made others, can said fairly that the General Electric Co. has consistently led the world. Capacitor units 300 kva. are now larger than 1/3 cu. ft. volume. Discharge Gap The discharge gap also was con- tinuous source trouble. was early discovered that discharge operating between solid electrode and mercury was better than one operating between two solid electrodes, and thut was still better alcohol was dropped into the chamber housing the gap the chamber was flushed with hydro- carbon gas. The earliest. discharge gaps were noisy and ineffective, and only small 150 kw., 2000 cycle motor genera- tor equipment was one the first make commercial appearance and has piloted most the induction heating and melting processes used widely throughout the world today. power could obtained with their use; but the development moved from the open gap, the enclosed ro- tary gap, the enclosed tungsten mercury gap and the tungsten mer- cury gap with hydrogen atmos- phere, the power obtainable rose from hundreds watts kilowatts and 1923 kva., kw. With poly- phase units, 105 kva., kw., could taken from the mains, and goodly proportion could turned into useful energy the furnace. More recently the gaps have developed kw. rating, and the smaller ones have been hermetically sealed with atmosphere hydro- gen eliminate the necessity for the continuous flow gas through the gap chamber. Hydrocarbon gases are explosive when mixed with air; hence the ear- liest enclosed assemblies were made with blowout seals mercury; later, with semifragile insulating sleeves; then still later, with mica explosion windows which, after blowing out, could replaced easily. Today, with the development better insulators, the gap assemblies are being made porcelain and steel, designed that the chamber will strong enough withstand the maxi- hydrogen-air explosion. some these gaps, the hydrogen gas her- sealed within the gap cham- ber, while ‘others flowed THE IRON AGE, March 22, 1945—49 r in- } lagic were the original split wedge type focus inductor blocks used Ajax develop- ing the surface hardening method for the Ohio Crankshaft Co. WORLD USE AJAX-NORTHRUP HIGH-FREQUENCY INDUCTION FURNACES a =] wn = NOUCTION heating installations have doubled each four years since 1920. This chart includes sales licensees Ajax Electrothermic Corp. (Tocco, Budd and foreign). melting. 5000 charge steel destined soon whirled into mm. anti-aircraft gun barrel the Dickson gun plant. Courtesy Hughes Tool Co. 50—THE IRON AGE, March 22, 1945 through the chamber under the con- trol pressure governor. Surface Heating Surface heating for hardening, widely exploited and talked about years later, also made its appearance the early 1920’s. Vacuum melting, the degassing the elements vacuum tubes, the making furnace linings, and the like also had received wide attention. “Electronic” vacuum tube converters were being only one the many new alloys invented the Ajax-North- rup high frequency furnace. This photo- graph shows one these furnaces operation the Bell Telephone Labora- tories the early Courtesy Bell Laboratories. ° ° ° supplied for certain work that same time. The first equipments were sold 1917-1918 the Pyroelectric Instru- ment Co., Trenton, J., com- pany formed Dr. Northrup and few his associates make instru- ments, but licensed the Ajax Metal Co. build and sell high frequency furnaces pending the establishment company incorporated particularly for that purpose. Court ° 4 vac 1916 1920 1924 1928 1932 1936 1940 1944 ex ° ° ° 1200 kw., 960 cycle motor generator set with motor drive. Courtesy Westinghouse Electric Mfg. Co. The list includes furnaces for preci- ous metal melting, for steel and ailoy melting, for the heating vacuum, for the heat treatment metal parts, for high temperature work and for many laboratory pur- poses. Sales, however, were far from suffi- cient cover the cost necessary development. 1920, the Ajax Elec- trothermic Corp. was formed ex- ploit the Ajax-Northrup furnace, and basis. Starting with deficit the for- mation, Dr. Northrup and Dr. Clamer embarked program make and sell the furnace that had been de- veloped and try find way extend the power rating high fre- quency equipment point where the method heating could applied the industry large. Bigger Units Needed For many years the only generally available means for obtaining high frequency current for induction fur- naces were spark gap converters and vacuum tube oscillators. Alexanderson alternators could have been used, but few were available, their cost was very high, and was not yet known that frequencies their range were applicable. Furnace units capable melting charges steel, its equivalent, about min. were available the early 1920’s and focus inductors had been perfected for con- centrating large amounts energy small localized areas. that time too, substantially all the present day applications had been described Dr. Northrup his many patents and publications. All needed was source power sufficient capacity make larger commercial indus- trial applications practicable. One attempt build larger fur- naces was combine three heating coils around single melting chamber, and operate the combination from three phase supply. this way 105 kva. could drawn from the lines. One such furnace was sold the Handy Harman Co. for melting 175 lb. charges pure silver. Another was sold the Naval Research Labo- Anacostia, C., for melt- ing 200 charges steel 500 charges copper. The operation these units left much desired, and they were replaced when motor- generator operated furnaces were available later. Lower Frequencies Studied 1922, high frequency induction heating received one its greatest boosts. For some time before that date, Dr. Northrup had concluded that the very high frequency obtainable from spark gap and vacuum tube con- verters was not necessary for most in- dustrial work; that while the higher _frequencies were necessary for small diameter charges, considerably lower frequencies would suffice for larger charges. believed, frequencies low 1000 10,000 cycles could used, motor-generator equipments could built almost any power rating desired. first contacted Dr. Steinmetz and others the General Co. and obtained the limited use type alterna- tor. These units were very expensive, and low power rating, but pre- heating. Here long in. diameter steel tube heat treated the fly passes through inconspicuous heating coil. THE IRON AGE, March 22, liminary tests showed that his calcula- tions were correct. Following these tests, purchased 100 kw., 540 cycle generator which had been built for radio use. With the cooperation Frost the Na- tional Machinery Co., had the generator installed the company’s plant Tiffin, Ohio, and carried -on tests which further proved his posi- tion. His tests were sufficiently broad their scope cover both heating and melting, and for charges vari- ous sizes and material. Patents were obtained and they have been recog- nized throughout the world. could not begin materialize, how- ever, until all parts the motor- generator operated equipment could designed and built, and the indus- try large could convinced the value this type equipment competition with existing heating methods. This period was from four ten years. Although did not show visibly general industry, induction heating advanced very definitely from 1922 1926. During those years, much effort was expended in-designing and im- proving equipment for generator op- erated furnaces, and studying the possibilities for its application the 52—THE IRON AGE, March 22, 1945 4 many branches the industry. Converter development overlooked during this period and its use was extended laboratory and semicommercial work. 1923, ex- clusive rights for using the equipment for heating the elements vacuum tubes during the sealing period, drive off the occluded gases, were sold Westinghouse. Had the Northrup furnace done nothing else recommend it, its place history would have been assured because its contribution the vacuum tube and radio art. The ability the high frequency furnace act through the glass envelope and heat the vacuum tube elements during the sealing period has made possible the enormous improvement which has resulted that art. Large Power Generators the period after 1922, the Gen- eral Electric Co. again came Dr. Northrup’s assistance designing and building high frequency motor- generator equipments the range frequencies from 540 2000 cycles. The units were the salient pole type and were the forerunners the pres- ent inductor type alternators.. The first commercial induction fur- NDUCTION heat- ing. These three heaters the United Engineering plant are used for heating 155 mm. shell blanks for hot nosing opera- tion. The blanks are elevated into the coils air cylinders. nace operated with motor generators were installed 1925-1926 the plants the American Brass Co. Waterbury, Conn., for brass melting; the Babcock Wilcox Tube Co. Beaver Falls, Pa., for steel melting; and the Ajax Electrothermic Corp. Trenton, J., for general experi- mental work, the melting special steel magnet alloy, and for demon- stration purposes. These, with the almost simultaneous installation licensees the plant the Edgar Allen Steel Works Sheffield, En- gland, were the pioneers for this type equipment. The American Brass Co. was quick appreciate the value the furnaces the brass industry, and 1926 pur- chased exclusive rights for high fre- quency melting the wrought brass field. The funds made available from this sale were inestimable value advancing induction heating. Today there are men high government positions who condemn restrictive li- censes; but only making the agree- ments, first the vacuum tube field and later the wrought brass field, was induction heating developed the state where considered indis- pensable the winning the war. With the help Dr. Northrup and Dr. versit the speci the insta indus Leba hem, lowe unde Ele tio for als | Dr. Comfort Adams Harvard Uni- versity, consultant, Isaac Harter the Wilcox Co. early built one the largest and most flexible specialized casting foundries the United States. With these first installations examples, induction furnaces quickly spread into the steel industry. Heppenstall, Firth Sterling, Lebanon, Carpenter, Durion, Bethle- hem, Midvale, Hoskins and others fol- lowed early date. Simultane- ously equipments were being installed other parts the world licensees under the Northrup patents. Surface Hardening Early the 1920’s, the Midvale Co. purchased converter type equipment and used for experimental steel melting and for heat-treating appli- When generator operated equipments became available, was the first take license and induc- tively heat large rolling mill rolls for surface hardening. was proposed carry the work for other surface hardening applications such hard- ening internal bores cylinders, and the like, but the depression the early 1930’s made difficult get industry interested. Surface hardening opened 1932 when the Ajax Electrothermic Corp. applied induc- for the Ohio Crankshaft Co. Cleve- land. Budd Induction Heating Corp. also was interested surface hard- ening, but more particularly for in- ternal surfaces. license was granted jointly these two companies make NDUCTION heat- ing. Tubes being heated for nose spinning operation. Courtesy National Tube Co. and sell induction heating equipment for hardening. Later the field was further divided into external and in- ternal applications respectively. The licenses were limited fre- quencies 10,000 cycles and below, and non-exclusive licenses were broad- ened cover other applications such heating for forging, brazing, weld- ing and the like. What these compa- nies have done spread induction heating well known. Howard Somes, chief engineer the Budd company, has been responsible for most the recent development internal hard- ening applications. High frequency heating was fast becoming industrial “must” when the depression the early 1930’s hit it. The result the depression was slow its pace, but not hold back for long. Its value had been de- termined for large scale production work melting, forging, hardening and the other applications listed the beginning this paper. the very middle depression Ajax received order for 4-ton steel melting fur- nace powered with 1200 kw. genera- tor. This unit was for the Steel Co. Other large sized units were sold first licensees abroad the war production began rise there, and then the United States. Future Trends The number kilowatts induc- tion furnace equipment installed the present time over 300,000 kw., disregarding equipment put into op- eration the Axis countries during the war, and disregarding some the vacuum tube applications which record obtainable. The rise use has been very steady, the total amount substantially doubling itself each four years since the first stalled 1917-1918; and the trend yet unchanged. These installa- tions are divided roughly per cent for melting, per cent for forging and for hardening applications. The largest generator built has rating 1800 kw. The largest melt- ing furnace will melt 10-ton charge steel. The largest single installa- tion melting equipment over 10,000 kw., capable turning out tons steel-every hour. The largest single installation heating equip- ment for forging 7000 kw., capable heating billets for average pro- duction one 105 mm. shell every sec. one plant over 158 dif- ferent parts are being heated in- duction for various hardening opera- tions. Over year ago one gun plant publicly declared that had turned out its 100,000th gun barrel—prin- cipally the mm. anti-aircraft size— melted induction and cast the centrifugal casting method. Induction heating equipment lasts long time. believed every gen- erator operated equipment sold, bar- ring war damage, still operation. Even though the market may over- sold account war, there will much conversion work do. Indi- cations are that not only will the ex- isting equipments turned peace- time effort but the war averages soon will adjusted and more new equip- ment will required keep the in- dustry abreast the times. THE IRON AGE, March 22, 1945—53 at- ire ra- : ire he y q aluminum fabricating method which has become favored producers items such tanks, pipe, vaults and similar structures, the automatic shielded carbon are welding process which pro- vides low costs construction and high quality welds that are frequently better than those specified the de- weld signers. number interest- applications automatic welding aluminum have been recently reported. One such job consists the welding thousands tanks having dished head one end and made in. aluminum. The vessels measure ft. length in. diameter. Specifications called for strongly reinforced seam inside and out. High speed fabrication was obtained welding both the longitudinal and girth seams one pass, producing high quality bead such that shown in. Fig. The tank shells are first tack welded and short length the joint, Fig. These scrap pieces; which serve starting and stopping points during the automatic welding, are knocked 54—THE IRON AGE, March 22, 1945 Stop dense even bead weld metal shown here inherent character- istic the automatic carbon arc welding process applied aluminum. off the work after the longitudinal seam weld has been completed. Both longitudinal and girth seams are square butt welded without joint prep- aration such beveling. Using automatic machine similar that shown Fig. known the “Electronic Tornado,” speed in. per min. obtained. 2—Sketch showing method tacking scrap pieces tank shell for starting stopping longitudinal weld 3—Typical machine the carbon arc welding type. With this system the carbon arc fully controlled focusing the heat concentrated area directly un- derneath the arc. dense uniform head obtained automatically de- positing autogenizing element the form powder flux directly the work just ahead the carbon arc. The powder melts and forms slag which protects the molten metal. welding the in. aluminum tank, 3/16 in. filler wire having the metal was used conjunction with in. carbon. The machine was set 350 amp. and volts. Accord- ing the manufacturers, excellent results are being obtained. Each tank fully tested and leakage has been found negligible. welding various aluminum structures the automatic arc welding further evidenced data received for exal dian sections the the bevelin The type approx for dis backu] LEFT ° ° BELOW ° ° ° q mille & metal strip seam. ment ° 16.5 ; . Aluminum Structures heat un- form de- inum the with was tank been ling the current applications. One job, for example, the fabrication in. diameter aluminum pipe in. sections. Pipe thickness in. the are welding the tanks pre- viously described, the joints are the butt type and welded without beveling. The formed pipe placed horn type jig with hold-down shoes located adjacent the seam shown Fig. The work bowed upward in. the joint and the fixture compensate distortion due heat. copper bar having 1/32 3/16 groove placed along the under- side the seam illustrated With the machine set from 360 380 amp. and volts, the carbon carries the current which penetrates the joint and the molten metal takes the form the backing strip which this case forms re- the underside the seam. The added 5/32 in. filler rod supplies sufficient volume metal produce the necessary reinforce- ment the top side the seam. Speed the travel this case was 16.5 in. per min. with in. 5/32 filler rod consumed per foot. The Copper back-up with groove 4—Cross-section in. pipe welded the automatic process. head Spun head 5—Aluminum tank with casi head and spun head welded aluminum tube. Casting dam 1G. 6—Flux dam arrangement used joining seam cast head and alumi- num tube, CONLEY Consulting Engineer, Lincoln Electric Co., Cleveland Smooth welds can obtained in. aluminum carbon sheets speeds in. per min. with automatic arc welding equip- ment, without the necessity beveling the edges butt welds. The automatic carbon process for welding aluminum described this article now being used vast scale fabricate special military bridge structures (See The Iron Age, Feb. 15, 106). Last month engineers from companies involved this new program attended courses the application Tornado" weld- ing the Lincoln Electric Co. plant. report further states that No. 520 Aluminflux was used throughout autogenizer, 1.2 oz. the flux being used per foot weld footage cost The automatic welding aluminum alloy heads aluminum tube in. diameter presented another in- teresting automatic welding setup. cast head welded one end and spun aluminum head the other (see Fig. 5). welding the cast head the tube, rings are located adjacent the joint act dam for the flux, Fig. 5/32 in. aluminum filler rod also used for this appli- cation with amperage set 325 and voltage 32. speed in. per min. maintained welding this casting, with the carbon arc posi- tioned in. off center the left, with the work rotating clockwise, shown Fig. The aluminum tube in. thickness. The spun head welded the tube first positioning the work removable copper backing jig, Fig. with groove the joint the hold- ing arm. Here again, flux dam pro- vided means shoes located ad- jacent the joint shown the sketch. The same machine current, voltage and speed are obtained the welding the cast head. Also, the same finx and type and size filler rod employed. all cases presented, the high quality and low cost indicates that the automatic shielded arc method extremely efficient for the welding aluminum well for other metals. The process fast because: The joints are square butt (no bevel) and therefore require very little deposited metal compared with the conventional type joint with bevelled edge. The filler metal does not carry the welding current the size the wire (5/32 3/16 in.) does not limit the maximum current which may used. The flux introduced the independently the filler metal the carbon electrode the amount flux can regulated meet the re- quirements the high weiding cur- rents. Uniform travel speed and auto- matic control the current, voltage, filler metal, and flux permit the use high welding currents. 7—Carbon arc positioned in. off center aid controlling the flow weld metal before solidification. dam 8—Detail joint and weld bead for joining spun aluminum head tube, THE IRON AGE, March 22, 1945—55 ° ° ° ° ° Carbon down q poorly cleaned surfaces. Alkaline and acid cleaning solutions with proper control can consistently provide chemically clean surfaces necessary for joining any metal surfaces. JEAN GAUTHIER tempera- ture Supervisor, Kelite Products, Inc., Los Angeles, Calif. brazing (1175 1300 deg. F.) has become the most widely used methods for joining metals the aviation, munitions, and other war industries and fast re- placing welding and soldering pro- cedures many types construction and repair. The comparative high speed and ease operation well the high degree tensile strength obtained through the use low tem- perature silver alloy brazing has re- sulted widespread demand for means metal joining throughout wartime The proper application method has invariably resulted 56—THE IRON AGE, March 22, 1945 large savings time and money. has many released ing equipment simplifying manufacturing operations that they could handled less critical equipment and has also saved much material. Using silver alloy brazing has made possible repair many tools that heretofore had replaced with new ones. the case other metal join- ing operations like plating, soldering and some instances spot welding, brazing with silver alloys requires ° installation dip tanks for precleaning metal parts prior brazing with silver alloys. clean metal surfaces upon which work. The presence oil, grease, oxides, scale inert soil particles all interferes with good braze joint since the melted alloy will not wet and flow over unclean surface. The advantageous low temperature range emphasizes the importance clean surfaces when metal being joined. High temperatures and the the resultant long cooling periods, such found torch welding, re- quire less critical cleanliness and operators familiar with high tempera- ture welding are inclined think low temperature brazing the same light. However, Handy Harman, one the largest suppliers silver brazing materials have discovered definite relationship between surface cleanliness and successful silver braz- ing and they have repeatedly stressed the importance cleanliness their technical bulletins. the seven steps necessary satisfactory brazing out- lined them, the importance properly cleaned surfaces second only the face ing hea rep bee pri cle: bei ref sul all all ‘les all joint rature being the eriods, ig, re- npera- ink same one razing very urface ressed their out- gases their feeling that the manufac- turers silver brazing alloys cannot logically held responsible for un- satisfactory results when such are the result improperly prepared sur- faces and cleaning negligence. Regardless whether furnace in- duction, resistance gas torch heat- ing are used, the metal must chemically clean for best results. This means the complete removal of: (A) Oils, greases and fatty acids (B) Oxides, scale and foreign mat- ter. Flux used prevent fresh oxida- tion the metal surfaces during the heating period and not intended replace cleaning sense. Abrasives and wire brushing have been accepted some past instances being satisfactory for cleaning prior brazing, but this type cleaning slow and therefore ineffi- eient for production brazing, besides being costly. Existence any the deposits referred above can cause any and all the common failures which re- sult rejection. Some these fail- ures are the irregular flow the alloy, complete misses spots, and porosity the braze alloy. When impurities exist beneath the flux they create excessive gassing and when the alloy reaches the molten state these erupt through the metal. Impurities inert nature also will rise and deposit themselves the surface. the heating cycle fast these gases and impurities not have time purge themselves from the alloy and porosity and craters are the result when the braze cools. chemically clean surface will not evolve such disturbances, conse- quently, the shortest cycles will still give excellent results. The oils, greases and fatty acids require wetting out and hot alkaline bath treatments for their removal since the value these deposits definitely the acid side. the other hand, oxides and scale are opposites the oils and greases and will only respond acid pickling treatment. intelligent attention given these cleaning processes, they may simply and efficiently installed and operated. Low operating costs are easily maintained. Vapor degreasing often misused, the assumption that replaces chemical cleaning. Only under cir- cumstances where clean oil grease removed can this method relied upon produce clean surfaces. Unfortunately, this very When other deposits exist, such scale oxides, they remain tubular part before and after cleaning prior silver brazing. the surface and prevent tory braze joints. Steel frequently oiled treated prevent corrosion and oxidation and these coatings often present diffi- securing thorough and com- plete removal. Fish oils, lard oil and petroleum products are encountered and parts which have been machined, stamped drawn bear various types drawing and stamping oils. the case stubborn deposits, where oil grease may have become oxidized from heat, min. soak solu- tion such Kelite Ketrex, mixed 50/50 with kerosene indispensable. The soak wets out the stubborn bond between the deposit and the metal that subsequent bath alkali such Kelite Keprocess (13.0 13.2 pH) can saponify and the deposit away. acid can work effectively the presence greases since grease insulation against acidic action. Having removed this deposit oils two Tivit tanks, one hot rinse and the other hot alkali, are heated gas and correct temperature maintained thermostatic control. THE IRON AGE, March 22, 1945—57 = ii and greases, the oxides, scale and inert soil are laid bare the action the acid pickle, and the acid does thorough job removal. soak pickling agent like Kelite Off, which inhibited against attack- ing healthy metal, will complete the cleaning and prepare the metal for satisfactory brazing. The following procedures are used for cleaning various metals prior silver brazing: Stainless steel Monel metal: EAT treating steels directly from the rolling forging tempera- tures was found improve the physi- cal properties the steels according Kuentscher and Sajosch report- Stahl und Eisen, vol. 62, Dec. 17, pp. 1067-73. The steels used included unalloyed steels with 0.16 0.52 per cent carbon and steels containing chromium, nickel, molybdenum and vanadium. hardening direct from the heat FROM horizontal vertical one swing: Here views the way Heppenstall auto- matic tongs are used handle and in. shells, weighing about 250 each. Left, Presoak Kelite Ketrex 50/50 with kerosene for min. room tempera- ture. Rinse thoroughly cold water, pres- sure preferred. Immerse hot alkali (Kelite Keproc- ess) 190 200 deg. 13.0 13.2 for min. until water break surface exists. Rinse hot water 120 140 deg. Immerse acid pickle (Kelite Scale- off) min. thoroughly remove oxidation and discoloration. Rinse thoroughly cold water. Steps and can eliminated de- posits are not stubborn. Heat Treating Steels From Rolling Temperatures rolling and then tempering, im- provement 140 ft.-lb. per sq. in. the notched bar impact values was obtained. The danger cracking due quenching the unevenly heated bars was minimized using tempera- ture-indicating colors and withdraw- ing the bars from the quenching bath temperatur