The Iron Age 1941-10-02: Vol 148 Iss 14

2 % 4% THIS you hear rumbling and noise your overhead traveling crane, sign excessive friction and wear between vital parts. Suc THESE FEATURES REDUCE NOISE its sig exc etween vital parts. Such means needless shutdowns and expensive repairs. Whiting cranes, herringbone gears transmit power quietly and outlasting ordinary spur gearing least two one. Flexible couplings reduce vibration and binding. Roller bearings keep the gears positive alignment and reduce friction. Extra years Rolier life are added tapered-tread wheels, rotating axle bearings, and load brake. Capacities range from one 400 tons. Also electric hoists from tons. Whiting Corporation, 15601 Lathrop Ave., Harvey, Ill. Builders quality cranes for over years. Tapered-Tread Flexible Wheels Couplings a q e*ee « | OCTOBER 1941 VOL. 148, NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager News & Markets Editor. J. A. ROWAN Machine Tool Editor F. J. OLIVER Associate Editors W. A. PHAIR G. RICCIARDI Art Editor, F. J. WINTERS Editorial Assistants M. M. SCHIEN G. B. WILLIAM J. |. BUTZNER S. H. BARMASEI Washington Editors L. W. MOFFETT JAMES G. ELLIS Resident District Editors T. C. CAMPBELL HERMAN L. KLEIN Pittsburgh Chicago B. W. CORRADO W. F. SHERMAN Cleveland Detroit CHARLES POST San Francisco Editorial Correspondents Buffalo Cincinnati Bostor Los Angeles Milwaukee Birmingham ROY Toronto, Ontar St. Louis Newark, N. J. Seattle Advertising Staff merson Findley R, bert BI 621 Union Bida. Cle vel L. Herma Chilton Bldq., Philadelpt H. K. Hottenstein, 1012 Otis Bldg., Chicag Leonard, 100 East 42nd New Peirce Lewis, 7310 Woodward Ave., Detroit rane Ober, 100 East 42nd St., New Don F. Harner, 1595 Pacific Avenue, Lona Beach, Cal Johnson, Market Research Mar. - B. H. Hayes, Production Manager. and Baur, Typography and Layout. Member, Audit Bureau Circulations 2s keep Member, Associated Business Papers Indexed the Industrial Arts Index. Put ears lished every Thursday. United States and Possessions, Mexico, Cuba and $6.00: Canada, Foreign, $12.00 year Single copy, cents. Also Cable Address “lronage N. Y.” athrop Owned and Published CHILTON COMPANY (Incorporated) Executive Editorial and Office Advertising Offices Chestnut and East 42nd St. Philadelphia, Pa. New York, N. Y. U.S.A. OFFICERS AND DIRECTORS C. A. MUSSELMAN, President JOS. HILDRETH, SEORGE GRIFFITHS EVERIT TERHUNE VAN DEVENTER, BAUR, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE HARRY DUFFY CHARLES HEALE Vice-President Vice-President Vice-President Vice-President Editorial Priorities and Pipe Dreams Technical Articles Forging Pierce and Draw Method Stepping Magnesium Casting Production. Nickel Free Steels New Steel Airplane Propellers Big Miller Trims Armor Molybdenum High Speed Steels Iron and Steel Engineers Meet. Spring Tension Fasteners Features Assembly Line Washington The West Coast Fatigue Cracks News and Markets This Industrial Week News Industry Government Awards Personals and Obituaries Construction Steel Machine Tool Activity Non-Ferrous Metals Scrap Markets Iron and Steel Scrap Comparison Prices Finished Steel Prices Warehouse Prices Sales Possibilities Products Advertised Index Advertisers Copyright, 1941, by Chilton Company (ine.) | ° ° | | WESTINGHOUSE COMBINATION LINESTARTER For Motor Control and Circuit Protection CLASS 11-206 Magnetic motor starter—motor- circuit switch—motor overload protection—nofuze circuit protec- tion—all one unit. Bi-metal gives permanently accurate over- load protection. quench- ers protect contacts—save main- tenance. Four-in-one Unit saves installation time—saves space— Call your nearest Westi saves greater protection for operators. WESTINGHOUSE AB-I BREAKER For Circuit Protection Eliminates switch and fuses. Bi-metal overload protection. protection for con- tacts. Saves maintenance time and production time— circuit outages can re- stored operator. live parts exposed. Door opens only when switch position. Occupies approxi- mately 40% less space than switch and fuses. ghane Sales Office Distributor WESTINGHOUSE SAFETY SWITCH For Circuit Protection Diamond-pointed break jaw and extended-blade construc- tion prevent burning and beading contacts. One- piece copper construction saves money preventing power loss. make, quick-break Types and Ample space for wiring. Solderless lugs. arc quenchers 575-V WESTINGHOUSE “DE-ION” LINESTARTER Magnetic Across-the-line Starter CLASS 11-200 Push-button operated—built- mounted separately. Small, compact construction saves space. Bi-metal over- load protection hand automatic reset. ‘‘De-ion” protection for contacts re- duces maintenance. Vertical magnet operation speeds con- tact opening and prevents accidental operation. —— ction re- vents 137-A OCTOBER 1941 ESTABLISHED 1855 Priorities and Pipe Dreams whole object priorities, when supplies are limited, get the most out what got. That applies manpower, both military and civilian, materials, machines, electric power, petroleum what have you. Take steel, for example, especially plate steel. Normally our steel plate mill capacity was more than enough satisfy demand. But along comes defense program and goes the demand for plates. Plates for cargo ships, plates for oil tankers, plates for tanks, plates for armored cars, plates for aircraft armor, for railroad cars, plates for boilers naval vessels, plates for gun mounts and shields, plates for water, oil and chemical tanks for our new defense plants, plates for thousand purposes either nature quantity undreamed normal times. gentlemen Washington who are administering steel priorities are tne same position commanding general the front who has make the most limited supply ammunition. Their problems combine into the one making every pound metal accomplish the most toward maintaining the time table successive objectives. The field general cannot afford either waste his shots nor fire too few them. And the steel priority managers must similarly put the available tonnage where will what most needed the time most wanted. seems that this sort thinking should apply the proposed petroleum pipe line from Houston New York, for which steel priority has been wisely refused, thus far. Here project which with its feeder lines and branches would engage 450,000 tons plate capacity its equivalent. And that amount steel sufficient for medium heavy battleships, light cruisers, 553 destroyers, 18,000 medium ianks 173 average merchant ships. true that Mr. Ickes’ office now says that half this steel tonnage could seamless drawn steel instead plates. But steel steel and all goes back the ingot the scrap pile. And our seam- less tube mills are going pretty busy making stock for bombs when our rapidly expanding air program soon makes its demands for them. course, our military and other necessities for oil must served. But our modern oil tankers will carry much oi! this pipe line would. And tankers will need only one-fourth much steel the pipe line. England, believe, now amply supplied with the tankers she al- veady has. And Russia any case must get its oil and will get plenti- fully, from sources nearer home. with these new Ameri- can tankers scheduled for launching the end 1942, let’s use our precious steel where will the most good, rather than putting into pipe line that will not and cannot completed before these new tankers have made quite unnecessary. j | ° ° 4 ° ° — — a =) — 4 ia Inland, Too, Ships “BUNDLES FOR BRITAIN” Deep the holds ships plying the Seven Seas are many “Bundles for Britain” from Inland Steel—billets for the rolling mills England tin plate for the canners Australia— sheets for the oil drum manufacturers Egypt. Inland started early 1940 doing its part aiding “nations resisting aggression” with shipments steel products the British. Today, Inland supplying steel the Allies through Treas- orders, issued under the Lend-Lease Act. These orders bearing high priority ratings, are im- portant part America’s defense—Inland’s No. Job. \ x \ RAY \ _ AN \ \ 4 EVANS District Manager, American Car Foundry Co., Buffalo OUR months after receiving order for 9.2-in. howitzer shells from the British gov- ernment, the Buffalo plant the American Car Foundry Co. had set and equipped complete shop forge this shell. The Baldwin Southwark division the Bald- win Locomotive Works, which was awarded the order for the hydraulic piercing and drawing presses used the forging operations, built and installed their equipment record time. Although the plant turns out the complete shell from forging through finished machining, this article discusses only the forging operations. From the bloom storage yard the steel for the shell brought into the shop the form blooms ap- proximately ft. long in. square. Each bloom picked magnet crane, checked for weight, and placed roller table. Adjacent the table pair Air Reduction gas-cutting torches which nick the bloom depth about in. two opposite sides that may broken into five 20-in. billets. The rollers the table underneath the flame nicking fixture extend horizontal bull- dozer, whence the bloom passes broken into forging billets. Before moving the billets storage the forging shop they For information other methods forging artillery shell, the reader referred the following articles previously published THE IRON AGE: With Baldwin- Omes mechanical presses, Oct. 10, 1940; upset method, Jan. 16, 1941; Witter process, July and General set-up heating and upset method), Aug How small plant forges the difficult trench mortar shell will told early issue. are inspected the fractured ends for seams pits. Forge Shop the forge shop there are two units, each having pusher type furnace, 1000-ton piercing press and 260-ton drawing press. The furnace the oil-fired type, ft. long and in. wide, and each its three tracks served pneumatic pusher cylinder. Billets travel through the furnace Ni- chrome billet shoes assure uni- form heating. These shoes fall into special trough when the billets are ejected and are returned the charging end conveyor. Each furnace has capacity bil- lets per track, 120 per unit. provide continuous operation, the doors both ends are left open enough permit entrance and ejec- tion the billets. The temperature the billets they emerge from the furnace ranges between 2125 and 2175 deg. the billet ejected from the furnace, falls onto roller pushed through high pressure water descaler and dropped into steel basket. The basket raised and then traversed pneumatically special trolley bring the billet into position over the pierc- ing pot the press. automatic trip releases the hot billet into the die pot which its retracted position. The piercing press the mov- ing-down type with 1500-lb. work- ing pressure and 5-ft. stroke. Attached the bottom platen the piercing pot mounted slid- ing table. This table moved la- inder that the die pot can readily loaded outside the press. THE IRON AGE, October 1941—27 ‘ | — ag cutting device, fitted with two torches, nicks the bloom preparatory breaking into billets. type furnaces heat the billets temperature 2150 ° ° ° deg. Capacity the two furnaces 240 billets. 28—THE IRON AGE, October 1941 Piercing sliding table, attached the moving platen and operated pneumatically horizontal cyl- inder, are mounted piercing and slugging mandrel, well the vertical bar which actuates the piercing pot stripper mechanism. the first stroke, the slugging punch exerts force the top the square billet, compressing and converting into cylinder which fills the round pot. the second stroke, the piercing punch moved into position over the die pot. Before bringing the ram down second time, however, steam blast applied remove excess tuminous coal applied top the billet, and the piercing punch swabbed with mixture and oil. The piercing operation converts the billet, originally in. square and in. long, into cup with outside diameter approximately 10°, in., inside diameter billet from adhering the punch and rising with the return stroke, special stripper mecha- annular ring built into the top the die pot and actuated bar mounted the moving platen parallel the piercing punch. the punch descends, the bar pushes the ring off center that one side over the billet, but does not interfere with the motion the punch. When the punch withdrawn, this ring acts stripper. After the piercing stroke, the die pot moved out the press the loading position, whereupon 30- ton ejector cylinder, mounted under the pot, actuated remove the pierced cup. Before passing down gravity conveyor the receiving cradle the draw bench, the forg- ing given descaling treatment the cavity, using high pressure steam. Centering Punches The use laterally moving dies requires great care centering the slugging and piercing punches. Cen- tering the latter particularly important order produce con- centric forgings—for eccentri- cally pierced forging cannot cor- rected the drawing operation. Before the piercing mandrel enters 7 : the hot billet the die pot the piercing punch holder well guided insure concentricity. The die pot chamfered and the punch holder fitted with chamfered guide ring hardened steel minimize wear this point. The piercing process requires little over minute. Speed es- sential throughout the forging op- eration that the hot billet will not remain contact with the piercing and drawing longer than absolutely necessary. The Southwark piercing and draw- ing presses and valves were there- fore designed with this mind and they require considerable quan- tities high pressure water for fast operation. Drawing The 260-ton horizontal drawing press used the next operation has 12-ft. stroke and subjects the forging three reductions di- ameter. The end its double- acting hydraulic piston carries cross-head which guided the tension rods the press heavy bronze bushings. this crosshead attached alloy steel drawing mandrel and holder. Three die holders, each carrying annular ring type die, are mounted the tension rods and permit horizontal adjustment. When the forged cup leaves the draw bench its outside diameter approximately in.; its in- side diameter 5/16 in., and its length approximately in. Its temperature still excess 1200 deg. One and half minutes have elapsed since the billet left the fur- nace. Production rate forg- ings per hr. each the two lines, 640 forgings for the shop each 8-hr. shift. The forging removed from the draw bench special two- wheeled truck and brought inspection rack. Here checked for length, base thickness and con- centricity. The horizontal rack designed that rotates the shells they move along it, permitting inspection the entire outside surface. From the rack the finished forgings move down onto tracks laid sand where they cool. When they are down 200 deg. their lot number chalked them and they are moved storage prepara- tory shot blasting and machin- ing. travel billet carrier releases the billet and falls into the die pot. Movement the latter the left will bring into position the piercing press. ° ° ° ENERAL view one the 9.2-in. shell forging lines. Lower left, the draw bench; middle, piercing press, and right rear, furnace. THE IRON AGE, October 1941—29 : 4 billet. The vertical bar immediately its left actuates eccentric ring which strips the shell from the punch. Pierced billet starting through the 260-ton Southwark ring-type draw bench. IERCING punch moving after performing the second operation the 30—THE IRON AGE, October 1941 Hydraulic Installation Shell the pierce and draw method described demands fast presses and long strokes under high pressure. Great quantities high pressure water are therefore essential. The Buffalo plant American Car Foundry, meet the demands the 9.2-in. shell shop well other shell forging installations, uses seven pumps and four accumulators, all the same line. Working pressure 1500 Ib. per sq. in. Three the accumulators have capacity 325 gal., the fourth, which the master accumulator, 900-gal. capacity. The instal- lation presents excellent solution engineering—that op- erating number pumps and accumulators the same line. The three smaller accumulators are arranged that the top their strokes, and blowholes are exposed, they will stopped added weights until the master accumulator has risen. Con- tanks each are series weights. When accumulator reaches its normal top position, the chains become taut, tending crease the hydraulic pressure the system. the extra weights were lifted the pressure would rise 1600 per sq. in. Due packing friction, the accumulators will vary slightly the pressure needed raise them, but this variation does not exceed 100 per sq. in. There- fore, all three the smaller ac- cumulators will rise until their weights are taut and the master accumulator, which set slightly above them, will then begin rise. This latter unit controls all seven pumps means electrical limit switches which turn, through thrusters, operate the pump by-pass valves. The pumps operate con tinuously. operation, the main accumu- lator starts downward from, let say, midpoint its stroke due heavy demand for water. nears the bottom its stroke trips the first limit switch and closes the by-pass valve pump No. the demand remains heavy will continue falling and cutting additional pump each time switch tripped. The three smaller accumulators will begin ° ° ° ‘ ORGED emerging from the 260-ton draw bench. Movement the handle the foreground strips the shell the return stroke the drawing man- drel. charge into the line the master unit becomes exhausted. this point the condition such that all pumps are working; the 325-gal. accumulators will begin rise and finally will the 900-gal. master unit. The latter will trip the first group upper limit switches nears the top its stroke opening the by-pass valve No. pump. demand low, will continue its upward travel until all switches are tripped and all pumps by-passing. Westinghouse Extends Bonderizing Facilities facilities for bonderizing large metal switchgear and electrical control enclosures have recently installed and put into service the East Pittsburgh works the Westinghouse Elec- tric Mfg. Co. Formerly, these enclosures were bonderized and then velded together. The new equip- ment permits bonderizing the en- tire enclosure after assembled and eliminates the un- satisfactory paint base obtained welding after bonderizing. The new facilities also reduce the amount handling necessary these enclo- sures and effect saving actual bonderizing time. ° new bonderizing unit con- sists five tanks, probably the largest unit ever built for this pur- pose. The process consists washing hot alkaline solution, rinsing, submersion the bonder- izing solution, rinsing, and then hardening hot chromic acid solution. After this last step, the enclosures are ready for painting. THE IRON AGE, October & LEFT HIS one the several pairs furnaces for super- heating the magnesium alloy This crucible being re- moved from the furnace and will transferred cooling rack prior pouring. ° RIGHT HIS crucible, having cooled the rack, about ready poured. Molds are brought the mold conveyor the right the picture when the magnesium ready for pouring. Superheat- ing furnaces are located the booths separated fire walls, the left background. The workman the left has dusting can con- taining mixture sulphur and boric acid cover the molten metal prevent oxidation. 4 32—THE IRON AGE, October F A AY VLA De & A. J A that the Ford Motor Co. orders for 10,000 Pratt air-cooled engines and well along the development its own design liquid cooled aircraft engine, production magnesium castings being increased the company’s new foundry built for this purpose. Ford has long operated one the largest and finest gray iron foun- dries found anywhere and its experience foundry work has been put good use designing the even though practice the latter differs widely from that making iron castings. ° Magnesium castings are produced the second floor the remodeled south end the iron foundry, but entirely separate from operations iron. All the equipment expressly for casting magnesium and use made the best mag- nesium casting practice developed. Casting done, course, sand molds. The sand prepared the third and fourth floors the build- ing and then conveyed the second floor where both molding and casting are done. the first floor are located: core-making and baking facilities, the charging and unloading openings two vertical heat-treating furnaces which all castings produced are heat treated, and other equipment not required the casting floor, such inspection benches, surface treatment tanks and completely equipped sand test- ing laboratory. Some the equipment which will operation when the foundry reaches full capacity was not place when this article was written, but enough was installed and operation produce some 800 Ib. castings day about 20,000 lb. per 26-day month. When this article was released for publication, about 137,000 castings per month was the capacity, with the estimated needs for motors day nearly double this quantity. This will require the use four furnaces 2000-lb. capacity for melting the alloy used, which the Dow “H” alloy, received ingot form. addition the melting furnaces there will provided, for superheating the metal, two 400- capacity, eight 200-lb. capac- ity, and three capacity. Superheating and pouring are done small batches largely prevent excessive oxidation. Furnaces are arranged separate booths with fire brick partitions, avoid the spread fire, should one occur. Gas from Ford coke ovens used —Already producing some 137,000 magnesium cast- ings month, Ford Motor Co. expects that the time developments are the design its new liquid-cooled airplane engine, productive capacity for the light-metal castings will doubled. firing because available and less destructive metal pots. Melting done with about per cent scrap and per cent pigs, the scrap content being large chiefly because many risers are required insure sound castings. The alloy 1250 deg. F., sufficiently above its melting point insure fluidity and then run off into 100 400 Ib. casting crucibles. the metal crucibles, are then ORKMEN are pouring the mol- into mold one the reels. Surface metal kept covered with flux during pouring pre- vent oxidation. placed superheating furnaces where the temperature raised 1600 deg. refine the grain the alloy and bring the metal above the casting temperature. Be- fore pouring, the crucibles are re- moved from the furnaces and set racks cool 1500 deg. While standing, flux cleaned off and 0.3 per cent calcium stirred act deoxidizer. While standing and pouring, the metal dusted with mixture half sulphur and THE IRON AGE, October 1941—33 half boric acid prevent from catching fire and avoid rapid sur- face oxidation. Firing the fur- naces controlled hand with the pyrometers connected thermo- couples immersed the metal it- The layout the casting floor contemplates the use four lines which molds are brought to- ward the line furnaces. There space for molding floor where molds which cannot well handled conveyors are made. Each the four lines includes loop reel for the drags and belt conveyor, parallel the reel, for handling copes. Reels and belts come close together the casting end and there the copes and drags are as- sembled, using chain hoists, and made ready for pouring. ex- pected that pouring will con- tinuous when production reaches capacity. Pouring done into trap, and the gates are designed keep ox- ides out. Down sprues are com- monly in. section and one, two three number. Long runners and long gates, the walls which much the oxide forms deposits, are used. shrinkage high (11/64 in. per ft.) many chills and numerous risers used. Chills are filled with holes facili- tate the escape gas. Patterns used have undergone process development that now sound cast- ings are produced within the nar- row limits dimensions specified work. Gating technique was developed with the help X-ray equipment get sound castings. idea the amount metal required sprues, gates, risers and runners may had when stated that one complex rear crankcase casting weighs when cleaned, but requires 114 lb. metal fill the mold. The usual yield per cent for magnesium castings from metal poured has creased the Ford foundry per cent some cases the use central risers feeding several sections simultaneouly. These risers are removed subsequent machin- ing. Shake Out Technique After pouring, molds continue around the reel until they reach the shake-out station where they are removed. The casting, then cooled, remains the shakeout screen equipment. 34—THE IRON AGE, October and risers are cut from the magnesium castings these band saws. Chips from the sawing operation are sucked off into water spray and operators must wear fire resistant coats and masks while operating the saw. along with some chills and the sand sifts through. Chills remaining the sand are removed magnetic pulley. All molds, except those unusually large which are prepared floor provided for this purpose, are made turntables provided with stripping machines which copes and drags are placed along with the aluminum patterns. necessary much hand work molding, the patterns are complex and must handled with care and many chills have placed. Sand first shoveled hand and con- siderable hand ramming required until recesses are filled and the pat- tern well covered. Additional sand added slinger, followed air tamping. After molds are completed and stripped from the pattern, drags are loaded onto the reel and copes onto belt conveyor. Cores are inserted required the way the pouring station. Only silica sand employed A.F.A. fineness and 130 permeabil- per cent moisture, per cent each sulphur and boric acid and per cent glycol. Also added mixture containing one part Dixie bond and three parts bentonite quantities sufficient give bond strength per sq. in. All sand shaken molds elevated the third and fourth floors where re- conditioned before use. Then carried conveyors the slingers the second floor. After sand has been shaken from castings, they are delivered hydro-blast setup where each cast- ing subjected fine stream water which sand mixed. The stream under pressure 1200 lb. per sq. in., sufficient give velocity greater than three miles minute the nozzle.* This blast takes the place the usual initial air blast with sand, but its main advantage the rapid core removal which effects. Blasting done double-end booth with the cast- ings resting each two turn- tables made grating through which the sand and water run off recovery station the ground floor. Each the two turntables has vertical partition across one diameter and extending upward, normally flush with the wall the booth and half the turntable inside and half outside the booth. This makes possible load castings the outside half the turntable while those the inside half are being blasted. Castings are next passed battery band saws, where gates and risers are cut off for return the melting furnaces. Castings are then ready for heat treatment. All magnesium dust from sawing and from grinding (done booths) immediately sprayed with water and piped settling tank, which cleaned out once week. Other chips are swept frequently dur- ing the day and are deposited containers where they are covered with oil. Saw operators must wear long flame-proof coats and helmets. Grinding wheels used for mag- nesium may never used for steel tools, sparks might ignite mag- nesium dust. water tends spread magnesium fire and chem- ical extinguishers are not effective x iy ¢ ° ° ° such fire, special magnesium fire fighting equipment, employing sand spray, must kept hand. All magnesium castings are sub- jected heat treatment after gates and risers have been cut away. This done vertical oven which the temperature maintained be- tween 715 and 730 deg. for hr. Heating done electrically and controlled thermostatically, the air being circulated continuously while the oven use. The operation the oven not continuous, how- ever, the castings being charged batches onto the shelves con- veyor arranged distribute them from top bottom the oven. the end the treatment, the cast- ings are coated air from purg- ing fan. Although the oven tem- perature well below the ignition point the castings, there pro- vision for automatically introduc- ing into the oven sulphur-dioxide atmosphere should fire occur. The oven extends from the ground floor the roof the building, three floor levels. Subsequent heat treatment, castings are subjected finish snagging and grinding, well occasional hand chipping, bur- ring and filing. Much this work handled individual booths with gratings for work tables that chips can drawn through into water spray, eliminating the dan- ger dry magnesium dust. Final sand blasting done similar booth, after which each casting subjected chrome pickling sur- face treatment the monly applied magnesium cast- ings minimize surface corrosion. Many castings are subjected test water insure against porosity that may result leak- age. When leaks are found, they are stopped impregnation with drying oil or, point where this not permitted, the casting About per cent the cast- ings produced are subjected X-ray examination for soundness, but patterns and gatings have been carefully designed avoid de- fects, and control rigid throughout production that once permanent gating technique has been established rel- atively few rejects are found. until July nearly all the castings produced Ford Motor Co. have been supplied Pratt Whitney plants already produc- tion aircraft engines, but, the new Ford aircraft engine plant swings into the foun- dry will supply its needs and the castings will then machined and finished completely Rouge plant which the magne- sium foundry located. Corrosion and Acid Resisting Nickel Free Steels SURVEY corrosion and resistant nickel free steels, given Scherer the Breslau Achema congress the Deutsche Gesellschaft fur Chemi- sches Apparatewesen reported the Aug. issue The Iron Coal Trades Review. Steels containing per cent chromium are now mainly used for household utensils and for fittings which had heretofore been made bronze brass. Owing high chemical re- sistance, steels with per cent chromium have been success- fully applied various branches the chemical industry, especially the manufacture nitric acid. these steels are also resistant weak organic acids, their use the food preparation industries place chromium-nickel steels, tinplate, and non-ferrous metals use sugar and liquid fuel indus- tries. Washing machine drums, heretofore made copper brass, and water meters, previously made pure nickel, have recently been made nickel free chromium steels, and they replaced bronze certain ship components these steels are unaffected sea water. The corrosion resistance steels can raised further the additions per cent molyb- denum, their resistance chemical attack then being comparable and some instances superior that chrome-nickel steels. Another type nickel free low nickel steel are the chrome- manganese steels, with roughly per cent chromium, per cent manganese, and 1.5 per cent nickel, per cent chromium and per cent manganese. These have about the same resistance chemical attack chromium steels, have mechanical properties that compare favorably with chrome-nickel steels, but have adverse factor their cold hardenability. These steels are used mainly where high corrosion resistance required and where nickel, copper and tin previously have been used. They have lower tenacity low temperatures than the chrome-nickel steels and hence are widely used refrigerating machinery. The author also reported re- cent research which nitrogen successfully introduced into the steel, increasing corrosion re- sistance, well acid resistance. Nitrogen increases the stability the austenite and gives better workability the chrome-manga- nese steels and enables per cent nickel replaced 0.1 per cent nitrogen standard acid re- sisting chrome-nickel steels with- out any loss physical properties. The addition nitrogen per cent chromium and per cent nickel steels per cent chro- mium and per cent nickel steels has provided new materials with the same chemical and mechanical properties standard chrome- nickel steels. This trend toward nickel economy has been forced the shortage nickel supplies Germany, the author stated. discussion Mr. Scherer’s report, paper was referred that dealt with the manufacture ni- trogen alloys and showed that alloy containing per cent chro- mium, per cent nickel, and 0.25 per cent nitrogen, with less than 0.1 per cent carbon gave the best results. Compared the per cent chromium alloy mentioned Scherer, the austenite this steel stable even after heating for more than 1000 hr. and the an- nealed state has the same high tensile and yield point values the steels, well mally only found with the soft austenitic chromium-nickel steels. This alloy per cent chromium and per cent nickel suitable for deep drawing purposes, and, since not subject intercrystalline corrosion, can welded. The hot yield point roughly double that ordinary 18-8 steels; the corro- sion resistance nitric acid practically the same that the 18-8 steels; and better its behavior certain mixed acids and salt solutions. THE IRON AGE, October & 3 nail Something New Steel Airplane ABOVE plant Aeroproducts Division General Motors Corp., Dayton, now experimental production type hydraulic airplane propeller for the Army Air Corps. About 900 are now engaged 1500. % LEFT side blade nickel-molybdenum steel forging, SAE 4640, weighing 240 unmachined. Equipment for embedding this forging flat steel handling plate with low melting point metal shown the background. LANING the steel forging. This special machine equipped with accurate follower which traverses the master. The use this forging with central rib gives blade which surprisingly light when its great strength and rigidity considered. LEFT the propeller blade forging from matrix fixture operation. This forging now goes through number different machining operations, assure exact sizing and balance, and also reduce weight. z : ag | = Propellers ABOVE ILLING out the inside the forged blade. The profile and depth masters are the top, and from one (as shown here) three forgings may milled the same time. RIGHT TEEL sheet, SAE 4640, ground from 0.09 in. thick 0.07 in., then blanked and camber side propeller. this camber sheet being laid onto the fully machined forging. The assembly passes through gas furnace having cracked gas atmos- phere, where the two are brazed {around edge and along rib), to- gether with pure copper. Clamps hold the assembly together during cooling. BELOW FTER final finishing operations, heat treating, dull chrome plating, and rigid inspection, the finished blade (weight goes make three-blade unit with hydraulic pitch regulating hub. The test run here shows carbon re- sistance rods cemented along each blade for examining vibration stresses. The hub remarkably simple and permits shooting through the center. ) ABOVE LADDER needed for the operator climb the operating position when the saddle elevated. Push but- tons and selector switches are mounted ‘long flexible cable which the operator with him moves around the machine get closer the cutting position. Independent feed boxes gov- ern movements housing and saddle curvalinear contours can milled. BELOW spindle saddle swivel type. swivel saddle mounted one square ram with in-and-out move- ment in. and fitted with right angle attachment that will swivel around the axis 360 deg. and sturdy enough for milling the largest rabbets used armor plate one cut. Main spindle speeds from are obtained through change gears and variable speed 20-hp. motor. Feed and rapid traverse through two motor controlled units. The feed from in. per min. with feed changes. The rapid traverse constant ft. Armor plate milling now possible times faster than old equipment. Cutter life same steel castings. 38—THE IRON AGE, October Big Miller Trims 18-In. Armor Plate big milling, boring and drilling machine for and in. armor plate, built the Ingersoll Milling Machine Co., Rockford, Ma- chines this design will ship- ped the United States Naval Arsenal, Charles, Va.; Bethle- hem Steel Co., Bethlehem, Pa., and Midvale Co., Philadelphia. This joints plate edges, mill odd con- tours where plates fasten hulls and cut out windows plate for big guns fire through. Heavy armor plate, such this unit, de- signed process ranges length from ft. and weighs much 100 tons. The miller has housing which travels ft. along the bed, and the head adjusts ft. vertically the housing. Housing and saddle swivel horizontal and vertical planes, respectively, and to- gether with universal right angle face milling attachment, permit any compound angle ma- chined. ‘ ‘ i gr Electric Salt Bath Furnaces For ° ° ° HOWARD LINN EDSALL Ajax Electric Co., Inc., Philadelphia and LLOYD Editor, The Age ° ° ° ITH the mandate from the Office Production Man- agement requiring everyone ordering conventional type high speed tool steels ac- cept half his requirements molybdenum steels, every American toolmaker has been finally faced with the necessity making changeovers his tool making tech- nique. The government, through OPM, issued urgent call tech- nical societies the metal working industries aid manufacturers and users tool steels the These societies have been doing their utmost bring about suc- going far hold courses instruc- tion for tool makers and users various cities throughout the coun- try. While there are tungsten bearing ores the United States, high grade tungsten ore used this country for the most part im- ported. The substitution molyb- denum for tungsten making high speed steels has become necessary because present world conditions have disrupted these imported sup- plies. However, molybdenum can readily substituted great part for tungsten. Molybdenum cheaper, pound for pound, than tungsten, and, the United States believed have the world’s greatest molybdenum deposits, Heat Treating High Speed Molybdenum Steels Electrically heated salt bath furnaces present many ad- vantages heat treating high speed molybdenum steels, having inherent controls that eliminate decarburization, oxidation and carburization that form soft skin other surface defects. mainly Arizona, New Mexico, Colorado and California, there Heat treating the chief ob- stacle overcome before molyb- denum high speed steels can uni- versally substituted for tungsten steels, and this problem has for many years hampered the more ex- tensive use ‘of these new steels. The molybdenum alloying effect steel the same direction and greater magnitude than tungsten, and tools equal and many in- stances better than tungsten tools have been made molybdenum steels. When Europe problem substituting material for limited tungsten supplies early World War molybdenum was one the first successful sub- stitutes found, and European heat treating methods began undergo changes. Liquid salt baths heat treating medium have been the accepted method since metal- lurgists first began apply scien- tific procedure heat treating metals; and today, with furnaces developed give higher efficiency and greater yield lower costs, the application salt baths heat treating molybdenum steels appears the trend. One authority re- cently stated, “An important con- tributing factor the development and adoption the molybdenum types high speed steels sub- stitute for 18-4-1 and other tung- sten alloyed high speed steels has been the electric salt bath method hardening.” The electrically heated salt bath, with immersed electrodes, has al- most proved itself some ways the “sulfanilamide” the metal industry, being used for cyanide hardening, carburizing, tempering, annealing, quenching baths for austempering steel, for patenting steel wire, and for heating steel forging temperatures and for braz- ing, well for heat treating high speed steels the molyb- denum and tungsten types. The first development heat treating baths for molybdenum and tung- sten high speed steels goes back several years, almost the incep- tion the Ajax-Hultgren electric salt bath furnace, which was de- signed primarily for this purpose. Watertown Arsenal, Watertown, Mass., early 1934 recom- mended the use the salt bath for THE AGE, October 1941—39 ° heat treating high speed molyb- denum steels, before the present electric heating system for the bath was developed. the field heat treatment the goal has been perfec- tion control over variables furnaces, heating mediums and fuels, and the salt bath furnace heated means immersed elec- trodes, system introduced com- mercially 1936, assures the heat treating molybdenum high speed steels and tools without danger affecting the surface oxidation. Many users are reporting very high yields with minimum re- jections, the case the Amer- ican Twist Drill Tool Co., Detroit, which found that salt bath heat treating “has about tripled the pro- duction and has made the whole proposition (of heat treating) matter routine—automatic and trouble Salt Baths for Heat Treating the term “salt bath” for heat treating molybdenum high speed steel meant liquid bath com- pounded melting one more chemical salts, designed form heat treating medium which the steel immersed for suitable length time. This medium shall not impart either hard soft surface the steel, and shall not alter the chemical composition IRON AGE, October 194! the surface. The hardness, edge, the finished tool not due chemical, but physical change the steel, altering only the grain structure and grain size. Salt com- positions, which there are stand- ard types marketed under special trade names, should meet several general requirements: they should compositions chlorides with acid rectifiers, melting tem- peratures between 1000 deg. (1832 deg. F.) and 1050 deg. (1922 deg. F.), which temperature range considerably lower than the operating temperature the bath, (2) the bath should free from poisonous obnoxious fumes operating temperatures, (3) the salt should wet the work and conduct heat uniformly and contact, (4) sludge formations the bath should relatively low, (5) the composition the bath should such that will not re- act chemically with the pot holding the bath, (7) the salt should water soluble that tools may readily cleaned after hardening, (8) should remain neutral with- out the necessity replenishing daily (small additions due drag- out only), and (9) the salt should inexpensive and readily avail- able. The use electrically heated salt baths for heat treating molyb- denum tools offers several advan- tages automatically controlling many features that might vary greatly under ordinary conditions. One inherent feature this type furnace its exclusion atmos- phere from the parts being treated, thus eliminating atmospheric sec- ondary chemical reactions. the part being treated immersed the liquid salt, oxidation and other atmospheric effects are inhibited, and, withdrawing the part from the bath, liquid salt film adheres the tool, completely encasing another. This, combined with proper bath analysis, virtually pre- vents any chemical reactions the surface the steel. Another feature electrically heated salt bath furnaces the very close control that can main- tained the temperature the bath, keeping within very narrow ranges. For instance, Ajax fur- naces are guaranteed maintain temperature range throughout the bath well within deg. The internal temperature controlled with utmost precision the reg- ulation the flow electricity into the bath through the elec- trodes. Likewise, the cision control can exercised the heating rate. Properly arranged electrodes the bath set “motor effect” self-agitation electromagnetic circulation that keeps the bath thoroughly mixed, maintaining constant tempera- ture all points the bath with- out reliance upon convection cur- rents thermal flow. Fuel-fired externally heated pots often interrupt production be- cause pot failures due heat = being transmitted through the ves- sel, making crucible rather than container. Since immersed electrode heated pots never come contact with flame, pot failure reduced minimum. Where pot failure occurs, warn- ing given ample time for the spare readied for installation. Salt bath furnace pots are usually made refractory shapes cast heat-resisting alloys. The melting point either refractory metallic pot much higher than operating temperatures the bath, and the practice set the pots high-temperature insulation mounting. Metallic pots have ser- vice life ranging between 1500 and 3000 hr., but newer type ceramic pots, first introduced and tried the makers the Ajax-Hultgren immersed electrode furnace, are re- ported undamaged after one year operation the high temperatures required for heat treating high speed steel tools. Further installa- tion records are being watched, and considerable research continues with refractory pots. Precautions are necessary when using pots, mainly regards cooling; and the beginning, when start- ing the furnaces, necessary dry the new ceramic pot thoroughly applying small amount heat before starting the new pot spare. Substituting Molybdenum for Tungsten There believed nothing lost tool properties the sub- stitution molybdenum for tung- sten high speed steels. While molybdenum steels tend brittle and seamy, vanadium addi- tions will stabilize these variable properties. Furthermore, cobalt ad- ditions will prevent molybdenum the steel from sweating out the form thick bluish vapor during forging operations. The belief investigators has been thoroughly confirmed the action these two additions that molybdenum can substituted total for tungsten. the use molybdenum making high speed steels focussed the attention the American tool- maker his biggest problem, the simplest and least complicated method heat treating this mate- rial, extensive investigations were made several years ago the Watertown Arsenal, and precise heat treating system was designed for steels that contained very high percentages molybdenum, rang- ing between 9.0 and 10.0 per cent. The peculiarity molybdenum steels oxidize rapidly during handling high temperatures, forming soft, white, powdery skin, makes difficult forge and shape the tools. This skin, due decarburization and some extent de-molybdenumization, begins when the steel, 400 deg. (752 deg. F.) more, comes contact with air, and has been observed deep in., requiring allowances made for subsequent grinding and refacing. This, while costly any case, may nigh impossible when intricate twist drills, milling cutters, threading dies, reamers tool, rendering practically useless unless reground. For another article dealing with Molyb- denum High Speed Steel, see THE IRON Sept. 25, 1941 Molybdenum high like other similar steels, charac- terized its property “red” “secondary” hardness that enables the tool made these steels take heavy cuts while running high speeds and elevated tempera- tures exceeding 500 deg. (932 deg. F.). Machining con- ditions made possible this prop- erty are all too well known re- quire repetition. However, this red hardness due combination 2—These molybdenum steel twist drills have just been removed from the quenching bath after heat treatment the American Twist Drill Co., Detroit. and hobbers are being heat treated for precision work. Decarburization, this powdery soft skin, lowers the car- bon the austenite, resulting precipitating ferrite within the grains near the tool surface. Fer- rite, being soft, causes the tool lose its cutting properties. the other hand, carburizing the steel surface through the use baths atmospheres high carbon, may likewise have deleterious effect the finished tool, since carbon additions will lower the melting point the steel. Thus, harden- ing temperatures, fusion may take place the cutting edges the things, one which the per- centage alloying agent the steel. While tungsten additions high speed steels range per cent, molybdenum steels require considerably less this element get the desired properties. Ratios the amount of. molybdenum the amount tungsten produce corresponding effects vary with the properties the finished which the comparison based. are estimated, and the mean ratio would run about plus. This corresponds the approxi- mate ratio the atomic weights THE IRON AGE, October i- l- e- molybdenum tungsten. Strength, ductility, and hot red hardness molybdenum steels are not widely different from those tungsten steels when this ratio maintained. Commercial Molybdenum High Speed Steels Different steel manufacturers vary the ratio the elements suit specific needs and purposes, and make their brands unique. However, molybdenum steels gen- erally fall within the following analysis range: C—0.60 0.85 per cent Mo—3.5 9.0 per cent Cr—3.5 per cent —0.00 6.00 per cent 0.90 2.25 per cent Co— per cent identification system for high speed steels has been worked out that assigns letter each man- ufacturer. This letter the same for all products the manufacturer and may specified following the num- ber designating the type analy- sis. partial list these identi- fying letters for various manufac- turers follows: A—Vanadium Alloys Steel Co. B—Firth Sterling Steel Co. C—Henry Disston Sons Cyclops Steel Co. E—Bethlehem Steel Co. F—Latrobe Electric Steel Co. G—Allegheny Ludlum Steel Co. H—Columbia Tool Steel Co. recent “1500 Tool Steels” appearing THe IRON in- dexes tool, metal-cutting, and die steels and lists the names, manufacturers, and analyses all known American and im- ported tool steels, many which are molybdenum type steels. Also, handy reference chart appeared Aug. 28, that shows comparative tungsten and molybdenum steels, list- ing them grade grade, according producers. 42—THE IRON AGE, October 194! 3—American Twist Drill Co., Detroit, operates this battery salt bath furnaces hr. day, six days week. Drills from 0.040 in. thick are hardened these furnaces. After weeks c