The Iron Age 1944-07-06: Vol 154 Iss 1

This Tie Vice-President Seneral Manager Vol. 154, No. 1944 Editorial and Advertising Offices 100 East 42nd St., New York N.Y., Johnson, Market Research Mgr, Typography and Layout Editorial ° ° Regional Business Managers 428 Pork High Frequency Brazing Mortar.................... Chilton Bidg. 1134 Reduction Ferromanganese High Quality Steel Pro- 7310 Box Presses and Processes for Metal Powder Products II...... Reclaiming Foundry Sand the Wet Method........... Platers Discuss Industrial Finishing Methods............ Owned ond Published CHILTON COMPANY Features Executive Offices . JOHN BLAIR MOFFETT, Secretary News Industry JULIAN CHASE THOMAS News and Markets Member, Audit Bureau Circulations Farm Implement Makers Fear Tank 107 Forge and Foundry 112 Non-Ferrous Metals Prices; Scrap Iron and Steel Scrap News and 162 Finished Iron and Steel 165 Steel and Warehouse Prices....................... 166 Semi-Finished and Tool Steel 167 Railroad Material and Stainless Steel 171 q 4 ll ha he. F A fs ARE PLACES FOR BOTH... Firth-Sterling, long specialists making steels for shop tooling, early recognized the possibilities carbides means extending the improvement shop practice brought about the super high- speed steel—CIRCLE But, there place Where the highest speeds are obtainable ma- terials are hardest, FIRTHITE the “last word” ten times those possible with high-speed steels. Where speeds above average are permissible materials are the hard CIRCLE will cut least faster than ordinary grades high-speed steel. Send for descriptive literature these remarkable materials. STEEL COMPANY Fis. IRON AGE, July 1944 SUPER HIGH-SPEED For instance: FIRTHITE removes 730 pounds gray-iron cast- ing metal per hour instead 180 pounds; drills gun barrel minutes instead hour; enables milling-cutters run 1,000 feet per minute instead 100 feet with previous ma- terials. For instance: CIRCLE machines hard die blocks hours instead hours ... doubling production tweer grinds versus regular high-speed steel; turns two ten times more pieces heat treated alloy steel between grinds than other speed steels. j | hard hours tion versus times between ce — July 1944 VAN DEVENTER President and Editorial Directer BAUR Vice-President and General ° ° DIX Reader Service ° ° ° Editorial Staff Commercial Editor, CAMPBELL Associate Editors WINTERS BARMASEL Assistants SCHIEN WILLIAMS ROGERS News and Technical Pittsburgh 428 Park Bidg. POST Chicago 1134 Otis Bidg. DONALD BROWNE EUGENE HARDY Washington National Press Bidg. MacDONALD Cleveland 1016 Guardian BRAMS 7310 Woodward Ave. OSGOOD MURDOCK San Francisco Market St. Correspondents ROBERT Cincinnati PENLEY Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ont. RAYMOND KAY Los Angeles JOHN McCUNE Birmingham ROY EDMONDS St. Louis DOUGLAS Seattle Are You Muscle-bound Manager? EOPLE have way lumping things together and labeling them with names that are confusing. Take the well-known terms, capital, management and labor. Three pigeonholes, these, into which ostensibly you can neatly separate three functional classes. This lumping gives one poor start towards clear thinking. For there probably more difference and variety the contents any one these pigeonholes there between any two them. friends defines “capitalist” person who lives the work others, whereas another friend will define him man who makes possible for others live providing the opportunity for them make living. labor, there the same loose conception terminology. Spell with capital “L” and means the CIO the AFL. Spell with small and means the unorganized workers and the independent union members. Spell with “u” and means British labor. Spell without one and you are Uncle Sam’s territory. too with management, which the subject want dwell upon today. not like the thought compulsory grade labeling, but might well apply voluntary grade labeling management. The and shades are many the hues the rainbow, running all the way from super-super pooper-dooper. Good management must always well rounded. You can’t say good well developed one limb and atrophied another. Good management takes into account quantity, quality, cost, labor relations and where the business coming from and the money make go. People say, very justly, that management has done splendid war job. But has been one-sided job with tremendous emphasis quan- tity. has been weight lifting job rather than juggling feat and weight lifting apt make one muscle-bound. have heard good deal about plant reconversion and what should done about but not word yet about the need management reconversion which just important. You have reconvert the managers before you can successful reconversion job the plants. Two years and more weight lifting with quantity pretty nearly the one and only objective o.k. for war but not for peace economy. War has made improve production wise but this after all one sided improvement. Because have concentrated hard meeting schedules, with cost and other considerations distinctly secondary, have probably lost something that will have regained when the emphasis changes from quantity cost the postwar world. Most you who read this page have managerial functions and may pay you think about getting your muscles flexible again after all that heavy lifting. | q | q | q | | Official Navy photograph. Mississippi River days have given way watercraft many kinds. These vessels, built the Great Lakes, travel down the river the sea join the fight against America’s enemies. Among these fighting ships are submarines that down the Mississippi Water- way ferry float. When sub has been delivered New Orleans the ferry towed upstream Lake Michigan where takes another cargo. Many floating dry docks, well the ferry float above, were built the Chicago Bridge Iron Co. plates furnished > Ferry float transporting submarine down the delivery New Orleans. FLOATING SUBS THE SEA Inland. The dry docks are made three parts; large center section and two smaller end sections. When neces- sary examine repair the bottom plates the dock, the center section can docked the two end sections. Likewise, the two end sections can docked the center section. When tow, the end sections are usually docked the center section. Before the war, Inland shipped large tonnages plates structural shops, tank builders, pipe manufacturers, for peacetime products. When our fighting fleets return home waters, Inland again will furnish steel for the growing needs America peace. Sheets Strip Tin Plate Bars Plates Floor Plates Structurals Piling Rails Track Accessories Reinforcing Bars INLAND STEEL COMPANY Dearborn St., Chicago Ill. 56—THE IRON AGE, July 1944 work oar the wer prec: sion 1s. Paul News July 1944 Now that the government has permitted automobile companies experimental work and place orders for tools, the prediction that the immediate oar Will not the 1942 model but really new design. And: With automotive concerns particularly strong the stock market rise, Detroit gossips are busily whispering about the possibility mergers. This the last war that will fought off the Mesabi iron ore range, according Hamaker, Berger Mfg. Co. (Republic), speech last week New York. Beneficiation poorer grades iron ore still rather expensive process, and for many plants may become cheaper import ore than benefi- low-grade domestic deposits after the war. commercial aviation should increase ten times its pre-war volume would present producing capacity about per cent rate. The Germans now claim that (jet) fighter airplane being service under operational conditions. named the Messerschmitt Schwalbe. The Allies now have enough jet fighters that they also could soon throw them into combat. With reports new German jet (robot) bombs operating speeds excess 400 m.p.h., perhaps the Allies will soon use their jet fighters run them down. Nothing like setting jet catch jet. The jet fighters furthermore would operating over home territory, and there wuld danger one being brought down for enemy examination. The German jet bombs have far more significant implication than being recognized. This new German weapon, perfected two years ago, could have won the war for Germany. But: technical principle has been proven. one-ton bomb can sent 100 miles with fair accuracy and speeds wer 400 m.p.h., the assumption sound that future development can send any wight bomb far greater distance, much higher speed and with far more precision. There loss life the part the aggressor. And, the bombs sion equipment simple and inexpensive. Far greater energy and great amount equipment must used knock down small country could secretly build many bombs and blitz many enemy cities space hours. could make the possibility sudden wars far more than has the airplane The hundreds railroad passenger cars that are now order with carbuilders not built for some time. Orders have been placed with builders when basis, depending upon WPB steel allocations. Greatest hindrance not steel aluminum but components such air conditioning units and equipment. Axles and wheels are short. actual tentative steel for this use are reported yet. The armed services including the Navy are planning "war reserve" machine which will set soon. generous supply hard get and special munitions tools will taken out production lines quickly they idle and set pool temporary storage pending another emergency such the current shell program. These may drawn upon from storage during the war after the war will part completely modernize all arsenals while the will into permanent storage the arsenals for future use. More than one steel company mentioned rumor these days looking ase additional barrel making facilities. One Chicago barrel maker actively soliciting offer. More barrel shop mergers may the soon. The war has completely changed the character electroplating, from protective coatings. However, the total areas now plated are approxi- equal those plated peacetime. | | | | ~ | | { q 7 | i if - | 7 | | | | | | Eaton Mfg. Co., Cleveland, widely known manufac- turer various types air- parts and subassemblies, inas- much most its plants have been kept busy doing this kind work since the beginning the war. However, one the divisions the company that peace time assembled automobile heaters, for the past two 1G. drawing the base and duction coils are sta- tionary and the shot are dropped into them. The shot the left are the quench stage the hardening while those the right are being Shot brought and taken away from the machine the trough conveyor ground. 58—THE IRON AGE, July 1944 years has been doing outstanding job the hardening armor ing shot. the present this division working two shifts day the production mm. armor piercing shot and two types the mm. armor piercing shot, the mono- block one-piece shot and the three- piece with the hardened body and cap and windshield. Previously, another Induction Hardening type mm. armor piercing shot was produced, but this type was dis- continued favor the more recent design. The heart the shot hardening arrangement the battery Tocco hardening and drawing units the plant. For the mm. shot, there two hardening machines, each which has two six-shot stations. For ° mm. armor piercing shot one the battery duction hardening ma- chines Eaton Mfg. Co., Cleveland. The shot are ready removed from the sta- tion the left after heating and quenching, while the indicates shot the hardening cycle. Shot are raised hydraulic the inductors. chi ing the cor an chi ing hot dis- the For Shot hardening the mm. shot, two ma- chines are operation, each likewise having stations. For drawing the bases both the and mm. shot, there are three machines with two stations each, accommodat- ing shots per station. addition there two-station hardener for the penetrating caps for mm. shot. Shot shipped from seven sub- contractors with plants Cleveland and northern Ohio, who rough ma- chine the shot from annealed 4150 bar stock some other Ordnance approved shot steel. the shot received, inspected and then ground Cincinnati centerless grinder insure concentricity and size. After cleaning alkali spray washing machine, the shot trans- ferred overhead conveyors the hardening unit. With each shipment shot from new heat steel, pilot lot run through the hardeners determine the heat treat cycles. The obvious purpose heat treat- ing these various types shot develop them hardness characteris- tics that will enable them penetrate the armor tanks, vessels, and other vehicles war. Induction hardening the Tocco process used Eaton Mfg. Co. heat treating the three types shot THOMAS LLOYD Associate Editor, THE IRON AGE ° ° Eaton Mfg. heater plant line for heat treating and finishing and mm. armor piercing shot has been operation for many months. The Tocco induction heating process—the heart the operation—provides fast, easily manipulated and con- trolled method heat treating. manufactured this company for several reasons. First, the process easily controlled once set up. starter button begins the process heating and quenching predeter- mined cycle, requiring very little the way trained skilled person- nel. Being fully automatic, the proc- ess eliminates the possibilities variations the hardness the fin- ished shot. Once the cycle estab- lished for given shipment rough machined shot, there little need for maintenance other than spot checking see that the equipment stays register. The installations Eaton operate 440-volt, 3-phase, 60-cycle line. addition the water intake and outlet lines, the only connection neces- sary the units the power line. The units have motor generator sets kw. output capacity for the hardening operations, while the base draw and cap hardening equipment have kw. capacity motor genera- tors for each unit. All machines are equipped with the automatic controls and preset timers that once the hardening and drawing cycles are de- termined, the operator need only load the machine, push the starter button, wait for the cycle complete itself, and unload the machine. The operation induction harden- ing equipment based high fre- current flowing through inductor thus producing high fre- quency, magnetic field within the re- gion the inductor. When metal, such shot, placed within this field, the dissipation energy the steel produces heat, the result the friction set within the steel the molecules attempt aline themselves with the polarity the rapidly chang- ing magnetic field. The and mm. types shot ° ° 1G. 3—One type mm. shot requires piercing These ardened similarly the shot hardening machine. Samples the cap can seen the tray before the oper- ator. ° ° THE IRON AGE, July 1944—59 ° ° ° ° ° ing ercing the ma- Mfg. The hot cycle. ° are placed hydraulic locator pins that fit into the base the shot, shown Fig. the cycle Started, the shot rises into the induc- tor field. After predetermined heating around 1550 deg. F., the shot water-quenched for specified period and then unloaded. Two stations each machine permit the operator unload and load one station while the other operation. The funda- mental principles the hardening operation hold good also the draw- ing. The equipment used the draw- ing operation similar that used for hardening except, shown Fig. the shot sct down into the induction coils. Likewise, the harden- ing the mm. nose caps, shown Fig. basically the same hard- ening the shot itself. hardening the body the and mm. shot, there delay between the end the heating phase and the quench permit the heat soak from the body the shot toward the nose and also inward toward the cen- ter, thus making for uniformly heated shot. hardening, the metal the shot undergoes definite change. The structure the metal originally pearlitic spheroidized struc- ture. This changed homogen- eous austenite heating, and quench- ing the proper rate converts this austenitic phase the desired mar- tensitic structure. The base draw 4—This photomacrograph illustrates the gradual differentiation hardness from the nose the shot the base, with the hard martensitic structure the nose and the tempered martensite the base. This sample was hardened and base drawn mm. shot, deep etched. treatment, after hardening, formed that the finished product consists material with high hard- ness the nose point impact, and gradually decreased hardness the base approached. This gives the shot good penetrating well de- structive power. further impart ductility the pieces and relieve stresses built the shot drastic quenching, the shot stress relieved. After stress relieving the shot, which carried out gas fired, air recirculating type unit, the shot are aged for hr. This aging acts some- what the manner stress relief but much reduced scale. While specifications call for this treatment, plant metallurgists question its value. thermal shock examination follows. This thermal shock performed placing the shot water deg. for min., followed immediate immersion into boiling water for min., followed again immediately immersion water deg. for min. This supposed open any cracks seams the shot, but quite doubtful that the effect desired, because the treatment believed not severe enough. show the difference appear- ance and the nose base gradation hardness the shot, Fig. photomicrograph was prepared. This shows longitudinal section hardened and base drawn mm. armor piercing shot. Deep etching brings out the difference from the hard martensitic micro-structure the nose the tempered martensite the base. High Frequency Brazing Mortar Shells LAYING key part main- taining the production 4.2 chemical mortar shells Lempco Products, Inc., the use high frequency electrical induction for brazing the nose adapters and the base plugs the 14-in sections seamless tubing that make the shell. Originally, shells were forged and only the nose adapter was brazed the piece. Switching tubing (X1335 steel) and perfecting operations for the brazing the base have proved highly successful. Forging facilities were relieved and much metal saved. Two Tocco motor generator ma- chines producing 9600 cycles high frequency current are used. One, kw. unit, silver solders the base plug the shells; the other, kw. output, the nose adapter. Base plugs turned out steel are prepared for brazing ap- plying the flux and slipping 11/16 60—THE IRON AGE, July 1944 in. diameter silver solder ring onto the base before assembled hand into the shell. The solder ring in. diameter wire. Shells are placed two together double water-cooled inductor coil which there are two the unit. One station heating while the other being unloaded and loaded. The braz- ing cycle sec. for twe shells while #38 sec. for cooling are provided. Pro- duction the rate one shell every sec. Temperature reaches 1400 deg. Rejects are less than per cent according Lempco officials. Should pressure tests reveal irregularity braze, the shell returned the Tocco unit, the base reheated melt the solder and the p!ug removed. After determining the the trouble, the base reassembled and again brazed. During the brazing process, shells are held place with lb. pres- sure exerted 4-way air driven equalizer the top each shell. This insures proper fit the base plug with the casing the silver alloy melts. Next induction operation that silver soldering the adapter the nose sec.—or sec. per shell. The Tocco unit with two stations, each having double inductor, handles four shells, two heating while the other two are being unloaded. air cylinders are needed the weight the shell this stage production such insure proper joint be- tween the brazed parts. both these operations controls are automatic once the starting button pushed. Complete uniformity braze attested the exceedingly low rate rejections, the greater majority which result from foreign matter getting between the parts. r Worm. Gear Ratings Raised Fan Cooling view Cleveland Speedaire worm gear reduction unit. Air under induced draft from radial fan the worm shaft enters through the grille left and distributed effectively over the warmest sur- faces, which are finned. land Worm and Gear Co., Cleveland, the Speedaire worm gear reduction unit, incorpo- rating fan cooling system which permits pronounced reduction the size the unit required for given horsepower output. Cleveland’s application fan cool- ing the Speedaire unit based upon new type double wall con- struction which provides air pass- age completely enveloping the oil reservoir which the gearing oper- ates. (See cutaway views.) The in- ner housing wall, forming the oil reservoir, deeply finned the air announced the Cleve- Horsepower 600 800 1000 1200 1400 Worm speed horsepower transmitted with given speed reduction Cleveland Speedaire unit and standard type unit the same size. side, providing marked increase heat-dissipating surface. exhaust fan located the coupling end the worm shaft draws air high velocity through the space between the hous- ing walls from grille the opposite end the unit. This fan designed operate with either direction rotation. The effect the double wall con- struction maintain uniform flow cooling air against the fins and housing wall over the whole oil reservoir surface. Thus the operating temperature greatly lowered, giv- view Speedaire unit show- ing size and distribution the fins, which are cast integrally with the inner wall the housing. ing the Speedaire unit much greater load-carrying capacity than stand- ard worm gear unit equal size, when operated the usual motor speeds. obtain operating capacity with Speedaire units equal that standard worm gear units having ap- proximately double the housing di- mensions. Under given ¢onditions installation advantage may de- rived from reduced size from re- duced weight. either case there material reduction the dollar cost the Speedaire unit per horsepower capacity. Reduction Ferromanganese High Quality Steel Production the plants located the Urals has succeeded saving considerable amount ferroman- ganese the production high qual- ity steel the open hearth furnace, according Doobrov, the Rus- sian magazine Stal, No. 1-2, 61. During the period from January September, 1942, was possible re- duce the consumption per cent per ton. The raw materials plan called for consumption lb. per ton ferromanganese the first half 1942 leaving per ton for the sec- ond half the year. The surprising reduction the use ferromanganese was achieved the following means: (1) The practice sweetening the bath with small amounts ferroman- ganese was abandoned. But care was taken keep the manganese content the steel above 0.30 per cent. Re- fining completed when the metal contains 0.25-0.30 per cent Mn. Since the furnace charged with per cent pig iron containing from 1.5 per cent Mn, special additions ferromanganese are needed. (2) the specifications for the fin- ished steel call for manganese con- tent between 0.35 0.60 per cent, the plant produced containing more than 0.45 per cent Mn. (3) The plant substituted the for- mer method deoxidizing the steel the furnace deoxidizing the ladle. Thus saving per cent the ferromanganese was achieved. (4) melting the heat the maxi- mum and minimum temperatures the furnace were closely watched. Also, mild steel was longer pro- duced since consumed most the ferromanganese charged. Simultaneously with the reduction the ferromanganese the plant re- duced the use specular iron ore from lb. per ton January lb. per ton September, 1942. The quality the steel produced during this period improved together with the greater economy the use ferro- manganese. THE IRON AGE, July the de- part lieve astic shot, This the nsite pres- riven This plug alloy the shell. tions, ndles the ion ntrols utton and Processes For UNDAMENTALLY, common powder metallurgy practice, suitably prepared powders are pressed dies suitable density and intimacy particle contact. Heat for the interatomic welding bonding may applied either during pressing more commonly after pressing the sintering (baking recrystalliz- ing) furnace. Subsequent sizing squeezing op- erations are common for porous bush- ings, filters, etc. while further hot pressing cold forging and inter- mediate annealing operations are re- quired where greater density de- sired (see table preceding article). Where continuous porosity needed 62—THE IRON AGE, July 1944 CRANE BUREAU Development Engineering Department Bliss Co., Brooklyn for lubrication for filtering, the voids between particles must kept connected opened up. this about per cent stearate other finely powdered metallic soap mixed throughout the metal powder before briquetting and then boiled out low temperature baking be- fore sintering. Porous and oil impregnated bush- ings for self-lubrication are commonly produced powder metallurgy competition with solid bushings, Fig. 10. Many iron powder bushings use binder and are sintered hydrogen atmosphere (to prevent oxidization) well the recrystallization range copper. such temperatures, eutectic copper-iron solution can form the contact points join the iron particles, copper brazing. the bronze bearings, the tin acti- vated form the copper-tin bonding eutectic among the copper grains. Dies, Fig. 11, for preliminary mold- ing briquetting the powder, may serve also for metering the charge LEFT limited lot compacting flanged bushings Moraine Products Division General Motors Corp. weighed charges are transferred from cups the dies which are pulled out the single action press. The punch inserted and the die assembly placed under the ram. Courtesy The Modern Industrial Press. BELOW with highly polished walls for flush fill measuring and briquetting por- ous bronze and iron bushings mechanical presess fitted with hopper, vibrator and timed knockout. (After Langhammer and ° ° ° Metal Powder Products... Fig. use ion) form iron for por- anical and and (compression ratio usually approx. Fig. 12, after ejection the bushing preform, the knockout below the platen drops back leaving cavity proper depth take the re- quired amount powder. The op- erator sweeps level full and trips the press for the compression stroke. The geared press run slowly enough permit entrapped air which has been compressed escape during the slow period the stroke. The bush- ing preform then ejected and placed the tray for sintering. The press might equipped with hopper for gravity flush filling indicated the left Fig. 11. the latter case, however, the hand filling permits consistent control together with in- spection work the parts are removed. Fig. shows one the double action cam presses also used briquetting bushing compacts. shows the cam bottom knockout but not the dial feed, hopper ejector. Except where heating done simultaneously with the pressing op- eration, the preforms briquettes are sintered, usually furnaces con- ABOVE 12—Flush filling self-metering bushing die Bliss No. press with scale for occasional checking weights the left. Courtesy National Molded Products, Inc. RIGHT 13—Bliss-Toledo No. double action cam presses with timed cam bottom action arranged receive dial feeds for use automatic briquetting porous bronze bushings. the second and concluding part the article, which began last issue, the authors discuss and illustrate the principles for selection dies, heat treatment and presses that have over- come many the shortcomings powder metallurgy techniques. fining inert neutral atmosphere, reducing gas vacuum. The tem- perature employed determined the metals under treatment and the characteristics desired the finished product. the case pure metals and many combinations metals, part the material melted during the sintering operation. some cases, however, where small amount relatively low melt- ing point metal used conjunction with high melting point metal, the lower melting point metal may fused. This occurs during the heat treatment hard carbide composi- tions. fixed rule can laid down the treatment alloys. Fig. electric, double-decked sintering furnace with hydrogen atmosphere prevent oxidization. Preforms trays are pushed through manually and retrieved opposite end. They move from the charging chamber successively through chamber and the cooling position which usually water jacketed bring the temperature down avoid oxidation before reaching the unload- ing chamber. After sintering, the bushings must sized and burnished accurately either single double action presses. direct connected lift-out used and the inner mandrel the moving punch. also possible employ design which both inner and outer burnishing surfaces are the fixed die, and the punch sleeve con- THE IRON AGE, July acti- ding nold- may ighed the single die urtesy tains only centering spring pin. Single action presses tooled this way can operated nongeared speeds comparable those sizing and ironing rolled bronze. The double- action toggle press Fig. timed little differently from the ordinary drawing presses that outer holding slide maintains endwise pres- sure the bushing until the punch has traveled through the bushing and back, strip completely. The dies, Fig. 15, for sizing precise dimensions have much com- mon with other metal sizing iron- ing operation dies. Both the briquet- ting and sizing dies are substantial construction and for production pur- poses, Langhammer and ad- vise high speed steels for dies and punches and oil hardening steels for strippers and knockouts. Allowances for sintering contraction and subse- quent sizing are suggested per cent the briquetting die diameter. They specify dimensional tolerances 0.0002 in. and superfinished sur- faces. force porous oil impregnated bushings into motor and frames other holding presses are used with suitable fixture and punch assure straight entrance the bushing. After pressing into position quantity work, often desirable burnish the bushing for precise diameter and positive align- ment. Long stroke inclinable presses 64—THE IRON AGE, July 1944 BELOW 15—Detail dies for sizing pre- formed porous metal bushings, after sin- tering, either sin- gle-action double- presses with direct connected liftout cam bottom knock- out. (After Lang- hammer and Smith.) LEFT 14—Charging powdered iron compacts trays into zone hydrogen atmosphere sintering furnace. Courtesy American Metal Corp. reducing presses with uniform strokes are used with such multi- shouldered punches have been used for solid bushings. For in. diameter, the Chrysler Amplex Oilite data book shows punch with six burnishing shoulders increasing successively diameter 0.001 in. 0.750 in., plus two more for final size 0.7503 in. dia. Dense Powder Products Metal powder products which are dense, opposed the porous types ABOVE toggle presses, used for sizing porous metal bushings. These also permit use split molds for other powder briquetting. just discussed, may divided into two classes: Those products which probably could not made otherwise satisfactorily, such refractory metal wire and sheet, cemented car- bide tools, electrical contact materials, etc.; and those parts which can also made such methods die cast- ing, precise machining wrought cast metal, such gears and other complex shapes, 17. often possible powder metal- lurgy briquette and sinter piece the finished size tolerances +0.001 in., that expensive ma- chining and scrap are entirely elim- inated. Density, especially the case 7 A / metal powder products, decidedly important. Upon depends tensile strength, impact strength, hardness, and ductility, all which increase with increasing density. Accurate Charges Necessary charge exactly the right amount powder especially im- portant the production dense compacts precise dimension. Fig. illustrates method weighing the metal powder charge cups for convenient hand feeding the die cavity. Here, the nearly pure iron powder has been thoroughly mixed with small percentage vegetable binder stearate (used lubri- particle friction and contact with die walls) and placed the in- verted conical shaped hopper. The vibrating hopper and trough conveys the powder container scale. The scale arranged with photo- electric cells and relays stop the vibrators, first the hopper and then the trough, slow down and then stop the flow powder when predetermined weight mix has en- tered the container. The operator then places the charge the die cavity (see Fig. 5), using profiled scraper for proper dis- tribution. important place the powder nearly possible its final position when filling the die. typical hydraulic press for such solid compression the fast Bliss self-contained 200-ton Hydro-Dynamic press, Fig. 19, with hydraulic knock- out the base, adjustably timed suit. Oil the tank the top the pressure medium with variable de- livery pump and motor the rear. ABOVE esting variety Compo bronze (pow- der) and Powdiron shapes. Courtesy Bound Brook Oil-Less Bearing Co. RIGHT 18— Precise weighing the powder charge ac- complished com- bining the graph" two tubes controlling two vibrators which con- trol flow the pow- der. shadow line ground glass window the operator visual check. Courtesy Electro Metal Corp. and the Syntron Co. Limiting positions the quick ad- vance period, the pressing stroke, the quick return, and the knockout (be- low) are conveniently adjustable. Both pressure switches and position stops are provided govern the work stroke. Hot Pressing For improved hot pressing the use transfer feed presses, Fig. 20, has been favorably considered combine closely progressive heating and dense pressing powder preforms. The process related common progres- sive forging double crank presses. The difficulty obtaining die ma- terial which will stand both the temperature heating and also the pressures forming without loss accuracy leads clearly the close coupling the two functions, each with suitable materials which are available. The transfer feed press provides series stations close to- gether and enclosable, with the neces- sary movements. The powder briquetted the first station pre- ferably preforms are delivered the first station the conventional fric- tion dial feed, then transferred from one position the next suitably shaped ceramic fingers the feed bars. The initial stations form sub- stantially automatic furnace with refractory ceramic die blocks and re- sistance heating contacts. Where greater speed required, induction heating coils could used. The press- ing station and possible restrike sta- tion permit the use high tempera- ture forging steels with hot oil cir- culation for control. Flame protection transit enclo- sure with Pyrex window and cir- culated reducing atmosphere re- quired minimize oxidation. Press Design Considerations Press construction for powder com- pacting requires all the precision and ruggedness the best metal work- THE IRON AGE, July orm c=. car- also etal- ma- | ing presses. Die clearances are even closer than most metal working that precision gibbing and carefully keyed frames with prestressed tie rods are particular value both hy- draulic and mechanical types. Fast crank actions contribute uniform- ity compacting. Bottom dwell peri- ods for relief entrapped air are available the presses used for curing plastic materials, Fig. 21. For the smaller sizes, the cut-back gap- frame construction gives the opera- tor freedom movement for conveni- ent hand feeding. While the particular application should always considered and may readily alter the consideration, prac- tice seems bear out the choice mechanical equipment for quantity production for porous compacts. For dense compacts and especially for closed dies where the powder charge where other unknowns are present, hydraulic equipment affords close con- trol working pressures. Timing also altered more easily instances where that advisable. The fast self-contained hydraulics also offer extreme flexibility and fast adjust- ment where shapes and production problems are varied. IRON AGE, July 1944 LEFT 19—Bliss Hydro-Dynamic fast cycle molding press compact self-contained unit with its own motor, pump and reservoir. has intertimed bot- tom ram for knockout with such dies Fig. for synchronized pressing from below and above. ° ° BELOW Fis. 20—For progressive heating and dense pressing powder preforms this automatic transfer feed press lends itself well use. refractory molds heating stations and oil cooled forging type dies. > RIGHT IG. tom dwell period the plastic curing presses has value permit trapped com- pressed air escape when making powder preforms. Uniformity powder compacting may favored some cases op- posing motions, differential motions special timings. Wall friction, tendency powders arch filling and differences thickness dif- ferent areas flanged bushings all enter into the problem. The sim- ple solution Fig. where the die ring floated springs not always practical. hydraulic presses such Fig. bottom cylinder and ram suitable tonnage capacity may timed desired with the top ram. Mechanical presses, Fig. 22, may arranged with crank toggle actu- ated slide under the press bed, op- posing the usual upper slide. Double action presses are available many sizes both mechanical (Fig. 16) and self-contained hydraulic types, Fig. 23. the larger sizes both use the keyed housing construc- tion with shrunk rods hold the frames solid under load. The usual timing such that the outer slide closes first, possibly pressing some portion the charge and then holds while the inner slide completes the compacting operation. Duplex presses, which combine two double action presses, one above and the bed, are also offered for some applications. these, independent pumping units for each slide are available give complete flexibility relative speed control and timing. Such actions are also advantageous the closing split dies for odd shapes the operation wedge mandrels for side cores. general, all such dies should the rugged construction charac- teristic cold forging dies. Often BELOW presses may arranged with top and bottom move- compressing from both di- rections and then stripping powder metal preforms. ( sizes truc- the slide some holds the ction some ident are bility ning. odd arac- they require hardened backing load distributing plates, wedge pre- stressing substantial holders shrunk rings Fig. Such die constructions are also advisable many cases for cold flowing heavy sizing operations performed knuckle-joint presses like that shown Fig. For such heavy sizing hydraulic presses and often me- chanical presses, advisable furnish hardened size blocks dis- tance pieces substantially built into the dies assure precise dimensions finished parts. Warnings dies design have much common for all powders whether plastic, ceramic, metallic mixtures these. Corner radii, fillets and bevels are important, avoiding sharp corners. Feather edges, threads and re-entrant angles are usually impractical not impos- sible. Refractory materials the powder mix are highly abrasive and often require carbide inserts, chrome plating highly resistant die steels. Reasonable uniformity section and avoidance thin flanges long thin barrels are important. Inserts backing plates may molded and sintered place many instances. The variety presses available for the cold and hot compacting opera- tions and the straightening, sizing forging operations after sinter- ing are keeping with the variety appearing powder products. Note Fig. the range sizes, shapes and relative proportions. Note also that some the parts shown have porosity for filters, others have lesser porosity suitable for long time lubrication while others are sub- stantially solid. Silica, graphite and 23—Bliss double-action Dynamic press with lower liftout at- tachment. The main inner slide ca- pacity adjustable tons and the capacity the outer holding slide tons. Duplex units this sort with double action presses both above and below have advantages for certain applications. 24—An assortment metal pow- der compacts, dense and porous bear- ings, filters, friction rings blocks, electrical contacts, pole pieces; from various ferrous and non-ferrous base alloys. Courtesy Unexcelled Mfg. Co., Inc., New York. carborundum may included mix- tures for friction clutches and brakes. The materials represented are also broadly significant. Greatest strides have been made with iron powders, copper powders and the bearing mix- tures. Unexcelled Manufacturing Company notes that while some fabri- cators have tried make alloy steels the individual addition powders such nickel, chromium, molybdenum and the like, practice has shown that inordinately long heat-treatment required achieve homogeneous material from such mixture. This has somewhat limited the application powdered metallurgy techniques but such shortcomings can many cases alleviated the use prealloyed powders. Metal powders may also supplied with suitable stearates other plasticizers ready mixed. Im- proving supply and improving tech- nique are constantly expanding this vital section the pressed metal art. REFERENCES ciety for Metals Handbook). Lenel, Moraine Products Divi- sion, General Motors Corp. “Pole Pieces For Electric Motors,” A.I.M.M.E., Feb- fuary, 1944. Wulff—Powder Metallurgy, A.S.M., 1942. Stanley Smith—American Prass Co.—The Early Development Powder Metallurgy, A.S.M., 1942. Hardy—Fundamentals Neces- sary Apply Powder Metallurgy,A.S.M., Hardy and Clarence Balke —Powder Metallurgy, Metals Handbook, A.S.M., 1939. Fulton, General Electric Co., “Sintered ary, 1944. Langhammer, Milton Smith, Amplex Powder Metallurgy, A.S.M., 1942. THE IRON AGE, July 1944—67 | 4 He | Reclaiming Foundry Sand the Wet Method HEN the Cincinnati Milling Machine Co. 1939 sketched program for the construc- tion sand reclamation system for its proposed new foundry, provided for the eventuality basic change the procurement types new sand. The satisfaction which the com- pany now has its system put into operation four years later can traced, small degree, this step back” anticipation the sys- tem ultimately installed. For some time the management had realized that within period years, the area available for dumping spent foundry sand would used up. was also felt that monetary saving was had suitable reclama- tion system could designed and built. Then again the use re- After long planning and research, the Cincinnati Milling Machine Co. decided the wet method reclaiming its foundry sand. The authors review the course development and give the reasons for timely decisions which have led the present working highly compact and money-saving reclamation setup. sand would great extent eliminate the storage large quantities various types WILLIAM RENGERING, CH. Assistant Foundry Superintendent, and WALTER HORTH, Foundry Plant Engineer, The Cincinnati Milling Machine Co. ments and becom- ing less depen- dent rail traf- fic situations was also considered. With these TABLE new sand, order tide the foundry over the freezing weather which exists least four months out the year. The factor cutting down rail ship- Screen Analysis Foundry Sands Showing Relative Amounts Coarse and Fine Material Old Type Sands New Type Sands thoughts mind research program was created find the answers the following questions: Were the sands then use the foundry such nature claiming? What characteristics should reclaimed sand possess? How should reclaimed sand reused? what process can the company best reclaim sand? Core Molding Core Molding may noted that these questions were not independent but were defin- ilica oarse edium ine oarse ine Core Natural Natural Natural Lake Bank the types Per Por Per Cent Per Cent Per New Types Sand Chosen 1.14 7.48 3.49 0.91 0.10 0.00 vulged that the three natural 10.47 43.75 25.95 2.22 3.20 1.60 bonded molding sands that the com- 3.26 4.38 4.88 12.80 0.70 16.60 cessive loss due grain breakdown down -badly due to. cleavage 4.33 13.43 12.39 63.16 0.20 1.20 present the grains. 4.00 25.00 16.00 20.00 None Consideration this fact was the Total fines (mesh —150) cause the first and all-pervasive 8.33 38.43 28.39 83.16 0.20 1.20 decision. was that the former sands mesh 22.70 24.30 69.10 0.20 1.20 would. This new sand had 68—THE IRON AGE, July 1944 grain structure that was free { = | ‘ ‘ 7 the king traf- was ed, mind stions defin- first sands com- itable ex- and core break sands was sand ree cleavage planes and also rounded form. Thus the first the above questions was answered. was next decided buy straight “clay free” silica sand minimum number sizes and try use the same sands all the foundry oil sand core mixes well the molding sand heaps. After many experiments the company decided buy lake sand for coarse grained silica sand and clay free bank sand for fine silica sand blend with the coarse sand. Here was the answer the second the questions, that using straight silica sands the be- ginning, the reclaimed used sand must approach the straight new silica sands cleanliness, grain size, havior. After series experiments was found that bonding clays would pro- duce satisfactory synthetic molding sands when mixed with the silica sands. Answering the third question “how should reclaimed sand used?” was apparent that its re- use oil sand mixes without requiring extra oil develop comparable dry strength since the reclaimed sand was clean and be- haved like the new sand. Also, using synthetic molding. sands made from straight new silica sands and bonding clays would permit the reuse re- claimed sand the same basis. Table shows the screen analysis the old type sands and the two now use. was found the prelimi- nary work that every type recla- mation process would eliminate most the material finer than 150 mesh, the larger sized sand grains were thoroughly clean. Hence, all new material finer than 150 mesh was con- sidered loss after one use. may also noted that all the old type sands have considerable percentage loss compared that the new sands. Search for New Method answer the fourth question, namely what process can the sand best reclaimed?—three meth- ods were open for consideration: Dry scrubbing followed air separation. “Burning off” the sand high temperature followed dry scrub- bing and air separation.* Wet scrubbing the used sand fol- lowed wet classification remove unwanted material and then drying the cleaned sand before storage reuse, the research work each *See the article: “Core Sand Reclama- tion the Thermal Method,” Tue Ace, Dec. 17, 1942, CORE DIG SUMPS (3) ELT STORAGE TANK GRAB BUCKET SCRUBBER CLASSIFIER CENTRIFUGE CONVEYOR DRYER BELT SAND-WATER FLOW CHART THE SAND-RECLAMATION SYSTEM LUMP CRUSHER SUMP DEWATERING TANK STORAGE RE-USE FOUNDRY DUST SUPPRESSION EQUIPMENT Used water water Fig. flow chart the sand reclamation system. these methods the main goal was produce reclaimed sand which was good better than new sand. the same time thought had given processing costs. Any sand reclamation project can feas- ible only the entire cost reclama- tion per ton materially less than the delivered price the new sands per ton. The operating costs sand recla- mation system involves many factors, for example: Depreciation Interest Taxes Ground rent Overhead Service charges—heat, light, air, ete. Power (processing) Fuel (processing) Water (processing). 10. Labor (supervision, direct and indirect labor) 11. Maintenance (parts and labor) 12. Loss reclaimed either through intentional rejection through inefficiencies equipment used the process. the other hand, credit against reclamation costs may.be taken follows: the reclaimed material put back bins ready for reuse, handling charges incurred put new material same place may credited. Handling charges previously in- volved hauling reclaimable material dumping areas well cost procuring and maintaining dumping areas may credited. Experiments Made summarization the work these problems the time the foun- dry engineering group assembled June, 1939, design the new foundry was about follows: All cores both large and small used the old foundry had been made from core sand mixtures containing THE IRON AGE, July — WATER 4 2—A view the inside the sand reclamation building, showing the dewatering tank left, grab bucket over muller and belt conveyor which carries the muller sand the classifier. Sand water suspension enters pipes extreme left. x 3—The good sand discharged into the tank shown the background. the left the sump the lump crushing unit. Foreign matter falls into the bucket. Concrete trench containing pipes that carry water and sand the centrifuge and the reclaimed water from the centrifuge. coarse lake and fine bank sands, since June, 1937. This used core sand was being sent the dump. Sufficient work had been done synthetic molding sands prove the posed new foundry and producing all the various types castings with synthetic molding sands. Very many tests, experi- mental basis, had been made towards reclaiming used core sand each the three methods previously outlined. was felt that the wet method re- claiming promised produce re- claimed sand nearest new sand properties. However, view study- ing further the relative operating cost data and unexplored possibilities the other methods the engineers had not arrived final decision. Research work continued these problems throughout the design and construction period, and when the new foundry started operations Decem- ber, 1940, all molding sand used the various departments was synthetic and the core mixes were made from the same base silica sands were the molding sands. addition the spent core sand from the core knockout was pumped hydraulically from points the shop dewatering tank just north the foundry build- ing. This used core sand was piled the foundry yard awaiting the day the reclamation system. Wet Method Selected Later the wet method reclaiming foundry sand was finally decided upon for the following reasons: Wet scrubbing and classification produced reclaimed sand with proper- ties nearest those the sand when new. Handling sand wet permitted pumping instead using long belts and vertical elevators for conveying from one point another. The wet method eliminated need for dust suppression equipment. Based study the equip- ment alrea