The Iron Age 1942-03-19: Vol 149 Iss 12

We’re Fighting This War Together The men who carry guns, bombers and fire torpedoes are our first line action. But less important the work men the second line—men who make these guns, bombers and torpedoes. Our job here Inland make the steel that necessary win this war. Inland steel- makers feel their responsibility keenly. They have smashed all previous production records. They are giving their holidays maintain the highest possible rate operation. They are working arm arm with the men service. INLAND STEEL CO. Nie 3 19, 1942 | Every “noise point” crane “wear point’’—and every wear point and when you purchase cranes, sure that every vital point Continuous production possible only when your cranes operate smoothly and breakdown. Wear points Whiting cranes have received special attention. Anti- friction roller bearings eliminate shaft and axle wear. Tapered-tread bridge drive wheels reduce wear rails and wheel flanges. Smooth-running her- ringbone gears transmit power efficiently and outlast ordinary spur gears two one. Capacities from one 400 tons. Also, electric hoists from tons. Whiting Corporation, 15601 Lathrop Ave., Harvey, Builders quality cranes for over fifty years. “ FOR Traveling Crane OVERHEAD TRAVELING CRANES : ° “Tre -Fiusheg a4 Rotating MARCH 19, 1942 VOL. 149, NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager ° ° Managing Editor, LIPPERT News Markets Editor, ROWAN Technical Editor, Associate Editors PHAIR JAMES OLIVER LLOYD Art Editor, WINTERS Editorial Assistants WILLIAMS BARMASEL Washington Editor MOFFETT SCHIEN BUTZNER Resident District Editors CAMPBELL Pittsburgh CORRADO Cleveland CHARLES POST HERMAN KLEIN Chicago SHERMAN Detroit San Francisco Editorial Correspondents DEARING Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ontario ROBERT Cincinnati RAYMOND KAY Los Angeles BACON Seattle ° ° ° JOHN McCUNE Birmingham ROY EDMONDS St. Louis DIX, Manager Reader Service Robert Blair Ober, Robinson Fitzgerald ° ° ° Advertising Staff Findley Herman, Chilton Bldg., Philadelphia Hottenstein, 1012 Otis Bldg., Chicago Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit 100 East 42nd St., New York 428 Park Pittsburgh Johnson, Market Research Mar. Hayes, Production Baur, Typography and Layout. ° Manager. Member, Audit Bureau Circulation Member, Associated Business Papers Indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price United States and Possessions, Mexico, Cuba, and South America, $6.00: Canada, Foreign, $12.00 year. Single copy, cents. ° Owned and Published CHILTON COMPANY Executive Offices Chestnut and Sts. Philadelphia, Pa. (Incorporated) Editorial and Advertising Offices 100 Eost 42nd St. New York, U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, GRIFFITHS, EVERIT TERHUNE, VAN DEVENTER, BAUR, Vice-President Vice-President Vice-President Vice-President Vice-President WILLIAM Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY CHARLES HEALE Editorial Shush! Shush! Technical Articles Fuel Effects Atmosphere Furnaces....... Photometric Determination Methods Light Alloy Armor Machining mm. Gun Cadmium Plating the Victory Program Heat Treating Tubular Airplane Home-made Photo Identification Artillery Cartridge Cases Made from Steel Magnafluxing New Equipment: Small Tools and Gages Features Washington News and Markets This Industrial Personals and Obituaries Non-Ferrous Metals Iron and Steel Scrap Comparison Finished Steel Prices Warehouse Prices Products Advertised Index Advertisers Copyright, 1942, by Chilton Company (Ine.) q HOW TURN TIME 3 3 ae Weld-O-Trol, the power switch with moving parts, speeds production reducing outage time. Installed with your existing resistance welder and timer facilities, this lightweight and compact unit completely eliminates the maintenance necessary with any mechanical method making and break- ing contacts. Its two Ignitron tubes are guaranteed for full year—consistently last much longer even high speed, heavy current resistance welding. For more productive time, less maintenance time and expense, switch this power switch with moving parts. Write today for latest bulletin gives full details about the savings possible with WESTINGHOUSE ELECTRIC MANUFACTURING CO., EAST PITTSBURGH, PA., DEPT. 7-N. 34—THE IRON AGE, March 19, 1942 DIVIDENDS @IN TIME: saves man-hours formerly required for maintenance. @IN PRODUCTION: increases effective production time. @IN WELD QUALITY: makes possible re- sistance welding many nonferrous metals; produces more uniform, stronger welds. THE RON AGE ° MARCH 19, 1942 ° ESTABLISHED 1855 Shush! Shush! deadly poison depends, very largely, upon how prescribed. And this same thought applies censorship the business and industrial press. The Iron Age, let say, has absolutely complaint make the exercise censorship, date, connection with what have published attempted publish. matter fact, ourselves determined take the bull the horns and whatever have omitted from our columns since Pearl Harbor, has been our own volition and not from mandate. That, understand it, just what the Office Censorship wants done. wants every editor good American. And good American certainly going help his country the best his ability. Now, far the technical press America concerned, there are two ways that. One way keep helpful information from the enemy; the other furnish helpful information American industry. first sight this seems like impossible straddle, it? But after you analyze it, the situation not all anomalous. The present Axis assets are their great usage their total industrial capacity for war purposes, plus their long term experience making muni- tions. These assets theirs are now almost fully capitalized. The future asset America lies our great number manufacturing plants not yet making munitions but which should and will making them. far larger potential asset, this, than the Axis powers can hope marshal. The liability which carry present the widespread lack experi- ence the part our manufacturers making the tools war. compared the industrialists and workers Germany and Japan, are beginners and babes the woods. The big job ahead us, are realize our war assets, get the average American industrialist know much about the technique muni- tion making Germany and Japan already know. And there better, quicker more practical way just this than through the services the business, industrial and technical press America. That was the philosophy and the policy our government during the last war. gave our technical editors the “run” our arsenals and munition making plants and encouraged them publish, detail, the muni- tion making. even allowed these publications precious cargo space transatlantic ships that this information could carried our allies. think that realistic censorship must weigh the good that publication may against the evil that may do. And that with the present comparative states war art possessed Germany and Japan compared ours, would unsensible suppress information that most need just because few Germans Japs may not have it, would close the kindergarten because some enemy high school senior had possibly neglected learn how spell cat. | a | | | | | | | i | | Dearborn Forming pockets Inland sheets the first operation making heads for 5-gal. containers, Deft Fingers Make Inland Steel into Victory Products Form 1400 Pieces Per Hour —Breakage Negligible Deft fingers gentle trained the feel cotton, wool and now working with steel supply many the needs for victory. Throughout all the free countries the world, women are tak- ing the places the metal working industry left vacant men who are moving the fighting front. Here America, thousands women are cutting steel lathes, millers, grinders, and drilling machines. Others are inspecting, welding, and as- sembling equipment ranging from delicate instru- ments tough jeep cars. Many other American women are making sheet metal parts. the photograph above, the operator performing the first operation making heads 2 g : Z A for 5-gal. containers used transporting fuel, oil and other vital materials for the war program. Pockets formed the rate 1400 per hour gauge Inland cold rolled sheets, with hardness 35/40 Rockwell, scale. Each pocket, formed one press stroke, 3-1/4 in. diameter, 9/16 in. deep, with pierced 1/2-in. hole. These 26-in. 26-in. sheets are coated lithography before form- ing. Wax applied the coated side, which placed the lower die, serves lubricant well protect the coating. Breakage these Inland sheets negligible. Just all America proud its women war work, Inland proud its part supplying the steel from which they are making “victory” products. { 4 | | ° ° LOCKE Syracuse, ° ° phasis being placed upon the use controlled atmos- pheres surround steels being treated elevated temperatures. Most the recent literature con- cerning the protection steel high temperatures has dealt with the application separately produced atmosphere used sealed container retort. How- ever, many processes, involving steel elevated temperatures, not lend themselves readily the use controlled atmospheres for one more the following rea- sons: (1) The operation not fin- ishing operation. good example billet heating furnaces for rolling mills. (2) The initial cost and operat- ing cost controlled at- mosphere equipment not warranted the process- ing some products. (3) The product being heated too large unwieldy readily adaptable treatment sealed con- tainers. (4) The design size fur- nace will not permit the use retort. Thus, the age-old problem decarburization and, occasionally, carburization steel, when heat- ing open direct-firing, still exists. Research the past decade has the present time much em- Fuel Effects Controlled Atmosphere Furnaces The effects gaseous, liquid, and solid fuels, well other factors, the amount and rate carburization and decarburization steel controlled atmosphere and regular heating furnaces are described herein. ° established the actions the vari- ous components the atmos- pheres surrounding the steel be- ing treated open firing, wherein the products combustion the fuel being used come direct contact with the steel. Table lists tendencies, with respect carburization and decarburization, the more common components open-fired atmospheres. The proportion which any one any combination the gases shown Table present deter- mines the ultimate action any atmosphere. great volume work has been done, making avail- able data and curves showing the effects various ratios and discussion, however, will directed more to- ward the ability various fuels change the surface carbon the steel when used open-firing, rather than the actions various concentrations the above gases. The atmosphere produced burning any the fuels shown Table dependent upon the de- gree combustion and the initial composition the fuel. Table lists the products combustion produced theoretical complete ° combustion the various fuels. The degree combustion, when burning any given fuel, deter- mined the proportions fuel and air present and the amount atomization the fuel. This is, course, assuming correct fur- nace conditions, such correct type and size combustion chamber, adequate flue area, etc. the case correct proportions air and fuel, the degree combustion dependent upon the amount and ease atomization the fuel. Atomization the intimate con- tact particles air (oxygen) with the particles the fuel be- ing combusted. Gaseous fuels lend themselves most readily this atomization, with liquid such fuel oil, being more diffi- cult, and solid fuels, such coal, being the most difficult atomize. Pulverized coal atomized rela- tively easily Thus, complete combustion ob- tained comparatively easily with gaseous fuels, and increasingly more difficult achieve with liquid and solid fuels. The atmospheres produced burning any these fuels will in- herit these combustion character- THE IRON AGE, March q : 4 2 a? > | 4 q id 4 | 7 | | | q | 2 f aw istics. The atmosphere produced the combustion solid fuel will possibly contain burned fuel, such particles and carbon monoxide gas, while the atmosphere produced burning liquid gaseous fuel will probably contain the products complete combustion, that is, water vapor and carbon dioxide. The chemical composition the fuel the other important factor determining the types atmos- pheres the combus- tion any these fuels. Com- bustion hydrogen produces water vapor, which has greater decarburizing power than carbon dioxide produced the complete combustion carbon. Thus, any fuel having relatively high hy- drogen content, either molecular combined, will probably pro- duce decarburizing atmosphere. From the information given Tables and II, possible predict the type atmosphere that will produced the com- bustion any these fuels, and also the effect will have with respect carburization and de- carburization the surface the steel being heated. group- ing the fuels into three classes, namely, gaseous, liquid and solid, possible predict with con- siderable accuracy the effect pro- duced each class. Gaseous Fuels Gaseous fuels comprise the first section Table II. The first two fuels this class, natural gas and coke oven gas, contain relatively large amounts hydrogen. Nat- ural gas approximately two- thirds hydrogen volume. Com- bustion these two gases will tend produce decarburizing at- mospheres for two reasons: (1) Combustion the large amount hydrogen will produce large amounts water vapor and pos- sibly some moist hydrogen, and, (2) these fuels, being easily atom- ized, will produce mainly products complete combustion, that is, water vapor and carbon dioxide. The other two fuels this class, anthracite and bituminous producer gas, will atomize easily and produce mainly products TABLE Carburization and Decarburization Tendencies Furnaces Carburizing Neutral Hydrocarbons, CH,, etc. Water vapor, Carbon, soot Carbon dioxide, Oxygen, Decarburizing complete combustion. However, since the hydrogen content these two gases comparatively low, only small amount water vapor will produced, thus the atmospheres produced the combustion these two fuels will less decarburizing than those produced the first two fuels this class. Liquid Fuels Fuel oil the main item considered the liquid fuel class. Although fuel oil general atom- izes easily, does not atomize easily gas, and the atmosphere produced the combustion oil might possibly contain some un- burned fuel the form carbon monoxide gas and particles car- bon, along with the products complete combustion. The hydro- gen content oil lower than the hydrogen content the first two gases Table Therefore, only moderate volume water vapor will produced. gen- eral, the atmosphere produced the combustion oil will less decarburizing than the atmos- pheres produced the combus- tion the gaseous fuels, particu- larly those having high hydrogen content. Constituents Gas, Per Cent Volume TABLE Products Combustion, Per Volume Gas Combustion Characteristics Various Fuels Products Combustion Furnace Tempera- tures, Per Cent Hydrocarbons Non-combustibles, 0.53 1:26 4.21 8.8 20.8 (bituminous coal) (anthracite coal) Products Combustion Products Combustion, Furnace Tempera- Constituents Fuel, Per Cent Weight Lb. Per Lb. Fuel tures, Per Cent Non-Combustibles, Fuel | CO, H.O (vapor) co, (vapor) 7.84 All values this table are approximate. 38—THE IRON AGE, March 19, 1942 il Solid Fuels Bituminous coal and coke are the two main fuels the solid fuel class. Solid fuels are the most difficult atomize, and the atmospheres produced their combustion will most likely con- tain unburned fuel. Bituminous coal contains very little and coke contains virtually hydrogen. Thus, combustion either these fuels produces little, any, water vapor. duced combustion the solid fuels will the least decarburiz- ing the three types, and might easily carburizing because the presence carbon monoxide gas and particles carbon. Several other factors that influ- ence the amount and rate de- carburization carburization addition the composition and combustion the various fuels are follows: (1) Composition the material undergoing treat- ment, (2) the temperature the treatment, (3) the length time that temperature, (4) condition the surface the steel under- going treatment, and (5) the oxi- dizing (scaling) power the atmosphere surrounding the steel. LOAD castings from heat treating furnace. Such furnaces afford close control surface conditions. ° ° ° The first three these factors can explained follows: In- creases temperature, and in- creases time temperature will raise the amount and rate decarburization carburization. The ease carburization varies inversely the original carbon content the material and/or the ease decarburization varies di- rectly the original carbon con- tent the material for any given time and temperature. The other two factors will considered together they are closely related. Recent investiga- tions have established several facts concerning the surface the steel undergoing treatment and the oxidizing power the atmosphere surrounding the steel. (1) coating scale any steel elevated tempera- tures retards the rate either decarburization mizes the ultimate amount surface carbon change. (2) oxidizing atmos- (3) phere produces scale, advisable take advantage this reaction whenever possible adjusting fur- nace atmospheres. Furnace atmospheres con- taining from per cent excess oxygen have been found produce the best rate and amount scaling for protection against de- carburization carburiza- tion. has also been found that for temperatures much above 1500 deg. the decarburization oxi- dizing atmospheres comes dangerously great. Some observers have found that excessively oxidizing atmospheres will produce carburization high car- bon steels (over 0.70 per cent carbon), only heated for short periods time. This has been explained the fact that the oxygen selectively attacks the iron the steel while the car- bides migrate back into the unoxidized steel, forming ring excess carbides THE IRON AGE, March 19, 1942—39 4 or) — or) 4 the interface scale and steel. However, the steel held temperature much more than hour under these conditions, the reaction quickly reverts decarburization. applying this information about scale and atmosphere oxi- dizing power the effects pro- duced various fuels steel surfaces, the must considered: (1) Fuels that atomize easily and thus pro- duce products complete com- bustion have tendency pro- Photometric Determination HOTOMETRIC methods for de- termining columbium and tan- talum when present together, with without titanium, steel, ferro- alloys and slags, were recently described Thanheiser Mit- teilungen aus dem Kaiser-Wilhelm- Institut fur Eisenforschung. The yellow color columbium with hydrogen peroxide con- centrated sulphuric and phosphoric acid mixture the basis for colum- bium determination. mixing these acids properly, the color inter- ference titanium suppressed such degree that the columbium determination 40—THE IRON AGE, March 1942 HILE heat treating furnaces are many instances de- signed for control atmospheric conditions, often times when the operation not finishing opera- tion, such billet fur- naces for rolling mills, the installa- tion and operating costs such furnaces are not warranted. ° ° duce decarburizing atmospheres due the presence only the products complete combustion (CO. and H:O), which are both affected titanium occurrences, and only more than per cent present necessary make small corrections. this acid mixture the extinction colum- bium reduced two-thirds the value would have concen- trated sulphuric acid, but still remains sufficiently high value for accurate determinations made. determining tantalum pres- ence, the yellow color produces with pyrogallol per cent am- monium oxalate solution basis for the process. Since titan- decarburizing, and, (2) fuels that are not easily atomized produce some unburned fuel which car- burizing the steel. However, atmosphere com- posed entirely carbon dioxide and water vapor, along with nitro- gen, has greater oxidizing power than atmosphere containing some unburned fuel. Thus, the oxidizing power, with the ultimate formation scale, produced such atmosphere will some extent counteract the decarburiz- ing effect carbon dioxide and water vapor. Methods ium with pyrogallol also produces yellow color, simultaneous deter- mination this element indepen- dent the columbium and tanta- lum necessary make the proper correction. The titanium determi- nation made with chromotropic acid the same solution. The authors also reviewed vari- ous known methods separating columbium and from steel, ferroalloy, solutions. The results check analyses show that the photo- metric determination methods de- scribed are accurate. | | — ECENTLY investigations were Italian physicist, the use strong light alloy plate pro- tection against small arms projec- tiles, and were reported Light Metals, London. Tests were carried out the depth penetration such projectiles into various thick- nesses Avional and aluminum alloy plate, and also with other light metal alloys. the first series tests, steel clad, lead filled bullets weighing 0.369 oz. (10.45 and with muzzle velocity 2295 ft. per sec. (700 meters per sec.) were used, these being fired Avional circular plates, in. diameter, rigidly clamped entirely around the circumference. The rifle used was the Italian “model 91,” the distance the plate from the muzzle was 5.61 ft., and behind the plate were arranged number poplar boards, in. thick and in. diameter. Tra- jectory was perpendicular the plate. With plate 25/32 in. (20 mm.) thick, the projectile went entirely through the plate and penetrated the wood from 23/64 in. 9.1 mm.), while the energy remain- ing after penetration compared the initial energy was from 0.822 per cent. The plate, other words, absorbed from 99.178 100 per cent the energy the pro- jectile. the plate thickness was de- creased, penetration into the wood backing naturally increased. With 23/32 in. (18 mm.) plate, the pro- jectile penetrated 114 in. (31.8 mm.) into the wood; with 19/32 in. (15 mm.) plate, penetration into the wood was in. (85.7 mm.); and without any plate, the projectile penetrated the wood 3.6 ft. (1.106 meters). Cross-sectional through the axis the bullet hole demonstrated that the plate fully heat treated Avional had behaved perfectly plastic ma- terial, armor under similar conditions tended crack and splinter, ex- hibiting very little plasticity. thus appears that the light material not only resists penetration bodies high velocity, but also reduces the risk against secondary Light Alloy Armor Plate dangers fragmentation, preva- lent with steel armor plate. The action the light alloy plate comparable that sand bag. Not only the plate, but also the projectile subjected some de- gree deformation, but ultimately the plate completely embraces the projectile and entirely absorbs kinetic energy, which dissipated mutual deformation. Hardened steel plate, the other hand, tends cause the projectile rebound. The plate itself does not necessarily become deformed shattered the impact, but does not absorb the energy the mov- ing body, which may ricochet and still possess enough kinetic energy constitute source danger. The Italian “type 91” small arm, because the small diameter the bullet and its high initial ve- locity, particularly adaptable armor plate piercing. Successful resistance such penetration re- quires armoring capacity for dissipating considerable energy per area. Actually, had rifle bigger bore been used, prob- able that the penetration resistance Avional would have proved even greater. Further tests were carried out light alloy armor plating which hard lead ball ammunition in. diameter and weighing 0.381 oz. (10.8 gm.) was fired against plates aluminum alloys the form in. disks. The gun used for these tests was smooth bore type, charges being give ball speeds 723, 855 and 921 ft. per sec., these speeds corresponding energies 243 ft. lb. (26.67 kgm.m), 327 ft. lb. (37.23 kgm.m), and 380 ft. kgm.m), respectively. Sheets Avional alumi- num-copper-magnesium alloy, Anti- TABLE corodal aluminum-magne- sium-silicon alloy, and Anticorodal another aluminum-magnesium- silicon alloy both 0.118 and 0.157 in. and mm.) thick were used the experiment. Physical prop- erties these sheets are shown Table these tests, the impact the projectile produced shaped depressions, and instance penetrated the sheet. The mechanism such deformation metal inter-crystalline slip, and the resistance such deformation under impact, therefore, greater for materials showing high capacity for plastic deforma- tion. Thus, Avional with cent, more satisfactory than Anticorodal the elongation which only per cent, but both materials have about the same tensile strength. The experiments indicate that light alloys may usefully em- ployed for helmets and similar pro- tective devices. Aluminum base alloys, has been proved least theoretically, not only main- tain considerable plasticity under high velocity impact, but even show increased plasticity under such con- ditions. Tests indicate that pro- tective value strong aluminum alloy armoring about equal that afforded steel armor the same weight. The prime cost the light alloy higher than that the steel, but the other hand, working costs for the light metals are less than for the steel. The idea combined armoring also suggested. That is, light plate faced with thin penetration- resistant steel sheet, the purpose which deform the bullet point and reduce the capacity the pro- iectile perforate the light alloy backing. Physical Properties the Investigated Aluminum Alloys Tensile Strength, Elongation, Material Lb. Per Sq. In. Per Cent Hardness THE IRON AGE, March 19, 7 J 3 q 7 ‘4 ta- ni- pic des lag eir de- Barrels LEFT IRST operation the 37-mm. gun barrels, which are received from the Midvale Co. rough turned and rough bored, rough and finish ream the bore the LeBlond gun drilling and reaming illustrated. Wood packed, two lipped ream- ers are employed, using coolant under 300 pressure carry the chips out the bore and pre- vent scratching the finished surface chips. Work held and driven the breech end with four-jaw universal chuck and supported the muzzle end revolving rest. The reamer guided separate bushing. Feed the tool hydraulic power. The finishing cut removes 0.050 in. from the bore, and the tolerance +0.002, —0.000. LOWER LEFT planer has been converted perform the using special support for the hone arbor cross rail the The Micromatic hone en- ters the barrel the breech end and stroked the full length in. mixture Union base oil and kerosene pressure pumped into the end and carries the fine chips and grit out through the breech end. series baffles the coolant reservoir allows the solids settle out before the | | 4 & these and the following pages shown the complete sequence operations the manufacture 37- mm. rifled barrels for anti-aircraft batteries. The Baldwin Locomotive Works, which set special depart- ment for the these cannon, commended RIGHT the breech end for the cartridge done Libby turret lathe with hollow spindle, allowing the barrel protrude through the rear the spindle. rough ream, followed semi- finish and finish reaming both diameters and the cone step. For the last two operations, the tools are two lipped, wood packed bits. All tools are force lubricated in- ternally. Coolant lard oil and kerosene under pressure. First two operations are LOWER RIGHT grooves are cut this converted Lodge Shipley lathe with long bed, using the disk wafer multi-pass method. Altogether, disks, each slightly larger than the preceding one, are successively pushed through the bore. The disks may seen the board under the magnify- ing glass used inspect the cut- ting edges. Barrel clamped firmly during this operation, and the helix angle generated the disks the driving bar piloted through helix control bushing shown front the operator. the end each stroke, the cutters inter- changed. Lubricant again lard 150 are and kerosene under pressure. their choice equipment, tooling and methods two espe- cially—use standard machine tools wherever possible breaking down operations into simple steps, and the adaptation existing machinery perform tasks highly special nature. Honing performed planer one such example and gun rifling converted lathe an- other. The amount equipment that had purchased the outside was thus kept minimum and the time needed get into production thereby shortened time when machine tool deliveries were !ong. > a q 44—THE IRON AGE, March 1942 3 LEFT URNING the breech end the gun barrel lathe. After the cut, straight portion turned for in. for the recoil slide. previous operation duplicate lathe, the tapered portion the barrel turned means taper turn- ing attachment. Carbide tipped tools are used for both these lathe opera- tions, and soluble com- pound used for the coolant. LOWER LEFT recoil portion the barrel must ground mirror finish and tolerance -+0.000, —0.002 in. This view shows the job being done Landis grinder. Barrel supported six steady- blocks. Size control dial indicator and microm- eter. | ; ° ° ° sage 7 7 7 RIGHT HREAD breech end being milled Pratt Whitney thread modified Acme thread cut with 29-deg. included angle. The tolerance the root diameter held —0.002 in. LOWER RIGHT ILLING cartridge clearance slot No. vertical Cincinnati miller, using special fixture support the this operation pleted, the fixture swung deg. the side mill the cartridge ejector Location the barrel from locking slot pre- vertical die sinker adapted for this work. The only re- maining operation the flats either side, using end mill cutter Kearney Trecker model miller with vertical at- tachment. THE IRON AGE, March 19, 1942—45 7 7 3 | the ‘ 000, hows ady- a rom- . q 4 Detailed data the properties, maintenance and control cadmium plating solutions, with complemen- tary information the factors involved automatic plating. far more important role national defense than im- mediately evident. The most com- monly used electroplating process for corrosion protection mium. The reason cadmium pre- ferred over zinc most cases, and tin some cases, due one more the following facts: Cad- mium plated parts are more easily soldered than articles coated with zinc. The ease soldering com- pares favorably with tin plated parts. Cadmium chosen for elec- trical contacts because has lower electrical resistance than that zinc. Government specifications demand cadmium plated parts more frequently than zinc tin plated parts. Also, these specifications the cadmium thickness demanded from three five times thinner than that demanded zinc. this, add the fact that cadmium de- posits much more quickly than zinc tin, that the cadmium bath more easily operated than the zinc bath, and that cadmium protects steel from outdoor corrosion much better than tin, and the reasons for preferring cadmium zinc and tin become evident. Another advantage cadmium deposits their high ductility. Parts formed stamped may plated prior these operations the ductility the deposits permits the cadmium spread over the areas bending. Cadmium protects iron because the coating non-porous and be- cause cadmium anodic iron. Since the coating non-porous, excludes corrosive media from the iron surface and hence prevents corrosion. The fact that cadmium 46—THE IRON AGE, March 19, 1942 reacts were above iron the electromotive series causes the former dissolve preference the latter surfaces where both the metals are contact. Since zine more electronegative than cadmium zinc will protect iron over greater range than cadmium. However, this same property zine will cause dissolve more rapidly, leaving the iron bare and subject direct attack. The rela- tive positions certain metals the galvanic series are shown the following table. Each metal more active than the one below and will therefore protect it. This built upon actual experi- ence with corrosion and laboratory measurement. Metals grouped to- gether have strong tendency McKay and Robert Worth- ington, “Corrosion Resistance Metals and Alloys,” pp. 33, 180-199. produce galvanic corrosion each other; connecting two metals dis- tant the list from each other tends corrode the one higher the list. Voltage figures are not given because these vary with every new corrosive condition. Relative positions metals change many cases but unusual for changes occur across the spaces left blank. Magnesium Aluminum Duraluminum Zine Cadmium Chromium iron (active) Chromium nickel iron (active) Soft solder Tin Cadmium Plating the Lead Nickel Brasses Bronzes Nickel copper alloys Copper Chromium-iron (passive) Chromium-nickel-iron (passive) Silver solder Silver Gold Platinum will noted that cadmium placed immediately above iron the series. This not the “Electromotive Series” shown most text books. However, from its position the periodic table and from its havior, believed that cadmium would correctly placed above That does protect iron against corrosion has been shown and numerable others, and also tests made the The closeness iron and cadmium the electromotive series also aid protecting cad- mium plated steel parts since any corrosion cell that may formed could only driven small electrical force. Blum and Hogaboom, “Elec- troplating and Electroforming,” 124. Industry Journal, Vol. pp. 509, 1911. Mankowich, “Corrosion Resistance Cadmium and Zinc Electrodeposits Under Marine Conditions,” Monthly Re- view American Electroplaters’ Society, 1940, pp. 833-839. “Significance Corrosion Iron and Tin when Immersed the Expressed Juices Fruits and Vegetables,” Canner Journal, 68, April 20, 1929, pp. 17-21. Tin stands below iron the ordi- nary electromotive series and the galvanic series presented above. well recognized, how- ever, that the electrochemical be- havior metals couple under certain conditions controlled factors that not necessarily exist the test conditions under which these series are built. Although tin placed below iron, there are many cases under which tin anodic This due the high overvoltage hydrogen tin. notable example anodic tin tin —iron couples the tin can. The value the tin can very greatly increased because the sacrificial corrosion tin preference iron. the past, there has been much controversy over the relative pro- tection offered and cad- mium coatings, with the consensus opinion that zine gives the su- perior protection. However, data’ obtained the Air Service indicates that cadmium coating equal protective value one that three times thick. Cadmium far more resistant alkali than zinc and this leads its being used protect certain die castings from alkali. When sub- jected corrosive media, cadmium holds its brightness longer than and tarnishes about the same rate nickel. Maintenance Plating Solutions The throwing power cyanide cadmium plating bath unusually good. The alkali tin bath the only plating bath possessing su- perior throwing power. This ability deposit cadmium recesses in- sures fairly uniform coatings the intricate parts used defense which require protection from cor- rosion. The rate depositing cadmium fast partly because deposited fairly high current densities and with high cathode efficiency and partly because its high atomic weight. Calculated the basis 100 per cent cathode efficiency 2.1 gm. cadmium are deposited per amp.-hr. compared with 1.2 gm. per amp.-hr. and with 1.1 gm. tin per amp.-hr. these days speeded-up pro- duction for defense, the rate deposition becomes important factor. Although cadmium plating baths are easily operated and for production purposes close con- trol solution composition, opera- tion and thickness deposition essential for production high quality, corrosion protective coat- ings. This not disadvantage, since the range concentration the ingredients the bath and op- erating conditions for proper con- trol larger than for most plating baths. The concentrations the constituents the cyanide cad- mium bath common usage are Per Gal. Per Gal. Cadmium metal 2.3-3.8 Equivalent cadmium oxide (CdO) 2.6-4.3 Total sodium cyanide 11.5-17.5 9.0-14.5 Caustic soda addnone Caustic soda equiva- lent cadmium 1.6-2.7 Ratio total sodium cyanide/cadmium 3.8 3.8 Bright current density range with addi- tion agents 5-25 amp. persq. ft. ft. 1-4 7-14 Temperature, deg. 80-95 80-95 Anodes for high cur- rent density ..... Cadmium bar Anodes for low cur- rent density Bar basket great many brighteners have been suggested for cadmium plat- ing, good many which have been patented. Some brighteners are organic, some inor- ganic and some are combination both. The addition agents which have proven most successful have been patented. However, there are other addition agents which ANTHONY FUSCO and NORMAN WOLDMAN Assistant Chief Chemist and Chief Metallurgical Engineer Respectively, Eclipse Aviation Division, Bendix Corp. ° improve the brightness the de- posit. These brighteners include small amounts nickel, glue, Hull, Plating,” Plat- ing and Finishing Guidebook, pp. 33-35, 1941. casein, gulac sulfonated castor oil. Tests have been made the past the relative protective value bright deposits versus dull de- posits and all cases the bright deposits gave superior corrosion protection steel than the dull de- The most important single factor regarding the concentration sodium cyanide and cadmium oxide the ratio between the two. For lower current density operation the lower concentrations cadmium should used, and for higher cur- rent density operation higher con- centrations should used. Cad- mium plating baths have been very successfully operated concen- tration metal low oz. per gal. The Udylite process for plating cadmium has been very successful, and the recommended metallic cad- mium content 2.0-2.5 oz. per gal. However, the concentration sodium cyanide also relatively low. the Udylite process the brightener and sodium cyanide are mixed homogeneously and such proportions that the proper concen- tration brightener will pres- ent when proper additions sodium cyanide are made. The Cadalyte process, also, takes advantage controlling the con- sodium cyanide. The mix- ORTY-SIXTH Series Articles the Technical and Economic Aspects Metal Cleaning and Finishing THE IRON AGE, March 1942—47 Program the nin be- bove iron and cad- med mall tance bosits Re- ciety, oon, essed anner ordi- nted how- be- nder A ture sodium cyanide with addi- tion agents called the “Cadalyte Maintenance Compound.” For mak- ing new bath the “Cadalyte” salts, which contain cadmium well all the other necessary com- pounds, are dissolved water and the bath ready for use. The de- posits obtained from these baths are said bright and lustrous. Both the Cadalyte and Udylite proc- esses have helped the plater control the concentration 48—THE IRON AGE, March 19, 1942 brightener the cadmium plat- ing baths. Both companies supply test sets for analysis cadmium and cyanide content the cad- mium plating bath. Frequent analysis should made cadmium plating baths. The concentration some constituents the bath more important than the concentration others. Anal- ysis for sodium cyanide content and additions the salt should made least twice week and ac- curate record should kept these analyses and additions. From these records may possible af- ter time apportion certain amounts cyanide added each day. Even after standard daily addition decided upon complete analysis should made least once week. Low cyanide content results low anode ef- ficiency and finally depletion metal the bath. Improper cy- anide content may also aid the ° ° ° degreasing operation, parts are brought the loading plat- form shown here the left tank No. Other tanks matic plating. _set-up. Nos. and are water tanks, and tank No. contains muriatic acid. rom tain lard nide ef- cy- the formation sodium carbonate. Carbonate excess eight oz. per gal. leads narrowing bright current density range plating. cases where cadmium plating solutions are not analyzed for long periods time very possible that the bath will become inoperable due working im- proper concentrations. The carbonate content should range within oz. per gal., preferably the lower level. Since ° ° IS. 3—Tank No. con- tains cyan- ide solution dip, and tank No. the cyanide rinse tank. 4—This the 2100- gal. plating tank. The an- odes are the basket and ball types. the accumulation carbonate well controlled bath slow, analysis for carbonate concentra- tion made every three four months usually considered ade- quate. Carbonate may removed from the bath precipitating cal- cium carbonate with special gyp- sum prepared for that purpose. Al- though rather cumbersome, the best method for removing car- bonate cold weather “freez- ing out.” This ailowing the bath cool outdoors deg. this method for- eign ions are introduced into the bath. Since the ratio between cadmium content and cyanide content very important, check metal content should made weekly. Although caustic soda im- portant constituent the bath, not usually added, since any ad- THE IRON AGE, March 19, ig 7 ditions cadmium oxide produce caustic soda the bath. Cadmium plating barrel tends heat the solution above the recommended temperatures bright plating. all other condi- tions specified are present, the deposits formed will dull, unless some means are taken cool the solution. High temperatures also lead rapid formation sodium carbonate and requires frequent analysis and removal the excess carbonate. The main cause for the heating barrel solutions the large amounts current which forced flow through the solu- tions. therefore advisable equip the tanks containing the solu- tions with cooling coils, and tem- perature readings should taken frequently bright deposits. Automatic Cadmium Plating The Eclipse Aviation division Bendix Corp. makes use full automatic equipment for the plat- ing cadmium. The crew required operate the automatic equipment consists seven eight men, de- pending the ease racking and unracking the work. One member the crew charge and his main duties are control the speed plated and adjust the current and voltage their proper values. The duties his assistants are rack the work plated the begin- 50—THE IRON AGE, March 19, 1942 ning the cycle and remove the work the end the cycle. The sequence operations outlined below and the description follows: Degrease (2) Rack work plated (3) Load conveyor (4) Cathodic alkaline cleaner Rinse (6) Muriatic acid dip (7) Rinse Cyanide dip Rinse Plate cadmium solution Rinse thoroughly (cold water) Rinse (hot water) Dry (air dry—compressed The degreasing operation car- ried out separate unit from the automatic equipment. The type degreasing both liquid and vapor. Since the vapors are free from grease nearly so, most the im- purities that may have been picked the liquid immersion are rinsed off the condensed vapors. From.the degreasing operation, the parts are placed racks and brought the loading platform which shown Fig. left tank No. the racking opera- tion, the pieces must hung such way that there minimum drag out from tank tank. Also the parts plated must not touch each other since such points contact there likely only thin deposits formed owing the shadowing one piece another. Tanks No. and No. are the alkaline direct current cleaning tanks. The time allowed for the work immersed the alkaline cleaners permits only the cleaning work which does not contain too much grease oils. The reason for the two smaller cleaning tanks instead one large one that the more concentrated grease and dirt will removed and deposited the first tank, thus allowing the second tank kept relatively clean. Tank No. shown Fig. and Fig. and tank No. shown Fig. are both water rinse tanks. Tanks No. No. 13, shown here, can used bright dips for the cadium plate. The reason for having these two tanks instead one large tank similar that stated above regard- ing the two alkaline cleaners. The thorough removal the alkaline cleaning solution important since any alkali carried through would neutralize the acid dip solution and thus shorten the life the acid bath. Fig. also shows tank No. which contains solution 1:1 muriatic acid. This dip will re- move any slight rusting scale. Any heavy scale heavy rusting must removed before the begin- ning the cycle. The acid dip tank also equipped with blowers which remove the hydrogen gas evolved from solution. The acid dip followed water rinse tank No. Tank No. shown Figs. and This cyanide solution | 7 7 i q q | q 4 and iks. two The since vould lO. 5, scale. isting dip owers gas acid nse ‘igs. sprocket Cadmium plate work carriers Total number work carriers=47 rinse am Drive sprocket Fig. 6—Top view the automatic cadmium plating apparatus. dip which contains approximately oz. per gal. sodium cyanide. Any remaining acid which might retained the work after com- ing from the acid rinse water would neutralized this bath with the evolution sonous hydrogen cyanide. therefore necessary have blower above the tank remove these poisonous fumes. The cy- anide dip also helps remove any last traces oil that may still ad- here the work. Since sodium cyanide major constituent the plating bath, the cyanide dip placed just prior the cadmium plating bath. Tank No. the cyanide rinse tank. Fig. shows the 2100-gal. plat- ing tank (No. 9). The anodes the bath are the basket and ball type. the balls cadmium are dissolved the solution new cad- mium balls may added from the top and hence the anode area may kept fairly constant. Another important advantage the ball and basket type anode that there little waste each indi- vidual ball remains the bath un- til completely dissolved. One peculiarity automatic cad- mium plating which does not exist still tank plating the variation current density that may occur when starting and finishing load work. the first rack work immersed the plating solution the cathode area present only small fraction what will when the full load immersed. Hence the desired current for full load should produced only after the first rack has reached the end the plating tank. Therefore the current increased gradually the beginning the the typical analysis the cadmium plating bath would show from 2.5 oz. per gal. cad- mium metal and 5.0 6.0 oz. per gal. sodium cyanide free cyanide. Incorporated with the cyanide brightening agent sup- plied the Udylite Corp. Anal- ysis the bath for concentration the brightener not necessary since the amount varies.somewhat the concentra- tion the sodium cyanide. Since the installation the automatic cadmium bath analysis for con- centration brightener has been found necessary the deposits have been consistently bright. There are six rinse tanks follow- ing the cadmium plating tank, four which are shown Fig. Tanks No. and No. can used bright dips for the cad- mium plate; however, the bright dip has not been found necessary Cross- section through the automatic cad- mium plating tank. the Eclipse process. The final two rinses are hot water aid dry- ing the work. sketch the top view the automatic cadmium plating appara- tus, Fig. and cross-section the end view the cadmium plat- ing, Fig. tank are shown. The successive steps the plating proc- ess may followed starting “load” and proceeding the left. The number minutes that each piece work remains immersed each bath and the type bath shown each tank. The speed the chain may varied the time chain speed in. per min. transferring the work from one tank another, the lift arms raise the work carriers height in. above the tanks allow ample space for the work and rack transferred without touching the tops the tanks. 4 Overall THE IRON AGE, March 19, too acid the lo. e The conveyor Hanson-Van Winkel-Munning return type. The operating mechanism attached supporting frame well above the solution tanks. Work carriers are mounted upon the conveying chain spaced regular intervals. The electrical connection made means drum finger contacts the cathode rail. The transferring done means steel transfer arm operating ball bearing equipped guide. The working end has double ended stud; the inner end which engages the welded steel cam, causing the arm fol- low continuous predetermined path. The outer end the stud serves pick the work carriers succession and them through the transfer operations. Automatic cadmium plating ac- complishes two aids the defense program. First, the process dimin- ishes the number experienced help (of which there always shortage times like these) be- cause only one member the crew control the entire plating cycle. Secondly, the output cad- mium plated parts per man in- creased tremendously compared with still tank plating. There are, however, certain limi- tations automatic plating. First, there certain minimum amount work which must always pres- ent since the process must run continuously, otherwise the maxi- mum efficiency the process will not attained since there fall-off production the begin- ning and finishing each cycle. Secondly, when plating cer- tain thickness required, there should great number one type pieces, otherwise new values amperage and speed operation must calculated for each new load depending mainly the sur- face area and partly the shape each new type piece. conclusion, may stated that because its speed deposi- tion, because its excellent pro- tective value on. steel, because the ease with which the bath con- trolled and maintained, continuous cadmium plating ideal for coat- ing certain metals during these periods when time and experienced help are such high premium. Heat Treating Tubular Airplane Parts UBULAR parts for Lockheed interceptor planes are now be- ing produced record time the Menasco Mfg. Co., Los Angeles. Since these vital parts must both elastic and tough withstand the strain the movements these fast airplanes, careful heat-treat- ing essent