The Iron Age 1940-12-19: Vol 146 Iss 25

DECEMBER 19, 1940 VOL. 146 NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager Managing Editor News Editor Technical Editor Machine Tool Associate Editor Editor Art Editor Editor Emeritus Washington Editors MOFFETT JAMES ELLIS Resident District Editors T. C. CAMPBELL HERMAN L. KLEIN Pittsburgh Chicago Cleveland Detroit Editorial Correspondents DEARING ROBERT McINTOSH Buffalo Cincinnati FRAZAR CHARLES POST Boston San Francisco HUGH SHARP JOHN McCUNE Milwaukee Birmingham SANDERSON ROY EDMONDS Toronto, Ontario St. Louis LEROY ALLISON Editorial Bottlenecks Technical Articles Limitations Powder Metallurgy Influence Basis Metal the Flame Hardening Cast Iron Bearing Rings............ Welding Sheet Copper Brass Die Castings What's New Power Transmission Feature Reports the Assembly Line Washington News ... News and Market Reports Personals Metal Working Activity Summary the Week The Industrial Pace District Market Reports Free Industrial Literature Products Advertised Index Advertisers Copyright, 1940, Chilton Company DIX, Manager Reader Service Advertising Staff Emerson Findley Herman, Chilton Bldg., Philade!phia Hottenstein, 1012 Otis Bldg., Chicago Leonard, 100 East 42nd St., New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, 100 East 42nd New York Robinson Warren, Box 81, Hartford, Conn. Don Harner, 1595 Pacific Avenue, Long Beach, Cal. Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price: United States and Possessions, Mexico, Cuba, $6.00; Canada, $8.50; Foreign, $12.00 year. Single copy, cents. Machine Tool Activity Non-Ferrous Market Scrap Market and Prices Construction Steel .......... Iron and Steel Prices Ferroalloys, Pig Iron Prices Warehouse Prices Sales Possibilities Owned and Published CHILTON COMPANY (Incorporated) Publication Editorial and Office Executive Offices Chestnut and Sts., 100 East 42nd St., Philadelphia, Pa. New York, U.S.A. U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, GEORGE GRIFFITHS, EVERIT TERHUNE, VAN DEVENTER, BAUR, WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY Vice-President Vice-President Vice-President Vice-President Vice-President CHARLES HEALE 104 108 110 115 Assures Quicker Deliveries after hours, any the ten plants, almost any night the year! The Ryerson night shift putting the finishing touches today’s orders; loading out the fleet big, red Ryerson trucks for tomorrow’s deliveries. immediate Steel Ryerson tradition. The entire Ryerson organization geared handle quickly the steel requirements, simple involved, thou- sands customers the country over. Special tele- phone order desks, hourly mail pick-ups the post office, telegraph lines right into our offices—all help delivery, even before the order reaches us. Night loading the decks” for tomorrow’s new crop orders the regular course business. Every order RUSH Ryerson—most are shipped the day received. Ryerson Steel Service fast and sure; Ryerson Cer- tified quality your assurance uniformity and exactness. Make the Ryerson Stock List your unfail- ing source for all steel requirements. you the latest Stock List send one gladly. Joseph Ryerson Son, Chicago, Milwaukee, Louis, Detroit, Cleveland, Buffalo, Boston, delphia, Jersey City. \ - ¢ = DEC. 19, 1940 ESTABLISHED 1855 Bottlenecks hear good deal about nowadays. Industrial bottlenecks. Much what hear this subject comes from people who not know great deal about industry. You not hear industrial experts saying much about bottlenecks, because they are familiar with them. They have contended with “choke points” every day every year that have been part industry and they will con- tinue contend with them long they remain part it. You cannot make bottle without neck, for you did would longer bottle. Even milk bottle has one. And you cannot make industry that potential choke point. Plants are not made rubber. What the layman understand that bottleneck matter relativity, whether industrial plant bottle. The neck does not become choke until you try get too much out the bottle too short space time. Take the steel industry, for example. hear demands, again from laymen, for sharp enlargement capacity. Yet during the past five years, the utilization existing capacity the steel industry the United States has been but 65.5 per cent. Expressed another way, the industry had been kept busy its optimum production rate per cent over that period, would have produced million more tons steel than Enough additional steel take care armament programs. What these people really are asking for not the elimination bottleneck but the enlargement bottle that has been demonstrated already have twice the capacity required any normal demand. The same thing true the machine tool industry, although not like measure. This industry has expanded its capacity fully six times the past four years. You could not expect any industry expand faster than that and not catch fire from spontaneous combustion! The machine tool industry devoting least per cent its out- put the defense program. Thus far, the steel industry has been able fully satisfy requirements for the defense program and exports England and Canada from less than per cent its present normal capacity. That means that more than per cent its output going into non- defense projects. There are certain steel companies that have been loaded with defense orders that they have had will have expand individual capacities. But that does not change the fact that the industry whole still has very substantial reserve margin that could switched from peace purposes and products war purposes required. might well think twice before permit clamor stampede industry into staggering capital investment expansions that may turn out white elephants. The public always pays the upkeep for idle plant capacity, either prices taxes. he t tell ‘ J | jae it. 4 : { | | - ~ > =~ irders plate and These simple and increase effective floor HEN the Bankers Life Company, Des Moines, Iowa, planned its new home, special attention was given the efficient flow people and paperwork. the first five floors, girders ft. long ft. in. centers span the area without intermediate sup- ports, for the 235-ft. length the building. sub- stantial increase effective floor space developed the use these 53-ft. girders. Over 62,000 sq. ft. unobstructed area available for line production insurance work. These special girders were built Inland plates and SHEETS STRIP TIN PLATE BARS PLATES FLOOR PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS Bankers Life Building Des Moines gained valuable floor space using special built-up girders UILT-UP GIRDERS LINE PRODUCTION space newest insurance building angles. They were designed with different cambers the upper and lower chords. When the dead load was applied, the upper chord flattened out and the lower chord retained sufficient camber for optical effect. combination with the method welding the flat tile arch support beams, these girders add great rigid- ity the building, and save large tonnage steel. Inland engineers are prepared, long experience, cooperate with fabricators the problems which lead economy construction and the utility steel == d uns use Dearborn Sales Offices: Milwaukee, Detroit, St. Paul, Kansas City, powder metal industry today showing much activity that many are find- ing difficult define the limits application. There- fore, this article particu- larly timely that sets forth the commercial limitations powder metallurgy. These data were originally pre- sented recent meeting the Newark Chapter the A.S.M. IKE every other important devel- opment this technical the commercial limitations powder metallurgy are reduced the basic three factors that are chines. well known, the early develop- ment powder metallurgy was built largely around the desire for metals and technical characteristics that were not obtainable conventional melting methods. was the development the electric lamp filament methods that were commercially feasible that led broader study the possibil- ities metallic powders, which work resulted present-day products. The first these newer products, less unit value than the filament material, was the so-called bearing. There are probably use this country, today, billion more these bearings. Their development has been, many respects, engi neering triumph, and their economic advantages have made profitable man- ufacture possible. This development, turn, has carried the industry over into the study those problems relat- ing articles lower unit value. connection, that the earliest competi- Limitations Powder EARL PATCH Moraine Products Division, General Motors Corp., Dayton, Ohio tion which the so-called bear- ing had meet was that the bearing. Thus, often the case, synthetic product capable accurate control gradually replaced natural product which was subject all the variations nature. This the then, for the present-day developments industry things mechanical na- ture—things replace parts made other methods. Fundamentally, pow- der metallurgy believed rap- idly developing technique capable taking its place along with drop forg- ing, die casting, synthetic molding, screw machining bar stock, and similar basic operations the reper- toire the production engineer. The writer can well recall, years ago, his first contact with die castings. advertisement was noticed the old American Machinist, the Franklin Co., Syracuse, offering send sample die casting anyone who was interested. One was sent for, and was treasured for years rep- resentative new manufacturing technique. The casting had reasonable accuracy—it had cheapness, appear- ance, and just about every surface quality that could desired. Under- neath this surface, however, was low tensile strength, had very little shock resistance, and was subject such problems inter growth. Because all this, was probably years before die casting really became prominent factor American industry. Today, ac- cepted standard method pro- ducing parts. Before this acceptance however, enormous amount work was necessary the laboratories the die casting industry. Furthermore. designers had learn how design for die castings rather than attempt duplicate this new material de- sign which had been satisfactory for some other mode production. Such the state powder metal- lurgy today, and this emphasizes the current dependence the art the first and second factors—material and men. The development powder metal- lurgy has carried from the rare metals into the cuprous metals, and now to- day the threshold wide-spread use the ferrous materials. This probably represents about stage the material development. hard visualize this time much lowering cost beyond that which possible through the use iron pow- der. For this reason, laboratories, men, and equipment are being used primarily the solution problems involved the metallurgy pow- dered iron. economical standpoint, the THE IRON AGE, December 19, 4 | foo, =< » 3 ~ ° ° ° zt | | | 3% | it - use iron powder offers several jor advantages somewhat akin those offered die castings. the first place, finished article can pro- vided having some rather definite phys- ical factors, without waste either stock finishing time. exam- ple this the manufacture spur gears. possible make such small gears, finished, costs which are from one-half three quarters the cost finished gears machined the conventional manner from cast- ings. This, course, due the fact that the ratio machining cost material cost high the conven- tional process. With powder costing have net gear cost which slightly less than that even though small gray iron castings can bought for around 4c. per What, then, are which prevent powder plants from get- ting all the gear business this country? The gear has been selected being rather typical unit ma- chine design, and one with which ail readers are familiar. does have unique advantage that the ratio finishing cost material cost high, although this does not represent the high limit this respect any means. Taking gear, then, good example for general study, what are the limitations which powder metal- lurgists have work? 32—THE IRON AGE, December 19, 1940 parts made from iron pow- der. The porosity about per cent and the tensile strength about 25,000 per sq. in. The H-shaped piece the right used textile machine, the two small pieces front are used push button radio tuner, next are three pieces from dictating machine, the two next pieces are clutch cross shaft release bearing, the extreme outboard motor gear case bearing, and behind gear for auto oil pump. the first place, consider the Gears can made from iron powder experimentally with strength high 100,000 Ib. per use much higher generally operations. The heat treatment must longer and higher temperatures. The powder must more carefully controlled, and tool wear excessive. Therefore, inasmuch most gears are designed for resis- tance wear rather than for ability withstand shock loading, particu- larly those applications where large numbers are possible, found desirable furnish some gears with tensile strength low 25,000 lb. per sq. in. The properties such gears are generally ample. Therefore, using less ma- terial there less wear and tear tools, and short cuts heat treatment and powder control are possible. Thus, make production the part attractive and profitable. Strength one gear now being made entirely satisfac- tory 18,000 Ib. per sq. in. There need providing higher strength than that which necessary for the safe functioning the piece. purposes quietness, powde: metallurgists would like make cal gears. the present state the art, however, not known how this can done commercially. Some have fore the operation not impossible However, impracticable. The sult all this has been that powder plants have been forced into careful study and design tooth provide quietness operation com- parable that the helical gear This where the designer has come in. some jobs, low strength not sufficient, and necessary for pow- der metallurgists improve physica! characteristics, with 45,000 50,000 Ib. per sq. in.. for instance. This possible, ting pressure, sintering time, cer- tain other However, this can only done in- creased cost. The tool cost creased, and they wear out quickly The manufacturing operations, them- selves, are more expensive than with the lower strength material, but product secured which requirements the job. Such ap- plication, for instance, might the 7 + — $ wine ‘of ¥ drive gear washing machine rack bar. For this, there available iron metallurgy wide field alloys and heat treatments, including quench- ing, and from all this possible commercially produce gears having much higher wear resistance, strength and impact resistance than case hard- ened low carbon steel. the gear field the powder metal- lurgist may find impossible meet all the dimensional tolerances which may have been laid down for produc- ing the gear some other method. Some gears, for instance, show axial length plus minus tolerance the pitch line perhaps the same amount. possible hold the diametral allowance, but axial tol- erance cannot held, mainly because all the variables are largely flected length the briquette, the sintered and sized piece. replacement job, therefore, final fin- ishing operation necessary the length tolerance which given, whereas the same diametral tolerance can held without touching the tooth surface. This the fundamental difficulty adapting the methods powder metal- lurgy designs which were made with other materials mind, and defi- nitely brings home the importance designing for the use powder metal parts. There are few basic things which affect the type product which can made powder metallurgy. They are follows: material does not flow freely, and result pieces having reentrant angles cannot This pretty much fundamental the processing, and made more portant the fact that necessary compress the powder anywhere from one-half one-third its orig- inal powder volume. This means that where reentrant angles are formed any point along the axis, neces- sary depend conventional meth- ods machining for those surfaces Second—length tolerances somewhat more liberal than those nec- essary with conventional methods finishing, extra machining costs are exercise reasonable control length. design must, course, con- sidered individually, but general length tolerance less than plus minus 0.005 in. liable result machining and unnecessary cost. must sidered and reasonable limit eccentricity provided. This necessary because the powder formed largely with tools which have radial fits within one another, and clearance must provided. some circumstances, these fitted pieces are liable all one direction, which may show eccentricity high 0.003 in. some cases. This ec- centricity can largely guarded against compression operation, swaging, rolling, something the kind, but here again additional han- dling necessary additional cost. design must such molded parts made from bronze powder. This copper, parts tin, and parts graphite. would normally require considerable cost for machining, compared the cost material. stated, with powder costing 8c. 10c. per most attractive have the finished weight the piece around per cent the rough blank weight, whether the blank grav iron steel, because within this zone lies the powder metallurgist’s best portunity for economical able production. quantity. This, like every other factor, largely related the design the particular piece. Generally speaking, the more complicated the machining the piece conventional methods, the smaller the annual consumption neces- sary carry the considerable expense for tools and equipment handle powder. With vast quantities, pieces made oversize accordance with sug- gestions already made, there prac- tically method forming parts accurate dimensions which cheaper than powder. possible, for stance, turn out lots tens mil- lions year. This being done with flanged bronze bushing, costs that are insignificantly higher than the cost similar pieces made from flat strip stock. This, however, only accom- plished the spending perhaps $40,000 $50,000 for special equip- ment and tools make the piece. Once made, the operation set for perhaps ten years. the other hand, there are some pieces which represent the other extreme, where tool expense $1,000 warranted lots 10,- pieces, less, per year. This largely due the fact that some such cases possible avoid very expensive machining. Incidentally, ex- pensive machining these days THE IRON AGE, December 19, 1940—33 | a | | 2 | | 4 4, high wages and high factory expense something considered care- fully. some plants with which the writer familiar, costs, labor and burden, about nickel minute perform machining operation. The days government jobs, such one which the writer keenly remembers when was apprentice boy, making collar buttons from brass rods, are just about over with. Within the framework set forth herein, there are enormous num- not only production but are also adequately financed. Thus, there seems doubt but what there will adequate source domestic material available constantly lowering price. The next problem facing the pow- der industry that getting adequate information what can done into the hands the engineer, the design- er, and the draftsman. This tough job, and exactly the same one that has been faced the die casting and VARIETY filters made from bronze (92 Cu-8 Sn, weight) powder. The porosity about per cent, and the filters will remove diameter particles. The large filter the right about in. length and used filter fuel Diesel engine. Some the others are for the same pur- pose, and several are used filter refrigerant liquid. Filters are also being de- veloped for use domestic oil heaters. ber parts used industry which can well made both economically and profitably from powder, and going national interest and advantage this. For several years the industry has largely used powder made from ore from the well known Swedish mines. This is, course, out the question today, and the writer’s plant now producing iron powder from domestic sources, which powder completely satisfactory. Many other people are working along similar lines—there are least different groups this country studying with ness the question making iron pow- der, and some these groups are 34—THE IRON AGE, December 1940 plastic industries. Probably, can only come from slow development, al- though everything possible being done accelerate it. illustra- tion what can done when sym- pathetic hearings and opportunities work are provided, consider the fol- lowing case. For years, Moraine worked closely with one large indus- try, and particularly with two large interests this industry. They are making machines the same general type very large quantity. With one these interests was not found possible work directly with the de- signers and draftsmen, the result be- ing that only seven eight parts made from powder are used. With the other interest, where the engineers are highly sympathy with the use powder products and are constantly open suggestions, there total pieces used. Every one these additional pieces were put into the ma- chine with considerable saving the cost the product. Every one them, however, had designed within the framework in. Another limitation, occasionally en- countered, this question cost. Necessarily, those the powder met- allurgy business have know their costs pretty well order compete with the machine shops their cus- tomers. Frequently, however, plants served not know their own should used practically all man- ufacturing plants, particularly those that have any thought bringing new process, parts made out- siders. Consider the case gear mak- ing, for instance. questionable whether any high production gear velopment can operated manu- facturing plant for less than 250 per cent burden, whereas the overall fac- tory burden rate may around 120 per cent. Unless departmental burden rates are set and used, entirely false idea costs may built which may distort the picture that new process such powder may not given adequate consideration. Too many plants not have department costs specialized point where they show the actual cost, rather than accountant’s averaging out. really important factor the rate which powder metallurgy can come into more general use. There has been lot misunder- standing the various trades served powder metallurgy the results that can accomplished. has been most difficult job attempt draw the line between the things which can accomplished the powder labora- tory, and those which can produced economically the factory. There question that proper treatment, already mentioned, results can obtained from the use basic pow- ders which will rival results obtained with steel other materials. The same thing can said die castings plastics. Many parts can made iron powders with very low moderate strength values lower cost when the design line, than similar pieces can made any other process. But impossible this stage the game get the high- values strength, which are avail- able the laboratory, excepting costs that throw away all advantage. | adi q ; NDIUM, named because its indigo spectrum, has been since only the past few years rare me- tallic element following its discovery 1863 Reich and Richter. Indium belongs the aluminum group re- gards properties, being very soft, silvery metal, not acted water ture, 155 deg. (311 deg. F.), and boils red heat. fairly heavy, having specific gravity 7.28. 1924, order was placed with prominent New York chemical house for substantial quantity indium. After several months’ effort one gram was found and purchased, being all that was then available the world. The price was $10 gram, consider- ably higher than platinum. The metal stabilizer for certain non-ferrous me- tals, and uses other directions were indicated. Therefore, with demand in- creasing, made secure quantities price considerably lower than that demanded for the first gram. —This rare metallic element rare longer, and today finding use variety industrial applications. are data the properties and uses, well detailed instructions plating and thermally diffusing the metal. Technical Director, Indium Corp. America After considerable searching, sizable quantities indium bearing ores were found Mohave County, Arizona, and the property was thoroughly ex- amined means shaft and drift- ings. However, demand for the metal has not yet become sufficient justify exploitation this property for the indium content alone. far, the in- dium coming onto the market has come out zinc refineries the same area, indium usually associated with small quantities. Electrolytic indium, 99.99+ per cent pure, now sells for $30 troy commercial indium, per cent pure, sells for $15 troy ounce; and the metal also available various salts. Over the next few years, with the use indium growing, the price will undoubtedly drop considerably lower, according Indium Corp. America, East 42nd St., New York. Probably the first use indium was dental castings, where was found that quantities from 0.5 per cent greatly improved the dental alloy in- sofar corrosion resistance, melting range, hardness and strength were con- cerned. Next, large optical company indium treated the small pins the hinges spectacle frames order Herein increase corrosion resistance. These pins had always given considerable trouble corroding because body perspiration. Indium’s latest develop- ment and probable major use for some time come protection against wear and corrosion internal combus- tion engines, particularly for the bear- ings. has been particularly effective the airplane engine field, and only lately the White Motor Co. has adver- tised indium treated bearings, the aviation type—copper, lead bearings impregnated with indium prevent deterioration due acid condition the oil. The metal indium also show- ing excellent experimental results the electrical contact field well the field low melting alloys. Indium, used protect metals against corrosion and wear, usually plated onto base metal, and then dif- fused alloyed the surface low temperature treatment. The patented procedure used with complete success the indium plating metal pieces follows: Racking: The pieces plated are racked suitable manner that the back the piece protected. This may done employing rubber THE IRON AGE, December 19, 1940—35 | | | | | | | | } | | | ‘ | | IG. plating layout. The plating bath the the cleaning bath the right, and rinsing bath the left. the foreground plated bearing (right) and cathode holder band rubber sleeve into which the pieces are slipped, good contact being made with the cathode wire the back the pieces the pressure the rubber band. ‘That part the band, used, which stretches across the face the piece will not produce action—the bath has exceptional throw- ing power. Cleuning: The racked pieces then are immersed hot alkaline electro- lytic cleaning bath for sec., made the cathode, and sufficient cur- rent (10 amp. per sq. ft.) applied give good evolution gas over the surface. When clean the pieces are removed and rinsed twice ‘running water; the first rinse preferably warm water, and second rinse cold water. The pieces are now ready plated with indium. The composition the alkaline elec- trolytic cleaning solution may vary suit requirements, i.e. greasy articles require more concentrated solution. However, matter what cleaning method used, the article plated 36—THE IRON AGE, December 1940 must clean and free from “water suggested formula for the cleaning procedure follows: oz. sodium carbonate (or tri-sodium oz. sodium hydroxide. gal. water. 100 deg. (194 212 deg. operating temperature. added remove stain. Plating: The pieces now are plated with indium (see Fig. immersing them indium cyanide plating bath and using current density 0.1 1.0 amp. per sq. in. The time required, course, depends the rate de- position the bath and the amount indium required for the protection the pieces. The indium bath consists essentially the following for gal. plating solution: oz. troy indium (as chloride oz. dextrose. oz. sodium cyanide. Making Bath: make the indi- chloride solution for gal. bath example, indium metal are cut into small pieces and converted the acid will required put the metal into solution, and gentle heat applied effect solution the last pieces metal. The solution indi- chloride (InCl,) now heated volatilize any excess acid, or, until the surface the solution slightly crusted, Care should taken see that the solution does not being heated too long allowed cool without dilution. The encrusted solution now diluted with distilled water volume 500 This solution called the stock indium chloride solution. Stock indium chlor- ide solution may purchased indi- trichloride solution—one fluid ounce containing one ounce InCl,. One 8-oz. bottle this solution generally used make gal. plating solution Two ounces dextrose (No. Merk’s USP equivalent are dissolved little water possible. Slight heating used hasten solution and, used, the solution allowed cool before using. Then, sodium cyanide are dissolved little water pos- ° oO sible, approximately 750 cc. means solution cone, and, when all the cyanide has dissolved, the dextrose so- lution poured into the cyanide solu tion. The resulting solution known the sodium cyanide-dextrose solu- tion. The indium chloride solution now added, small portions, with constant stirring, the cyanide-dextrose solu- tion. This operation should only carried out good fume-hood, other well-ventilated place, owing the generation dangerous fumes. the small portions indium chlor- ide solution are added, will noticed that precipitate formed which dis- solves stirring. Under conditions should more chloride added until this precipitate However, the solution this precipi tate should take place almost imme diately and permanent precipitate should exist this point. All the chloride solution should added this manner the cyanide-dextrose solution and the resulting solution di- luted about liters gal. with distilled water. plating solution should allowed stand least hr. longer, pos- sible, before using make bath. After the concentrated solution has aged for hr. longer, will found have turned from color dark brown. Also, dark carbon-like precipitate will found have settled out. should not gelatinous con- siderable volume and may readily filtered off. The solution tered, suction through funnel for speed, using Whatman No. filter paper, into the plating tank and diluted gal. with distilled water. analysis for free cyanide should made this point, and will found that the free will quired bath composition, sodium cyanide should, therefore, added bring the free cyanide content the final bath 0z., least 100 gm. per liter. The plating bath now ready for use. operate the bath insoluble anode used, such carbon platinum, and current density high enough give gassing the cathode (0.1 1.0 amp. per sq. in.). The resulting plate deposit soft, gray and matte-like appearance. Rate Deposition: The rate dep osition the bath determined plating weighed cathode for defi- nite length time current density which expected will used for op- eration. The rate deposition may readily calculated from these data. will found that the rate depo- sition new bath will run the neighborhood mg. per amp.-min., and that the bath used ages the rate deposition gradually falls off until about mg. per amp.- min. remains fairly constant. De- pletion metal the bath free cyanide may still lower the rate dep- osition, which time additions should made maintain the efficiency the bath. Since insoluble anodes are used, all metal plated from the bath, and must replaced addition the bath. Analysis the bath and/or record the plating will show when these additions are neces- sary. additions are necessary, they are prepared, the required concen- trations, the original preparation the bath, and are added the bath the concentrated solution tering but not diluting. The cyanide content should allowed fall below oz. per gal., gm. per liter, and 100 gm. per The indium content should not fall below oz. per gal. for consistent plating results. Analyses: The method determin- ing the amount free cyanide the bath the same that for silver plating bath (by means silver ni- trate), with the possible exception that the sample should diluted several times its volume order that the color will not obscure the end point. The indium content determined breaking sample the bath with aqua regia; precipitating the indium hydroxide with ammonium filtering; washing the precipitate with ammonia water until nice and white; the igniting In,O, over moderate flame; and from the weight oxide, calculating the amount indium. careful record the analyses, addi- tions and rate deposition should kept. Diffusion: The plated pieces are moved from the plating bath and given several water rinses. The first rinse should hot, and should retained will contain considerable drag-out, the final rinse should clean hot water. The pieces are now ready for diffusion. Diffusion means heating the plated tet? w Bee =" chloride sold the form shown, for use the plater. Two solid bars indium metal also may seen. automobile connecting rod half-bearing, plated with indium, THE IRON AGE, December 19, 1940—37 4 ig | i IG. 3—Specimens from bearings after corrosion test. (Left) Cadmium-silver- copper diffused hr. 340 deg. corrosive oil; loss, 0.1370 gm.; badly corroded. (Middle) Bearing plated with 0.0170 gm. indium; diffused hr. 340 deg. F.; 144 hr. 340 deg. corrosive oil; loss, 0.0290 visibly corroded. (Right) plated with 0.0290 gm. indium; diffused hr. 340 deg. F.; 216 hr. 340 deg. corrosive oil; loss, 0.0120 visible pieces temperature above the melt- ing point indium and maintaining that temperature long enough per- mit the indium diffuse throughout the base metal. This may accom- oven under inert atmosphere having air circulation. Indium as- plated very soft; after diffusion will found have hardened, actually have alloyed with the base metal. The time diffusion employed with success and without danger weak- ening the bond steel-backed type pieces, hr. 340 deg. The pieces are permitted cool slowly and AGE, December 1940 are ready for use without further treatment. Engine Bearing Tests already mentioned major use indium, plated and diffused de- scribed herein, the protection engine bearings. (See Figs. and 2.) Modern engines have high bearing loads and elevated operating tempera- tures. These conditions have caused engine manufacturers turn from those bearings having low fatigue value those alloys which have greater strength and wear, such cadmium alloys, lead alloys, copper- lead alloys and cadmium-nickel alloys. Unfortunately these alloys ceptible corrosion the presence lubricants containing organic acids. These acids may have been derived from additions animal vegetable leum oils under operating conditions. Additions fractional percentages indium metal bearings the finished-machine state, reported fore the A.I.M.E., showed ficial effects the addition indium laboratory beaker corrosion tests, bearing tests and engine tests. Comparative tests one the major oil companies confirm his conclusion. one engine test, connecting rod bearings lined with cadmium-silver- copper alloy, treated with approxi- mately 0.20 per cent indium, were run for over 5000 miles high speed. the conclusion the test these bear- ings showed only slight evidence etching, whereas untreated bearings run one the connecting rods were replaced three times because their badly corroded condition. The acid number the oil used reached value 3.3. another engine the fatigue life babbitt-lined bearings ranged maximum about hr. under the severe conditions used testing (4250 r.p.m., full throttle, with oil temperature 250 deg. 260 deg. the bearings). Cadmium-silver-copper bearings treated with 0.4 0.5 per cent indium run under these test con- ditions, and the presence oil con- taining 0.5 per cent oleic acid, were excellent condition after showing evidence corrosion and very slight indication fatigue cracks. Such tests bearings, engines run high speed and with corrosive oils (see Fig. 3), verify the information obtained from laboratory tests—name- ly, that the indium treatment de- scribed prevented corrosion the cadmium-alloy bearings im- pairing the fatigue resistance other bearing-metal properties. | . plate copies the struc- ture the underlying metal. Impurities, irregulari- ties and other imperfections reduce the quality the de- posit. All this described herein, are also the stand- ards quality for basis metals. HROUGHOUT the history the metal finishing industry most the effort and energy expend- the improvement the art has been concentrated the finish itself. Imperfections, faulty work and rejec- tions have always been attributed the finish the finisher. Only re- cent years has been borne upon metal products manufacturers and pro- ducers that the condition and quality the finish are vitally affected that once neglected factor—the basis metal. Transactions Faraday Society 1905, Vol. Transactions American Electrochemical So- ciety, 1923, Vol. 44, 305. American Electrochemical So- ciety, 1923, Vol. 44, 427. the Basis Metal the Struc ture Electrodeposits. The Structure Me- tallic Coatings, Films, and Surfaces; published for the Faraday Society Gurney and Jack son, London, 1935, pp. 1242-47. Metallic Coatings, Films and Surfaces; published for the Faraday Society Gurney and Jackson, London, 1935, pp. 1218. AGE, Apr. 11, 1940, Study the Struc- ture Electrodeposited Metals, Finch and Sun. Transactions Faraday Society, Vol. 23, 1936, pp. Faust, THE IRON ADOLPH BREGMAN Consulting Engineer, New York Although the earliest recognition finishing department operations metal (i. smooth, uniform, non- porous metal) took “good” plate other finish, scientific workers have for some time been aware the in- fluence the basis metal. Fundamental Considerations was first noted that the microstructure copper deposit can influenced that the copper upon which deposited. Blum and and showed that the microstructure cast annealed copper can continued copper deposit prepared under conditions which favor the formation coarsely crystalline deposit. Blum and Rawdon pointed out that the ori- entation the copper base, cated etching figures, copied the deposit. Hothersall* found clear evidence the continuation microstructure the basis metal the deposit the electrodeposition copper copper, nickel, silver and alloys. Also, with nickel and tin copper, the macrostructure the deposit was metal. continuation basis metal structure, Hothersall concluded, possible (a) when the deposit and the basis metal belong the same crystal system over range differ- ences parameter (from —2.4 +12.5 per cent difference) (b) when deposit and basis metal be- long different systems. also appeared probable that the high degree adhesion obtainable with electrodeposited coatings asso- ciated with their ability, some cases least, continue the crystal lattice the metal upon which they are de- posited, only over limited thick- ness. tribution the Experimental Study Deposits Obtained Aqueous Solutions,” they found that the fine structure electrodeposits may influenced the crystalliza- tion the cathode, and especially the number crystals per unit sur- face the cathode. sure, other conditions, such the composition solution, current density, temperature, etc., affect the structure the de- posits. However, the structure the basis metal cathode one the important factors. Nickel plate electropolished 18:8 stainless steel shows continuation the crystal structure, while me- chanically polished 18:8 stainless steel, shows ordinary structure. Elec- tron diffraction studies show, how- ever, that the diffraction patterns mechanically and electrolytically pol- ished 18:8 stainless steel the Finch and Sun some time ago stated the case although perhaps too broadly. “It found that the structure the sub- THE IRON AGE, December > — | | | | | | | | ° ° ° | | | basis metal upon porosity. Nickel deposits 0.00012 in. thick after hot water test. left, electrolytic iron (no pores); right, finished black plate. Photos courtesy Electrochemical Society. strata upon which metal electro- deposited nearly affects that the deposit, that the orientation the substrate crystals de- termines that the deposit.” The smoothness the basis metal surface has been shown vital factor. found that electro- deposited nickel adhered more firmly buffed brass surface than brass which had been similarly buffed and then roughened with emery. investigating the causes porosity plated coatings, Hothersall and Ham- mond’ found that rough condition the surface, well foreign matter the surface the steel, were the most important causes porosity nickel deposits formed steel. Polishing the steel revolving wheels dressed with polishing compo- sitions, bonded with grease, resulted increased porosity the nickel de- posit, due inclusion foreign mat ter the surface. Porosity (which they defined “the presence mi- croscopic channels extending through the coating the basis also derived from loose particles the cathode work surface. These Transactions Electrodepositors’ Technical So- cietv, May, 1932. Causes Porosity Electrodeposited Coat ings, Especially Nickel Steel; transac- tions, Electrochemical Society, 1938, pp. 171- 196. Particles metallics and carbon, etc., from the anodes, and dust particles from the atmos- phere will have the same effect. The benefits heavier coatings reducing porosity have been described the “Sum- mary Exposure Tests Plating Steel and Non-Ferrous the National Bu- reau Standards, March 1939; also the Fifth Progress Report the American Silver Producers Research Project, Mar. 1938, 20a. 40—THE IRON AGE, December 1940 loose particles may result dissolution metals chemical Small particles metal non-metal- lic impurities, such carbides steel, quently loosened from the surfaces. The constituents the basis metal may also attacked, during anodic etching, with the formation non- conducting particles; for example, sil- ica, tungstic oxide, etc. Some these particles may remain attached the surface and will function pended particles the solution which settle the cathode surface, causing the formation growths, acting nuclei for the local discharge hy- drogen gas, which will prevent nickel deposition the shielding action the bubbles.” addition its effect hydrogen overvoltage and also the number gas pockets, surface roughness may important cause porosity be- cause the failure the deposit cover the bases pits and the fissures the metal, especially solutions comparatively low throwing power. \lso, pits may formed steel sur- faces local rusting, and even the rust removed cleaning, the minute pits may remain. actempting produce thin, non- porous nickel deposits, variable results were obtained due the differences the surface the steel sheets used. the use prepared electrolytic iron sheet high purity the cath- ode, was found possible deposit nickel 0.00006 in. thickness, non-porous condition, whereas even double this thickness showed high degree porosity bright rolled mild steel. (See Fig. 1.) The further refinements technique, par- ticularly the production electro- lytic iron with very smooth surface, would make possible produce even thinner coatings non-porous The authors roughened the surfaces machined bright rolled mild steel bars along half their length and then nickel plated the bars over their full IG. Reduction porosity nickel deposits, 0.00006 in. thick, produced machining bright rolled mild steel bar. Courtesy Electrochem- ical Society. rous than the smooth half. (See 2.) These bars were improved machining away few hundredths inch light cut with sharp tool and afterwards smoothing lathe light pressure with smooth file, that results were obtained very close those electrolytic iron. The important duced machining was the formation smooth surface and the removal and other foreign matter contained crevices and difficult remove or- dinary cleaning methods. Micro-ex- aminations the deposit machined and bright rolled surfaces, showed the presence inclusions the bright | i AB ‘ ~ cf — | x . rolled surfaces, which were also con siderably more uneven than the ma- chined surfaces. Both the inclusions and the roughness may have been sponsible for the greater porosity the bright rolled surfaces. The importance roughness cause porosity was also shown the invariable occurrence pores the sheared edges the electrolytic iron sheets after nickel plating, even though the faces were free from pores. This tendency was considerably reduced even eliminated careful smoothing the sheared edges with file. plating bright rolled bars with parts machined away above, was found that the thickest ‘coating was practically non-porous the polished specimen, but highly rous the roughened specimen, the pores being located the scratches. Some pieces were sand-blasted plated and very marked concentra tion pores was found the sand blasted area, probably due particles ot sand which had hecome embedded the surface. ABOVE 3—Localized porosity the site mark chalked sheet during manufacture. Cour- tesy Electrochemical Society. 4—Section plate containing foreign particle inclusion. Crystals may seen grow- ing normal the particle surface and the inter- ference caused neighboring crystals results continuous semi-circular crystal boundary. Such nodule may completely pulled out during buffing. Courtesy Society WENTY-THIRD Series Articles the Technical and Economic Aspects Metal Cleaning and Finishing The conclusions were that the case the roughened porosity the coating was due the inability the nickel deposit the bases the pits and fissures the metal. might, therefore, pected that plating with solution throwing power would result lower porosity, and that increasing the thickness the coating, with resul- tant bridging over the pits and fissures would have the same effect.” was found also that hydrogen gas were more freely discharged from rough surfaces than smooth surfaces, because the lower hydrogen overvoltage and because the was excluded the pres ence trapped gas. Polished sheet steel did not give posits better than the unpolished. bright rolled sheets The polished areas seemed somewhat more than the unpolished areas. The conclu sion the authors was that the crev ices become filled with the pol- ishing matter which with ing. the surfaces were not etched be- plating, porosity was not evident, due the Howing the metal over the fissures during polishing, thus covering them The etching removed this thin flowed- over layer metal and exposed the fissures filled with polishing compound. The important effect which may produced foreign matter the sur- face the metal was also demon- strated the reproduction pores the nickel deposit, figures which had been originally chalked the surface during rolling. (See Fig. 3.) removing rust from parts pumice scouring. pumice scour- ing, the particles rust remaining the base minute pits were respon- sible for the pores the coating. general, Hothersall and Ham- mond concluded that porosity nickel caused chiefly by: (1) the presence inclusions non-conduct- ing poorly conductive areas one sort another the surface the basis metal; (2) the shielding action gas bubbles particles solid matter derived, among other ways, loosening from the basis metal; (3) the failure the deposit cover the surfaces crevices the rough sis metal; (4) the inclusion grease over which thin skin metal (dis- solved away etching prior plat- ing) flowed during polishing. interesting side-light the ef- THE IRON AGE, December | 1 . ‘ ‘ . | fect roughened surfaces the fact that the adherence silver, nickel and copper lead was lowered when the surfaces were scratch-brushed be- fore plating, remove the discolora- tion produced the cleaning proce- dure.” his work the “Effect Pol- ishing Corrosion Resistance,” investigated the effect polishing the resistance corro- sion electroplates copper and nickel steel, comparing unpolished cold rolled auto body sheet good quality with some sheets polished with various sizes abrasive grain some sheets buffed with white chro- mium compound, but without grain polishing. The grades emery used were Nos. 46, 80, 120, 180 and 240. The wheels used were felt and set with hide glue. One group sam- ples was plated with copper thick- ness 0.0005 in., nickel in., and then chromium plated. Another group was coated with nickel 0.001 in. and chromium plated. All the sam- ples were tested the salt spray, using equipment the Navy carefully baffled. The conclusions drawn following (1) The pieces not polished with any grain stood better than the grain polished sheets. (2) The type failure with the coarse grits Nos. 46, and 120 was different from those polished with the Mesle, Proceedings—American Elec- troplaters’ Society, 1939, pp. 152-168. So- ciety, 1936, 249. Phillips, Private Communication. metal polishing the character nickel plate, Transaction Society, 1940. Metallurgical Aspects Hydrogen Elec- troplating, Transactions platers’ Society, 1940. Bulletin the New Jersey Zinc Co., The Finishing Zinc Alloy Die Castings and Rolled Zinc, 1934, 42—THE IRON AGE, December 1940 5—Hydrogen evolving from in. steel wire placed previously boiled water deg. (200 deg. F.) after min. pickling warm dilute sulphuric acid. Thirty seconds after immersing (left), min. after immers- ing (middle), and min. after im- mersing (right). Note the large vol- umes gas. Courtesy American Society. fine types, Nos. 180 and 240. The fail- ure the coarse polishes was the closely cropped, fine while those polished with grades showed failure rust spots seemed come from holes the base metal. (3) The panels finished with chro- mium buffing compound tinctly bet