The Iron Age 1943-11-11: Vol 152 Iss 20

NCV 1943 — Hot Rolled Sheets Cold Sheets Tin Plate Terne Plate Sheets Tin Mill Products Porcelain Enameling Sheets _ GRANITE CITY STEEL CO. CITY, ILLINOIS Chicago Cleveland Denver Houston Indianapolis Kansas City Les Angeles Memphis Milwaukee Minneapolis Moline New York St. Lovis | = == SEE GB 3 > SS ¥ y y ERHAPS you have 1909 quarter one claw the American eagle holds bundk arrows, the other, olive branch- ready for war—ready for peace! Our nation didn’t follow this advice the letter. were not ready for war. made for lost time. America’s will prevent the world being ruled and Nazis. must not make another mistake unprepared for peace. What after this war help stricken world will important our leadership and during this war. your pocket right now. Look it. private industry anticipates the postwar demands which will fall American industry, and plans for there will work and jobs for millions off returned soldiers and ex-war workers. great reconversion program, can industry will need power—and skilled management. will new machines, new tools, and new recent survey indicated that major dustry groups plan spend over dollars for reconversion and this sum 47.7% allocated for new equipment, 26.4% replace old 25.9% repair old equipment. turer who handicaps his workers duction lines with outmoded, equipment and machines will left far behind fast-moving postwar q PATRIOTIC PLAN NOW FOR THE POSTWAR Warner Swasey offers you practical help postwar planning. have corps who are skilled machine operations volved production precision parts made metal. They are helping many war plants methods and machines for greater They will continue so, but their services are also available management interested planning now for the future. Write Warner Swasey, Cleveland Ohio. ra Cent American WS 3 VAN DEVENTER President and Editor BAUR ° Editorial and Advertising Offices Johnson, Market Research Hayes, Production Manager. Baur, Typography and er in ° ° ° it. Business Managers undle New York New York 100 42nd St. 100 East 42nd ROBERT BLAIR FITZGERALD Cleveland Pittsburgh Guardian Bidg. 428 Park Bidg. Chicago Bur Chilton Bidg. 1134 night PEIRCE LEWIS WARREN RAYMOND KAY Los Angeles 2420 Cheremoya Ave. after CHILTON COMPANY upon Executive Offices Chestnut and Sts., OFFICERS AND DIRECTORS WILLIAM BARBER, Treasurer ment, Mamber Audit Bureau of Circulations ficient far ginee ons 3 Cahbie Address “‘lronage N.Y.” | uction. sted The IRON AGE Vol. 152, No. November 11, 1943 Editorial ° Technical Articles Current Zinc Electroplating Practice Production Surface Grinding Magnesium Castings Impregnated New Method Tool and Operation Planning Aircraft Machining and Forming 14ST Aluminum............... Chrome Ore and Chrome Phosphating Prior Silver Plating Steel ° Features ° ° News and Markets Non-Ferrous Metals News and 136 Non-Ferrous Metals Prices; Scrap 137 Iron and Steel Scrap News and 138 Comparison Prices Year 140 Finished Iron and Steel Prices 141 Steel and Warehouse 142 Semi-Finished Iron and Steel 143 ° ° | Wartime production WELDED. STEEL PLATE products, parts and fittings has developed intense interest throughout all industry the almost endless possibilities for peacetime applications. Greater strength with less weight—lower machining cost —elimination pattern expense and finer appearance—these are the reasons why after industry investigating and adopting this ECONOMICAL construction. Methods developed Mahon—coupled with extensive production and engineering facilities—have set standard the art fabricating weldments all shapes and weights. determine whether your part product adaptable WELDED STEEL PLATE fabrication, consult with Mahon engineers Fabricators Machine Bases and Frame: oar —‘—‘—é—™ Other Welded Steel Plate PLATE q — : | | tensive new sizes, ESTABLISHED 1855 Nov. 1943 VAN DEVENTER President and Editor BAUR Vice-President and General Manager ° ° DIX Manager, Reader Service ° ° ° News, Markets Editor...D. JAMES WINTERS ° ° ° Associate Editors MacDONALD BARMASEL BUTZNER Editorial Assistants SCHIEN WILLIAMS BUTTERS Regional News and Technical Pittsburgh 428 Park POST Chicago 1134 Washington National Press DONALD BROWNE EUGENE HARDY Washington National Press LLOYD Cleveland Guardian BRAMS Detroit 7310 Woodword Ave. OSGOOD MURDOCK San Francisco 1355 Market St. Editorial Correspondents ROBERT Cincinnati PENLEY Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, RAYMOND KAY Los Angeles JOHN Birmingham ROY EDMONDS St. Louis JAMES DOUGLAS. Seattle Pearl Harbor—Plus OUR walkouts have occurred seven months the most essen- tial industry country that throwing its all into the world conflict. that does not mean that something radically wrong the home front, not know what would. What the use sending eminent emissaries abroad Moscow draw the plans for future world management when becomes more obvious, day day, that are unable, even Presidential order under war emergency powers control industry with mere half million workers? depict the fragrance world relationships when have stench our own backyard that reaches high heaven! Well, this time, those Americans who are not completely gullible should have learned that plans and promises from politicians’ port- folios are not related any way performance. And that all the exhortations united action defense our democracy not pre- vent one citizen from fellow citizens the back when self interest dictates. And neither does government. That’s the pity it, neither does government. family with unruly children who will not obey, the fault lies with the parents. Likewise, this disastrous controversy between the operators, miners and War Labor Board, the blame sits squarely upon the doorstep the Administration. one can say that has not had time act, for this the fourth walkout seven months the coal industry and all them time war. Any general the armed forces who had four mutinies his hands seven months and who was impotent putting stop them would recalled, demoted and disgraced. And any general who permitted men under his command seize guns and ammunition and attack their own fighting comrades would, should face court martial and possible firing squad. Strikes our coal industry have put more ships out action denying the steel with which build them than two Pearl Harbors. The first stoppage cest Liberty ships steel tonnage; tonnage that could not possibly replaced because capacity operation our mills. The President has put the mines the hands Mr. Ickes and has ordered the men back work. important that they back producing the coal that need badly, but more important, much more so, that they not back under face-saving agreement that sell-out and surrender government. The proposed agreement, latest this written, giving the miners all they demand exchange for min. lunch period may Mr. Ickes’ idea the easiest way out but like general claiming victory when exchanges his sword for the enemy’s coat button. Whistles for lunch periods not blow underground. God help the cost putting the miners back work our loss confidence our government’s ability preserve order without appeasement. you really want know who has won this battle the domes- tic front, forget the newspaper headlines emanating from Washington and watch the steel production rate. That will tell you who boss. | 4 7 ] ‘ q 4 € 3 | | | q : | | | | | | Tle ef | URGENTLY NEEDED BEFORE JAN. retul Between now and January America’s steel mills must rom uninterrupted operation throughout the coming winter} indus months. Steel mill inventories scrap, adequate for the} present, will quickly depleted coal shortage or} stoppage reduces production pig iron—if iron receipts drop because unfavorable lake shipping condi- Almost year has gone since American industry intensive drive for scrap. the months that have passed, many industrial scrap piles have grown again— many pieces equipment have become —here and there building has been abandoned. Scrap} from all these and other sources needed for production ingo steel for ships, tanks, guns, shells and other War tung; urge you revive the scrap committee which ¥ successful your plant last year. Will you help with can industry gather and ship more than its share the 15,000,000 tons scrap needed before the start the new year? INLAND STEEL Detroit Paul Cincinnati New York Milwaukee Kansas City 4 7 NOV. i] t indi atta crap ‘tion was the York IRON News Front Batcheller has been asked Steel Corp. directors return active management the company, move made particularly pressing yet unannounced retirement some weeks ago Detwiler, Chairman the from active participation company affairs. Mr. Batcheller's eminent performance, first Director WPB's Steel Division, then vice-chairman charge all industry operations WPB, said make Mr. Nelson reluctant relinquish his services such early date Dec. view Mr. Batcheller's conviction that winning the war paramount importance, averse arbitrarily resign such action would even small way jeopardize the production effort. Disposition the matter still rests with Mr. Nelson. Chromium, tungsten, molybdenum, and vanadium will all likely off allocation Jan. Existing rules forcing percentage use alloy scrap will, however, remain force. steels now account for per cent total monthly alloy steel consumption. Additional substitution for higher alloyed steels now rising only very slowly and likely will never reach per cent, which considered the top limit. The bulk Kaiser's Fontana export ingots are leaving the country via Gulf ports. The $43 base plus the long freight haul presents with pretty stiff bill pay. Meanwhile: Kaiser asking OPA lift his ingot base over $45. With batting average requests this kind, likely the petition will granted. Current alloying element ccnsumption, pounds per net ton total alloy steel ingots produced, 10.6 for nickel, 19.5 for chromium, for molybdenum, 0.302 for tungsten, and 0.10 for vanadium. the freight airplanes designed and fabricated Budd Mfg. Co., one has passed all static tests and the other was week ago, with performance exceeding all expectations. Six additional ships are about ready roll off the line, and the company now swinging into full production its plane order. These freight planes will undoubtedly influence far greater acceptance stainless aircraft construction material. Tubular railway axles, 500 day, are now being turned out Pittsburgh Steel Co. The tubular unit weighs per cent less than the conventional solid and preliminary tests indicate far greater strength and fatigue resistance. recent raids the Eighth air force abandoned its former policy bombing favor mass sortieS similar the British night "area" Growing number bombers does not make strategically advisable wait for the occasional winter weather conditions suitable for precision bombing. The German radio recently announced shooting down five Allied aircraft new type, called "hedgehoppers," and designed for low-level strafing. This the first indication that the Allies may have production specialized ground-strafer for attacks infantry. extraordinary airplane has been developed the Allies, and already use anti-submarine patrol. has the and landing properties within foot two, but far faster and more maneuverable than the helicopter. Used ball and roller bearings and component parts are now funnelled from all British industry into the Bearing Control, Ministry Supply. They are cleaned, graded and for re-use; excessively worn balls and rollers are used purposes (paint, grinding, etc.) Despite current flood rumors that recently captured German tanks have Carried greatly inferior armor, the Ordnance Department has not yet found the deterioration the excellent construction metallurgy German materiél. New scrap depots are being set Frederick, Md. (for the ports Norfolk Seattle and San Francisco. The New York and Boston depots, for sometime, could easily handle the 12,000 tons entering September, very heavy shipments require additional facilities. 7 | | | | 4 ‘ 4 4 | * | ADOLPH BREGMAN Consulting Engineer, New York this, the first two-part article, the author discusses the com- mercially important methods electrogalvanizing and evaluates their relative merits and disadvantages. more than century coatings have served the most satisfactory commercial method protecting ferrous products against corrosion. This rather remarkable considering the vast amount scien- tific and technical knowledge that has been amassed during this period. The explanation first the position zine the electromotive series the metals, and second, the relative abun- dance and low cost zine normal times. The primary function zinc coating provide resistance corrosion, rather than any decorative purposes, protection against me- chanical wear. The factors that de- termine the durability the zinc coating are its uniformity, its thick- ness and the nature the atmosphere The production zine coatings electrodeposition offers number advantages over the other methods coating (hot dipping, sherardizing, and spraying). Particularly rela- tively simple shapes and forms, which good current distribution can obtained, uniform coatings pre- determined thickness are obtained controlling the amount current and the time deposition, and threaded parts can coated. Brittle deposits are eliminated, there appreciable alloying zine and basis metal*. Furthermore, These statements should not taken mean that hot-dip galvanizing neces- sarily non-uniform and brittle. well known that steel strip and wire, coated continuously, take uniform coatings; and that commercial methods hot dipping ate use which produce deposits which ‘will withstand drawing and bending. due the absence heat, the basis metal not warped, and its temper hot impaired. The electroplating pro- cess yields coatings sufficient duc- tility permit drawing bending. Electrogalvanized coatings that ad- here well castings, and other basis metals, are obtained suitable meth- ods preparation. The commercially important meth- TABLE Consumption Zinc Hot Dipping and Electrogalvanizing Applied, Tons (Minerals Yearbook, Bureau Mines, Vols. 1933 1941) Electro- Ratios galvanizing Hot Dip Total** 1933 2500 26,500 148,000 10.6 59.2 1934 1900 24,000 152,000 12.6 80.0 1935 30,000 195,000 9.6 62.6 1936 36,000 242,000 8.0 52.6 1937 5443 40,000 256,000 7.3 47.0 1938 3978 19,200 198,000 49.5 1939 5740 40,700 275,000 7.1 48.3 1940 42,200 287,000 7.0 47.3 wire and wire cloth only. Zinc consumed for all purposes. Johnstown, Pa., Bethanizing plant started. 46—THE IRON AGE, November 1943 ods electrogalvanizing are the fol- lowing: (a) Acid zine plating. (b) “Rapid zine process.” (zine acetate so- lution.) (c) Cyanide zine plating. (This processes for bright zine, and the Pont Ductile Zine Process.) (d) Hubbell-Weisberg process. The growing importance electro- galvanizing recent years shown Table Acid Zinc Plating Electroplating with zine from acid solution used principally for the production galvanized steel wire, strip, wire cloth and some hardware plating baths are characterized high rate deposition and low oper- atings costs, and are generally suited for large production. Their main disadvantage their poor throwing power, which limits their application relatively simple forms. However, moderate throwing power obtained first coating the article cyanide “strike” bath, and completing the deposition the acid bath, although this practice not often followed. Where only limited corrosion pro- tection required, the case box strapping and stapling wire, thin (0.0001 0.0005 in.) inexpensive coatings zinc are employed. wide range coatings used steel wire, and coatings exceeding 2.4 02. per sq. ft. (0.004 in. thick) are ap- plied commercially. Wire cloth usually protected with 0.1 0.2 oz. per sq. ft. (0.00017 in. 0.00034 in. thick) zine electroplate, which frequently coated with var- nish for additional protection. Coat- ings 0.05 0.5 per sq. ft. (0.000085 in. 0.00085 in. thick) are used small hardware. Following are the minimum thick- nesses significant surfaces spe- Testi shee thick for trial Shel ami for mini “Sig face Ame per adopi desig meta and use. pl York (Cou Van Co.) fol- for zine, Zine well acid the vire, vare per- heir poor rms. the and acid not pro- thin wide steel ap- late, var- are spe- cified the American Society for Testing Materials, (A164-40 T). American Zinc Institute specifies oz. per sq. ft. for the best grade hot The initial letters were adopted the arbitrary designations grades plating. The second letter refers steel the base metal; other base metals are indicated the letters for brass, for copper and for zinc. galvanized sheet for general outdoor use. This average weight oz. per sq. ft. each side the sheet, and corresponds average thickness 0.0017 in. For general outdoor service, except for unusual conditions some indus- trial atmospheres, 0.001 in. minimum thickness Sheltered outdoor minimum thickness 0.0005 in. and for indoor temporary use only, “Significant surfaces” are “those sur- faces that are visible and subjected wear corrosion, both; ac- i—Part the plating unit the York Ice Machinery Co., York, Pa. (Courtesy, Van Co.) j cording suggested definition, those surfaces which can touched in. diameter ball bearing. Continuous processes are employed for the acid zine plating wire and strip. For plating steel castings, and the larger and heavier hardware and parts, racking wiring the meth- commonly used. Plating barrels are employed for bolts, nuts, rivets, washers, nails and other small hard- ware. Anodes for acid supplied three grades zinc: Prime Western spelter (containing 98.5 per cent Zn); Intermediate (99.5 99.8 per cent Zn); and High Purity (99.95 99.99 per cent Zn). uniform grain size, which results even corrosion the anode and minimum sludge, obtained casting control. Considerable difference opinion exists concerning the type anode use. Much work being done with the Intermediate grades, and some even with Prime Western, but many feel that the absence heavy metals essential. reported that lead, plating are for example, over 0.02 per cent results lead film the anode which Economic Aspects Metal Cleaning and Finishing aluminum-mercur causes high polarization and resist- ance the flow current into the solution. Other impurities also cause more less trouble. the quantities normally present zine anodes not detrimental. Following the spectrographic analysis Intermediate grade zine anode, satisfactory quality, according Lyons:' Pb, 0.08 per cent; Cd, 0.08 per cent; Cu, 0.01 per cent; Fe, 0.01 Lyons, Modern Electroplating pub- lished the Electrochemical Society, Inc. (1942). per cent; Mg, 0.005 per cent; Sn, 0.002; Al, trace, and Zn, difference, 99.81 per cent There also appears some dif- alloy anodes zinc-alumi- num-mercury anodes offer any advan- tages over zinc anodes the acid bath, although those favor onsiderably sludge and zine loss, and more stable pH. Wire and sheet steel are some- uble anodes; these are made lead lower polarization, THE IRON AGE, November cy y 4 - | 4 4 containing small amount silver, silicon-iron, where low current densities are used. Zine sulfate forms the basis most the acid zinc baths use today. The commercial grade zinc sulfate usually sufficient purity. Ni- trates are objectionable impurity the plating bath, they produce dark, unattractive porous coatings. Sulphuric acid which added the bath lower the pH, should low arsenic, this impurity produces poor deposits. Addition agents that are commonly used are licorice, glu- cose, dextrin and gelatin. Numerous others have been used, and other sub- stances have been recommended produce smoother, brighter deposits, permit with less criti- eal control temperature, and current density. Following are four approved for- mulas for acid FORMULA NO. oz. per gal. Zine sulfate, Ammonium chloride, Aluminum sulfate, FORMULA NO. oz. per gal. Zine sulfate, Aluminum chloride, Sodium sulfate, ....... FORMULA NO. oz. per gal. Zinc sulfate, Ammonium chloride, Sodium acetate, FORMULA NO. oz. per gal. Zine sulfate, Sodium acetate, Aluminum sulfate, 0.13 For the operation plating barrels, should increased oz. per gal. The basis metal cleaned before plating the standard methods with very thorough rinsing, prevent contamination the pickle, plating solution. Wire and certain types cold rolled are cleaned special methods. Overpickling prevents satis- factory zinc plating, and castings are easily overpickled, they require special treatment. Abrasive cleaning (sand grit) recommended preliminary cleaning for castings. The preferred methods for castings are tumbling with sand and water, sand-blasting; pickling weak hydro- fluoric acid sometimes employed alternative method. For pickling steel, acid used (40 48—THE IRON AGE, November 1943 per cent) room temperature preference sulphuric acid (10 per cent) 150 deg. important element pickling keep the time immersion the work short prevent overpickling; that from few seconds not over min. Anodic pickling also used some instances, activate the sur- face. Unless the residue from inhibi- tors are completely removed after pickling, the use inhibitors not recommended. “strike” cleaning cyanide bath has good cleaning effect, due the alkalinity the bath, but poor adherence the acid zine plate will result unless the cyan- ide solution rinsed off thoroughly. Current Densities amp. per sq. ft. used for the still tank plating. Current densities may increased, depending upon the agi- tation the solution and the char- acter the work. the plating round wire special baths, current densities 2000 amp. per sq. ft. are employed. Bath temperatures should between deg. and deg. F., deposits become duller, darker and coarser above 100 deg. some cases, artificial cooling used when high current densities are em- ployed. Acid zinc solutions are usual- termined electrometric measure- ment. obtain uniform results, the should not fluctuate more than 0.3 unit. High values, usually above 5.0 are used for barrel plating, except when aluminum sulphate used since precipitates. this case, the may 3.5 4.0, electrometric. Roughness, pitting and discolored deposits may result from suspended matter the plating bath. is, therefore, customary filter the bath continuously for large, continuous plating installations, but this refine- ment not generally used for still plating which the solution may filtered periodically, say once week. adjunct filtration, activated charcoal has been used times remove oils and other impurities. Or- ganic addition agents may also removed its use. Metallic impuri- ties baths give some trouble, but the metals are deposited replace- ment the zine anodes, when the equipment idle. The anodes should taken out the bath intervals, treated with acid and scrubbed order remove these deposited im- purities. Iron frequently introduced the bath insufficient rinsing after pick- ling the work. iron content few grams per liter not considered objectionable, but higher concentra- tions may contaminate the de- posit with iron. Iron may removed from the bath oxidization the ferric state bubbling air through the liquid, adding hydrogen peroxide, manganese dioxide, per- sulphates. The ferric tate ferric hydroxide, the bath tends rise when electrodepo- sition not progress. Other im- purities such antimony and arsenic, which may present amounts, also precipitate with the ferric hydroxide. the the bath increases, due the reaction between the free acid and the zine anodes, neces- sary add sulphuric acid order maintain the optimum 3.5 4.5 (Zinc-aluminum mercury anodes, stated, eliminate this necessity). sometimes necessary add zinc sulfate the bath, the content has been depleted due excessive drag-out losses. These losses may also necessitate the addition other components the bath. When oper- ating with insoluble anodes, acid liberated the anode, and the bath becomes depleted zinc. The bath restored its normal condition dissolving scrap zinc, zinc dust, zine oxide calcined zinc ore, the accumulated acid. This method used for galvanized wire and sheet steel, bath impurities being removed oxidation, neutralization and treat- ment with zinc dust. difficulty that encountered basic zinc, iron, lead and aluminum compounds low-purity, unalloyed anodes. This condition, which due local consumption acid the anodes, does not affect anode efficien- seriously, but does increase the ohmic resistance the anode. This current loss may decreased low- ering the bath pH, agitating the solution near the anode. The control acid baths usually limited determination and estimation zine content means specific gravity, but this method not effective with aluminum sulphate chloride present. Titra- tion the zine most satisfactory. The quinhydrone glass electrode well suited for determination, but approximate values may obtained colorimetric methods test papers. not customary buff. and polish the deposited zinc, although some cases the zinc coating given light brushing rolling. After- mer the 0.1 cien “sti pos usu cya gre bet wei sig tal tor car ha: thi sin cor thi lia “4 di: tra- de- the ugh per- epo- im- mal] the free 4.5 zine tent sive may ther per- the heet eat- rust num due the the the tion this tra- ory. but ined ers. and ven ter- treatment the Cronak Process discussed elsewhere this article. Cathode efficiencies approximate- per cent can obtained com- mercially. both anode and cathode, the polarization quite low (less than 0.1 volt). The throwing power acid zine baths poor comparison with cyanide zinc baths, but this defi- ciency may remedied some ex- tent first coating the work cyanide zine bath. The de- posits obtained acid zine baths are usually whiter than those produced baths and, although they are sometimes coarse-grained, there great difference protective value between deposited from acid and alkaline solutions given minimum thickness zine applied. Testing Coating Thicknesses Determination the thickness weight the coating the most significant test, the amount me- tal deposited one the main fac- tors the length life. The Ameri- ean Society for Testing Materials has approved the microscope test for thickness, but not widely used since too slow and involved for commercial application. Average thickness can determined most re- liably the strip. test. The strip- ping solution prepared adding grams antimony oxide per liter hydrochloric acid) 100 hydro- acid (sp. gr. 1.19). The area the sample and loss weight dissolved zine are observed, and from these data the average coating thick- ness calculated. Magnetic methods are used some extent for determining coating thick- ness given point, but this usu- ally determined dropping test. One method employs ammonium nitrate 100 grams per liter and nitric acid (sp. gr. 1.42) grams per liter; the reagent used uses solution chromic acid 200 grams per liter and sulphuric acid grams per liter; this solution used deg. either case the solu- 110 drops minute and each second required, until the steel base ex- posed, represents zinc thickness 0.00001 in. The precision this test said within per cent, al- though times difficult deter- mine the endpoint. test the adhesion, the plated work bent various ways, and the coating then examined for cracks and peeling. The salt spray test has been used TABLE Effect Addition Agents Bright Zinc Baths Addition Agents (1) Ammonium thiocyanate-formaldehyde resin Phenol-thiocyanate Thiourea-formaldehyde resin Purpose Effect tolerance Cu, Ni, and bath. oz. per gal. 0.06 0.13 Henrichs Udylite Corp.) (2) Methyl-ethyl ketone (conditioned with oz. per gal. Improves brightness sulfuric acid not conditioned) (3) oxide and similar compounds 0.33 1.0 Produces bright deposits directly from bath. (U. Pat. 2,080,520. Westbrook Pont Nemours Co.) (4) Piperonal other methylene dioxy- phenyl compound 0.4 Improves brightness, espe- cially with molybdenum, low current density. (U. Pat. 2,218,734; 2,233,500. Westbrook Pont Nemours Co.) (5) Gelatin with certain oxyheterocyclic compounds 0.13 Improves rate covering (6) Thiourea with metal brightener 1.0 Pat. 2,080,479, Hoff; 2,080,483 Hull; 2,080,520 Westbrook Nemours Co.) Improves Pont (7) alcohol conjunction with bath purification 0.02 brightness and covering power, particu- larly barrel plating. (U. Pat. 2,171,842. Wernlund Pont Nemours Co.) extensively accelerated corro- sion test, but many authorities now consider very limited value. Although the copper sulfate, Preece test still widely used determine uniformity coating thickness, its utility has also been questioned. The Rapid Zinc Process Hanson-Van Winkle-Munning Co. has developed new type acid bath and method application, which they term the “Rapid Due the ductility the deposits, stated that even the case thick Diggin, “Recent Develop- ments Zinc Plating,” Monthly Review, pages 249 270 (March, 1943). coatings steel, they may severe- deformed without rupture. Two important applications are found the manufacture ridged roofing and plating wire. For construction electroplating tanks, the company recommends the use rubber-lined steel, ceramic ware tempered glass. ex- changers, made Pyrex, Duriron, Karbate heating coils ceramic Karbate, may used for heating the plating bath. The solution should filtered. before use, but the anodes produce very little sludge, con- tinuous frequent filtration con- Society, 30, sidered unnecessary, unless there contamination dirt and dust drop- ping into the bath. Filters are con- structed preferably stainless steel, are rubber covered. Turbulence, rate solution flow, impor- tant factor the successful operation this process. Good results are ob- tained with directed discharge from submerged propeller housing which directs the flow. The plating bath formula simple, consisting solution only zinc chloride and zine acetate without ad- dition agents. Used with num alloy anodes, corrosion pro- ceeds when plating not progress. Current densities range from 1000 amp. per sq. ft., depending upon the nature the work. density 100 amp. per sq. ft. employed for depositing zine steel parts simple design. Steel sheets ft. wide can electrogalvanized 400 500 amp. per sq. ft. Wire can plated 1000 amp. per sq. ft. The optimum bath temperature 120 deg. F., but range 100 deg. 130 deg. permissible. Bath while plating 3.6 electrometric 4.1 color- imetric. For the recommended anode- cathode spacing, required voltages range from the lowest current density, volts for density 1000 amp. per sq. ft. These spacings THE IRON AGE, November are in. in. over 100 amp. per sq. ft. and in. in. below 100 amp. These conditions are especially adaptable simple shapes—sheet, strip, wire, etc. The process includes simple method analysis for bath control. Due the stability the bath con- stituents and anode and cathode effi- ciencies practically 100 per cent, said that solution nearly constant. remains Deposits can obtained straight cyanide baths varying rates 0.005 0.006 in. thickness per hour, “Cyanide Zinc Plating Modern Electroplating. Special volume published the Electrochemical Society, Inc. (1942). Pont Bright Zinc Operating Manual,” issued the Electroplating Zinc Molybdenum Plating technical service manual issued Zinc” issued the Electro- plating Division, Pont Ne- mours Co. 100 amp. per sq. ft. with cathode current efficiency per cent. the modified bath for rapid deposi- tion, the efficiency per cent. The zinc-mercury bath, when amp. per sq. ft. has per cent cath- ode current efficiency. Bright baths operate with efficiencies per cent. The advantages cyanide bath 50—THE IRON AGE, November 1943 processes for zine plating are the fol- lowing: (1) High throwing power, which permits plating deep angles, recesses, and produces deposits uniform thickness. (2) Semi-bright deposits can obtained. These coat- ings are excellent appearance and have relatively little tendency stain during rinsing and drying during as- sembly operations, and upon exposure the atmosphere: (3) Equipment cost low, steel tanks may used. (4) Plain steel auxiliary anodes can used for plating holes and recesses. The disadvantages cyanide plat- ing are: (1) The rate deposition lower than with acid baths. (2) Both the initial and mainte- nance costs cyanide solutions are higher. Cyanide zine baths are classified as: (1) the straight cyanide bath; (2) the (3) semi- bright and bright zine baths, giving ductile deposits, and (4) Pont Ductile Zine Abraham Van Winkle, Pat. 901,- 758; Proctor and Wernlund, Pat. 1,435,875; Haas, Jr., Pat. 1,451,- 543 and 1,497,265. linger), Pat. 2,146,439. The field application for the straight cyanide bath protection against rust, the ap- maica, plant the Dicta- (Courtesy, Hanson- Van Winkle-Munning Co.) pearance the deposits not partic- ularly atractive. Malleable iron and iron not plate readily this bath. The bath char- acterized good covering power low current densities, good throwing power, uniformity deposit and ability coat many basis metals. However, not recommended for coating cast iron malleable iron rule; and may produce season brass. The bright baths yield products having both good appearance and good rust resistance. Clean steel rubber lined steel tanks should used for bright zine plating, wood lead-lined tanks are not satisfactory. Tanks for bar- rel plating should have capacity 150 175 gal., with coils installed for cooling during hot weather. Hard rubber, rubber covered steel and bake- lite are satisfactory materials for barrel plating cylinders, but wood and fiber cylinders are not recom- mended. Steel angles should used cover copper brass bus bars, protect them from corrosion any plating solution that may drop them. Capacity tank rheostats should sufficient supply current densities amp. per sq. ft. for still plating, and 250 450 amp. per unit for barrel plating. Bar- rel plated material may bright dipped clean steel baskets, pref- erably rubber covered steel bas- kets. The solution for bright dipping should contained rubber lined steel tanks stoneware vessels, metal tanks are unsatisfactory. The solution for ductile plating sho 3 q pe a should circulated four times hour pump adequate capacity. The solution enters the tank through seamless iron pipes, containing 1/16 in. holes spaced in. in., placed the bottom the plating tank. For use the straight cyanide bath, high purity zine anodes such Special High Grade High Grade, are recommended. Anodes Inter- mediate Prime Western al- loyed with 0.5 1.0 per cent mer- cury, are employed the zine cya- nide-mercury bath. Baths for bright plating should supplied with anodes high purity zinc, such Special High Grade High Grade, zine alloyed with such metals aluminum, magnesium, which not plate out. Following are two approved for- mulae for the straight cyanide zinc bath’: FORMULA NO. per gal. Zine cyanide, Sodium cyanide, NaCN........ Sodium hydroxide (caustic soda) modification this formula permit rapid deposition high cath- ode current efficiency the following: FORMULA NO. oz. per gal. Zine cyanide, Sodium NaCN....... Sodium hydroxide (caustic soda) Formulas for process resemble the cyanide formu- las, but with the addition small amount mercuric compound, such mercuric chloride, mercuric ox- ide dissolved sodium cyanide solu- tion. Formula No. used still IG. 3—Plating room the Co- lonial Bronze Co. Photograph Flieg Newbury. (Courtesy, Hanson- Van Winkle-Munning ° ° ° plating, and Formula No. em- ployed plating barrels. FORMULA NO. oz. per gal. cyanide, Sodium cyanide, NaCN........ Sodium hydroxide (caustic soda) Mercuric compound ............ 0.003 FORMULA NO. oz. per gal. Zine cyanide, Zn(CN),........ Sodium cyanide, NaCN....... Sodium hydroxide (caustic soda) Mercuric compound (see notes above) NaCN Ratio The concentrations compo- nents for bright plate baths may varied through wide range, indicated the following formulas. However, important maintain definite ratios (M) between the con- centration total sodium cyanide and the concentration zine content. For still plating, the ratio (M) should between 2.0 and 3.0. the case barrel plating, the ratio (M) lies the range 2.5 3.2. bath compo- sition for still plating and barrel plat- ing given Formula No. Pont Nemours Co. their “Du Pont Zine Operating Manual.” FORMULA NO. oz. per gal. Zine cyanide, Sodium cyanide, NaCN........ 5.6 Sodium hydroxide (caustic soda) Sodium sulfide, 1/15 RH-309 (Purozine Brightener). Matte-white, ductile zine deposits are obtained with Pont’s patented process, which employs the bath com- position Formula No. 11. FORMULA NO. oz. per gal. Zine cyanide, Sodium cyanide (NaCN)....... Sodium hydroxide (caustic soda) Sodium sulfide, Na,S........... 0.1 Steel prepared for plating the usual alkaline cleaner, followed acid pickle, taking care avoid over- pickling. Hot rolled steel generally requires heavy pickling, whereas only very mild pickling usually needed for cold rolled steel. Hydrochloric acid preferred for pickling the lat- ter, although sulphuric acid may FORMULA NO. Range Suggested oz. per gal. oz. per gal. Sodium hydroxide (caustic soda) NAOH........ 10.0 15.0 10.5 Corresponding zinc content 6.0 Total equivalent sodium cyanide ............... 12.3 From Plating and Finishing Guidebook, 1943. The addition agents that are com- monly used bright zine baths are listed Table II. All these prod- ucts are the subjects patents. ; used some cases. Hot sulphuric acid generally used for heavily sealed steel. The work should well THE IRON AGE, November 6 ‘is J 4 ne rinsed water after pickling. This may followed soaking cold sodium cyanide solution oz. NaCN per gal.), for min., and then transferring the plating bath. When necessary hold cleaned work before plating, can stored this cyanide solution prevent rusting. Smut due pickling may removed anodic cleaning. Castings are frequently difficult plate, but machined ground sur- faces yield better results than sand- blasted shot-blasted work, and this turn better than treatment pickling. When the use cadmium following cleaner, either for soaking for electrocleaning: oz. per gal. Sodium hydroxide (caustic soda) Trisodium phosphate, electrocleaning, the cleaner used 190 deg. with current density range amp. per sq. ft., first making the work cathodic for min. then anodic for sec. Cyanide baths operate best the range 12.2 12.7. The straight cyanide hath should held a (Courtesy, Hanson-Van Winkle-Munning Co.) Fig. 4—Still and barrel plating installation the Sikorsky Aviation Corp. permitted, castings may plated after coating with flash cadmium, but this necessitates extra equipment and operations. Another method for plating gray and malle- the following composition: FORMULA NO. oz. per gal. Zine cyanide, Sodium cyanide, NaCN........ Sodium hydroxide (caustic soda) Sodium carbonate, Ketonic Brightener..... per gal. current density 125 amp. per sq. ft. applied for min., and the work then transferred plating bath the same composition the strike bath. The Pont technical service man- ual for “Zin-O-Lyte” zinc-molybde- num plating salts recommends the 52—THE IRON AGE, November 1943 temperature between 104 deg. and 122 deg. F., using current den- sity 9.3 amp. per sq. ft. The modified straight cyanide bath for rapid deposition (Formula No. employs current densities 110 amp. per sq. ft., with temperature range 104 deg. 158 deg. For the bath (Formulas No. 8), maximum cathode current density amp. per sq. ft. with amp. per sq. ft. used. The tempera- ture range deg. 122 deg. the optimum being 104 deg. Bright zinc baths may operated between deg. and 113 deg. F., but prefer- ably between deg. and 100 deg. Cathode current density may range from low 100 amp. per sq. ft. although the average limits are and amp. per sq. ft. The anode current density amp. per sq. ft. Operating conditions for Pont bright baths are: For still plating, amp. per sq. ft. cath- ode current density, with temperature between deg. and 113 deg. F.; for barrel plating, the maximum cathode current density obtainable used bars, and temperature deg. 113 deg. The Pont ductile zine process operated between 115 deg. and 120 deg. F., with normal limits amp. per sq. ft. cathode cur- rent density for still plating, and 100 amp. per sq. ft. when either the cathode the solution agitated. Control Bath Composition The control two factors cya- nide bath composition essential for satisfactory operation. These factors are: (1) Sodium hydroxide concentra- tion. (2) The ratio total sodium cyanide zine content. Total sodium equal the actual sodium cyanide, plus the sodium cyanide equivalent cyanide. For straight cyanide zinc, Formu- las No. and should maintained within +10 per cent. The ratio total sodium cyanide zine should within the range 2.0 2.5 for For- mula No. and between 2.2 and 2.6 for Formula No. Constituents the baths, Formulas No. and should also held within +10 per cent. Mercury cyanide concentration should within the limits 0.013 0.027 oz. per gal. mercury metal deposits the anodes during shutdowns, necessary replace this addition mercuric compounds the bath. Excessive concentration zinc the bath may corrected replacing about one-third the anodes with steel anodes, preferably case- hardened. The bath should filtered occasionally, remove ferric droxide and the suspended matter. Bright zine baths require more careful attention than the straight cy- anide baths. The first requirement that heavy metal impurities must almost completely eliminated. Lead precipitated the addition sodium sulfide con- centrated solution, using 0.033 0.33 oz. the sulfide for each gallon plating solution. Copper removed adding 0.033 0.33 oz. zine dust per gal. and then stirring well and filtering. second requirement, the ratio must maintained within certain limits. The optimum values the ra- tio for Ter The diu gal alt tai tio total sodium cyanide zinc, for various temperature ranges are follows: Ratio Temperature deg. Optimum 82to 2.6 88to 2.8 100 3.0 The optimum concentration dium hydroxide given Formula No. but bright deposits can ob- tained within the range oz. per gal. For the normal operation the Pont bright zinc bath (Formula No. 10), the ratio should 2.75, although this may varied for cer- tain applications. ratio 2.2 employed the operation the Pont ductile bath (Formula No. 11). The Hanson-Van Winkle-Munning Semi-Bright Zine produces deposits which range from semi-bright bright, the degree luster depending upon operating con- ditions. The deposits are highly duc- tile and are pure unalloyed electro- lytic and are therefore highly protective. For highest luster and surface uniformity, bright dipping the deposits recommended. FORMULA NO. oz. per gal. Sodium cyanide Sodium hydroxide Zine addition agent S-B....... 0.8 Which will analyze when solution, approximately: oz. per gal. Total sodium cyanide ......... 12.0 Sodium hydroxide 12.0 essential that all heavy metal impurities excluded from this solu- tion. the deposits come from the bath with dark color the de- posits show dark streaked ap- pearance after bright dipping, im- purities are present. The permissible cathode current density solution No. high; high speed plating bath. Good results are obtained with cathode current density from amp. per sq. ft. with optimum amp. per sq. ft. Below amp. per sq. ft. there noticeable diminution deposit luster. voltage the tank between and volts required in- sure proper operation the solution. With current source volts, volt drop rheostat recommended. Solution No. produces deposits highest luster when operated current density amp. per sq. ft. the cathode efficiency ap- proximately per cent. Zinc-aluminum anodes are recom- mended this solution. After the work has been plated necessary rinse thoroughly be- fore the bright dip. This rinsing important the highly caustic film plating solution difficult re- move and any remains there possibility obtaining dark and streaked work. The rinse water should clean. Staining will occur nickel, cadmium copper from previous rinsing operations carried into the bright dip. The work immersed for few seconds the bright dip which con- sists 0.5 per cent nitric acid so- lution. The work again rinsed cold water, hot water and then dried. Ed. Note: Next week concludes with data bright dipping, the Hubbell- Weisberg process, etc. Post-War Uses Seen for Nylon Plastic YLON, now used for several secret military purposes, will enter vast, new field plastic after the war, according duPont Nemours Co. The which means that under heat and pressure can reshaped and re- formed any number times. The softening point for most thermoset- ting materials about 160 deg. F.; the highest previous limit was about 280 deg. F.; Nylon’s 450 deg. F., approaching that thermosetting materials which cannot remolded once they are formed under heat and pressure. Its toughness particularly useful where sections with great strength are required. light weight; burns slowly; undergoes little deterioration with age; only slightly affected sunlight; resists oil, grease, solvents, alkalis and weak acids; easily machined; has good elastic properties; and can molded with existing equipment with minor modifications. All Nylon now strictly allotted for military and essential civilian re- quirements. The bulk goes into fibers for parachute cloth, bomber tire cords and glider rope, and into large, single ARS, tubing large and small diameter, cords, sheet strip, woven fabric molded shapes, are some the varied forms shown here which Nylon plastic will available generally after the war. Pres- ent day uses are chiefly military. strands for brush bristles and surgi- cal sutures. THE IRON AGE, November ANY factors must kept mind when attempting grind surface with finish expressed terms micro-inches, especially when flatness, parallelism and dimensional accuracy must maintained production rate equal requirements applicable fixed gages, forming tools and the like. Such feat course now defi- nitely possible, but results are gov- erned more what built into the machine than extended operator experience particular technique which might have some effects his acquiring advanced skill. How fast derived without sacrificing any allied essentials, depends per cent the extent development the equipment and per cent the application basic rules for pre- cision grinding. Any surface grinding machine the horizonal spindle and traverse table type obviously intended for fine precision work; otherwise shaper planer would just well. also assumed that this precision will repeat itself from day day the unit will not prove trustworthy production tool. One cannot expect obtain, simultaneously, high pro- duction rate and three-way accuracy unless the machine used incorporates certain characteristics. Primarily, where vibration exists there can precision com- plete form; hence ample but not ex- cessive weight the major essential. Weight itself, however, means ab- solutely nothing unless properly distributed all members com- bine and function unit 100 per cent balance. All Eliminated All components must developed the highest degree effectiveness support that weight. They must expertly machined and fitted and this especially true the sliding surfaces table, saddle and vertical ways. Ample area and wide spac- ing ways are most significant the many hours spent hand scrap- ing and fitting remove play are prove most effective maintaining the accuracy the machine over long period time. The most frequent source vibra- 54—THE IRON AGE, November 1943 tion traceable the spindle, even though might direct drive construction. and therefore deliver maximum ac- curacy, the spindle must necessarily both staticly and dynamically bal- anced. Obviously, this also applies the motor when integral construc- tion used. For long life and great- est efficiency, ball bearings used particular spindle should the same production lot. recent im- provement along these lines the mounting the ball bearings such way that the contact between balls and races changes with each revolu- tion the bearing. The balls thus wear evenly and retain their true spherical shape. dependable hydraulic longitudinal and cross feed mechanism asset for maximum production and 100 per cent precision. When chuck being used full nearly full capacity, Fig. with fluid power chance distorting both ends the surface being ground usually the case with rack and pinion con- struction when the table operated automatically. With draulically operated table having cushioned cut-off the end each longitudinal stroke, the only sensa- tion one feels when touching the table vibrationless traverse motion. Generally speaking, there suffi- cient “jump” with table operated with rack and pinion develop cer- tain amount vibration that will find its way the spindle and cause plenty trouble. This indeed true vibration from table reverse amplified column that light construction. improperly functioning forced feed lubricating system something else that will affect the finish con- siderably. Adjustments must that the oil will flow rate cient lubricate properly but not great enough build pressure be- tween the sliding members. The lubricating and hydraulic systems re- test for efficient performance surface grinding machine the horizontal spindle and traverse table type determined the accuracy will simultaneously impart full chuck load parts. . m n a Nn 1 4 | ( q sly main their best when using only oils recommended the manufac- turer the machine. Magnetic Chuck Considerations chucks play prominent part with tool room and parts pro- duction surface grinding. Their re- spective electrical and magnetic char- acteristics have much limit- ing extending the efficiency the machine. field, such the pole pieces magnetic lines force possible and said saturated. this con- dition further electrical power required maintain the lines force, once the power turned on, the only power consumed mag- netic chuck the current lost the heat the current passing through the coils. The magnetic lines force the pole piece will dissipated, however, the current turned off steel used t