The Iron Age 1943-09-02: Vol 152 Iss 10

SEP VARIOUS TIMES AND TEMPERATURES CASE DEPTHS HOURS t "9s; un CASE ANALYSIS inch round bar carburized four hours 1650° 100 HOURS HOURS case .35 carbon HOURS 2nd .005 in. turned from surface .948 content 3rd .005 in. turned from surface .807 for Your Copy HOURS Warehouses ses: Detroit, Chicago, \ 013 Editor Pom Chilton » m Whiting lets nothing interfere production keyed today’s with steady production Victory needs, Whiting 60-year old demands. using materials that Every Victory Crane must pass are immediately sim- the most rigid engineering tests Memb plified building methods, guaranteed give are avoided and labor minimized. dependable service the job for Earliest possible crane delivery which designed. Whiting assured. Corporation, 15601 Lathrop While Whiting Victory Crane Avenue, Harvey, North Offices Chicago, Cincinnati, Detroit, Los Angeles, New York, Pittsburgh, St. and Agents other principal cities. Canadian Subsidiary: Whiting Corporation (Canada) Ltd., Toronto, Ontario. critical ‘SS NING OVE OVERHEAD TRAVELING HEAD TRAVELING CRANES President and Editor BAUR Vice-President General Manager ° ° ° Editorial and Advertising Offices Johnson, Market Research Regional Business Managers New York New York East 42nd St. 100 East 42nd Guardian 428 Park Chicago Chilton 1134 Otis PEIRCE LEWIS WARREN RAYMOND KAY Los Angeles 2420 Cheremoya Ave. ° Owned and Published CHILTON COMPANY Executive Offices Chestnut and Philadelphia 39, Pa., U.S.A. OFFICERS AND DIRECTORS HILDRETH Vice-President BAUR WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary DUFFY CHARLES HEALE Member, Audit Bureau Member, Associated Business Papers every Thursday. Subscription America, South America and Single Copy, Annual Number, Vol. 152, No. The AGE Editorial You Will Need After the War Technical Articles Increase Performance Hot Work Tools. Physical Characteristics Gold-Indium Alloys Control Residual Stresses Through New Swedish Sponge Iron Process Magnesium Casting Practice Control Mass Production Arc Welding Iron and Steel Corrosion Prevention Features News Front Assembly Line Washington West Coast Fatigue Cracks Dear Editor News and Markets Continued Labor Difficulties Seen War Affects Pipe and Tubing Trends Canadian Ore Project Progressing WPB Clarifies Placing Personals and Obituaries Machine Tool News Non Ferrous Metals News Non-Ferrous Metals Prices; Scrap Prices Iron and Steel Scrap News and Prices. Finished Iron and Steel Prices. Steel and Warehouse Stainless Steel, Tool Steel Semi-Finished Iron and Steel Ore and Coke Prices Ferroalloy Prices Index Advertisers September 1943 143 148 150 152 153 154 157 158 159 159 162 163 164 193 | | j ° ° | > ° ° ° 4 = 8 | Wy | | | q > =D cw ° 2 Zt FIRTHITE Sintered ing, reamin A Tools spreads boring, fac- -metall through shop—for utting ing, materials higher speeds, faster feeds. Carbides cut metals FIRTHITE Engineers and non over! New production records are chalked day after day the use FIRTHITE turning, "Li wea * | \ | 4 | IRON ESTABLISHED 1855 VAN DEVENTER President and Editor BAUR and General Manager DIX Monager, Reader Service Managing Editor....... LIPPERT Morkets Editor...D. JAMES WINTERS Associate Editors MacDONALD BARMASEL BUTZNER Editorial Assistants SCHIEN WILLIAMS BUTTERS CAMPBELL Pittsburgh 428 Pork Bidg. PHAIR Chicago 1134 Otis Washington Notional Press Bidg BROWNE Washington National Press Bldg LLOYD Cleveland 1016 BRAMS Detroit 7310 Ave OSGOOD MURDOCK San Francisco 1355 Market St. Correspondents McINTOSH PENLEY Buffale FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ont. RAYMOND KAY Los Angeles JOHN McCUNE Birmingham ROY JAMES DOUGLAS Seattle Creating Post-War Employment HERE good deal “balony” circulation regarding the crea- tion post-war employment. Many people are telling how neces- sary create but few, any, are telling how it. Some the starry eyed boys Washington, who, incidentally, are being moved further and further away from the throne, have told how they could done. “Just keep taxing, spending and piling debt,” they say, “and everybody will have job good course, common sense tells that this procedure would soon lead Government being the sole proprietor and employer because the privately owned profit making companies the black would bled white make for the Government red. And most would rather continue live under the red, white and blue than chance the aforesaid red, white and black. Government not creator employment the basic sense. never was and never will be. Some the admirers Sovietism among may take exception this and point Russia. But whatever Russia has accomplished the way industrial development since the Czars has been based upon techniques production and management originated capitalistic countries under ‘private enterprise and borrowed thereform. Even the much advertised Stakhonovism Russian “speed up” was long antedated our Taylor System and incentive plans. There great difference between being originator and being adapter imitator. Let consider what that creates employment going back and seeing how has been created. How has been created the country, our country, that has made more employment and more highly paid per capita than any other country the world. Our employment was created individuals. men, not Government. Government, outside granting patents, did not help Thomas Edison invent the incandescent lamp, the talking machine the moving picture projector. Nor did Government develop, even help develop the great industries, employing millions that grew out Edison’s private initiative. Government did not help Ford and Chrysler and other production geniuses the automotive industry build employment hun- dreds people. true, however, that Government, time war, turned these tools production that private enter- prise had provided and the management that had developed. Government did not help Charles Schwab putting together the United States Steel Corporation and later the Bethlehem Steel Company thus providing employment for thousands upon thousands people. Nor did suggest George Verity that should develop the American Mill Company from the embryo metal roofing shop Cincinnati. Private initiative, organizing put power work through machinery; private initiative, and enterprise mer- chandising useful products, not Government, built American employ- ment. will well remember these things the times come. ° ° ° | q | Its Powder Dry Stored deep the holds Allied fighting ships are water-tight boxes—each containing 100 powder. These powder boxes must with- stand hard usage, stack easily and keep precious powder condition for instant use our fighting men. Thousands have been made Inland hot-rolled pickled and oiled sheets. They are welded construction, and galvan- ized inside and outside for full protection. The opening the top sealed with gasket drawn tight hand screw and spider. The bodies are formed from 16-ga. sheets. Dearborn St. Milwaukee Detroit St. Paul St. Louis How the Navy Keeps Longitudinal seams are clamped before ance welding. Powder boxes keep fighting ship powder dry. Tops and bottoms are made 13-ga. sheets. The tops are formed four operations—blank and punch opening, deep draw and emboss opening, trim corners and roll back edges. The excellent working qualities Inland sheets help speed production and save time and materials. When Victory ours, the modern Inland continuous sheet and strip mills, which now are producing full capacity for the war effort, will again making sheet and strip for hundreds peacetime products. Chicago Illinois Kansas City Cincinnati New York war imperi percen plants sinter out handle ating Servic severa planes per far risen INLAND STEEL COMPANY inc bod ire IRON News Dwindling manpower and wishful two conditions have stalled the war program plateau, are causing consternation Washington, and may well imperil many phases the Allied war effort. The war the bag, the type wishful thinking softening management and labor alike. The military, without exception, subscribe way this Even Washington's WPB being drained exodus men back industry nail down post-war jobs. Partly because this, WPB will soon announce widespread decentralization into the hinterland; many functions the steel section may end Pittsburgh, other metals inland cities. Manpower deterioration has cut utilization aluminum and magnesium plants percent capacity; requires hiring five get one worker shipyards and aircraft plants; resulted not one man yet hired for newly completed eastern lump ore and sintering plant, infinitum. Unrelenting bite the draft and high school boys going back school will soon further weaken the situation. Currently, high school boys constitute percent hot room labor aluminum and magnesium plants, have bolstered industrial tions equally dramatically elsewhere. top this crisis, drastic moves are imminent which will affect the lives the least citizen. First: Within few days the Buffalo Plan will slapped down several large industrial areas. This CMP for labor controlled district citizen committee, apportions labor among war plants, kills off labor wastage and duplicating activities, recommends WPB withdrawal war contracts that can't handled the district labor potential. Second: utilization the Buffalo Plan doesn't quickly show signs allevi- ating the situation, will given very sharp would Universal Service, the final step all-out participation the citizenry total war. Many bigwig looks for Universal Service laws before year's end. Many producers are none too sure that electric furnace capacity will used the possible sacrifice open hearth capacity the post-war period. fact, several plants are experimenting with small open hearths possible competitive against the electric furnace for low tonnage orders special purpose steels. Out every 100 bombers produced 1942, were fighter planes, out every 100; light tanks, out every 100; medium tanks, out every 100 went Overall munitions shipments were per cent production. percent magnesium output goes into incendiary bombs. Fire damage cities far exceeds high explosive that magnesium estimates for incendiaries have 400 percent since the war's beginning. Countrywide "Brown into effect Sept. 15. Publicity, warnings, and displays. Thus about percent yearly coal consumption will saved, quantities oil, and, oddly enough, very worthwhile amounts tungsten used incandescent bulb filaments. Tapered rolling steel for manufacture steel propeller blades has been American Rolling Mill Co. The taper, longitudinal, permits forming thé without machining taper previously necessary, thus saving ale machining time and steel. The tank program sinking its lowest ebb. Three plants will make medium against nine earlier. Light tanks will made one plant. Locomotive are switching from tanks badly needed engines. The tank destroyer program te increasing; new models have greatly improved hydraulic transmissions, better While current supplies scrap are considered adequate, there undercurrent fear that supplies will hit new lows this winter. mu hi q | stress put hot working tools depends number factors which vary with work- shop conditions. The effect the de- sign and condition the machine tool and the care and attention the operator well known, fluences such lubrication and cool- ing are not sufficiently understood, article Dr. Hauffer, the German periodical “TZ fur praktische Metall bearbeitung” points out. All hot working tools are stressed mechanically and thermally and, de- pending the working temperature, the one the other stress can pre- dominate. The mechanical stress put hot working tools can defined combination abrasion and ten- sile forces, the article goes on. The material displaced hot working slides over the surface the and friction causes abrasion, especially corners and edges. This stress can visualized both abrasion and welding particles onto the surface. nearly all hot working operations, conditions favor welding effect fol- lowed tearing; these conditions are high temperature, pressure, and diffi- culty lubrication. Therefore tear- ing scouring the main cause tool wear. tools Friction depends surface condi- tions, the metal worked, the material the tool and particularly other treatment. Polished tools will often show considerable superiority over ordinarily ground tools. The working faces all hot working tools should always carefully ground and polished possible. must borne mind that small lines tend concentrate stresses and favor the formation fine surface cracks which will extend the tearing-off welded parts, abrasion, and will finally lead the loosening and breaking away small sections the surface. The tool will wear out very rapidly particles from the work adhere. The hardness the tool important preventing the welding effect. well known that welding aluminum hot working 44—THE IRON AGE, September 1943 uvoided the use particularly hard tools. surface treatment also prevent adhesion. Since clean metallic surfaces tend stick together high temperatures, friction must reduced the ap- plication strong surface layers. Hard, black magnetic oxide iron --Maximum Temperature the tool surface Distance from tool surface IS. course tempera- ture the surface tool (a) imme- diately after contact, (b) little later, (c) still later, and immediately after cool- ing. layers have performed well. They can produced burning oil other means. Hard chrome plating was successful flat drop- forging dies, but upon being heated 660 750 deg. F., the chrome layer loses hardness Tools which are exposed consider- able surface temperature variations such injection molds, cannot chrome plated because the chrome layer will break Therefore, hard chrome plating cannot ap- plied high temperature tools. Adequate lubrication larly difficult the service tempera- ture hot working tools. punch- ing, graphite suspended oil water being used successfully. loose. swaging dies for the working non- ferrous metals, bees’ wax, tallow, and similar materials are often used Oil must very care- fully applied avoid explosions and damage the die. large forging dies, sawdust used great deal and lubrication effected the formation gas layer. The appli- highly volatile bituminous coal the material punching processes acts similarly. application 703,161 (German) the use thin sheet copper sug- gested effect good lubrication the press-forging nickel and othe alloys which require particularly high temperatures. low 2012 deg. F., sheets metal with lower melting point than cop- per should introduced between die work. especially careful descaling and wear tearing the application in- termediate layer non-metallic metallic character, lubrication with fats, oils, graphite the formation gas layers. Tensile Stresses Tensile stress depends, first all, the kind process which the tool used. Also depends Temperature the surface Heating “Heating ture changes the tool surface. number other factors. Deforma- tion processes have only rarely been investigated; pressing, punching, drop forging, much more thoroughly. Strength needs punching depend very much the process under the rate jon, the et, and ng, the The tip the pre trength the workir ng, the deper ect naterial the the edges are the shap bulg ible and are stre naterial pres eve the force | the shape the punch, the rate and temperature opera- jon, the size and material the bil- et, and the cross-sectional ratio billet and punch. punch- ng, the die stressed pressure. The tip the die likely upset the pressure too great the trength the tool insufficient the working temperatures. extrud- ng, the strength requirements the depend the process used (di- ect indirect), the shape and the die, its wall thickness, the composition the work and pressing temperature. articularly under pressure that edges the orifice will deform The die asily. Tube mandrels, the other are often subjected tensile tress the material which slides ast. They very often begin neck ist tensile test the heat the tool insufficient. drop forging, the strength needs the material, the tempera- ure, the rate deformation, and shape the die. Here, corners bulges are particularly unfavor- ible and likely wear fast. Forging are subjected reversing im- stress. Strong local stresses are the first blows since the does not fully fill the die. the pressure can cover the total die only when the whole shape evenly. Pressures acting the and sides cause tensile stress- the corners the bottom die. These stresses very often the die break. The fractures tually begin from the profiled side fatigue cracks, but frac- With extremely thorough and methodical approach, this German article discusses the effect friction, lubrication, oxide layers, heat, heating and cooling rates, original tensile strength and other factors, the performance hot work fools. tures beginning from the opposite side occur also. punching, shape and size the hollow usually precisely defined that the pressure depends upon only the working temperature and the punching speed.. According some recent German work, ordinary in- dustrial use pressures the punch are not function temperature. punching speeds are increased per cent from 7.3 9.8 in. per sec. Hoffman observes increase the punching pressure only per cent. LEFT heating and cooling periods upon the depth penetration. the formula given, depth penetration (E) the distance millimeters from the hot wall which the total temperature va- riation attains part the tempera- ture variation between the maximum and minimum temperatures. ° ° ° BELOW 4—Tempering curves some hot working steels. Steel No. 9.0 was treated oil 2100 deg. F.; No. with the same composition, was treated oil 1830 Deg. F.; No. (2.5 Cr, Also, friction increases with the rate deformation, and can cause very considerable surface heating. This thesis agrees with the observed fact that small profile dies used extrusion perform particularly badly owing the greater pressing speed and friction. extruding, wear present often reduced the working shorter bars. also reported some workers that the strength requirements dies with angular orifice per cent be- low those dies with radius orifice. The use angular dies, however, possible only with materials low extrusion temperature, for example, aluminum, since edges are exposed temperature effects and are likely soften. The excessive wear dies forg- ing can reduced suitable pre- forging. has been recommended for the reduction friction and tool wear, will have favorable effect suitably applied. The surface hot working tools exposed heat operation. Stress- deg. F.; No. (1.0 Cr, /b. per Mo) was treated 800 900 950 1000 1050 1100 1150 1250 1300 Tempering temperature, deg. frequently assumed that hot working tools would stressed less when used more rapid rate owing the shorter time contact with the hot material. But should borne mind that the pressure in- crease may such offset the slight gain temperature exposure. result, the surface thermal reversing stress set up, and the tensile properties the tools are influenced the temperature effect. Hot working tools can vary re- spect many functions, but they are all exposed heat stresses. definite amount heat transmitted the THE IRON AGE, September 1943—45 h- as e- 1g } al 1e li- us e) Ae] p- Cal i To = Sec on T me, seconds a a- en op nd surface the tool the billet bloom. The heat cannot first conducted away sufficiently fast. Fig. shows diagrammatical tempera- ture distribution the surface hot working tool. thin surface layer heated according curve After very short time equilibrium set according heat conduction curve From the surface the tool, heat given out the body the ma- chine, the chucking setup and the air. working pauses the tool face will lose heat. Heat must always conducted away extent which balances increased heating tempering. Because the limited time which available for cooling operation, all tools have cooled artificially. Cooling media are com- pressed air and water. Once equilibrium has been estab- lished, heat will constantly flow from the working face the tool the colder parts. This heat flow modi- fied heat wave the warm side due continuous heating and cool- ing. Such temperature differences and variations cause stresses which may rapidly wreck the tool. The temperature differences and with them some extent the stress- es, will increase with the temperature the work, with the heat transfer, and with the size the tool, but de- crease with its improved heat con- ductivity. For this reason large and heavy tools hot working steels will tend crack, particularly those tools have higher strength and lower toughness. These stresses are cross-sectional changes. The sudden heating the working face causes relative heat expansion the warmer surface layer. The colder parts cannot follow this expansion. the workface, pressure stresses are set which can, however, usually relieved plastically, the elas- ticity the tool. Before use, cold tools must preheated very care- fully and evenly possible. Stress- caused too rapid heating are responsible for the eracking great number hot working tools, particularly winter and especially Mondays. The tools cool down completely over the holiday and are preheated too rapidly, insufficiently unevenly. Often interior shrinkage result which lead later fracture. Experience agrees with this theoretical discussion and better all- over performance secured the tool worked continuously until worn out, than when used intermit- tently. cooling, the heated layers contract the extent their temperature expansion. This causes deformation stresses which can plastically re- lieved. Stresses can even more increased when rapid cooling the interior temperature considerably ex- ceeds the surface temperature. The tensile stress caused rapid cooling particularly dangerous, since the surface the tool has cooled down and has lost its toughness. can, therefore, understood that tools crack particularly easily when cooled too rapidly. stresses increase with the dimen- sions, the walls the hot working tool should thin mechanical fittings 114,000 lb. per sq. in. sile strength. Thermal Reversing Stresses The surface the hot working exposed continual changes heating and cooling the course work, shown schematically Fig the continuous temperatur change, fatigue stress caused the surface layer which produces fine network cracks after more less extended use. These cracks pene trate only little below the surface But the course work they rapidly and can lead loosening surface material that are wrecked very quickly. The forma. tion this network cracks strongly influenced the notch-action surface lines. Since the strength decreased simultane ous corrosion attack may assumed that fatigue stresses are enhanced water cooling. Perhaps the ingly good performance the cent chrome steel water cooled punches, ete., has been due the good corrosion resistance this steel, tempering resistance per cent tungsten steel. The upper deg. F., tempered deg. and cooled 80,000 Testing time, min. air. The tool repre- sented the curve was oil quenched 40,000 from 1740 deg., tem- pered 930 deg. and Testing temperature deg. stresses permit. This consideration performance which cannot confirmed the observation that, for instance, the manufacture screws and rivets, solid, thick walled dies will not perform well thin walled inserts from the best hot work- ing steel which can shrunk into w Performance improvement, per =) Hardening temperature, IRON AGE, September 1943 Coarse grain hot pressing die manufac- ture hexagonal in. nuts, made per cent tungsten steel. This die was treated for Rockwell plained its other properties. The thermal reversing stresses will increase with the amplitude the heat waves, that is, with the differ- ence between the maximum and mum temperature the tool surface. Temperature variations, course, equalize themselves very rapidly they progress toward the interior, that the core the tool either extent, the surface temperature variations. The depth penetration hot working steel and for various period frequencies. Since many hot working tools, surface cracks gin appear after few hundred thousand work periods, their fatigue must then have been strength ceeded. The oper tion, wear are har able special their extende ture, pering and the resi for punch well hardne: fully =] Performance cent point ing Below steels tance paren for order 1240 and stood only but ing and ner exces | Aw | | The unavoidable heating tools operation causes tempering ac- tion, decreased heat strength and wear resistance. Hot working tools are hardened and tempered suit- able hardness and toughness for each special purpose. They must not lose their hardness service; even after extended use the working tempera- ture, they must have sufficient tem- pering resistance. Prominent edges and corners are particularly exposed the heat action, they lose their hardness easily and can then long- resist the work pressure. Thus, for example, the blunted tip punch has hardness only Rock- well compared with original working conditions are not care- fully watched nN =] 100 Performance cent 200900 220000 240000 Tensile strength, Ib. per 7—Influence strength the per- formance conical valve die 4.5 per cent tungsten steel. point can exceeded, ing may take place cooling. Fig. the tempering curves popular hot working steels shown. Below 1240 deg. F., none these steels reaches the tempering tance the per cent tungsten steel. (Editor’s note: This steel ap- parently was standard Germany for hot working tools until recent order took effect.) When less tem- pering resistant steels are used, exces- sive heating must avoided. Above 1240 deg., practically all steels anneal and only austenitic materials can used. Austenitic extrusion dies have stood well very high working temperatures. Tempering resistance depends not only the composition the steel, but also its heat treatment. Ac- cording more recent ideas, temper- ing resistance due the sluggish precipitation the dissolved special carbides. The hardening temperature and time must chosen such man- that these carbides are com- pletely dissolved possible without producing coarse grain structure excessive heating timing. The in- subsequent fluence the hardening temperature upon the tempering resistance the per cent tungsten steel can seen from Fig. comparison between curve and curve demonstrates the considerably greater tempering stabil- ity when hardening temperature in- creased from 1830 deg. 2100 deg. After tempering 1110 deg., the well Tools treated for greater tempering stability attain better per- formances than tools which were quenched from too low hardening temperature. Thus the performance per cent tungsten die steels used the manufacture hot pressed nuts improved per cent when the hardening temperature creased from 2010 deg. 2150 shown Fig. When the hard- ening temperature was increased 2190 deg. F., the structure tended become coarse-grained and the per- formance the tool dropped off again. Stress conditions tools are usual- complicated that they cannot calculated accurately. Therefore the forming and shaping hot work- ing tools, well the choice steel, depends almost exclusively em- pirical observations. For the calcula- tion tools which will used only over short working periods, high temperature tensile test will give good indication, while the permissible load for parts which have operate continuously elevated temperatures must calculated exclusively the basis creep strength. Useful com- parative values are given high tem- perature tensile tests min. minimum duration. Creep limit gen- erally decreases with the temperature. Reliable data regarding the creep limit hot working steels are not avail- able the literature. Strength elevated temperatures not only de- pendent chemical composition, but influenced heat treatment, just tempering stability. Fig. shows the influence tem- pering stability strength ele- vated temperatures. per cent tungsten steel was quenched (from 2100 deg. F.) produce mar- tensite; also, this steel was hardened only 1740 deg. that after tempering only structure was present. general, can said that higher tempering stability accomplished higher strength elevated temperatures. The strength elevated tempera- tures usually runs parallel the room temperature strength. (See Table I.) Thus per cent tungsten steel offers considerably better strength elevated temperatures when heat treated pull 230,000 per sq. in. ling, deg. per Distilled Cottonseed Temperature quenched part, deg.F. 8—Influence temperature cool- ing water the cooling rate the tool. than when was treated for ten- sile strength only 190,000 lb. per sq. in. practice found that the performance most hot working tools improves with strength. shown Fig. the performance dies the manufacture valves increases with the strength. Heat strength tube piercing mandrel, previously referred to, which necked pressing duralumin tubes, be- came adequate and necking was elim- inated, just increasing the strength from 206,000 256,000 per sq. in. High temperature resistance must also aimed improve wear re- sistance elevated temperatures. Al- though exact data are not available the literature concerning the wear resistance hot working steels, ex- perience has shown that hardness elevated temperatures, good work hardening properties and toughness are favorable. Hard adhering sur- face layers have proved their value while soft skin very detrimental and leads scouring. The tool maker might inclined the basis these data treat his tools for the greatest hardness order obtain high heat strength, tempering stability and wear hard- ness. However, very rapid elimina- tion his tools cracks would likely the consequence. The basic con- dition the heat treatment hot working steels requires that temper- ing should least carried the actual service temperature, which however not known and can hardly estimated. The tempering tem- perature must also chosen such manner warrant sufficient toughness with regard the effects THE IRON AGE, September 1943—47 9000 8000 6000 5000 4000 a ace | 2000 ~ or 1000 ools — ma. tion gue med per the eel, will the ace. not ited ture tion jous any be- ex- @ the unavoidable temperature stress- es. Also, tool strength fore the tempering temperature must adapted the shape the tools. notch effects, with their influence impact resistance cannot avoid- ed, correspondingly lower tensile strength must chosen. The temper- ing temperature, therefore, while de- termined the tensile strength and through the strength elevated temperatures, empirical value which depends very largely the kind and shape the tool and local working conditions. Reduction Heat Effect the effect heat and the thermal- reversing stresses upon the strength properties, and the temperature gradient the tools, well the difference between maximum and mini- mum temperature the tool surface, the surface temperature must kept minimum. The temperature the tool surface determined the temperature the work, the de- gree heat transmission, and the heat conductivity the tool. The surface temperature increases with the temperature the work, with the contact tool and work, and in- versely with the heat conduction the tool. The greatest temperature difference will the point the greatest cross-section. The working temperature deter- mined mechanical and chemical constants and can modified only very slightly. should kept low possible. operations are carried out temperatures higher than the possible minimum, tool costs will increase. Thus, the better wear dies die casting brass com- pared with injection molding obvi- ously due lower working tempera- tures. Also, the heat conductivity cannot changed will. decreases with increasing alloy content the tool. Under certain circumstances, the ad- vantage better tempering stability and heat strength hot working steel are cancelled its decreased heat conductivity and the higher sur- face heating occasioned it. Thick punches per cent tungsten steel tend form hardening cracks when they are water cooled owing the bad heat conductivity the steel. Under these conditions, less highly alloyed steels with better heat con- ductivity such the 4.5 per cent tungsten steel have been The coefficient heat transmission offers chance modify the service temperature. The transmission heat can reduced giving tools metallic cover. recent tests the Kaiser-Wilhelm Institute was found that the heat transmission drop forging dies can reduced about third when ferroso-ferric oxide surface layer imparted the tools. hot punching can observed that clean die absorbs con- siderably more heat than die pro- tected oxide skin surface cover. These oxide layers can, already stated, applied burnishing special salt baths burning with the manufacture seamless tubes recommended that the piercing punch provided with special iron chlo- ride surface layer salt treatment. prevent contact the tool with hot work and make the heat trans- mission poor possible, anthracite coal used punching and sawdust drop forging. The application graphite paste the die also fre- quent punching. future, the possibility modify- oil, special tempering. TABLE Effect Original Tensile Strength Strength Elevated Temperatures Per Cent Tungsten Steel Original Tensile Strength Service Yield Tensile Elongation Dia Reducti Lb. Per Sq. In. Deg. Lb. Per Sq. In. Lb. Per Sq. Per Cent Per 230 750 134 1220 deg. temper for hr. (2100 deg. quenched, 1255 deg. temper for hr.) 48—THE IRON AGE, September 1943 = ing the heat transmission coefficient surface layers gas producing substances, lubrication will increasingly made use of. The lowest surface temperature the tool depends mainly the degree cooling. The tool should always cooled such manner that only the heat quantity which was added the work cycle removed, After cooling the surface temperature should still remain 390 deg. more. Frequently, however, the tools can touched after cooling. Such extreme however, means unnecessary stress which must lead premature tearing the tool. all operation delays and lengthy work intervals, cooling should performed. the tools have been cooled down too much they should warmed. number tools, for example, pressing dies, additional heating during operation for the re- duction stresses has proved most efficient. order reduce unneces- sary stresses, also, the rate cool- ing should not too abrupt. number investigations have shown that the effectiveness water coolant depends high degree the water temperature, the motion the cooling water, and the tem- perature the tool. Fig. shows that heating the water the cooling effect can varied within wide limits. temperature about 122 deg. F., the efficiency cottonseed oil attained. practice, however, the temperature only rarely considered. performance not known. for- eign plant, punching operations, was observed that the die consump- tion was much higher winter than summer. investigation showed that the temperature the cooling water was about deg. F., win- ter; summer, however, was deg. the use cooling water heated about 120 deg. F., greatly improved performance was Cooling should not follow the work cycle immediately, but should wait for certain temperature stabilization (Fig. 1). premature cooling hardening may take place vice the surface the tool should reach the transformation point. Ow- ing the great difference the structure, stresses will cause rapid destruction the tools the forma- tion numerous cracks. [Translated Phy the econor cost. freque saving Indi but point not posur result gram gold point, conte gold tion, per ture indiu per beta peri forn and ECAUSE its high cost, gold seldom considered indus- trial material. However, like the industrial diamond, sometimes economical spite its high unit cost. Its use with indium solder frequently results considerable net savings. Indium alloys readily with gold. Although the melting point indium but 311 deg. F., has boiling point 2642 deg., there ap- preciable loss melting. Indium not easily oxidized, but prolonged ex- posure the molten metal air will result some oxide formation. shown the constitutional dia- gram (Fig. 1), indium additions gold cause rapid decrease melting point, making possible the production low melting alloys high gold content. The solubility indium gold is: Per Cent Deg. 8.5 1004 770 The alpha phase, stable condi- tion, has elementary cube 4.100 The beta phase close packed hexagonal structure with homoge- neous phase from 9.8 per cent 12.8 per cent indium. Heterogeneous struc- ture has been observed per cent indium. The lattice spacings 12.8 per cent indium are: 2.908+0.0032 4.777+0.004 c/a 1.643 lower indium content, creases and decreases. The gam- phase forms for the melting beta 910 deg. F., and has the for- mula Au,In (16.8 per cent In). The delta phase forms along the 921 deg. peritectic with limits 19.8 per cent 20.3 per cent indium and has the formula Au,In, (20.0 per cent In). deg. (26.7 per cent In). 1005 deg. (53.8 per cent In). has elementary cube 6.505+0.003 and forms eutectic with 921 deg. (41 per cent In). Alloys the alpha phase are workable. The following heterogeneous phase more 51000 occurs between 20.0 per cent and 36.9 per cent indium and forms eutectic with the delta phase 844 brittle but still workable, while Auln and are not workable. The hard- ness increase with indium additions shown the following values: Hardness Per PerCent (Rockwell 87.5 12.5 These alloys are precipitation harden- able. For example, the hardness the Au-8 alloy increases from after two hours 570 deg. Cold working gives higher value. Although the alloys containing more than 12.5 per cent indium are not workable, they well. has been found very practical produce coating the harder alloys suc- cessive plating gold and indium and then alloying diffusion about 330 deg. The continuity this type coating and the fact that less permeable than gold, well being very hard, are worthy em- phasis. Indium-gold has some unique char- acteristics for brazing. The alloy 77.5 per cent and 22.5 per cent has working temperature little cast Diagram the Gold-Indium System Atomic per cent indium 1600 Per cent weight indium above 930 deg. When used metal objects with glass inserts this ideal temperature, since any tempera- ture above 1110 deg. destructive glass-metal seals; and the other hand, working temperatures 750 deg. must endured. Furthermore, the low vapor pressure indium pre- vents unwanted contamination ad- jacent parts such occurs when used the brazing material. This sheet which made plating gold foil with indium and then diffusing. Alloys lower indium content may rolled into sheet instead follow- ing the above procedure. will observed that the indium- gold plate, diffused, approxi- mately the same distribution the per cent indium—60 per cent gold alloy. This alloy very hard, fact too hard and brittle for ball impres- sion hardness tests. However, diffused coating, the crystals are small and very hard and resistant wear without being brittle. The spectral distribution several other alloys has been measured and the intermediate percentages give curves falling between those shown. Increasing the indium content alloys lightens the color gold, which passes through white definite blue. The colors are pleasing deco- rative finishes and the same time provide maximum protection. Indium also value the ter- nary and more complex alloys con- taining gold. green gold with in- dium much more tarnish-resistant than the more commonly known green gold. From per cent indium produces fairly hard, workable alloys. representative alloy is: Per Cent This alloy has hardness Rock- well The tarnish-resistance su- perior that green gold usually produced. Indium-gold alloys deserve consid- whenever hard, corrosion resistant alloy needed, they can Worked mass, without putting fur- ther demands critical metals. THE IRON AGE, September e e ysica aracteristics > n n ~ n = ° 2000 > 400 T SSF > > | erection and welding sequence plan relating successive operations erection and weld- ing required the fabrication welded structures order control shrinkage, properly controlled, (1) Shrinkage result welding tends produce unfair structures (2) Shrinkage causes residual locked- stresses that sometimes result fracture (3) Shrinkage makes difficult con- trol overall dimensions. While welding the principal cause these faults, not altogether responsible for all them. Among other causes are: (1) Rolling and galvanizing stresses (2) Storage and handling distortions Gas cutting shrinkage Improper fitting, i.e., loose forced fitting (5) Unequal expansion from sun's rays (6) Unequal expansion because changes atmospheric temperatures ANGLE BAR BEFORE WELDING ANGLE BAR AFTER WELDING (7) Overshrinking (Overshrinking will sometimes destroy all that sequence may have accomplished There tendency most ship- yards spend time and money straightening shrinking and press- ing rather than adopt methods keep structures straight while erect- ing and welding. This mistake because takes quite large crew the straightening, and consumes large quantities gas and oxygen which these times are essential materials. The use water for quenching somewhat nuisance, especially the hulls. The belief that strict adherence erection and welding sequence may slow fabrication unfounded. Experience has proved that ulti- IRON AGE, September 1943 MONTGOMERY CELLERS Welding Superintendent, Shipbuilding Corp., Seattle, Wash. mately speeds production elim- inating most the time and cost straightening distorted members, and saving time necessary fit the hull and fair-up “unfair” warped assemblies. erection and welding sequence will also accomplish much beyond its general purpose. Where yard working more than one shift, pro- vides method and order proce- dure for each shift. there are dozen different ways doing job, and each shift tries dif- ferent way, very little will accom- plished; while each shift uses the same method and order procedure, the job will completed orderly Shrinkage weld metal one side angle bar results this type distortion. ° ° ° manner with minimum manhours. The objection sequence because the fact that ships’ hulls and their various parts cannot fabricated and erected sequence governing every operation down the smallest detail erection and welding sequence can more less general and need into detail very few instances. The more knowledge the shipfitters and welders have just what welding shrinkage and how affects the ship’s and its many sub-assem- blies and the various methods that are used control counteract that shrinkage, the less detail the sequence need have. There has been much discussion pro and con regarding welding under Stresses restraint versus so-called stress-free welding. prefer stress-free method because its use can eliminate much stress which, not eliminated, may prove disastrous. The hulls produced through welding en- tirely under restraint have consider- able locked-up opposing stresses them which may result fracture too much this stress part the hull that receives considerable stress use. restrained weld will relieve itself some contraction while plastic state, but there consid- erable contraction that place after the weld metal cools be- yond the plastic stage. There are objections using some the present type automatic weld- ing shell and main decks other than sub-assembly. While the high heat, speed welding and the large amount flux covering the weld re- sults annealed weld, the ob- jection that the detrimental con- traction parallel the weld and consequently automatic welding not flexible manual welding nor easy apply stress-free welding. automatic welding done under restraint, there considerably more locked-up stress than manual weld- ing were used under the same condi- tions. While the only stress-free welded structure properly annealed one, structure produced stress-free welding should have little more locked- stress than riveted one and has considerably more strength than riveted structure because the high- strength welded joints. Rivet- ing sets stress because the expansion the metal around the rivet holes. might well here briefly discuss the things that make erection and welding sequence. They are: Welding technique (2) Welding procedure (3) Order welding (4) Manner erection Order erection. Welding technique and procedure are much part erection and welding sequence are manner and order pos sults sults car help. Weldir things voltage the work and oscil size the welding, some and pro will tail. Those problems all-welde bly not order tant ing. Bot the desir Exp Metal tracts upset the amou the mem sults the restraine also rest call The ments. Fig. after flange. Fig. After hess ma in. Ing, a order erection and welding. While possible accomplish some re- sults without them, far greater re- sults can accomplished with their help. Welding technique pertains such things welding heat (amperage and voltage control), angle electrode the work, are length, speed travel and oscillation. Procedure relates size pass, number passes, and the order making them, back step wandering procedure, direction welding, most experienced welders have some knowledge welding technique and procedure control, attempt will made into them de- tail. Those familiar with some the problems encountered fabricating all-welded steel structures are possi- bly not aware that the methods and order erection are just impor- tant the methods and order weld- ing. Both are necessary accomplish the desired results. Expansion and Contraction Metal expands under heat and con- the expansion restrained, the heated metal will upset some extent (depending upon the amount heat and what extent the member restrained) which re- sults more shrinkage than would the case expansion were not restrained. Now contraction were also restrained, would have what call residual, locked-up stress. The explanation the accompanying will prove the above state- ments. Fig. angle bar before and after one pass welded along one The result considerable Fig. shows two plates bev- deg. with in. root opening. After tacking and before welding wit- marks are placed making punch marks either side the weld apart. After welding and cool- 0.055 in. found. The metal when deposited the was the fluid ttate, therefore was expanded Through Welding Sequence Minimizing residual stresses resulting from expansion and contraction during welding the most serious problem encoun- tered this method fabrication. The practical suggestions for obtaining stress-free joints set forth this article have been ex- tracted from privately published treatise the author “Erection and Welding Sequence Applied Welded Steel Ves- sels." The principles apply equally well all types large welded assemblies. the limit, and contracted drew the plates toward one another. order get better understand- ing what meant residual stress, the results produced dis- regarding erection and welding se- quence will demonstrated well what can accomplished through the proper use it. Through the application it, these faults are overcome. Fig. two plate members were PLAN VIEW 2—Measurement distance be- tween witness marks steel shows shrinkage that takes place butt weld. welded while both were entirely re- strained. The result was that the butt weld fractured because the contraction the weld metal. Each plate was welded the strongback and then one light pass was run down the joint before welding the two bars either side the joint; conse- quently the butt weld was not strong enough withstand the strain disregarding it, locked-up stress and warping oc- contraction. Had withstood the strain, there would have been con- siderable locked-up stress the mem- bers between the strongbacks which they were welded. If, the other hand, one plate welded one end the strongback, making immovable, while the other plate clamped and wedged the opposite end the strongback, allow- ing some freedom movement, Fig. light butt weld between the two plates will not break because one plate was not totally prevented from con- tracting toward the point welding. After removing the wedges find the plate straight. This the result restraint afforded clamp- ing. The free plate can now weld- the strongback and the job complete with minimum locked-up stress. now have Rule Leave one end member structure free contract toward the point welding. learn here too the importance method erection. Had both bars been tacked welded instead be- ing clamped, either tacks weld would have been broken, there would have been stress the member because the stiffness the strongback. Fig. shows disk with pad welded near the center. this job were welded without being clamped down, the result would considerable warpage. Fig. shows how this job clamped and welded without warpage. now have Rule Warpage may ing the members down. Fig. represents pipe which THE IRON AGE, September 7 7 q 7 4 | G 1 | | | 2 ' | collar were arc welded the bulk- head, then the collar the pipe, there would considerable locked-up stress the welds, although not great enough break the weld. Several years ago when attempt was made weld, with oxy-acetylene, pipe and collar large rectangular tank the above order, all the was locked the plating and the weld the pipe the collar frac- tured. the collar clamped the bulkhead while the pipe being allowed cool and consequently con- tract, and then the collar welded bulkhead, there would locked-up stress only one weld. Fig. represents subassemblied section main deck. way illustration let erect and weld this subassembly lock all the longitudinal stress possible. are not greatly concerned about trans- verse stress because the hull ship rarely, ever, receives much transverse longitudinal stress. longitudinal stress, the object eliminate the longitudinal stress. Longitudinal stress obtained from transverse welds and transverse stress from longitudinal welds when welding done manually. The longitudinal seams are erected and tacked first and the transverse seams second. the welding done without regard procedure, af