The Iron Age 1945-08-09: Vol 156 Iss 6

BAUR Vice-President LEONARD Assistant General Manager HAYES Advertising Manager JOHNSON, Manager Reader Service and Market Research BAUR, Production Manager Cleary, Technical Research Promotion Manager Executive Offices Chestnut and Séth Sts. 39, Pa., U.S.A. Editorial Offices 100 East 42nd New York Regional Business Managers New York New York 100 42nd St. East Cleveland Pittsburgh Bidg. 428 Park Chilton Bidg. 1134 Otis PEIRCE LEWIS WARREN, RAYMOND KAY Les Angeles 2420 Cheremoya Ave. Owned and Published CHILTON COMPANY OFFICERS AND DIRECTORS MUSSELMAN, JOS. HILDRETH, TERHUNE Vice-President VAN DEVENTER Vice-President BAUR Vice-President CHASE Vice-President WILLIAM BARBER, JOHN BLAIR Secretary THOMAS KANE CHARLES WILLIAM H..VALLAR, Asst. Member, Audit Bureau every Thursday. Subscription Price America, South America and Single Copy, cents. ° ° ° ° Gepyright (045, by Chitten Camgany (ine) Vol. 156, Ne. AGE Editorial Competition and Employment Technical Articles Sub-Critical Annealing Steel Castings Made Thermit Process Induction Brazing and Soldering Gas Cutting Stainless Aided Fluxing System Titanium Chrome-Manganese Stainless Steel Precision Founding (Part Casting Resin for Pattern Making Repair Defective Gray-Iron Castings New Features News Front Assembly Line Washington West Coast Personals and Obituaries Dear This Industrial Week News Industry News and German Steel Divided Into Zones Surplus Witnesses Conflict ICC Rate Decision Affects Rail Loading CED Sees Orderly Detroit Reconversion Small Business Steel Need Urged Sheet Group Asks CMP Freedom Machine Tool Market Developments Nonferrous Metals News and Prices Iron and Steel Scrap News and Prices Comparison Prices Week and Year Finished and Semi-Finished Steel Prices Warehouse and Steel Prices Iron and Steel Pipe and Tubing Prices Exceptions Steel Price Schedule Pig Iron and Coke Prices Bolts and Nut Prices Stainless Steel and Ferroalloy Prices Index Advertisers August 1945 101 107 110 122 124 128 132 134 136-7 138-9 140 142-3 144 145 146-7 148 149 150 228 | ° Member, Associated Business 5 Custore ORDER NO. Gate How Ryerson Assures Alloy Steel Quality Each alloy shipment personally inspected and tagged part rigid quality control system, which call the Ryerson Certified Steel Plan. This plan covers: selection the individual heats alloy steel, the testing samples from each heat, the positive identification every alloy bar with stamped heat symbol and painted color markings (or with metal tags), and Ryerson Alloy Steel Report, which sent with each ship- ment. This report shows complete test informa- tion for the particular heat steel used filling your order. contains: chemical analysis, rec- ommended working temperatures, the Jominy hardenability results, and interpretation physical properties for and inch rounds quenched and drawn 1000°, 1100° and 1200° The report serves positive identification, check quality and guide satisfactory heat treatment. The Ryerson Inspection Tag symbolizes the final culmination our quality controls, because places personal responsibility for the fulfillment every specification your order. This the Ryerson way making sure that you get the right steel. Ryerson alloys all receive the same systematic care. Call Ryerson for alloy steels, for any other type steel, and assured uniform quality and prompt action. RYERSON STEEL Joseph Ryerson Son, Steel-Service Plants: Chicago, Milwaukee, Detroit, St. Cincinnati, Cleveland, Pittsburgh, Buffalo, New York, Boston. + 4 ond Editorial Associate WINTERS ALBIN JOHN SCHIEN VAN CAMP MUNZER MILLER News and Technical Pittsburgh Park POST Chicago 1134 Otis MOFFETT EUGENE HARDY ANSBORO Washington Press LLOYO Cleveland Guardian Detroit Ave, HALE Sen McINTOSH BEAN SHARP Milwaukee SANDERSON RAYMOND los Angeles Birmingham ROY EDMONDS Senttic Competition and Employment among employers the best guarantee employ- ment. you will give this some thought, think that the truth the statement will become evident. There not much competition the diamond industry, for ex- ample, the beauty parlor business. Diamonds, you know, are cartel-controlled with tight price maintenance that keeps profits and employment down. But with respect competition tion, the sky the limit. according government figures, the wholesale value diamonds sold the United States was almost par with the business done the beauty and barber supply houses. However, the case diamonds, required the expenditure $64,290 create one job employment, whereas the business scraping the cactus and painting the little over $8700 did the same trick. Getting into the manufacturing end, there less competition manufacturing bluing than making automobiles. Only wage earners were employed the bluing business 1939, and took sales volume $20,763 keep each one busy. Whereas the highly competitive machine tool industry the same year, some 36,500 em- ployees were kept busy good wages sales volume $6000 per. Looking back over our industrial and commercial past record, think you will true that not only where employers are highly competi- tive there most employment, but also that such cases the employ- ment created minimum consumer cost. general, also follows that under these circumstances and because employer com- petition, wages are best. would seem that labor would recognize these facts and therefore strong for employer competition. And strongly against monopoly employment. Monopoly trade means monopoly employment. means the loss the competitive urge because there pacemaker dark horse, and nobody will bet one horse steeplechase. Most disastrous all government monopoly employment under state socialism. Nationalization industries means but one employer each, and the employer one who has ownership interest. His tenure office and that his political henchmen may temporarily secured the finagling national debt the point where and his heirs obtain their financial security the expense hungry millions. But the accounting must finally made. perhaps understandable why the people the United Kingdom after their years suffering have, spirit defeatism, turned state socialism out. And indeed “out” rather than “in.” Certainly, doing away with the spirit competition home will not help them the vital matter competing abroad. And labor will the chief sufferer. Perhaps should welcome demonstration the futility nationalization industry, but most will regret that our good British friends have the guinea pigs. a i ‘ | | | August ion The thi dis makers review all orders Und Det Ste ain. Tir hibitec but the eeling ished. dex Cor Sp! the ucive that enter the Inland mill. Steelmakers Confer With Metallurgists... every order...at Inland When Inland metallurgist away from his office—and that may large part each day—he can located in. the mill. may superintendent’s office talking proc- esses, may open hearth furnace following through heat, may mill laboratory getting record physical tests. Plate Piling Plates Rails Reinforcing Bars This close cooperation between steelmakers and metallurgists important factor producing qual- ity steel, improving processing methods, and meeting the exact requirements each Inland cus- tomer. Inland Steel Company, Dearborn St., Chicago Sheets Strip Structurals Tin Plate Track uctio yithou sea pro tandb erime racti Sales Offices: Cincinnati Detroit Indianapolis Kansas City Milwaukee New York St. Paul mall 4 Front August 1945 4 Official recognition order duplicating the mill level for nonrated steel important cause inflation may the forerunner some prohibitive ion the WPB. There are some doubts Washington that effective order could drawn this purpose, but may become essential. formal bids have been received for purchase the Geneva steel plant. The disposal policy report required law has not been submitted Congress, sale can made. Under certain conditions the plant could leased without Congressional proval the plan, but the leasee would have pay the reconversion costs. Detroit enthusiasm auto production being dampened construction and problems. The latter the most serious. Steel, tin, textiles, and protective coatings are the most difficult ain. Scattered steel tonnage coming through, but not production Tin can had for coating pistons and bearings production, but its use ibited for body solder. Experiments are now under way make substitution, they have not been brought successful conclusion. accurate signposts are seen the pricing 1946 cars, some sources eeling that industry-wide platform will established the near future, others feel that individual pricing basis for each firm will ished. Experiments wide variety steel compositions reveal that nnealing increases ductility and improves formability comparatively low cost. added advantage annealing the reduction scale formation decarburization tendencies compared with that the higher temperatures. Considerable experimentation with steels different analyses indicates that alloy content the metal plays important role the rate coalescence. easier spheroidize steel than produce the same spheroidization steel containing alloys. Spheroidization can secured first normalizing temperature slightly bove the upper critical and then reheating temperature the neighborhood the lower critical. The carbon temperature slightly above the upper ritical tends form into finely dispersed particles. higher temperatures, ooling through the critical tends produce coarser carbide structure not ucive rapid spheroidization. fundamental advantage the use high frequency induction heating for and soldering its flexible heat control. Also, the area heated uction can confined very narrow band and operations can performed the danger destroying plate, finishes electric components enclosed sealed containers. The planning production new size shell, 250 mm, which will probably National Tube Co. National Tube figured heavily the 240 project before its cancellation and has considerable production equipment tandby condition. order for nearly 50,000 has been about placed. Evidence the fact that the new rifle beyond the erimental stage and advancing the production stage was week when only producer, Pittsburgh firm, had its contract boosted from 100 1000 per month. This may call for plant expansion and possibly further racting parts. Tentative Higgins plans for invading the West Coast include construction mall boat plant Los Angeles, and dreams drydock costing millions and eattle plant enter the field. iJ | | Sub-Critical Annealing Sub-critical annealing may not panacea for all annealing problems, but the procedure has been used wide variety steel compositions with resultant increased ductility, improved formability, and lower cost. HOWE Chief Metallurgist, Chicago Vitreous Enamel Product Co., Cicero, ° function draw-tempering hardened steel structure and thereby produce softening the metal. some respects, draw tem- pering may considered form sub-critical annealing applied hardened structure. The mechanics this softening with subsequent in- creased ductility that accomplished the coalescence carbides. The struc- ture formed has been termed sor- bite, material possessing unusual strength with high ductility. ex- tension the length time tem- peratures approaching the lower criti- cal produces further coalescence with corresponding increase duc- tility. Since sub-critical annealing can enhance the physical properties fully hardened steel, similar benefits should realized utilizing this 52—THE IRON AGE, August 1945 type heat treatment steel the normalized the annealed states. Preliminary experiments based this assumption furnished sufficient evidence warrant further investi- gation. Sub-critical annealing when utilized wide variety steel compositions resulted the securing increased ductility with improved formability indicated the initial studies. The remarkable increase ductility secured obtained with relatively short heat-treating cycles comparatively low cost. The sim- plicity the operation, ease con- trol and reproducibility results makes this useful tool fabricators metal shapes working with steel. felt that insufficient attention has been given the utilization low-temperature heat-treating proc- esses obtaining marked increases the elastic properties steel. The Macro- graph steel showing results 90° bend. (Left) Before heat treat- ment; Bhn 250 (Right) After an- 1250° Bhn 195. reason for this probably lies the fact that the process has been known for years and has been disregarded due its simplicity. added advantage sub-critical annealing the reduction scale formation and decarburization tenden- cies compared with that the higher temperatures. Prolonged heat- ing does not produce heavy tightly adhering scale nor lead harmful carbon gradients. For this reason, furnace atmosphere control does not present any serious difficulties. interesting note that temperature 1250° used sub-critical anneal- ing can bring about structural re- arrangement which produces change physical properties. This structural rearrangement readily detected use the microscope. Considerable data have been pub- lished concerning heat treating, in- volving the cooling metal from above its critical temperature. There doubt that such treatments could augmented or, some cases, replaced with the use sub- critical anneal. those instances where strength secondary impor- tance some other specific property, such formability, sub-critical an- nealing can used good advan- tage. Steel, when subjected this type heat treatment can usually withstand more severe cold forming without rupturing. few typical examples will serve illustrate the this method. Considerable loss through breakage developed some gage perfo- rated mild steel sheet when given deg longitudinal bend with in. radius. annealing the same sheet for 1250 deg the breakage was completely eliminated. The sub- sequent improvement this prop- erty the steel was great that was even possible bend the metal back itself (180 deg bend) with- out indication failure. Another example which sub-criti- cal annealing improved ductility was the case some 3/16 in. hot-rolled NE8630 steel. These plates were hot- rolled material extremely fine grain with as-received hardness 250 Bhn. The photomacrograph, fig. clear deg heat- deg 195 bend ings brea dian sub- tion chan free ° | forn ness the tere X13 deg the ture pro cal den tite tha ma! hist che ing gov late lim for for res ° ° ° th e cor nat fig fig rit tre cas clearly illustrates the effect deg bend the unheat-treated and heat-treated samples. 3-hr 1250 deg anneal lowered the hardness 195 Bhn and permitted the deg bend without hazard rupture. One manufacturer steel stamp- ings was experiencing difficulty from breakage SAE-1045 steel. an- nealing for 1250 deg this breaking during stamping was en- tirely eliminated. The microstructure this hot-rolled %-in. steel shown sub-critical annealing short dura- tion hr) produces such marked change the structure evidenced fig. The resulting material was free from breakage during the cold- forming operation. this photo- micrograph, may seen that spheroidization has taken place. This accounts for the reduced Brinell hard- ness 145 Bhn and the ability the steel withstand the deforma- tion. similar experience was encoun- tered with plate composed SAE- X1340. heating for 1250 deg the Brinell hardness was re- duced from 290 190 Bhn. Com- parison fig. with fig. reveals the marked change microstructure resulting from the heat-treating pro- cedure. indicated this struc- ture, improvement working properties resulted. the foregoing examples struc- tural changes resulting from sub-criti- cal annealing, the metallographic evi- dence would indicate that the cemen- tite undergoes coalescence similar that encountered draw-tempering martensitic structures. Obviously, such factors nucleation, thermal history, mechanical working and the chemistry the metal have bear- ing the ability carbon react this manner. Prior structure governed these factors can regu- lated certain extent pre- liminary heat treating, such nor- malizing. some instances, there- fore, necessary normalize be- fore annealing and thus assure proper results the subsequent operation. the material prior annealing con- tains ferrite network that might harmful, the sub-critical anneal alone would not sufficient eliminate the condition. This borne out the photomicrograph, fig. Close exami- nation the microstructure this figure and comparison with that fig. discloses the presence fer- rite network which persists after heat treating. This condition not great importance this particular case, but might become critical Micro- structure SAE- 1045 steel prior heat treatment; Bhn 290. Nital etch and 3 f 4 7 = y % 4 some instances. would seem logical assume that the material prior annealing coarse lamellar pearlite form, greater time quired for coalescence due the dis- tance the carbide must migrate. The preferred prior structure secure the most rapid spheroidizing would there- fore, one “emulsified” pearlite so-called troostite. Considerable experimentation with steels different analyses indicates that the alloy content the metal plays important role the rate coalescence. has been observed that easier spheroidize straight-carbon steel than produce the same degree spheroidi- zation steel containing alloys. has also been observed that the micro- structures formed sub-critical an- neal alloy steel are not truly spheroidal, but more closely resemble dispersed fine lamellar pearlite. Even the small amount alloying agents encountered SAE-X1340 steel seem- zation. This brought out com- paring fig. with fig. fig. the particles carbide are clearly de- fined small globules, whereas the spheroidal nature the carbides fig. are poorly resolved 500 diam, which may attributed the effect alloys previously mentioned fac- tors controlling spheroidization. The lack well-defined spheroids alloy steels does not, however, minimize the advantages gained this type annealing. After considerable experience with sub-critical annealing hypoeutec- toid steels, method securing spheroidized structures became evi- dent. has indicated that spheroidization can accomplished reheating point slightly be- low the lower critical the steel, but mention made the time ele- ment involved. further points out that the prior form the carbide important the securing reduced THE IRON AGE, August | F spheroidizing time. These observa- tions are agreement with the re- sults obtained. thus evident that spheroidization can secured first normalizing temperature just slightly above the upper critical and then reheating temperature the neighborhood the lower criti- cal. selecting normalizing tem- perature slightly above the upper critical, the carbon tends form into finely dispersed particles, whereas the normalizing carried ele- vated temperatures, cooling through the critical tends produce coarser carbide structure not conducive rapid spheroidization. applying the principle sub- critical annealing one alloy steel, the problem ductility became secondary importance, since machin- ability was the property desired. cast steel part with analysis ap- proximating SAE-4335 required ma- chining before being hardened and Micro- structure SAE- X1340 steel prior heat treatment; Bhn 290. Nital etch and 500X. drawn. The rough casting as-received had hardness over 300 Bhn and poor machining structure. The pre- scribed annealing treatment called for 1750 deg normalize followed pack anneal 1450 deg with slow cool 1300 deg and 12-hr hold, also followed slow cool room temperature. Variations foundry practice and analysis often lead erratic results with subsequent com- plaint from the machining depart- ment. was not uncommon find adjacent pieces, which were nested the annealing box, exhibit much 150 Brinell points variation hard- ness. Uniformity hardness from part part with better machining structure reduction time and labor was consistently obtained through the use 20-hr sub-criti- cal anneal replacing the long pack an- neal procedure mentioned above. The hardness obtained this method was 228 Bhn less and the microstructure / 54—THE IRON AGE, August 1945 shown fig. typical the re- sulting material. The high tempera- ture 1750 deg normalize was re- tained with the latter procedure, order break the cast structure and afford uniformity. Sub-critical annealing was also used good advantage steel the following composition: Carbon 0.15 pet, nickel 4.06 pct, chromium 1.13 pet, manganese 0.33 molybdenum 0.21 pet. The requirements gears this analysis called for hardness not exceed 235 Bhn. view the low carbon content, this specification did not appear too difficult meet. Initial attempts achieve this softness furnace cooling met with lack success. Extremely slow cool- ing conjunction with spheroidizing arrests were also discarded because unsatisfactory results. Several times, temperature, transformation procedures also failed produce re- liable results. double heat treat- ment consisting 5-hr-1550 deg normalize followed 40-hr-1250 deg draw, produced hardness 150 190 Bhn and thereby solved the problem. spite the long time temperature the sub-critical an- nealing, the total annealing cycle was reduced materially over any others attempted and with more consistent results. date, the use sub-critical anneal temperatures around 1250 deg has been found very use- ful solving many annealing prob- lems. This furthermore has been ac- complished cost saving over that previously used methods. Experi- ments the annealing steels have included studies made with time-tem- perature-transformation processes described Payson*. While his pro- posed method annealing lends it- that sub-critical annealing many instances can used good ad- vantage, providing careful analysis the metallurgical problem made. Payson mentions his treatise that tempering treatments are applicable and sometimes necessary for certain steels. further states “The ad- vantage tempering annealing treatment its simplicity, since in- volves merely heating and holding lowed cooling air.” The plicity the operation the crux the matter and probably accounts for the reason that sub-critical annealing too often over-looked. not the purpose this article imply that sub-critical annealing pana- cea for all annealing problems, for evid obviou metho met heat Par the phere this coolin this porta gage the tende due can the bette rived shou. incre treat trary prob | cast The typ pro spe - sha ass the sig qu evident that the data are lacking regards hyper-eutectoid steels and obviously incomplete for hypo-eutec- toid ones. The advantages gained may offset those other met and equipment available the heat treater’s plant. Particular mention has been made the ease temperature and atmos- phere control which afforded this method. this may added, cooling rate. only one instance has this factor been found im- portance. When large pieces light- gage plate are cooled too rapidly from the draw temperature, there tendency for warping take place due unequal cooling rates. This partially compensated for the method loading, but usually better corrected retarding the rate cooling. few examples the benefits de- should serve guide toward the increased utilization this heat treating process. Although arbi- trary rule can set forth its adaptability for specific annealing problem, summary the advantages Micro- structure cast steel after anneal. 222. Nital etch and 500X. gained may serve govern the choice: (1) Simplicity operation. (2) Elimination atmosphere con- trol. (3) Freedom from effects. (4) Wide latitude operating tem- perature. harmful scale (5) Reduction formation. (6) Lessens the effect cooling rates. (7) Affords savings equipment and time. “Steel and Its Heat Treatment,” Bullens, vol. 4th edition. Annealing Steel,” Peter Payson, Tue Iron Ace, June-July, 1943. Steel Castings Made Thermit Process EVELOPMENT special type thermit, known Thermi- cast, for producing steel castings, has been announced the Metal and Thermit Corp., New York. The new type thermit said solve the problem obtaining sound, clean steel castings quickly and simply, irre- spective size and intricacy shape, when regular steel melting facilities are unavailable. Thermicast especially designed for the produc- tion steel castings and not associated with conventional thermit welding for which not suitable. The new casting material utilizes the well-known thermit which carried specially de- signed sheet steel lined with refractory ma- terial. Most the equipment re- quired produce the castings can improvised, and little experience produce castings the process necessary. bags, each which produces approxi- mately steel. The Thermi- cast steel, cast, has the following average mechanical properties: yield point, 39,250 psi tensile strength, 70,200 psi; elongation in., 30.1 pet and reduction area, 51.2 pet. Pouring Thermicast into ladle. THE IRON AGE, August Induction Brazing And Soldering High-frequency induction heating can fully controlled carry out low-temperature brazing and soldering without damage surfaces components within containers. Induction brazing per- mits salvaging cutting tools with minimum effects hardness. ° HJERMSTAD Vice-President, Federal Electric Co., Chicago control heat, high-frequency induction heating possesses fun- damental advantages brazing and soldering operations. The heat can closely controlled one the fol- lowing ways, combinations: (1) Varying the power input the high frequency oscillator. (2) Controlling the amount energy that goes into the work ar- ranging the shape and proximity the coil. (3) Varying the time. will found soldering opera- tions that all three variables fre- quently will have used mak- ing setups. Since the area heated induction based upon butt joints stainless steel. thickness Thickness joint, in. 56—THE IRON AGE, August 1945 can confined very narrow band, certain types operations that heretofore were impractical due the danger destroying plating, fin- ishes electric components enclosed sealed containers, can now han- dled. Furthermore, brazing opera- tions, the amount scale formation due oxidization very small, warp- ages are reduced and the amount energy required make weld kept minimum. Induction heating acts very rapidly since enables literally the dumping large amounts heat into small area extremely short time. This characteristic can easily brought out comparison. The maximum rate energy transferred from furnace whose walls are maintained the order Btu per in. per min. place piece steel properly designed induction coil and induce energy the rate 100 250 Btu per in. per min. order have even flow metal between two surfaces, essential that uniform gaps main- tained between adjacent pieces metal since the flow brazing metal solder going depend capillary action. will generally found that uniform, clean gap will result uniform joint; but the width the gap all important, since wide gap can completely stop the flow metal. The strength all joints whether they are soft solder, hard solder, copper, will con- trolled great extent the thick- ness the bonding material, which turn, controlled the gap thickness. The curve, fig. shows the relationship the joint tensile strength brazing alloys. may noted that clear- ances 0.001 in. 0.003 in. maxi- mum strength will obtained from such brazed connections. Too small gap will hinder capillary action and will result reduction strength the joint. When using too large gap, the strength the joint going dependent great extent the tensile strength the welding ma- terial. Clearances which are too close give bare spots, for the brazing alloy unable flow, but with the proper clearance maximum conduction the fluid brazing metal due the capil- lary action will had. The effect thickness joint soft solder its tensile strength shown the curve, fig. will noted here that quite high strength can ob- tained from soft solder the thick- ness the solder joint closely con- trolled and sufficient space left for capillary action take place. Generally speaking, the technique used silver brazing also applies soft soldering. Frequently neces- sary soldering operations pro- vide seal which sufficiently tight 2—Relation joint thickness tensile strength soft solders. Thickness joint, in. 3a.) dens ther fluid forn are cate tion est per bly sue ing bly ind hel for tin sil 140000 good capillarity Undependable bond the bottom the joint act seal dam prevent the flow solder through the joint. (See fig. 3a.) This important when making solder seals such items con- denser cans, transformers, etc., where there danger that solder may fluid enough conducted directly inside the enclosure. The necessity maintaining uni- form fits throughout all joints that are brazed soldered cannot stressed too much. Fig. indi- cates the effects straight and rounded edges corners. The designer will find that induc- tion heating can used the great- est advantage where only few welds per item are made. assem- bly made with several joints, such work means furnace braz- ing. Depending the type assem- bly the combination furnace and induetion heating sometimes most helpful. Solders There available the present time large variety solders and silver solders for broad range melting temperatures. The use particular brazing alloy will depend upon the specific application and type joint required. well known, melting points solder can varied greatly suit applications con- trolling the ratio lead tin. silver brazing alloy melting 1175° made copper, silver, zinc, and cadmium. the lowest melt- ing silver brazing alloy available the present time which suitable for both ferrous and nonferrous metals. alloy copper, silver and phosphorus recom- mended for use with nonferrous met- als such copper, brass and bronze. has melting temperature 1300° and self-fluxing copper. shoulders possible LEFT 3—A brazing rings snug contact between the metals important when silver Flush RIGHT surfaces sheet Methods providing shoulders for solder and brazing rings. Band brazing alloy Avoid this hole Other brazing alloys having higher melting points are brass, constituted pet copper and pct zinc melt- ing 1650° and copper and pet zine melting 1750° Cop- per, which melts higher tem- perature, namely, 1982° also utilized. Certain brazing alloys hav- ing higher remelting temperature than the original brazing temperature are also available. This factor defi- nitely advantageous when subsequent operations are performed where the temperature the second opera- tion approaches that the original melting point alloy. all types brazing and solder- ing usually necessary employ some form flux. The type flux used varies greatly with the application and, course, the type brazing alloy solder. Most braz- ing fluxes are some form borax borax plus boric acid. These will leave residue after brazing which can readily removed scrubbing the part hot water, pickling. Frequently desirable quench the brazed parts directly after the brazing operation while still hot, since will found that the flux deposits will come off more readily this time due the action the steam formed. The subject fluxes connection with soldering most important need maintaining uniform fits throughout, and the effect corners and edges effecting bond. corners throughout all joints THE IRON AGE, August Uniform bond | ‘Square bond ae ABOVE 6—Use wire alloy ring embedded within the joint illustrated. RIGHT 7—When using alloy the form foil, desirable have pressure one the bring about closer contact. BELOW SS F's. number work coils used obtain proper type heating for several types work. Note general simplicity coil forms. plications use acid type fluxes. Where this type used neces- sary wash the object neutral- izing solution remove acidity. How- ever, most instances, absolutely non-corrosive flux must used, especially when dealing with elec- trical apparatus. When using resin- core solder, the only satisfactory flux which free from corroding ele- ments, usual have the parts tin plated before soldering. Zinc and cadmium plating will solder well pro- vided that oxide coating not allowed form. removal the resin after completing the soldering operation can handled nicely placing the part vapor degreaser and employing solvent such tri- chloroethylene. Again, the success soldering operations will deter- mined largely’ the cleanliness the parts before the flux applied. Parts joined together should designed permit the most 58—THE IRON AGE, August 1945 pened ve convenient use solder brazing alloys any the following forms: Wire, foil, slugs, electroplate, metal spray and paste. Frequently sol- dering operations desirable make loop continuous and that event the solder ring should the form washer. This best ob- tained using sheet stock and punching out the washer. When making certain hermetic seals, the alloy ring the form washer insures continuous flow solder around the entire seal. Various methods have been devised hold the alloy ring position. are shown recommended pro- cedures. all possible, some kind shoulder should provided for the solder push against since has very high rate thermal ex- pansion and frequently the rings, not supported some manner, will fall off the object that sol- dered (fig. 5c). Sometimes the wire ring should placed slightly above fit permit settling down the joint that when the metal melts will flow down the wall the tube and enter into the joint, being drawn capillary action. some in- stances will found desirable chamfer one part assist the flow metal into the joint. This will allow greater tolerance the size the solder brazing ring and will contribute the ease the assembly the various metal parts. required place the ring above the work, make the ring slightly under- size order that will cling the part and stay position. Fig. illustrates the use wire rings embedded within the joint. The use foil brazed joint shown apply pressure one part bring about closer contact and allow the excess brazing foil flow out the The method applying heat the part brazed will depend great deal the type materials and whether thick thin sections are being joined. good rule have sections nearly equal thicknesses. However, the best method follow when brazing different types ma- terial and different thicknesses, concentrate the magnetic flux the section most difficult heat, that is, allow the part having the great- est mass the lowest electrical re- sistance, receive the largest amount concentrate the heat one part, and the second part then heated en- tirely conduction. Coil Design designing coils well allow for ample space between the heating coil and work. Usually fairly large gap between the coil and work can used when soldering and brazing, which will permit the work placed into the coil with the least amount trouble. Care should taken making certain that the part brazed centrally located with- the coil obtain even rise temperature the part. rotating device helpful obtaining uni- formity heating, and especially important the case mass pro- duction item, since the induction heater can then left continu- ously. The coil should not close proximity with any sharp corners which are liable burn due ex- cessive heating. This difficulty can eliminated having the coil fol- ABOVE low the contour the work. Use few turns the coil possible since large number the fluxes are good electrical conductors and high tem- peratures are liable cause turn-to- turn short circuits the induction work coil. The simplest type coil the best; complicated coil shapes make the job difficult and detract from the advantages inherent in- duction heating. (See fig. 8.) many applications where the heating energy must concentrated very small area, necessary use single turn work coils (fig. 9). the power concentration must 9—For concentrating great deal energy small area, the single turn coil works RIGHT 10—An automatically controlled lift table which brings the work into the coil for predetermined length time. LOWER RIGHT the design coil for brazing the tip high-speed tool steel onto the shank. BELOW broach was salvaged brazing the retriever shaft the end the broach, which had been broken off. The hardness only one set teeth was lost this operation. very great, will necessary use transfer the energy from the induc- tion heater into the single-turn work coil. The use lift table that lifts the work into the coil the induction heater, where the entire heating cycle automatic, shown fig. 10. All the operator has put the base place the locating pins the lift table, and press the start but- ton. The lift table then goes ing the work into the coil and the induction heater automatically turned on. the end the heating the lift table will stay the position for determined length time allow the brazing alloy set. will then lower and the operator takes off the finished piece and puts fresh mounting bracket for braz- ing. interesting application sil- THE IRON AGE, August ver brazing was the salvaging large broach without affecting the temper the cutting teeth. Fig. shows the broach, measuring long and in. diam. The retriever shaft the end the broach had been broken off and the tool was use- less. attempting the salvaging operation the broken end the broach was first ground flat and new retriever shaft was turned out cold rolled steel. The broach itself, however, was made high- alloy tool steel and the problem was weld braze this new retriever shaft the end the broach with- out overheating the tool steel the teeth the broach itself. Any con- ventional methods heating the end the broach silver-brazing temperature would have resulted loss hardness all the teeth for about The loss this many teeth would have made the salvage impractical. High-frequency induc- tion heating from machine was used bring the end the broach and the retriever bearing the temperature required for braz- ing, approximately 1250° The broach was heated the hardness was lost only one set teeth, located in. away from the silver soldered joint. This broach, which would have cost $1200 re- place, was salvaged and put back service about two weeks’ time. delay weeks would have been necessary get new one. brazing high-speed tool steel tip onto shank, necessary concentrate the heat the shank the tool order not overheat the tip. Fig. illustrates coil designed this. High production through the use turntable shown the setup, fig. 13. Rings silver sol- der that have been pre-fluxed are placed around the circular header 13—Turntable arrangement with this induction heater made possible the brazing 1000 brackets per hr. skirt top the washer that forms part the mounting bracket. these mounting brackets are placed the turntable the operator, they are carried into the induction heater Each piece rotated indi- vidually within the coil insure even distribution the heat. The top part the bracket where the braz- proper temperature after the piece about two-thirds the way through the coil, and the silver solder flows through the joint freely passes out the coil. After leaving the coil the part cools enough set the sil- ver solder before the piece reaches the wipe-off arm, which automatically removes the bracket from the turn- table dropping into chute that guides into container. possible operate this turntable have output about 800 1000 pieces per hr. Based per rate, the cost the power and tube replacement would about 15c for each 1000 units brazed. Resinous-Base Plaster Mold Sealant BASE ting plastic, known “Plaster Sealer,” now being used Consoli- dated Vultee Aircraft Corp. for the pur- pose sealing the plaster molds used casting plastics materials. Plaster Sealer can applied either spraying brushing wet ordinary room temperatures. considered superior the lacquers IRON AGE, August 1945 heretofore used sealing plaster molds, because does not necessitate heavy coating casting surfaces where close dimensions and minute details (such layout and trim lines) must preserved. high-gloss casting plaster mold, the basic coating Plaster Sealer sanded and recoated. many four coatings the material may utilized without destroying essential details the mold surfaces, although two coatings are usually sufficient. The new plastic heat-resistant temperatures more than 2500 deg While normally translucent, can dyed any color without los- ing its effectiveness. Plastic Sealer being produced Duorite Plastic Industries, 8564 Washington Blvd., Culver .City, ? : Yr q Gas Cutting Stainless Aided Fluxing System TAINLESS steel may now cut the oxyacetylene torch almost readily mild steel the result the development flux-injection process the joint efforts the Air Reduction Co. and the Rustless Iron Steel Corp. Because the very ele- ments which give their desirable properties produce, ox- ides which are extremely tenacious, when attempts are made cut such steels with oxygen, the slag produced viscous and tends create re- fractory layer which prevents the heat and gases from reaching fresh layers metal. The solution this vexing problem has been provide fluxing material the gas stream which reacts with the oxides chro- mium and nickel particular form fluid slags which are more read- ily washed out the kerf. recent demonstration the Air Reduction Laboratories, 1-in. plate 18-8 plus pct stainless was machine cut successfully the rate in. in. per min, using new Airco flux-injection process. 2%-in. slab 25-12 stainless was similarly cut the rate in. per min, leaving smooth- faced kerf. The crop end 5-in. slab was removed with somewhat greater difficulty, particularly the start. Tests made without the flux failed produce cut. Except for the addition the flux- ing apparatus and slight modifica- tion the oxygen control, standard equipment used throughout. cut- _ting the stainless steel plate mentioned above, for example, standard three-hose torch and No. tip was employed, attached standard Radiagraph traversing unit for straight cuts. The only auxiliary apparatus was dispenser and remote controlled solenoid actuated valve for quick cut-off the oxygen before passes through the fluxing unit. Hand control the acetylene Either hand machine cutting can employed. The flux employed the process mixture inexpensive chemicals used dry powder form. fed into the oxygen hose line screw feed injector from the bottom cylindrical container, the contents which are kept agitated motor driven impeller prevent cavitation the powder. Variable speed pro- LEFT stream seen the torch lighting the acetylene preheat- ing flames. cutting slab conventional torch and tip used with normal preheat. RIGHT the cut made with the Airco flux-injection sys- tem. Total elapsed time complete the in. thick min. Operating con- ditions are the same required for cuts ordinary steel. vided the feed motor, although expe- rience thus far has shown that flux consumption remains substantially the same approximately per min operation for cutting thick- nesses from in. in. The flux has capacity lb, provid- ing enough flux for continuous moved about from job job mill. The relatively inert nature the flux should assure trouble-free opera- tion the injection system well lending long time storage character- isties the flux itself. Possibility the oxygen lines and particularly the tip becoming clogged with powder largely overcome placing the oxy- gen cut-off valve ahead the flux dispenser instead the handle the torch. Abrasive wear the valve also obviated. Developed originally cut risers off ingots and castings, the Airco flux-injection process foreseen have application for quality cuts in. thick and rough cuts con- siderably heavier pieces austenitic stainless steel the 18-8, 18-8-3, 18-12-3 and 25-12 varieties. = | ~ properties the manga- nese-chromium have been rather extensively studied recent years, especially abroad, where nickel has been scarce. But practically nothing seems have been published, least this coun- try, the effects titanium steels this nature. Interesting discussions the general subject were published 1943 Parks and Mack*, but about the only reference titanium Parks’ concluding statement that “the influence small amounts ti- tanium, etc., not too well known.” *Metals and Alloys, February 1943, vol. 17, 330; November 1943, vol. 18, 507. Titanium Chrome-Manganese This statement led decision make the tests here reported. Since the articles referred in- clude excellent reviews the liter- ature based copious bibliographies steels, further discussion the general subject seems necessary now. view the past knowledge was decided confine this investiga- tion steels containing about pct manganese and pct chromium, which should entirely austenitic. The bars tested were forged from ingots melted basic-lined in- duction furnace, using melting stock electrolytic iron and manga- nese, well some steel scrap and low-carbon ferroalloys. The non- TABLE Chemical Compositions Test Specimens anor 4 ww Property Steel No. None pet pet pet None pet pet pet pet pet 100 pct 100 pct pet pct 100 pct 100 pet TABLE Hardness and Microstructures Quenched Specimens Not Tempered Reported 0.74 pet Steel No. No. 1.01 pet Steel No. 1.61 pet 3.15 pet titanium steels were deoxidized with aluminum, and the alloys used sources titanium contained appre- ciable quantities aluminum also. The chemical analyses the steels tested are given table These steels, except No. were round bars, and finished quite hot. No. however, could not forged, least that temperature, and broke under the hammer that the fragments could used only for hardness tests. Small specimens cut from the %-in. round bars were quenched water from various temperatures including and between 1800° and 2300° de- termine the quenching temperature giving the lowest hardness, and also the microstructures. The four steels with less than 0.2 pct titanium showed only irregular changes hardness between about and Rb, and ferrite their micro- structures. The results obtained from the four higher-titanium steels are given table II. the titanium, the quenching tem- perature with over 0.7 pct titanium, increases, the ferrite the micro- structure increases. The hardness generally decreases the quenching temperature rose from 1800° 2000° 2100° but all the steels ex- cept No. the maximum hardness was reached after quenching from the highest temperature, 2300° when the greatest amount ferrite was formed. From these results was decided that quenching temperature 2100° gave the lowest hardness, and specimens for tensile and impact tests were quenched from that tem- perature. Later some additional specimens for tensile tests were quenched from 2200° and 2300° re- spectively. The same small specimens that were quenched from 1900°, 2100°, 2300° were tempered for con- secutively 200° intervals from 400° 1600° with Rockwell hard- ness tests each stage. Again the sho sta pel tit me St e 0.117 16.60 0.115 17.60 11.79 0.100 16.84 0.12 1.2 0.092 17.52 11.76 0.14 1.5 0.132 17.28 11.68 0.74 0.102 17.72 11.99 1.01 10.0 0.100 17.39 12.26 1.61 16.0 0.090 17.36 12.29 3.15 35.0 = IRON AGE, August 1945 Stainless Steel steels with less than 0.2 pct titanium hardness, giving values most in- stances between about and Rb. The hardness variations tem- pering the steels with over 0.7 pct tanium are plotted fig. Temper hardening seen important only the steels with 1.6 pct more titanium and greatest speci- mens tempered least 1200° Two the curves for steel No. are shown duplicate, indicating how closely the results from specimens quenched and tempered separately checked each other. Every point plot- ted fig. represents the average from two more hardness tests. Since the tempering represented fig. was cumulative, without using separate specimens for each temper- ature, and the period tempering each temperature was only hr, seemed advisable check the results the higher tempering temperatures using separate specimens for each temperature and determining the changes hardness with varying pe- riods time about hr. This was done with small slices cut from the ends the tensile and impact bars that were quenched water after 2100° Tempering temper- atures 1400°, 1500°, 1600° and 1700° were tried with steels Nos. and one the low-titanium steels No. the high titanium steel No. not being available bar form. The results are plotted fig. Steels Nos. and with 0.74 pct 1.01 titanium are seen fig. temper harden only very little more than steel No. with only 0.12 pet titanium, but the increase hard- ness occurs chiefly within No. and No. while No. shows hardening until after tempering. steel No. with 1.61 titanium temper hardening occurred within the first hour, with slight subsequent increase and decrease hardness within temperature. The maximum hardness obtained, how- ever, was about five points lower ° COMSTOCK Chief Metallurgist, Titanium Alloy Co., Niagara Falls Interest continues grow the manganese-chromium stain- less steels which contain nickel. This research points out the valuable titanium the austenitic pct manganese pet chromium stainless steels, role which heretofore had been only part surmised. than the cumulative tempering method reported fig. was decided from these results that about Tensile test specimens were quenched water after 2100° and one specimen each steel was tempering would best, that condition, another being that 1400° was the best temper- tested after tempering 1500° ature for steel No. and 1500° for (Except 1400° for heat No. the others. 7.) The specimens were made with quenched specimens after tempering consecutively in- creasing temperctures Rockwell hardness Quenched from 2300°F <£ 100 hardness 400 600 800 1000 1600400 600 800 1000 Tempering temperature, THE IRON AGE, August ° | | } ° 100 Rockwell hardness Rockwell hardness Rockwell hardness Tempered /400°F Ss x Tempering time, hr. 2—Hardness specimens quenched from 2100° and tempered for different periods time. TABLE Ill Tensile Test Results Vield Strength, psi Titanium Tensile Per Cent Per Cent Content, Strain Strength, Elongation Reduction Specimens quenched from Specimens quenched from 2100