The Iron Age 1934-02-22: Vol 133 Iss 8

tairs the English for depart- Seems that repair shop The they say, kept pretty associations than ours: acturers oney inter- sto ast and memo with 300, last are re- har!” finance can manu- rapidly stencil rking and pread the ges this bottom secret life cold floors Steel der Settle was just one 1933 Feb. Wickwire posey ntation page A.H.D. YEAR SERVICE THE METAL WORKING INDUSTRY ODUCTION BETTER QUALITY MODERN FINISHES FOR YOUR PRODUCT LOW COST increasing the number products made Thomastrip. The advantages fast, continuous produc- tion—the advantages gauge and size accuracy —the advantages dense, uniform and attractive coatings which will not crack peel from the steel under deep drawing and forming operations —all meet the requirements today for material that will add product quality and salability low cost. Investigate Thomastrip. Thomas representative will gladly cooperate without obligation. PRODUCERS COL NTY- CONTENTS INDEX THE IRON 22, 1934 Page ELECSRIC you are looking for way improve the quality your product reduce its cost without depreciating its service- ability, give little thought the idea using Republic Electric Weld Pipe for those parts requiring tubular sections. Many manufacturers have found profit- able use Republic Electric Weld Pipe instead castings, forgings and machined parts—have shown real production savings the elimination patterns and dies and the reduction machining costs. Briefly, these are the qualities that make this new pipe adaptable mechanical ap- plications: weld strong the wall any other point—uniform inside and out- side diameters—uniform wall thickness— perfect concentricity—uniform grain struc- THE IRON AGE, published every Thursday by the IRON > Executive Offices: 239 W. 39th St., New York, N. ; A 1879. $6.00 a year in U. S., Canada $8.50, Foreign $12.00. WELD PIPE AGE PUBLISHING CO. Publication Office: N. W. Cor. Chestnut & ture the metal—freedom from scale, giv- ing smooth surface both inside and out. Look over the various parts the de- vices you manufacture with view fitting these qualities into your parts require- ments. Outline your specific applications and Jet make recommendations. | 7 56th Sts., Philadelphia, Entered as second class matter at the Post Office at Philadelphia under Act Vol. 133, No. 8. 7 | - Editor Managing Consulting Editor News Editor Machinery Bditor | Cleveland Chicago Editor Emeritus Washington Cincinnati Contents Let’s Examine the Price Record Effect Facing Quenching Efficiency Making New Type Steel Analysis Hard Metal Carbide Theory Speeds With the Automatic Sheet Jobbing Shop for Heat Treating Personals and Obituaries Automotive Industry Construction and Equipment Buying Products Advertised | & THE IRON AGE PUBLISHING COMPANY F. J. FRANK, President G. H. GRIFFITHS, Secretary Cc. S. BAUR, General Advertising Manager PUBLICATION OFFICE: Corner Chestnut and Sts., Philadelphia, Pa. EXECUTIVE OFFICES: 239 West 39th New York, Y., ADVERTISING Member, Audit Bureau Circulations Emerson Findley, 311 Union Bldg., Cleveland Member, Associated Business Papers Herman, 675 Delaware Ave., Buffalo, H. K. Hottenstein, 802 Otis Bldg., Chicago Published every Thursday. Subscription Price: Peirce Lewis, 7310 Woodward Ave., Detroit United States and Possessions, Mexico, Cuba, Charles Lundberg, Chilton Chestnut $6.00; Canada, $8.50, including duty; Foreign 56th Sts., Philadelphia, Pa. $12.00 year. Single Copy Cents Ober, 239 West 39th St., New York W. B. Robinson, 428 Park Bldg., Pittsburgh Cable Address, ‘‘Ironage, Sweetser, 239 West 39th St., New York Warren, Box 81, Hartford, Conn. YEAR SERVICE THE METAL WORKING INDUSTRY lel phia, ler Act 4 4 Ag { | Wak : wer ¢ | : THE IRON 22, 1934 Page That New Tool Steel Remarkable Product without doubt the most outstanding tool steel product developed recent years. This not only our own opinion but also that many tool and die shops and manufacturing plants throughout the country. has shown some remark- able results. The new revolutionary manufacturing process produces hard, tough, yet easily machinable tool steel. Used where high quality, uniform, water hardening carbon steels are needed. Let send you sample for testing. New Shock Steel for Heavy Duty Tools heavy duty alloy tool steel giving unusual sat- isfaction users. lends itself not only cold work, but also hot working applications. “Shock Steel” conforms the rigid Ryerson standards quality and uniformity. When annealed will machine without difficulty. Used for severe hot and cold punch- ing, hot and cold shearing and hot bending operations; for pneumatic chisels, concrete busters, track tools and where extreme shock and heavy service are encountered. Eraydo—the Zinc Alloy with Strength RAYDO zine base alloy us- ing silver and copper care- fully determined proportions give the greatest strength without metal with greater stiffness and rigidity than commercial zinc. non-rusting, non-magnetic—can bent, formed, stamped, drawn and spun; solders easily, spot welds; can etched, enameled—lacquered plated. low price, non- rusting white metal. New Steel Book Just Out than 200 pages information steel that ready for immediate shipment. you haven’t already received copy this new Ryerson Stock List, post card will bring return mail. Joseph Ryerson Son, Louis, Cincinnati, Detroit, Cleve- land, Buffalo, Boston, Philadelphia, Jersey City. oOo ETTER products improved pro- duction costs— and through all, the newer steels and allied lines are playing im- portant part. Can some the new developments save for you? Put the glad check for you. Sheets Withstand That Abrasive Wear ERE are sheets and plates man- ufactured from entirely new type steel for the express pur- pose abrasion resistance. Tests indicate that this steel will outlast ordinary steel many times and certain cases has proved better than expensive high manganese castings. Used for such applications scraper blades, concrete mixers, conveyors, hammer mills, drag line equipment, etc. Tell your abra- sion problem. will glad give detailed data the wse this new alloy. Now —Better Machinability Stainless Castings 18-8 castings have always been difficult machine, polish and grind. Now new process and the addition spe- cial elements, possible pro- duce castings that work much more freely. Considerable saving ef- fected machine work time, grinding and polishing. Valves and wearing surfaces east are comparatively free from any ten- dency seize gall. Let Ryer- son specialist tell you more about this new development. tr | | | - —, STOCK “19346, i| Hii} FEBRUARY 22, 1934 1855 Vol. 133, No. HERE quite general belief that the farmer, comparison with the maker industrial products, has taken severe price beating. There also opinion held some quarters that steel and metal product prices are relatively high. tries climb. This fact not always kept mind thinking relative price situations and obscured the statistician’s How far one can fall usually depends upon how high one level. The last normal long-term period that have known ended 1915, before the artificial stimulus the World War sent prices kiting. Agricultural prices have indeed fallen far from their war-time high levels. But Feb. 1934, farm prices, reported the official Government statistics, were but 4.3 per cent lower than the average farm prices from 1900 1915 inclusive. Metals and metal products, Feb. 1934, were 5.2 per cent under their average for the same 16-year pre-war period. These facts may surprise many members Congress, the Federal Trade Commission and others who are now attacking our present steel price structure. Finished steel price averages, the way, coincide from year year very closely with the group “Metals and Metal Products,” referred above. The metal-working industry wants see the farmer get more for his farm crops, for then will buy more steel, machin- ery and metal products. But the metal-working industry does not relish the injustice being misinterpreted uninformed public and private spokesmen. not preferential price position. contrary, has had more severe spanking than has the farmer. < s— ] new the WH | | | 4 | Will Wil i | | | Hill | Forging temperatures are held within close limits. Overheating causes the metal crumble and low forging temperatures often result cracked forgings. practice forging stainless steel the plant Charles Larson Sons, Inc., Chicago, has resolved itself into program education. Every man the shop has had learn that the principal factor forging stainless steel lies holding close few simple rules. There is, necessity, close inspection before forgings leave the shop, but addition, each workman effect inspector his work process. Such individual care important because the plant jobbing shop which takes all classes work not adaptable quantity production. In- dividual forgings range weight from few ounces each 600 lbs. each. Many orders are for experi- mental purposes; other words, the forgings are subjected trials and, shown satisfactory, later into quantity production and therefore out the realm the Larson shop. The price stainless steel makes 14—The Iron Age, February 22, 1934 imperative that stock cut length there minimum wastage. Weights must accurately calculated, espe- cially the forge shop furnished with billets the buyer forgings, who naturally expects receive stated number forgings return. the shop orders the stainless steel has the alternative cutting the billets length, usually cold saw, buying them cut length extra cost. The advantage cutting length the shop that trial piece may cut and forged, thereby checking calculations and reducing the possibility errors either cal- culations ordering. Practice this shop leads the conclusion that saw good investment which will soon pay out. Shop experience has taught that bil- lets should rough-turned and freed from defects before delivery the forge plant. further inspection should made upon receipt the orging ustless Steel ROGERS FISKE Western Editor, The Age steel avoid placing defective billets the furnace only have the forged product thrown out the expendi- ture much shop labor and other essential forging stainless steel make certain that billets are heated slowly and uniformly pos- sible. attain these results fur- naces are classified low heat, furnaces. The preheating furnaces are located the receiving end the shop. All pieces forged are there brought slowly temperatures that range between 1400 and 1500 deg. the piece billet extra large put cold preheating furnace. This then lighted and the temperature the billet brought with the fur- nace. Oil and gas are the fuels com- monly used throughout this shop. high-heat furnace located near & > ¥ = s | | 5 rged nless are pos- fur- ‘ated All ught ange the put fur- com- near each hammer. Pieces steel billets that have been brought the de- sired temperature the preheating furnace are quickly transported high-heat furnace, where the tem- perature raised within the limits 1800 2000 deg. Here again care- ful watch kept the rate heat- ing and the maximum temperature attained. Heating too rapid rate may result cracked forging. part raised too high tempera- ture results crumbling, while steel forged below 1700 deg. likely develop cracks. Most sizes forgings can worked desired size and shape one heat. However, the ham- mer men are charged with the re- sponsibility turning out first class product and they know preferable reheat rather than work below given temperature. Some forgings can made pass- ing billets through the preheating and high-heat furnaces. They are then hot-cut size the hammers, after which the pieces are returned the high-heat furnaces assure prop- temperature before forging. example heating time needed, 4-in. 4-in. billet requires hr. pass through the preheating stage. general rule stainless steel hammer-worked less vigorously than most ordinary grades steel. More and lighter strokes are the rule. Even though forging temperature correct, stainless forging can ruined working too hard. Forging dies shop this kind are not com- plicated. Die materials and designs conform the standard practice with other steels. Billets follow the same general rules. The buyer should remember specifying stainless steel forgings that one the important reasons for using Light and frequent strokes the hammer first quality forgings. stainless steel obtain the finish that can given it. Therefore, when figuring the forging dimensions, little more metal must left than the case carbon steels make sure that the machine shop will get below all pitting and all scale that may have been hammered into the surface: this point watched, stainless steel forgings can chined that resulting surfaces will meet all expectations. This shop finds that steel, properly worked, has more forging limita- (At Right) Sufficient metal must provided the machine shop can hold dimensions after cutting below scale and pitting. The forging (below) the right was worked either too hard too low temperature. Note defect where part was countersunk for turning. tions than ordinary After being forged, some parts are annealed, others heat-treated, accord- ing required specifications. This process follows the usual practice placing the parts containers, which are then filled with charcoal and sealed. Temperatures range between 1450 and 1500 deg. The part may left cool down with the furnace, may drawn the furnace and then air-cooled, depending specifications the buyer. oil quench preferred for heat treating. The Iron Age, February 22, 1934—15 i. Na See | ‘ ‘ 4 ‘ with facing. without facing. sec, Fig. 1—Steel samples, with and without facing, during quenching trans- former oil deg. The lower view shows how the vapor envelope inhibits the cooling. the purpose comparing the cooling velocities specimen during quenching, apparatus was designed and constructed permit automatic recording temperature- time curves. The apparatus similar the author’s self-recording dilato- meter constructed about four years ago. The specimens were heated elec- trically, the coolants were stirred au- tomatically, and all temperature vari- ations were mechanically reproduced. For the quenching specimen very important have constant sur- face condition which will not vary dur- ing repeated heatings and quenchings various cooling liquids. alloy— per cent Fe, Ni, and Cr— was finally selected since aus- tenitic and very stable very high very low temperatures. After the surface the specimen was finished the lathe, was roughened 90- mesh carborundum powder mixed with water. This state the surface very important obtain firm ad- hesion for the facing material and, therefore, taken the standard surface condition, whether faced unfaced, for quenching. facing material, various sub- stances such “tonoko”—the very fine powder razor whetstone pro- duced Japan—alumina, silica, lime, magnesia, carborundum, alundum, fire clay, pumice stone, ash, mold- ing sand, iron sand, glass, mica, coke, graphite, charcoal, sugar, sodium car- bonate, water glass, borax, etc., either them were tried. They were powdered (100 120 meshes), mixed with water, smeared the surface the specimen and then dried. About 16—The Iron Age, February 22, 1934 kinds facing materials were tested and the result was always increase the cooling velocity the specimen. was also found that one the most important conditions for facing the firm adhesion the material, the resistance the peeling off caused the sudden contraction during quenching. One the most favorable mixtures which was found very effective, is: Fire clay. gr. Borax (anhydrous) gr. the case steels, the surface should freshly ground machined rusty surface cannot hold the 21/2 sec. sec. sec. Effect SATO Tohoku Imperial University mixture firmly enough prevent from being washed off during quench- ing. Behavior During Quenching unfaced specimen heated high temperature is, when quenched, once covered with vapor envelope formed the cooling medium, and, the vapor bar heat conductor, the cooling the specimen thereby greatly retarded until the envelope be- gins break and direct contact the specimen with the cooling medium takes place. this point abrupt increase the cooling velocity in- dicated break the temperature- time curve. the other hand, faced specimens with facing. sec, without facing. sec. 121/2 Fig. 2—Steel samples, with and without facing, during quenching glycerine deg. The protective action the vapor sheath around the unfaced specimen apparent. 1/4 sec. 1 sec. 21/9 sec, 34/4 sec. 5 sec, 4 ar an : 7 = investigation regarding the practice facing steels prior quenching elicited considerable in- quiry for additional information. The experimental procedure and results presented here are ab- stracted from the original research paper. This method quench- ing has long been the practice Japanese cutlery makers, and con- sists coating facing the sur- face the specimen with mix- ture water and tonoko (very fine powder razor whetstone, form clay slate), and drying the specimen before quenching. Quenching faced material re- sults more rapid cooling, which turn produces more dense and uniform steel structure. are never enveloped vapor film, and, therefore, their cooling very rapid and uniform throughout the specimen. This the real reason that the old technique facing before quenching useful imparting intense and uniform hardening. The process pictorially presented Figs. and The photographs clearly show that the case the faced specimen, there always direct contact be- tween the headed “skin” the speci- men and the cooling medium, and the heat consequently rapidly dissipated seen the vigorous vaporization around the specimen. Thus, the case quenching transformer oil (Fig. 1), the cooling proceeds quickly that the evolution vapor bubbles has concluded after lapse only sec.; that is, the temperature the specimen falls from 800 deg. below 200 deg. during that short time interval. the case the unfaced specimen thin film vapor im- mediately formed around the heated specimen, and, therefore, its “skin” cannot come into direct contact with the cooling medium, and thus the heat loss the specimen greatly re- tarded. The cooling retardation con- siderable magnitude shown the lower row photographs Fig takes about sec. for the envelope begin break the bottom, and sec. the top. The break, there- fore, proceeds from both ends toward the middle. This break the envelope, is, course, accompanied direct contact the cooling medium with the specimen, and, hence, abrupt cooling velocity begins take place, shown the break the cooling curves Figs. and The effect the insulating film even more pronounced Fig. which shows the faced and unfaced specimens being quenched glycerine deg. Cooling Curves During Quenching The cooling curves Figs. and show that the difference cooling velocity between the faced and un- faced specimens especially great when they are quenched hot water. When faced specimen cooled water deg. C., the temperature reduced below 100 deg. within sec. the other hand, for long sec., the unfaced specimens are still completely covered with vapor envelope, though the rate cooling then gradually accelerated the sub- Without facing With facing Temperature Specimen Time sequent fracture the insulating film. trace the envelope, however, still visible after lapse sec. find the cooling behavior faced and unfaced samples the stand- ard specimen was inserted the self- recording apparatus mentioned the initial portion this discussion. The sample was quenched from 800 deg. various cooling liquids both with and without facing material, and the effect the facing the cooling velocity was examined comparing the individual cooling curves obtained during quenching. The cooling liquids used included glycerine, various kinds animal, vegetable and mineral oils, and water various temperatures. The results are shown Figs. and which abscissa represents time seconds and ordinates the temper- atures degrees centigrade. can concluded from the figures that for unfaced specimen when quenched, the rate cooling first small until the temperature falls certain value, and then sudden bend the cooling curve takes place. This sluggishness the initial part the cooling curve usually fails arrest the Ar’ change steel occur- ring the range 600 deg. 500 deg., (Concluded Page 68) Fig. 3—Cooling curves (at left) steel sample during quenching water various temperatures. Fig. 4—Cooling curves (below) steel sample during quenching various cool- ants. All quenching liquids are ap- proximately the same temperature. Without facing With facing 800 Glycerine Temperature Specimen @ Time Seconds The Iron Age, February 22, 1934—17 - é Le an 4 - 4 AY < ope tor, eby upt I ~ 800 New Type Steel ing plants has been turned the past few months the design and production steel beer barrels. Vari- ous requirements have had met produce containers that would ap- peal breweries suitable substi- tues for wooden barrels. These in- clude strength withstand severe service, lightness, appearance, most suitable kind steel use, ease handling, insulation and coating prevent corrosion. ingenuity many steel stamp- Closely coordinated with the devel- opment barrels acceptable the brewing industry have been the pro- duction problems covering design and methods manufacturing, the most satisfactory solution which would result economies manufacture. Among the leaders the list makers steel barrels the Midland Steel Products Co., Cleveland. Design and production methods were devel- oped the Midland plant produce barrel that possesses the required 18—The Iron Age, February 22, 1934 PRENTISS Cleveland Editor, The Age Strength, simple design, has few parts and made with simple oper- ations. The principal operations are rolling, forming and stretching, these being operations that increase the tensile strength the material. The barrels differ some their essential features design, fabrica- tion and assembling from any others that are now being made and their manufacture includes esting forming, welding and assem- bling operations. Departing from the usual practice applying protective coating after the barrel completely assembled, the shell, heads and other parts are coated after fabrication but before assembling. The barrel made both the sin- gle shell and the insulated double shell types. The single wall type bar- and rel has only four parts aside from the bung and tap. Steel beer barrels are either the cup type made from two drawn shaped half shells butt welded the bilge the cylindrical type with one-piece having longitudinal flash weld and the two heads welded the shell. The latter manufacturing method fol- lowed the Midland plant. The single shell barrels are made SAE 1025 steel sheets, the shells 14-gage and the heads 13-gage material. interesting feature the design and method construc- tion the provision wide pro- tective band the center the bar- rel which fastened the barrel expanding operation. This rein- forces the barrel sides. Beads which serve rolling hoops and pro- tective clearance for the bung are formed this band. The band slipped over the shell and both are expanded. this oper- The blank that becomes the shell beer barrel rolled into tubular form and the seam longitudinally flash weld- machine having capac- ity for welding 200 shells & Pe nN Features from the bowl tially the and The fol- made shells -gage pro- bar- ‘el rein- which are shell oper- barrel ubular weld- capac- 200 r ation not only the shell expanded fit tightly against the band but there sufficient additional expansion stretch the band slightly. bilge formed this operation and the greatest diameter the bilge the center the band, welding the band the barrel not required. Had the barrel been designed with two separate rolling hoops there would two additional welding operations fastening the hoops the barrel and there would the possibility the weld giving way under severe handling service. The expansion the shell the barrel in. the center and the expansion the encircling band per cent that the shell. The expanding done rate 200 shells hour cone type expanding machine built Grot- nos Machine Co. This machine also used for expanding bilge the double shell barrel. Equipment for fabricating the bar- rels arranged for consecutive opera- tions two rows one side the plant. First the shell blank sheared size and rolled into its tubular form. Then the seam flash welded Taylor-Winfield flash welding machine which has capacity for The heads are seam welded the barrel the outside resist- ance seam welding ma- chine, the barrel revolv- ing while this welding operation being per- formed. This machine equipped with Thyra- tron control, the control apparatus which shown the left. Manufacture unusual designs beer barrels are made the Mid- land Steel Products Co., Cleve- land. One single shell con- tainer and the other double wall, insulated barrel. Accom- panying sketches serve indicate chief features design and con- struction. Electric welding forms large part the manufacturing process, with flash, butt and seam welding included, and considerable production machinery built for the purpose. welding 200 seams hour. After welding the flash trimmed both the inside and outside Morton Mfg. Co. flash trimming machine. The circular band rolled form, the ends welded together, the beads are formed the band form the rolling hoops and then the bung hole perforated the band punch press. The completed band slipped over the shell after the latter has been welded and flash trimmed and the shell and band are then expanded the operation previously mentioned. After the band joined the shell the expanding operation hole the shell for the bung perforated and flanged, these operations being performed two Bliss punch presses. The bung, which steel forging, then fitted into the hole and the col- lar the bung spot welded the outside the barrel shell. This done locate the bung. Then the bung are welded the inside. The crimped edge the perforated bung hole fits against recess the bung forging, this recess filled with the weld metal and the bung welded flush the inside the barrel. After the bung welded on, beads are rolled the circumference the shell near the two ends. These beads are both for the purpose providing locating points for the top and bottom heads the barrel and establish accurately the distance between the top and bottom heads and thus control accurately the gallonage the barrel. Gagings some steel beer barrels now use show that they vary considerably from rated capaci- ties. The top and bottom heads when formed are flanged outwardly and these are pressed upon the shell with pneumatic press, the flange the heads fitting tightly against the shell The Iron Age, February 22, 1934—19 — 4 er 4 Ls SS 4 4 holes equally spaced Seam Weld Stee/ forging and the head nesting against the bead the shell. Then the head flange seam welded the barrel the out- side the shell. This construction provides double wall thickness the top and bottom flanges between the heads and chimes and insures tight joints. The longitudinal seam weld the shell the only inside weld ex- cept the bung and tap. The seam welding the top and bottom per- formed resistance seam welding machine built the Federal Ma- chine Welder Co. This machine equipped with Thyratron control. The barrel revolves welded. The machine controlled that there are interruptions per lineal inch weld with average speed in. per min. The machine has the capacity weld in. per min. The chimes are integral with the barrel shell. Forming the chimes curling the ends the shell inwardly 20—The Iron Age, February 22, 1934 forging Drain holes spaced The single wall barrel has beads around the girth, held the shell expand- ing operation and serving rolling hoops while the same time providing clear- ance for the bung. The chimes, integral with the barrel shell, afford easy gripping hand-holds. The double wall, insulated barrel, has four rolling hoops formed the outer shell, and the design features assembly cal- culated remove suspension stresses from the welded joints bung and tap. 0.050 ---Weld -- Stee/ forging done speedily special operation developed the Midland company. With the method head construc- tion followed the welding separate chimes the head avoided. The inwardly curled chimes assure easy handling and gripping. The double wall barrel practical- inner and outer barrel. Con- struction this barrel essentially the same that the single shell barrel except that instead curling the side walls the inner barrel form the chimes the side walls end above the head. this method construction the inner shell may assembled and tested for leaks before assembled the outer shell. This testing done hydrostatically. The outer shell rolled into cylinder and longitudinally flash weld- the same the single shell barrel. Four rolling hoops are formed this shell, these taking the place the band the single shell barrel. The shell the inner barrel 18-gage steel and the head and bottom are 16-gage material. The outer shell 14-gage steel. The inner barrel heads are similar the single wall heads except that they have added flange right angles the side wall. After the in- ner barrel built complete the outer barrel shell slipped over and the fabrication the outer barrel com- pleted. novel method suspending the inner barrel accomplished form- ing secondary step flange the outer head which permits the flange the inner head rest upon this sec- ondary flange. With this construction minimum amount surface area the inner shell contact with the outer shell. Both inner and outer heads are seam welded their respec- tive shells. The outer shell welded the top the bung, which the same con- struction that used for the single shell barrel and the outer head welded the top the tap bushing flange. this unique method sus- vension stresses are removed from the welded joints the bung and tap and the inner shell held securely While the form construction and suspension provide absolutely air- tight heat-insulating space between the shells, additional insulation af- forded the use quilt Cabots (Concluded Page 68) & : “4 _ orgin holes ( i around expand- hoops integral gripping has four shell, ses from tap. this the el. The 18-gage are shell similar that right in- outer and the com- ing the form- the ange his sec- area the outer respec- the top con- single sus- rom the ‘ap and rely ion and air- af- Cabots Hard Metal Theory KARL SCHROETER review the various theories governing the formation and behavior hard metal carbides continuation the discussion which appeared THE IRON AGE Feb. The concluding article the series will published succeeding issue, and will deal with the technique machin- ing glass and very hard and brittle alloys. The author, who was the pioneer investigator cemented tungsten carbides, herein reviews the known theories governing the internal behavior aluminum and magnesium-silicon compounds, and attempts expand those theories sufficiently explain the action the tungsten-cobalt system. finely granulated portions tungsten and cobalt are mixed proper proportions, highly compressed, and sintered crucibles containing suf- ficient carbon supply the system, the product cemented tungsten carbide. the bars are fired for hr. 800 deg. C., the hardness increases, and the temperature elevated, the hardness increases steadily until about 1350 deg. reached. The author attempts analyze the action this threshold temperature and explain the mechanism the cementing action. discusses the two alternatives, which consist simply extension the low-temperature effect, formation new liquid phase which produces molten sintering medium. their industrial application, their structural formation, and the relation their structures their properties, appear stand quite detached from other industrial al- loys. They conform laws entirely different from those governing other alloys. None the experiences gained with the latter seem pres- ent directly applicable hard metal carbides. metal carbides, according the previous article reference was made the fact that the proce- dure which know applicable aluminum alloys might throw light the problem hard metal car- bides. Before going into further de- tail regarding this parallel and the experimental material leading it, review will given sintering pro- cedure from theoretical viewpoint. This review will include the early dis- coveries the Americans, Merica, Waltenberg, and the results Wilen’s work duralumin, and the conclusions the most recent Ger- man researches. the duralumin process, the basic metal the alloy during the refining- glowing stage absorbs certain amounts the second constituent (copper) solid solution which, upon aging, precipitated out during the second step the improvement process. indicated, therefore, that mary condition the glowing process satisfactory only takes place above certain temperature—namely, above the demixing temperature the constituents. Between the glow- ing and the aging there occurs the cooling-off which successful, partic- ularly the product quenched. This results from the fact that the equilibrium condition higher temperature transferred the aging temperature, which practically corresponds the volume temperature (temperature when volume maximum), that there then present supersaturated solid solution. case the solubility the constituents decreases with dropping temperature, slow separa- tion can take place during aging. Im- provement this direction is, there- fore, possible only the case such alloys which fulfill the condition solubility depending temperature, which can considered indis- pensable condition their constitu- ents. the case pure metals simi- lar improvement can secured for the same reason. the other hand, common knowledge that not only aluminum alloys show this phenome- non, but also the systems, copper-iron, lead-antimony, iron- tungsten, etc., proved his valuable researches. Since alumi- num free silicon alloy with magnesium can improved with regard physical properties, Archer concluded that the aluminum system not similar magnesium-silicon compound, the separation which conditions the hardening. prob- ably separation the compound which influenced the mag- nesium, somewhat like loosening-up the aluminum screen with in- creased diffusion possibilities thereby made possible. The improvement the mechanical properties, especially the increase hardness, was for long time difficult imagine de- tail, since very little was known re- garding these conditions. was formerly generally that solid solutions were always harder than any one their constituents. view recent developments, how- ever, currently assumed that solid solutions, when they contain highly dispersed separations, repre- sent condition even greater hard- ness than solutions which the sep- arations are not well dispersed. Seemingly the excess solution constit- uent the lower aging temperature The Iron Age, February 22, 1934—21 Pane, E gee 3 oy = | Stee/ torgin pe ay 2% = : ALS A > 200 Aging Temperature Fig. curve the critical degree dispersion showing the break the curve about 150 deg. C., which valid for alumi- num alloy. This tem- perature designat- the “critical aging temperature.” Duration Aging Days separates out. This separation prob- ably occurs intergranular limits the crystal slip surfaces, thereby exerting “braking” action which inhibits deformation the solution external forces. Naturally there optimum particle size with regard the braking action the particles exert action they are extremely small. action will likewise become weaker when the small particles agglomerate into comparatively few balls. Relation Dispersion Degree Temperature From the consideration along Jef- fries and originally evolved the conception the critical disper- sion degree which sets op- timum temperature and best justi- fies the conditions mentioned above. Meissner* then produced curves for the critical dispersion degree which gave periods time which are neces- sary for reaching the dispersion de- gree for any particular temperature. This graph illustated Fig. where aging temperatures are graphed ordinates and the cor- responding aging periods which the critical degree dispersion reached are shown abscissae. When these aging periods are overextended, the temperature period the right above the curve, there reappears de- terioration the physical properties the solid solution. This concep- tion is, therefore, entirely justified from critical dispersion viewpoint. This curve additional interest and will discussed later connec- tion with its actual use hard metal carbides. The break 150 deg. C., which the curve shows valid for “critical aging temperature” Meissner. Above this temperature the optimum aging completed less than day, and below the time greater than one day. The second deterioration the properties which set during too long aging, before mentioned, can then possibly ascribed irregular course the coagulation 22—The Iron Age, February 22, 1934 due too quick maturing. From observations known that the separations finally become microscop- ically visible, after which further peculiar alterations appear. this point the alloys are particular practical use. Regarding the chemical nature the separation, Meissner’s data have not been expanded sufficiently per- mit satisfactory explanation. Meiss- proved that magnesium alone facilitates the improvement alum- inum, and that silicon alone does not. increase can obtained, however, additions two constituents, for instance iron and silicon, man- ganese and iron. examination procedure resulted from the use x-rays, means which better understanding was possible concerning the correlation mechan- ical characteristics and screen struc- tures. Likewise, attempts were made determine the alteration granu- lar size the separated particles. excellent work demon- strated that the sensitiveness the x-ray method general competent detect the smallest amounts separations. For this reason, numerous experiments con- cerning the separation the super- saturated mixed crystals were fruit- less until Goler and ignored the crystals which separated and de- voted considerable attention the aluminum-copper which remained after the separation. Because the small dependency the screen, lattice structure con- stants upon the copper content this procedure was more successful. With increasing granular separa- tion the easily measured position the reflex actions present from the beginning must change, and not necessary depend the proof the appearance newer and pros- pectively very weak reflexes. The details the experiments will not described, but, the whole, the results showed that annealing temperatures which strong im- provement sets in, change could detected any the screen con- stants. alteration only notice- able annealing temperatures about 200 deg. C., whereas the im- provement sets volume tempera- ture. Improvement Ascribed Complex Processes The result was the mono-crystals instead aggregates were examined. The mechanical im- provement processes appeared set even lower temperature for the mono-crystals. From this was concluded that the actual improve- ment process had nothing with Fig. 2—Tungsten carbide containing per cent cobalt, sintered 1450 deg. This view clearly shows the composite tungsten carbide particles matrix cobalt-rich phase which cements the particles together. the separation fine small particles taking place much later, but must ascribed other apparently very complex processes. Fraenkel and concluded from other observations that the process takes place before the removal from the mixed crystal the kind molecule question. The examination possibilities then the disposal experimenters were seemingly not sufficient penetrate further into the details Wasser- approached the problem from entirely new viewpoint. Wassermann questioned whether the alloy first separating out pres- ent the supersaturated mixed crys- tal after the quenching com- Investigation was also whether the compound formation takes place during the separation whether starts the supersaturat- mixed crystal. From the measure- ments with zinc-aluminum and mag- nesium-aluminum from the results other investiga- tors, Wassermann there exists greater possibility for the presence atomic solution than for molecular solution. This does not mean, however, that the ré but for cor Critica/ ple 125 ter : 8 could een con- notice- the im- omplex when ical im- set ture for was mprove- with tungsten balt-rich ogether. irticles must very rations before estion. hen were asser- from hether pres- com- ution. turat- mag- also stiga- that for This the separation hypothesis disproved, but means that further heretofore hardly recognized possibility open for investigation. and Wassermann” corroborated the above observations means further improvement the evaluation programs em- ploying ionization chamber—used with success Hengstenberg and Mark” another occasion—for in- tensity measurements. was shown that during crystalar arrangement volume temperature after the quench- ing, place the previously present irregular distribution the copper the aluminum screen correspond- ing the formation true mixed crystal, there only appears concen- tration copper atoms great number very small regions the aluminum screen. There is, however, separation copper alone new crystals from the structure copper-alum- inum alloy. There sets solely “interior demixing,” which consists deviation from the statical uniform Fig. 3—Tungsten carbide containing per cent cobalt, sintered 1550 deg. The crystals are large, and the structure con- sequently unstable, thereby causing the prod- uct have poor physical characteristics. distribution the dissolved atoms the mixed crystal screen. The nearly ideal homogeneity the latter thus displaced local inhomogeneities, which also Kohubo and interpreted collec- tion copper atoms distinct ver- ticals planes the lattice screen. what manner, however, the small screen disturbances thereby produced should effect the strengthening, which due the nature the improve- ment according these viewpoints alone, nothing can yet said. This especially true since very little known regarding the nature the strengthening. Improvement Related Screen Disturbances Very recently tried solve the question means theory which apparently placed the treat- ment the improvement question upon entirely new foundation, and brought the procedure itself into closer relationship with others already better known metallurgy. Feussner expressed the opinion that means the diffusion the erystals the screen the main ‘metal which separate out, disturb- ances are caused which perhaps are the same those which appear dur- ing mechanical treatment. This would, therefore, lead similar im- provement strength. According this viewpoint, the improvement would not blocking the gliding surface means separating small particles, and would not depend all upon whether not small part- icles had already separated out and what degree coagulation they pos- sessed. would depend, however, upon the action preceding the separa- tion, and further resulting diffusion molecules through screen always alters it. Also, the heretofore imagined fact that improve- ment lessens when aging carried too far, does the sense recent ob- servations, coincide fully with the known fact strengthening caused mechanical treatment and means temperature increase. not easy, however, decide whether the conception described actually correct, the nature the strength caused mechanical treat- ment not yet fully clear. Carbides Compared with Metallic Alloys Far more interesting the ques- tion whether not the pronounced properties sintered hard metal car- bides can explained manner similar the previously described improvement phenomena with pure metallic alloys. already indicated the previous article, this does not \, Fig. 4—Tungsten carbide containing per cent cobalt, sintered 1650 deg. The crystals are very large, the structure un- stable, and the physical characteristics are very poor. seem possible view knowl- edge currently available. improvement the mechanical properties might not occur the case pure carbides, which are con- sidered homogeneous substances, but might occur only when addi- tional component added. But pure carbides, apparently contradiction this conception, can improved without addition, produced sintering instead melting. This contradiction, however, only ap- parent one, for known that com- pact metal objects produced sin- tering always contain stresses which ultimately represent disturbances the screen when they are localized very small screen regions. this sense, perhaps, the greater toughness carbide alloys compared with poured ones understandable from the same viewpoint the metallic alloys. But beyond that, further considerable increase obtained the addition lower melting ary metals, and other additions, which those the iron group have proved most satisfactory practice. Regarding the influence tantalum additions, Comstock” has made val- uable data available. According the increase the toughness, general, follows stronger binding the small hard tungsten carbide particles resulting from the cobalt becoming liquid sintering. This forms eutectic with part the tungsten carbide, the melting point which lies about 1275 deg. During the sintering, temperatures beyond 1275 deg. are used, bubbles are formed and the product poor. Independent this fact, the case researches Wolff, was determined that upon increasing the sintering temperatures additional phenomenon sets in, namely enlargement the crys- tals. This shows that not only purely mechanical reasons, such as_ the formation bubbles, need the rea- son for the unfavorable influence the higher sintering temperature, but that actual alteration the struc- ture takes place. Therefore, the en- tire problem, after the increase hardness, extended the same direction the improvement alum- inum alloys. the latter case there also critical aging temperature, seen from the curve shown Fig. Beyond this temperature the material cannot heated with- out structural alteration setting in, and this alteration destroys the im- provement previously begun. few metallographic photographs tungs- ten carbide containing per cent cobalt additions are shown illustra- (Concluded Page 61) The Iron Age, February 22, 1934—23 s murals embellished with attractive pictorial figures range pleasing colors are new development the Ferro RCELAIN Enamel-on-Metal designs intricate Enameling Corpn., Cleveland. They offer new medium for color and design both for interior and exterior decoration. number these murals have been designed and executed for the company Edward Winter, “ - =” 24—The Iron Age, February 22, 1934 am & One the murals the Ferro Enameling Corpora- offices depicting the smelting porcelain enamel its experimental labora- tory Cleveland designer and artist. These include several 5-ft. panels de- picting scenes the Ferro factory and laboratory devoted the manu- facture porcelain enamels, well general subjects designed fit with the decorative schemes the various offices. These panels now adorn the walls the Ferro com- pany’s offices. There are four five colors each Porcelain Enamel-on-Metal these decorative pieces, the colors used being red, blue, green, yellow, black and white. However, any color may used. Other decorative pieces various colorful designs have also been made porcelain enamel. producing these murals there little departure from standard enamel- ing practice. The decorations col- ored enamels are applied No. gage Armco ingot iron. First ground coat sprayed the metal. This blackish blue enamel having large content cobalt that improves the sticking qualities the enamel. Then the piece fired and the color coats produce the design are ap- plied either with spray brush and with the use stencil. The fir- ing repeated after one more applications the color coats, de- pending the design being repro- duced. With their bright clear colorings pleasing design and with lustrous sur- Porcelain enamel-on- decorative tee 4 Por colors rellow, color pieces also ere col- rst aving color ap- brush fir- more de- epro- rative a Porcelain enamel-on- panel designed Edward Winter faces, the murals, pointed out, offer architects new medium for in- taurants, theaters and bath rooms and for spandrels and other building ex- teriors. Among advantages claimed for the vitreous enamel decorations are that they are easy install, easy clean, stainproof, not fade and are rust resisting. Another use porcelain enamel murals for building decorations was made recently the facade the International Music Hall Radio City, New York. Three mural orna- ments plaques, circular design and ft. diameter, were placed ft. above the ground the wall this building relieve otherwise dead wall expanse. These plaques, having large figures depicting song, dance and the drama, were fabricated various metals and the parts were porcelain-enameled before assembling. All-Welded Telescope Built for Wheeling, Va., Park XCEPT for the lens, periscope head, finding apparatus and field periscope, the telescope here pictured entirely welded steel construc- tion. was built the suggestion the Amateur Astronomical Society the Wheeling, Va., district for installation Ogelbay Park. least eight employees the Wheeling Steel Corpn., including Victor Bihlman the research laboratory, are members the society, and through the gen- erosity the officials their com- pany, mechanically-trained members and friends the society were per- mitted fabricate this telescope the company’s Benwood plant con- sultation with Wallace, general master mechanic. The part that welding played the fabrication this instrument de- scribed Lautner, the ap- plied engineering department and dis- trict supervisor the Air Reduction Sales Co., follows: concrete was poured, and then base- plate was bolted on. This plate was set line means instruments, using the North Star midnight assure correct reckoning. The pedes- tal the telesco