The Iron Age 1944-07-20: Vol 154 Iss 3

LINDERS and Director BAUR Vice-President Seneral Manager ° ° ° Editorial and Advertising Offices 100 East 42nd St., New York N.Y., Johnson, Market Research Mgr. Baur, Typography and ° Regional Business Managers New York New York 100 East 42nd St. 100 East 42nd St. ROBERT BLAIR GIBBS Cleveland Pittsburgh 1016 Guardian 428 Park Bidg. Chicago Chilton Bidg. 1134 Otis Bidg. PEIRCE LEWIS WARREN Detroit Hartford Conn. 7310 Woodward Ave. Box RAYMOND KAY Los Angeles 2420 Cheremoya Ave. ° Owned and Published CHILTON COMPANY (Incorporated) Executive Offices Chestnut and Sts. 39, Pa., U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH Vice-President GEORGE EVERIT TERHUNE Vice-President VAN DEVENTER Vice-President BAUR Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE THOMAS KANE HARRY DUFFY CHARLES HEALE Member, Audit Bureau Circulations Indexed the Industrial Arts Index. Pub- every Thursday. Subscription Price North America, South America and $8; Foreign, $15 year. Copy, ° ° ° 1944, Chilten Company Vol. 154, No. IRON AGE Editorial Technical Articles Manufacture 152 mm. in. Brass Cases Temperatures Frictional Wear Tests Preformed Plastics for Aircraft Stripping Copper Plate After Carburizing Double Sine Bar Block Speeds Electroplaters Discuss Industrial Finishing Methods Continuous Induction Heat Treating Cushioning Tipped Turning Tools “Welding for Postwar Radiographing Magnesium Alloy Test Bars New Equipment Features News Assembly Line West Personals and Obituaries Fatigue Cracks Dear This Industrial Week News Industry News and Markets Reconversion Developments the Week War Department Terminations Eric Johnston Views Russia Russian Lend-Lease Deliveries Labor Suggestions Steel Flat Rolled and Shell Steel Analysis Finished Steel Production for May. Price Policy Used Machine Tools Machine Tool Non-Ferrous Metals News and Developments Non-Ferrous Metals Prices; Scrap Iron and Steel Scrap News and Finished Iron and Steel Prices Steel and Warehouse Semi-Finished and Tool Steel Steel Pipe and Tubing Prices Pig Iron and Coke Ferroalloy Prices Index Advertisers July 20, 1944 / 101 101 104 106 107 108 110 113 114 152 154 156 158 162 164 166 167 168 169 170 171 172 269 Member, Associated Business Papers 7 flame similar that shown the plate from takes world Modern and Mahon has if! This diesel engine crankcase and The past couple years has produced such tremendous demand for welded steel products have been hard pressed times provide fabricate even the procure the type modern equipment needed, designed and and difficult weld- ourselves. result now have one the best equipped and best plate shops the country. Devoted exclusively war production are the applications this are also looking the future. Our own design engineers are working superior construction. engineering staffs different industries—developing products for time application. Can you also use this experienced assistance? Fabricators Machine Bases and Frames and Many Other Welded Steel Plate provide ossible manne? present, ing with ESTABLISHED July 20, 1944 VAN DEVENTER President and Editorial Director BAUR and General Manager DIX Manager, Reader Service ° Editorial Staff LIPPERT Technical Editor......F. OLIVER Commercial Editor, CAMPBELL Associate Editors WINTERS BARMASEL Editorial Assistants SCHIEN WILLIAMS ROGERS LLOYD Pittsburgh 428 Park Bidg. POST Chicago 1134 Otis Bldg. DONALD BROWNE EUGENE HARDY Washington National Press Bidg. MacDONALD Cleveland 1016 Guardian 7310 Woodward Ave. OSGOOD MURDOCK Francisco 1355 Market St. Editorial Correspondents ROBERT Cincinnati PENLEY Buffalo FRAZAR Boston HUGH SHARP Milwaukee SANDERSON Toronto, Ont. RAYMOND KAY Los Angeles JOHN McCUNE Birmingham ROY EDMONDS St. DOUGLAS Seattle Fiddling the Fog. ERO fiddled while Rome burned, the story goes, although haven’t any photographs him doing prove it. Since then this expression has become accepted typing indifference public needs ineptness meeting them. Nero had carried pails water directed the efforts the fire- fighters that historic occasion would have been better employed than making hot music. But such ordinary performance public duty would not have put him headlines. Nero hero was zero. His sense news values was better de- veloped than his sense duty the public. sometimes wonder this not true some our present day statesmen, especially election year, when headlines are prized more than ever politicians. think some them fiddling the fog. There was fog over Rome the night that burned. Nero could see what was doing, made his choice what and did it. Give him credit for being forthright about it. American business and industry are not burning today, perhaps thanks some 3000 miles ocean, but they are enveloped dense fog that makes impossible for their leaders look ahead. The weak squeaks political virtuosos which are heard the fog not help any. American businessmen and industrialists have heard great deal about the rebuilding job that are going for the world and sounds very impressive and noble you like that kind chin music. would like hear something definite about plans for rebuilding Amer- ica. It’s take some very definite and practical rebuilding make room for the millions returning sons from overseas. Passing laws give our ex-service men dismissal pay all very well but won’t what needed done. Money weekly pay envelope better than “once and for all” check from Mr. Morgenthau. Congress can great help but employers are the people who have create and furnish employment. And one the best things that Congress could for them and for the country would stop fiddling the fog and get out brass tack program that will let employers have least faint idea how much money they will have left invest postwar employment after the tax collector gets through with them. | : | | 4 j BRAMS — t ‘ 1 Not many months have passed since accident meant little more than some personal loss and tem- porary, but easily adjusted, work schedule. Today, that situation completely changed. Every accident the 9,000,000 that occur annually national liability, affecting, not only the output the injured worker’s shop, but also the production other shops. Yes, single accident “injures” millions other workers who are trying desperately reach maximum war output—millions American citizens who are striving retain their Ameri- Let’s All Back the Attack can fighting men who never can have all the equipment and supplies they need for INLAND STEEL COMPANY Dearborn St., Chicago Illinois Branch Offices: Cincinnati Detroit City Millions are “Injured” Single Accident Victory long America careless the home front. Anything you can prevent accidents will bea real contribution America’s fight for Remove hazards home, drive carefully, consid- erate others traffic, observe safety rules when work, promote safety and safety programs matter what your position may be. Start today! Think safety, promote safety! Keep more workers the job for Victory! with War Bonds pre News July 18, 1944 OPA has granted Pittsburgh Steel increases its prices ingots, $2.10 blooms, $4.25 ton; and billets, Appearance peacetime products will undoubtedly slowed because the inexperience workers. What has already been made for limited civilian consumption shown high percentage defects due improper assembling. Maury Maverick, while fanning the flames sectionalism his recent trip the Coast, expressed his belief the need for extension the life SWPC for years", since there are probably million contracts and sub-contracts and bankruptcy will result settlement not prompt. British steel houses for postwar rehabilitation have undergone some alterations layout and design since the prototype went inspect. They are pected cost about $2200, including stove, sink, refrigerator and other fixtures. Production the houses may start November. They will publicly owned and tenants. One June the Soviet government published detailed list all materials re- from the S., Great Britain and Canada. Between and per cent dispatched was lost transit through enemy action The sent 6430 aircraft, 3734 tanks, 206,771 trucks and 22,400,000 shells. Great Britain and Canada sent 5826 aircraft, 5480 tanks, 8649 trucks and 17,827,999 shells. British material was sent "military aid without payment". About million pairs Army footwear and nearly million yards cloth went tothe from Britain sent 6491 lathes, 15,084 electric motors, equipment. All three countries sent large quantities metals. Metlbond, "glue" liquid, paste and tape forms Consolidated Vultee Aircraft used attach plexi-glass aluminum, glass glass, etc. The joints have ashear strength 3000 lb. per sq. in., after curing 330 deg. Toolite, new thermosetting plastic made Adhere, Inc., Los Angeles, lighter than magnesium, has compressive strengths 20,000 lb. per sq. and can cast 1/32 in. exact size. has been used for legs and arms radial drill presses, and may soon used for structural airplane parts. Current German home propaganda reports the fighting great detail, stresses Allied losses, declares they are throwing troops spendthrift pace while Germany shepherds its own reserves. Propaganda the Dutch and Belgians "see what might happen the horrors invasion reached your shores;" the French the word is: "Keep quiet. Don't get into trouble. Spare yourselves avoiding the war;" the Allies, effort made play off Briton against American and both against Russians, with atrocity stories from the front line, thousands Allies killed horrible ways, with the question asked, The official British description the "flying bomb" "pilotless aircraft"; American flyers call them "doodle bugs"; Allied newspapers call them "robot bombs"; and the British Broadcasting Co., with characteristic aplomb, call them "things". bombs" the name that will likely stick. Berlin has announced that Luftwaffe Major Jabs destroyed two formation sight Spitfires over Berlin with new type aircraft", probably the Schwalbe (Swallow) single-seat fighters now undergoing service Band instruments are now being made regular commercial quantities q — front. bea edom. consid- hen matter more forming building electrodeposition. The technique differs radically from plating practice and calls for the last word control equipment. ical ingenuity probably the most factor solving the problems en- countered. bright alloy plate consisting ternary deposits copper, tin and been made available commercially. The alloy bright deposited, hard, has g00d tarnish resistance, non-magnetic and has high protective value over copper alloys. recommended replace nickel plate. ie SOPHER Director, Chicago Metallurgical Laboratory, and FOSS, JR. Chief Metallurgist, Eastern Division. Rheem Co. ITH the liberation North Africa Allied forces the battered remnants the French fleet made the hazardous At- lantic crossing and were docked the Brooklyn Navy Yard January, 1943. The ships included cruisers and destroyers and the mighty 35,000-ton battleship, Richelieu. One the most serious problems encountered refitting concerned the ordnance the French ships. There was choice between two alternatives. The first was dismount all the guns and regun with American ord- nance. Further investigation indicated that this would involve not only re- placing the guns but would also re- quire the complete refitting the loading arrangement and possibly re- placing all ammunition hoist equip- ment. Aside from this there would appreciable delay while French crews became familiar with American 52—THE IRON AGE, July 20, 1944 Manufacture 152 The 152 mm. shell case made for the French bat- tleship Richelieu. It's the longest its kind used any ship. The glam- our being provided Lily Pons, who autographed the symbol the shell. ordnance. The other choice was ask American industry undertake the manufacture all the neces- sary ammunition components required for the French guns. The latter choice was finally decided the most feasible. The secondary batteries the Richelieu and the cruisers and the main armament the larger destroy- ers are 152 mm. rifles. The Richelieu alone carries these guns. The problem providing cartridge cases for this unusual caliber was expected prove especially difficult. The cases are approximately in. long and weigh approximately They correspond roughly the Navy’s in. cases. They are, how- ever, larger across the base diameter and considerably longer than the in. case. Bureau Ordnance experts re- the 152 mm. cartridge case the most difficult manufacturing prob- lem yet undertaken this field. these considerations must added the fact that the precipitate flight these units the French fleet from their home ports France left their crews with very little tech- nical information and few drawings concerning items ord- nance carried the ships. Much the specifications and methods manufacture, therefore, were left the memory engineering tached the ships other officers who were fortunate enough escape from France. The 152 mm. cartridge case was hardly unfortunate. There were available drawings the case and there were samples the French cartridge cases But, there were methods manufacture available nor was there much the way raw specification such chemical compo- sition, grain size, and physical prop- erties. Neither was there available the required physical properties the finished cartridge case. Preliminary examination French case indicated that the original supply had been manufactured from aluminum bronze with somewhat higher percentage nickel, iron and manganese than found the typi- cal American analysis. Chemical and analy- sis sample drillings was follows: Copper, 92.87; aluminum, 5.49; iron, 0.25; nickel, 0.065; manganese, 0.10; tin, 0.02; silicon, 0.02; and nil. Qualitative spectrographic showed zine. The Bureau Ordnance, Navy De- partment, after considering the ma- terial analysis and the French design modified the case design and pre- that manufactured from conventional copper, zinc, Amer- ican cartridge brass, and accord- ance with Specification No. for the in. caliber case used the Navy. Ordnance engineers Rheem Mfg. Co. then developed method manu- facture based the conventional cup and draw method consisting ping operation and five ironing draws with intermediate anneals. The cal- culated press loads all fell within the rated press loads for the draw presses but some cases with very small margins safety. With the method manufacture finally decided upon the following lished: Disk Specifications: The cases were manufactured from Navy inspected, cartridge case brass disks made according Ordnance Specification No. 1051. Size: 16x0.813 0.010 in. Desired grain size: 0.055 0.120 mm. Ti D | ° | Was were nished the there prop- the iginal from ewhat and typi- llows: iron, 0.10; nil. alysis De- lesign pre- from mer- case Mfg. nanu- cup draws the resses small astab- from case ith. mm. Brass Cases Cupping (Operation No. 400 ton Bliss hydraulic press, in, stroke, single action. Average press load: 375 380 tons. Average height cups: 8.25 in. Outside diameter: 9.314 in. Inside diameter: 7.777 in. wall thickness: 0.7 per cent. Maximum eccentricity: 0.012 in. Desired hardness cups: 100 105 Re. Cupping punch: Water-hardening Cupping die: Oil-hardening tool steel— high carbon, tungsten steel with 0.5 per cent molybdenum added. Annealing Cups (Operation No. Type oven: Direct, gas fired recirculat- ing. Oven temperature: 1130 deg. Baskets: The baskets were made acid construction. Basket size: 53x33x12 in. Pieces per basket: The cups were placed the baskets mouth down one cups the basket. Desired hardness after annealing: 65 Re. Pickling, Rinsing Cups (Operation No. Pickling unit: Metal wash, spray type pickler. Chamber No. per sulfuric acid with per cent Ferrisul added. The acid temperature was maintained between deg. and 115 deg. F. ; Chamber No. 2—Cold water rinse. Chamber solution for coat- ing the cups aid the next draw- ing operation. First Draw (Operation No. Press: 250 ton Bliss press, in. stroke, single action. Average press load: 170 175 tons. Average height draw pieces: in. Outside diameter: 8.846 in. Inside diameter: 7.746 in. Reduction wall thickness: cent. Maximum 0.0095 in. Desired hardness after drawing: 105 Re. First draw punch: Same punch, First draw die: Same cupping die. 100 to Anneal First Draw Pieces (Operation No. Same operation No. except that were placed each basket one layer. hardness after annealing: Re. Pickling, Rinsing First Pieces (Operation No. Same operation No. Second Draw (Operation No. Press: 250 ton Bliss hydraulic press, stroke, single action. Average press load: 130 135 tons. Average height draw pieces: 14.5 in. Outside diameter: 8.448 in. diameter: 7.717 in. Reduction wall thickness: cent, Maximum eccentricity: esired hardness after drawing: 100 105 Re. draw punch: Same cupping draw die: Same cupping die. for the French Navy Herein are details what probably the most diffi- cult manufacturing problem yet undertaken the brass cartridge case field, that 152 mm. French cases about in. length, produced the conventional cupping operation and five ironing draws with intermediate an- neals. Particularly interesting the aluminum bronze from which the original French cases were made, which stronger than conventional alloys this type due the presence nickel, iron and manganese. Second Draw Anneal (Operation Same operation No. except that pieces were placed each basket one layer. Re. Pickling, Rinsing Second Draw Pieces (Operation No. Same operation No. Third Draw (Operation No. 10) Press: 250 ton Bliss 108 in. stroke, single action. Average press load: 110 tons. Average height draw pieces: 5/16 in. Outside diameter: 8.155 in. Inside diameter: 7.692 in. Reduction wall thickness: cent. Maximum eccentricity: in. Desired hardness after draw: 100 105 Re. Third draw punch: Same Third draw die: Same cupping die. Third Draw Anneal (Operation No. 11) Same operation No. except that pieces were placed each basket one layer. Desired hardness after annealing: Re. Third Draw Pickle, Rinse (Operation No. 12) Same operation No. Fourth Draw (Operation No. 13) Press: 125 ton Bliss hydraulic press, 108 in. stroke, single action. Average press load: tons. Average height draw pieces: in. Outside diameter: 7.992 in. Inside diameter: 7.666 in. Reduction wall thickness: cent. Maximum eccentricity: Desired hardness after drawing: 100 108 Re. Fourth draw punch: Same cupping punch. Fourth draw die: Same cupping die. Fourth Draw Trim (Operation No. The fourth draw pieces were trimmed rotarv trimmer uniform length 26.75 Fourth Draw Anneal (Operation No. 13) Same operation No. with the follow- ing exceptions: Temperature oven: 1100 deg. Time oven: min. Pieces per basket: 23. hardness after annealing: Re. Pickle, Rinse Fourth Draw Pieces (Oper- ation No. 16) Fifth Draw (Operation No. 17) Press: 125 ton Bliss hydraulic press, 108 stroke, single action. Average press load: tons. Average height draw pieces: in. Outside diameter: 7.872 in. Inside diameter: 7.660 in. Reduction wall thickness: 35.5 per cent. Maximum eccentricity: 0.007 in. Desired hardness after drawing: 105 Fifth draw punch: Same punch. Fifth draw die: Same cupping die. Note: Due difficulties drawing, pig- mented drawing compounds were neces- sary all draws. the fifth draw colloidal graphite was used with steel dies. When the carbide die stalled ordinary water soluble drawing compound was all that Was necessary. Fifth Draw Trim (Operation No. 18) The fifth draw pieces were trimmed Heading (Operation No. 19) Press: 2800 ton Bliss hydraulic press, in. stroke, single action. The cases were placed the heading post and die assembly and were moved under the bumpers means dial feed. The bumpers were located secondary dial which was part the ram. This dial had four stations each containing one bumper. The sur- face contours the bumpers varied depending upon which metal was moved. After each bump was completed, the upper dial moved the next station. Each com- plete revolution the upper dial com- pleted one case. Average press load: First bump: 2250 tons; second bump: 1900 tons; third bump: 2300 tons; fourth bump: 2400 tons. Thickness head after heading: 0.560 in. Desirable hardness after heading: in. from edge flange: 102 105 in. from edge counter bore: 102 105 Re. Allowable extent cold shut: 0.1204 in. The extent the cold shut func- tion the bumpers. When the cold shut exceeds 0.1204 in. necessary rework the bumpers. THE IRON AGE, July 20, 1944—53 4 Heading tools: The heading post nose, heading die ring, and bumpers were all made oil-hardening tool steel used where compression and shock re- sistance is necessary. Wash After Heading (Operation No. 20) Washer: Two stage spray type washer. This operation was necessary re- move the drawing compound from the fifth draw and the compound used the heading post and the bumpers. Chamber No. alkali cleaner used concentration oz. per gal. (Metax 300 AS.) Chamber No. 2—Hot water rinse. Tem- perature 120 deg. 140 deg. Pre-Taper (Operation No. 21) The cases were flame annealed from the mouth point in. from the base. This was prevent fluting, splitting, collapsing during tapering. this par- ticular cartridge case was necessary soften the portion within in. the mouth considerably more than the body the case prevent collapsing the taper die. This was accomplished rotating the cases pedestal be- tween two gas flames, one which ex- tended from the mouth the base point in. from the base. The other extended from the mouth point in. lower. Gas mixture pressure annealing flames: in. H,O—90 per cent aera- tion the gas. Time the flame: min. Desired hardness after annealing: See Fig. Tapering (Operation No. 22) Press: 175 ton Bliss hydraulic press, in. stroke, single action. Average press load: 110 tons. Diametral taper: 0.02920 in. per in. Secondary taper: 0.0625 in. per in. Taper die rings: graduated rings oil-hardening tool steel. Wash and Rinse (Operation No. 23) Same operation No. Stress Relief Anneal (Operation No. 24) Type oven: Direct, gas fired culating. Time heat zone: min. Time cooling zone: min. Temperature oven: 535 deg. The cases were stress relieved the above time-temperature cycle remove any residual strains set the previous operations without altering the structure the metal. recir- Mouth Anneal (Operation No. 25) The requirements the mouth the case was such that was necessary anneal the section the case from the mouth point in. lower. This was done unit similar that used for the pre-taper anneal except that the burners were shorter. Gas mixture pressure: in. per cent aeration the gas. Time flame: sec. Hardness desired after annealing: Machining (Operation No. 26) The cases were machined Coulter lather. The underhead diameter, and base facer were machined that the case had the proper dimensional characteristics. The primer holes and counterbores were drilled and the mouth the cases were trimmed these lathes. Tap Primer Hole (Operation No. 27) The primer holes were tapped Haskin’s tapping machine. Final Wash and Rinse (Operation No. 28) Same operation No. 20. 54—THE IRON AGE, July 20, 1944 the base the French and the American cases. Notice how the single radius the French case intersects the base angle, mechanically unsound design. Rheem Inspection (Operation 29) The cases were brought roll con- veyor into the company inspection crib where they were examined for surface condition inside and out and were gaged determine adherence dimensional tolerances for the following: Overall length; primer threads; primer counter- bore; mouth wall thickness; head thick- ness; flange thickness: flange diameter underhead diameter; mouth diameter; flange chamber gage. Navy Inspection (Operation No. 30) Same operation No. 29. Stamp Base (Operation No. 31) Press: ton Bliss gap frame, in. stroke, single action. Each case was placed fixture and the base stamped with identification accordance with the method mark- ing specified the drawing. Packaging (Operation No. 32) Cases were packed cardboard car- tons, one case to each carton. Spacers were used hold the cases firmly the carton. There were 500 cases each lot. This method manufacture proved very satisfactory. Production schedules were maintained with com- parative ease and the scrap loss was relatively low considering the nature the job. This substantiated the fact that the contract was com- pleted days less than the allotted time and the number pieces ob- tained from the disks allocated for this job exceeded several hundred pieces the number specified the contract. specifications were .available the French case was impossible determine whether the cases manufactured would meet the require- ments the gun. clarify this sit- uation, was decided draw com- parison between the sample French case and typical case manufactured the procedure described article. The physical properties taken into consideration this comparison were follows: (1) General appearance and con- tour; (2) chemical analysis; (3) hardness; .(4) tensile strength and elongation; (5) cold shut; (6) structure. Both cases were checked dimension- ally before and after sectioning. The heads were cut off about in. above the flange and half-sectioned. Com- parative dimensions the head tions were taken and drawings made show the differences the inside contour the two cases. Outside con- tours necessarily conformed the dimensions the gun chamber and breech, hence there could little variation. (See Fig. 1.) The bodies the cases were tioned longitudinally that the dif- ferences wall thickness could determined. differences outside the normal variations due tools and dies were detected. the chemical analysis has discussed previously further dis- cussion will made here. Specification requires hard- ness checks several specified posi- tions the case. _Examination the specifications and ‘blue prints dicated that would impossible adhere the hardness method manufacture contemplated. The Navy Department when informed how nically French actured this were and micro- ension- ig. The above Con- sec- made inside con- the yer and dif- outside tools been dis- hard- tion ints in- possible vith the nplated. Rockwell hardness Annealed Inches from mouth 2—Hardness range for the annealed and tapered 152 mm. cartridge cases. this revised the hardness specifica- tions follows: in. from the head: 114 Summary Very little information was avail- able concerning the method manu- facture used the French. Micro- scopic examinations, however, indicate that the case was made one the drawing methods. appreciable dimensional differ- ences were noted except those con- cerning the contour the head. The American case has considerably more metal the section where the inside wall meets the head. This due the long radii which join the inner wall and the head. The single radius the French case intersects the base angle. This mechani- unsound although the case may have sufficient strength fulfill the firing requirements. The American case constructed with compound radii order that the inner wall might blend with the base smooth sweeping curve. the event that choice was necessary the American design would undoubtedly prove the stronger. The aluminum bronze from which the French case was manufactured has higher ultimate strength, com- bined with increased ductility, than Temperatures Frictional Wear Tests Report No. 625 the materials committee the Verein deutscher published Archiv fiir das Eisenhiittenwesen April, 1948, Siebel and Ko- describe experimental work de- signed measure the temperatures attained when dissimilar metals materials are maintained sliding friction under high pressure 14,700 Ib. per sq. in. Cylindrical samples were mounted end vertical plane, and the upper one rotated 1465 r.p.m. The relative velocity was 123 ft. per and each test lasted sec. The stationary sample was all tests Cr-Mo steel, and the rotat- upper sample various ferrous and non-ferrous metals plastics. Tem- were measured the sur- face the lower body with thermo- couple, and time-temperature curves were plotted. With copper-steel pair samples, the temperature showed steady rise throughout the period each test, the maximum values being obtained with the higher pressures contact. With pressure 7350 per sq. in., the maximum pressure the end the sec. was 374 deg. F.; with 8820 lb. per sq. in., 464 deg. F.; with 11,760 per sq. in., 752 deg. after sec., and with 14,700 lb. per sq. in., over 752 deg. F., already after sec, the other hand with and pairs, limiting temperature was not exceeded, the for the former pair having already flattened out after sec., the 70-30 cartridge case brass the American case. This material might possibly stronger than ordinary aluminum bronze due the presence the nickel, iron, and manganese. This alloy appears modified 92-8 aluminum bronze with small ad- ditions the previously mentioned alloying elements give increased strength and ductility. The 70-30 brass used the Ameri- ean case has much better cold work- ing properties than the aluminum bronze which eliminates many diffi- culties processing. The strength cold worked 70-30 brass has proved adequate for all types cartridge eases. The hardness strength the French case con- sistently higher than the American case. From examination the micro- structure the French and the Amer- ican case evident that the French manufacturers employed material with larger grain size. Microstruc- tures also indicate slightly less cold working the French case 3.3 in. and in. from the head. The recrystalliza- tion in. from the head the Ameri- can case probably due the heat from the pretaper anneal. Although there are variations tensile strength, hardness, and the same general characteristics are dis- played both cases. The American case follows the same general pat- tern the French case with respect physical properties. This ac- cordance with the physical properties other cartridge cases. The ballistics tests, which consti- tute the final acceptance tests for the Navy, were successful. and for Bakelite and steel flattening suddenly with sharp kink after sec. the higher pressures, the maximum temperature attained be- tween zine and steel was around 482 deg. F., and all pressures with Bakelite and steel just over 572 deg. Also, this limiting tem- perature was reached, there was marked drop the coefficient fric- tion, which with the zine-steel pair was associated with the formation the liquid phase, and the case Bakelite and steel with the decompo- sition the plastic. The temperature distribution indicates that the melting point the decom- position temperature with the last pair attained only thin layer each side the plane contact, wear being experienced the steel. This temperature distribution ana- lyzed theoretically. THE IRON AGE, July 20, 110 } 40 Ne. Ge BOUT one-third strong and one-third heavy alumi- num alloys, preformed plasties are used make structural parts airplanes where buckling critical design factor. Preformed plastic the result five years joint search the chemists the West- inghouse research laboratories and the Mellon Institute Industrial the art paper making which dispersed fibers suspended water are felted out screens desired size and shape. This plastic begins life soup-like mixture cellulose fibers (from wood pulp), water (99 per and phenolic resin, whipped ABOVE forming dip tank consists per gether machine. The resin special type which has affinity for the pulp fibers, but does not tend dissolve the water. cent water and per cent wood fibers and resin. BELOW the copper screen form out plastic mixture after the vacuum pump has sucked resin impreg- nated wood fibers onto the form, fillet for airplane tail. the preforming process, fine copper gauze fashioned into the form % ABOVE Resembl- ing papier-mache, plastic pieces are dried and ready for molding. RIGHT 4—Out the press comes the airplane part made preformed plastic. 56—THE IRON AGE, July 20, 1944 and alumi- arts critical int re- ‘ial Re- ised which water desired “stuff,” fibers ped to- the finished product fitted the end suction pipe and then dipped into the mixture. vacuum pump sucks the mixture the gauze form which permits the water pass through the tiny holes, leaving the damp, resin-soaked fibers clinging the screen uniform layer, just like the felt hat. Then the preformed PHYSICAL PROPERTIES PLASTICS Tensile Strength Type In. Molded Flexural Strength Strength In. 18,500 10,000 Impact ABOVE tion: This screen used make the rough form for the finished shell noses, shown Fig. LEFT 5—The finished tail fillet held Dr. Allan Bates, manager the chemical and metallurgi- cal department the Westinghouse research nity for tend fine form piece peeled off the gauze form and dried warm oven. The dried piece then placed heated mold and pressed into its final shape. Under this treatment, the resin melts and flows through and around each tiny fiber. varying the time the amount suction dur- ing preforming, the thickness the preformed piece can varied, and the amount pressure changed make different varieties plactic, ranging from cork-like substance dense, strong material laboratories. resembling hardwood. dies made wood can used the press. The accompanying table compares the strength preformed plastic made from Kraft pulp fiber and simple phenolic resin. Stripping Copper Plate After Carburizing EVERAL methods and processes have come into general use for removing copper from steel parts that have been copper plated for se- carburization. The WPB urges that neither chromic acid nor sodium used for this purpose be- short supplies. Because developments regard the availability certain salts used stripping solutions, two methods recommended the Hanson- Co., Matawan, are especially timely. Copper Deplating Solution This all-potassium salt solution pre- follows: Copper cyanide—4.0 oz./gal. Potassium Potassium hydroxide—2.0 oz./gal. Potassium carbonate—5.0 Operating Conditions deg. Tank voltage—2-2.2 volts Anode current density—50-60 Cathode-anode ratio—2:1 Free potassium cyanide—2.4-2.6 Cathodes—Steel sheet empty ball anode containers which can periodically re- turned the plating tank. Agitation agitator—Mechanical motor Tank—Steel Time strip 0.001 in. copper—15 min. Immersion Method Described The copper plated work immersed sulphur, for min. The arti- cles are then rinsed and immersed solution sodium cyanide (16 gal.) potassium cyanide (21 gal.) for approximately min. tests with steel panel having 0.001 in. thickness copper, the mini- mum immersion time the liver sulphur solution was min. and the sodium cyanide min. Although the liver sulphur solution can oper- ated room temperature, sulphide formation hastened elevated tem- peratures such 120 deg. F., convenient heat the solution. THE IRON AGE, July 20, 1944—57 { al The author interprets the electronic tube tool comparable with tools the trade, such milling cutter tungsten car- bide bit and thus, obliterates the vague boundary surrounding electronics. describes electronic tube applications terms that are part the metal working field and presents imposing re- capitulation the new skills and savings that these applications have made possible. COCKRELL Industrial Engineering Division, General Electric Co. all this talk about electronics? Does concern only the communication and navigation fields? one long range postwar project that may bear fruit ten years from now? something that can ap- plied metal working today and to- morrow? the first place, the electronic tube itself tool. such, com- pares with the milling cutter, the grinding wheel, tungsten carbide bit. And such, more com- plete electronic equipment than the cutter the grinding wheel com- plete machine tool. The electronic equipment used industry com- bination the electronic tube, the electrical components, and the me- chanical parts driven the motor the solenoid. Each one these three parts must function satisfac- torily, the whole equipment cannot considered success. Almost all the electronic equip- ment which has proven unsuccess- ful has failed because lack ap- preciation the mechanical require- ments the whole equipment. Be- cause the extremely small amount power required operate the elec- tronic tube, and the extreme speed and rapidity its operation, far be- 58—THE IRON AGE, July 20, 1944 yond anything which mechanical de- vices can follow, the bottleneck the design ‘will very often found the mechanical parts rather than the electrical components. This re- flection the ability the me- chanical engineer. The problems solved with the assistance elec- tronic tubes are often very tough ones. Mechanical Comparisons What this legendary electronic tube? nothing more than one- way electrical valve. Since acts upon the electrical current flowing stream almost inertialess elec- trons and has moving mechanical parts, control obtained with mini- mum amount power, and the tube can made function with extreme rapidity and speed. other words, frictionless valve. Since the conventional form electronic tube only one the ele- ments permits the electrons flow past control element, the tube also one-way check valve. The tube may used for rectification, ampli- The action the rectifier might compared that the connect- ing rods and crankshaft in- ternal combustion engine, which transposes the reciprocating motion the system into the smooth rotary action the crankshaft. Just number cylinders will produce more even flow power, will multitube rectifier produce smooth direct current without the necessity large electrical filter flywheel. The amplifier action the tube may considered similar that any valve servo mechanism, since the use small amount power applied the control much larger amount power re- leased from some external power reservoir. this respect, must understood that the electronic tube does not generate power. The third function, that switch- ing, also form amplification, but might thought gate-valve action rather than needle-valve tion. Most interesting the ability the tube open and close electri- eal circuit many millions times without wear noise, such quired for the precise pulses cur- rent used resistance welding. Types Electronic Tubes Examining the types which are available for use there first, the phototube. The controlling element here beam light. light energy extremely small, the power that can controlled small, but just small stream water under moderate pressure call flow through long pipe small fice create high-friction drop proportional the flow, the small electron flow controlled the phototubes flow through trical resistance produce drop which can used the next larger electron tube. This next member the tube family the pliotron, vacuum tube. The control element electrical pressure. The current electron flow requirements for are almost negligible. Small can throttled from fully open col for tri are ra’ at ° ° in 10tion uce will mooth essity wheel. that mount re- power ust tube witch- cation, lity times cur- y tubes there Since the also eam can all ori- ressure lled by voltage operate vacuum voltage control liotrons completely closed voltage change only volt two. The pliotron can take the out- put signals from the phototube, any other signal which can trans- formed into electrical voltage, and amplify sufficient power oper- ate small electrical device such relay solenoid, control one the power electronic tubes which will discussed next. The plio- trons have characteristic unique among power tubes—their ability operate many thousands millions time per second. The big power tubes for indus- trial electronic use are the thyra- trons and ignitrons. The thyra- trons require very little control power, such might supplied the smallest pliotrons, like those used radio receiving sets. They are big enough control motors five ten hp. The ignitron the larg- est member the family. Although requires more control power small thy- raton usually necessary for control), can in- corporated equipments large enough handle many hundreds amperes controlling the part rectifiers check valves only. The vacuum tube then called and the thyratron be- comes “phanotron.” Applying the Phototube Present day applications the electronic tube the metal working industry begin even before the ore dug from the ground. some the largest electric shovels—large mon- sters that can scoop cu. yd. material time—the shovel housing leveled the four corners hydraulic jacks controlled means phototubes which watch the bubbles two spirit levels (Fig. 1). the bessemer converter, photo- tube, supplemented the proper col- ored filters, views the flame during the converting process and stops the proper time for production the best steel. this way, helps produce more uniform steel. may taken for granted that the phototube, the form photo- pyrometer, will hand indicate when the steel has reached the proper temperature for rolling. The presence the hot steel before the jets indicated that the high-pressure jets may turned only when needed. The photoelec- trie relay makes good limit switch Tubes similar and thyratrons but without for the operation reversing mill, while other tubes precise motor control application adjust the screw- ing down the roll exact dimen- sions. the end the line, photo- tubes synchronize the flying shear cut the strip into accurate lengths. the cold rolling process, where the thinner gages steel are made with higher strength and finer finish, Fig. unit for large power shovels. the electronic tube assists holding proper tension between the rolls for reduction, tempering, skin pass and the end the line assists coiling uniform, coils. Controls Brightening the steel tinned prevent cor- rosion the new electrolytic proc- esses which uses less tin than the old dip method, the control this bright- ening can obtained through photo- tubes which watch the melting tin. some points the processing the metal strip, such cleaning and side trimming, necessary hold the strip without tension the form loop. Here again, the shadow the loop the bank phototubes controls the drive motors order keep the loop within the required limit. Small holes the sheet, which might permit leakage liquids from the can into which the tinplate will ultimately made, are detected phototubes the alert “see” any small amount light transmitted through the sheet from bank high-intensity lamps the opposite side (Fig. 2). The pinhole detection usually takes place the shearing line, where the strip cut into sheets. this same line there usually thickness gage, one form which uses the photoelectric relay indicate under and over gage. When pinhole detected, electronic timing circuit permits farther along the machine operated exactly the proper time mark the position the hole. If, addition the pin- hole, the sheets are found out gage, the sheets cut from this section are diverted from the pile prime sheets. Here, again, photoelectric relays count the number good and bad sheets. The use phototubes for temperature indication and con- trol generally used con- nection with visible radiation obtained 1400 deg. and above. But for temperatures below this, such are used for heat treating and other processes, tube circuits and saturable reactors are used connection with thermo- couples and indicators for precise temperature control. This permits smooth, step- less flow heat the fur- nace, and hence more uni- form heat than could ob- tained where blocks re- sistors are cut and out the heating element. Using Paper Templates For flame cutting, particularly when many small pieces the same shape must cut, there has been developed template follower. this equipment, photo- tube viewing drawing either ink crayon white paper replaces the expensive metal fiberboard tem- plates previously required for this type work. Not only the mak- ing the templates greatly simpli- fied, but storing them sheet form much more compact and convenient than storing the mechanical tem- plates. Also, while the mechanical template soon worn out, the paper templates may reproduced photo- graphically many times neces- sary assure continued accuracy reproduction. interesting application one pipe mill that phototube which watches the edge the skelp with critical eye, insure that holds the proper temperature folded around and welded into pipe. One ingenious application the phototube that used control the removing covers from the soaking pits, that the desired ingots may removed the crane operator THE IRON AGE, July 20, q i f | j needed for rolling. relay mounted adjacent each soaking pit cover and light source mounted the crane cab. When- ever the operator desires uncover particular section the pit, has only move his crane the proper point and shine the light the de- sired phototube, start the uncover- ing application. color the paint can standard- ized, matched, compared photo- electric means. During the actual painting operation, the paint spray can started and stopped photo- electric switch action. Some work has been done the use electro-static precipitation and elec- tro-static fields insure even coat- ing and minimum loss paint. Motor Drive Control For driving grinders (Fig. 3), lathes, shapers, boring mills, and the like, the electronically controlled mo- tor offers distinct advantages. Perhaps the most important these its ability hold preset speed quite closely despite wide changes the torque requirements. Another the wide speed range available with simple control. ratio speed 10:1 20:1 supplied standard equipment, whereas, some special’ cases, much 100:1, greater, has been supplied. The limitation usually lies not the control, but the ability the motor commu- tate satisfactorily and dissipate the heat losses the extremely low speeds. For motor control, the rectification action the tube well the con- trolling action used that the advantages d.c. motor performance 60—THE IRON AGE, July 20, 1944 LEFT Fis. 3—A grinder equipped with G-E for headstock. View showing Thy-mo-trol (cover removed) and headstock motor, speed range 160 2300 r.p.m. Control station Providing START-STOP and speed shown operator's left hand. BELOW 2—A pin-hole detector and marking for inspecting strip steel. View showing scanning head for pin-hole detector and supporting stand with manually operated side which maintain proper pass line means air-operated sure blocks. may had where only a.c. power available. Standard ratings, and below, are quite common, and larger sizes have been built when re- quired. Another very practical contribution the tube control for motors the easily adjustable current limiting fea- ture. This feature limits the motor torque and current prevent damage tubes, motor, machine. Should the machine loaded too heavily and become completely stalled, more than the preset torque will applied and damage will done. Welding Applications the resistance welding alumi- num and stainless steel, where con- trol power must precise, elec- tronic tubes perform one three functions, and quite often all three single equipment. First, they must time the period application electric power insure that the correct amount heat Second, they may control the rate which heat applied. Finally, large ignitron tubes are generally used switch the high power and heavy current needed for the welding. The type resistance weld made may classified spot, pulsation welds. Spot welds, the name indicates, are produced single surge electrical through the joined metals. For gage material, sufficient heat may generated one-half cycle, 120th sec. Ignitrons, which may gered thyratrons, switch the circuit, whereas small pliotron forms the timing action. some spot welders, timing quence control provided givé completely automatic functioning. For instance, there may separate regulate: (1) the squeeze during which air pressure applied Speed acent scanning with strip ted pres. that the applied. the rate Finally, renerally wer and welding. ot, seam, duced For may the tron ming give ning. For ite eze time, applied the electrodes force the parts together; (2) the weld time, which may consist heat, cool and total time pulsation weld; (3) the hold time, during which pressure maintained permit the parts chill; and finally (4) the off time, dur- ing which pressure released from the electrode that the part may removed and new part inserted. Seam welds consist series overlapping spots, made the ma- terial moves beneath electrodes the form disks (Fig. 4). addition timing the length time power applied, second electronic timer must now used measure the time between heat pulses. The third type, pulsation welding, involves the use series heat pulses applied the This usually employed for the weld- ing heavy sections for the weld- ing more than two thicknesses metal. Electrically, weld control consists seam-weld control with separate timer im- pulse counter count the total num- ber pulses applied. ABOVE 4—Droppable gasoline tanks for airplanes being seam welded electronically controlled re- sistance welding machine. ° ° RIGHT Fis. 5—G-E electronic heater used for in- ductive heating metal parts. The demand for greater amounts power the number size the sections spot welded have in- creased has resulted heavy, in- termittent single-phase load the power line. some locations this cannot permitted. System avoid this difficulty, energy” welding systems have been employed. The energy taken from the three-phase power-supply through tube rectifier and stored the form magnetic energy. the electromag- stored energy type, d.c. current built the highly inductive welding transformer primary and then interrupted ferring the magnetic energy into the secondary where applied the weld. The second form stores the energy bank capacitors from which then discharged through the welding transformer. form both the charging and discharg- ing functions are performed elec- tronic tubes. Electronic control also assists are welding, particulary automatic welding long seams such are common the fabrication large tanks containers, ship construc- tion. Using the desi