The Iron Age 1942-07-16: Vol 150 Iss 3

JULY 16, 1942 Keep ‘em duce costs meet com- petitive conditions after- wards. Put Timken Bear- ings all roll necks. TRADE-MARK REG. U. &. PAT. OFF. TAPERED ROLLER BEARINGS 1942 Roll neck bearings are being put the test now never before. far Timken Roll Neck Bearings are concerned however, only confirmation the efficiency, endur- ance and economy they have displayed during the last fif- teen years rolling millions tons steel the lowest bearing cost per ton ever attained. With Timken Bearings all back-up and work-rolls you are assured continuous, dependable operation; simplicity lubrication; ease roll changing—no delicate parts handle. Existing mills can brought victory production standards with Timken Roll Neck Bearings. Consult the mill builder, get touch with our roll neck bearing THE TIMKEN ROLLER BEARING COMPANY, CANTON, OHIO 4 j has muffle; units radiate heat directly onto the work. This fact plus the ample input results very recovery the prazing fast prazing and good economically JULY 16, 1942 VOL. 150, NO. VAN DEVENTER President and Editor BAUR Vice-President and General Manager ° ° Managing Editor, LIPPERT News Markets Editor, ROWAN Technical Editor, OLIVER Associate Editors JAMES Art Editor, WINTERS Editorial Assistants BENEDETTO Resident District Editors Washington Pittsburgh DONALD BROWNE PHAIR Washington Chicago Cleveland Detroit CHARLES POST San Francisco Editorial Correspondents DEARING ROBERT McINTOSH Buffalo Cincinnati FRAZAR RAYMOND KAY Boston Los Angeles HUGH SHARP Milwaukee SANDERSON JOHN McCUNE Birmingham ROY EDMONDS Toronto, Ontario St. Louis BACON DIX, Manager Reader Service ° ° Advertising Staff Emerson Findle Herman, Chilton Bldg., Philadelphia Hottenstein, 1012 Otis Bldg., Chicago Raymond Kay, 2420 Cheremoya Ave., Los Angeles, Cal. Leonard, 100 East 42nd New York Peirce Lewis, 7310 Woodward Ave., Detroit Ober, 100 East 42nd St., New York Johnson, Market Research Hayes, Production Manager. Baur, Typography and Layout. ° ° ° Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Pub- lished every Thursday. Subscription Price North South America and Possessions, Foreign, $15 year. Single copy, cents. ° ° Owned and Published CHILTON COMPANY Executive Editorial and Offices Advertising Offices Chestnut and Sts. 100 East 42nd St. Philadelphia, Pa. New York, U.S.A. OFFICERS AND DIRECTORS MUSSELMAN, President JOS. HILDRETH, Vice-President SEORGE GRIFFITHS, Vice-President 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 Week 3 Editorial Hold That Tiger! Technical Articles Soaking Pit and Reheating Furnace Refractories Industrial Metal Spinning Care Flux Light Alloy Tubes Expanded Bond Fins Cooling Cold Heading Die Quenching Fixture........ Health Hazards Handling Magnesium. Specification Plating Features Assembly Line Washington West Coast Fatigue Cracks Dear Editor News and Markets This Industrial Week Personals and Obituaries Non-Ferrous Metals Machine Activity Scrap Iron and Steel Scrap Prices Comparison Prices Finished Steel Prices Warehouse Prices Index Advertisers Copyright. 1942, by Chilten Company (ine.) 122 125 126 128 130 131 132 134 193 rT ak l 1 | | | ‘ i Save Critical Metals HELP conserve nickel, chromium, vana- dium and other scarce metals, the War Pro- duction Board’s ablest metallurgists have developed (National Emergency) Alloy Steels. These new steels contain relatively small quantities alloying elements such combination produce physical proper- ties usually attributed steels much higher Carburizing Grades 4023 and 8620. Replace AISI and SAE Nos. 2300, 2500, 3100, Only limited data heat-treatment response physical properties will available when Alloys are first ready for shipment. The WPB anxious know how these new steels will function and requests all Alloy users report results working with these new steels. Ryerson will cooperate fully with Medium Hardening Grades 4042 and 8744. Replace AISI and SAE A4130-35, A5130-35, A6130-35. alloy content. The War Production Board stipulates the use the new Alloys replace the standard SAE and AISI Alloy Steels for wide range applications. Ryerson Alloy Steel stocks six speci- fications, all fine grain, will available shortly; and will consist sizes ranging from 7-inch rounds, three groups: High Hardening Grades 4047 and 8749. Replace AISI and SAE Nos. 2300, 3100, 3200, 4100, 4600, 6100. users, supplying laboratory test data, and all other information. you now use Alloy steel, let Ryerson help you adapting Alloys your require- ments wherever possible. Write, wire phone the nearest the ten Ryerson plants. JOSEPH RYERSON SON, Inc., Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City 32—THE IRON AGE, July 16, 1942 A 4 THE AGE JULY 16, 1942 ESTABLISHED 1855 ° ° Hold That Tiger! NCE upon time there was Bengal tiger, most ferocious beast, who escaped from his cage because his keeper had left the door unlocked. The zoological garden was visitors and great cry arose from the masses people who were mortal fear being killed terribly mutilated the sharp claws and slavering jaws the beast. Fortunately, the head keeper and number his assistants were hand and bravely seized the beast the tail after had inflicted serious injuries upon several the thousands persons present. After heroic struggle, the tiger was finally put back into his cage. Newspaper headlines, next day, called the intrepid keepers heroes and public benefactors who had prevented injury many people. And Congress voted them medals. any bystanders had suggested the keepers that they let the tail and permit him run large, think they would have been promptly mobbed justly irate public. There tiger breaking loose our land today; tiger million times more dangerous than any Bengal tiger could be. succeeds getting away from the men who have precarious hold his tail, will injure every man, woman and child America and all our Allies well. the inflation tiger. one can escape him, once loose, except the speculator, and his specialty putting the bite widows, orphans and old folks who live savings and the small fry among the wage earners. Leon Henderson has been doing grand job, with his associates, holding that tiger the tail. Everybody ought help him with moral support even though not all can lend hand. But unfortunately, there are people putting pressure upon him let the tail slip. The farm bloc Congress, for example, wants him let couple inches tail for the benefit its constituents. The Steel Workers representatives want him let out some more inches favor their members. course, nobody wants him let altogether, but just enough the tiger can bite some other fellow. The trouble that even price tiger has limited amount tail and when you let little bit out time, you finally get the end it. And then the fun begins—for the tiger. the best thing grab tight just close the tiger you can and then hang like grim death. And think that all ought encourage Leon Henderson just that. hold that tiger! | ° ° | | | } | | | 7 | ® | | ¢ & af \ \ } \ \ \ N \ \ 34—THE IRON AGE, July 16, 1942 this page will start all available scrap iron and steel its way the mills. Ama Offices: Milwaukee, the days when soaking pits were literally pits which ingots taken from the molds were allowed “soak” even heat, external heating being em- ployed, furnaces were little more boxes, fireclay brick met all needs. But today Litinsky’s as- sertion that “there such thing only good relation some specif- job, very much the point. This well illustrated the triple fired, two zone, continuous reheating represent peak reheating fur- nace design and which demand whole range refractories for effi- cient operation. One section the roof must built super-duty fireclay brick, whereas another zone, which operates lower temperature, can constructed high heat duty brick. The hearth exposed not only high tem- perature but also attack scale and made from chrome plastic rammed fireclay brick, which turn rests insulating concrete. The use even the best roof brick the hearth would soon put the furnace out commission due excessive slagging while tempt use second instead first steel plant refractories that have ap- peared IRON AGE are: Open Hearth Furnaces,” Aug. and 22, 1940. “Steel Plant Feb. and 13, 1941. “Basic Open Hearth Above Sill Plate Level,” May and 29, 1941. “Basic Open Hearth,” Aug. 14, and “Electric Steel Plant Refractories,” March and 12, 1942. Continuing the series steel plant refrac- tories, the author discusses Part two-part ac- count the materials required soaking pits, well for the continuous slab reheating furnace and the walk- ing beam furnace used for heating spring plates. quality brick the roof would lead spalling. these special re- quirements the re- fractories costs these furnaces are slabs heated. This achievement depends great measure the high through-put which sometimes exceeds 600 tons per furnace per day. Many different types cluded the heading: “Soaking Pits and Reheating Furnaces,” and even the subdivision into these two main groups far Thus, continuous bogie type fur- nace built the principle the ceramic tunnel kiln, but operating under far more severe conditions can used for soaking ingots for reheating material prior forging. Reheating furnaces work- ing high temperatures, 2372 deg. and over, are subject the same refractory difficulties soak- ing pits, and hence this article, the brick used for both types will discussed under each sub-head- ing. ordinary soaking pit has roof such, the top being cov- ered with lid series lids either with without arches be- tween. Even this characteristic does not differentiate between soak- ing pits and reheating furnaces CHESTERS Central Research Department, can also United Steel Companies, Ltd., Stocksbridge, England since the latter charged. Although from the refractory is, therefore, sharp division between the two groups, such division made regards their use. When- ever possible the hot ingots are taken the soaking pits, Fig. shortly after stripping, thus con- serving the heat the steel and minimizing strain due heating and cooling. most plants, how- ever, proportion the ingots are allowed cool and are heated again soaking pits. Reheating furnaces, the other hand, receive the product obtained when the ingot has been rolled, Figs. and This may the form billets, slabs, sheets, sheet bar. Where considerable hot work, such forging has still done, Fig. the material heated temperature compar- able with that used for the initial rolling; but for many purposes the temperature much lower and the demands the refractories corre- spondingly less severe. The fuels used reheating fur- naces and soaking pits vary with the type work and the local economy, but the cleanliness op- erating with gas oil and the THE IRON AGE, July 16, 1942—35 Soaking Pit and Reheatin | Fig. ingots their way the soaking pits. greater ease temperature con- trol have led the replacement considerable proportion the coal-fired furnaces. For very spe- cial purposes, such bright an- nealing, electrically naces are employed. Soaking Pits Gillies and Martin gested that soaking pits can di- vided into four principal types, follows: (1) The Reversing Regenera- tive Pit. this furnace combus- tion takes place the ingot heat- ing chamber itself. Regenerating chambers containing the checkers are located each end. one cycle the waste gas Fig. 2—Ingots for the soaking pit after passage through billet mill. 36—THE IRON AGE, July 16, 1942 through one the regenerator chambers heat the checkers, while the other chamber heating combustibles they pass through; the next cycle the functions the two chambers are reversed. The most modern fur- naces this type are equipped with sealing covers, the move- ment which the draught and shut-off are automatically controlled. (2) The One-way Fired Recu- perative Pit. the development this type pit, the aim was eliminate two the serious drawbacks the type pit just discussed: Irregularity heating, with consequent temperature dif- ferences destructive the furnace heating checker chambers, and the difficulty local temperature control the use the heating space combustion space with consequent direct flame impingement the ingots. The first drawback the older type pit was met using recuperators for preheating the air, and the second drawback was largely overcome firing high deep heating chamber where the ingot tops were out the path combustion. The waste gases were exhausted the same side from which the pit was fired point near the bottom. (3) The Bottom Fired Recu- perative Pit. One the most re- cent developments ingot heat- ing furnaces the rectangular pit fired from central point the bottom one burner and exhaust- ing the waste gases through four exit ports the lower parts the walls. The ingots are placed the area surrounding the burner open- ing the center and far enough back allow fair sized space combustion chamber. There the rising strike the cover and are turned back along the walls into the area where the ingots stand. The exhaust gases pass through four tile recuperators downward direction, while the in- coming air passed horizontally and upwards successive passes around the vertical tubes. Un- usually high preheat temperatures may obtained with this recu- perator. (4) The Tangentially Fired Cir- cular Pit. The last type ingot heating furnace that merits de- scription the so-called tangenti- ally fired circular pit, Fig. 15. consists circular furnace com- pletely encased steel—as are the 4 4 ator pre- pass the are fur- pped and cally nent was just ting, dif- nace 4 of juent the the ising the was the were from point Recu- re- heat- pit the four the the open- the the along the gases rators in- ntally passes Un- atures recu- Cir- ingot com- the modern rectangular pits also—and fired tangentially even intervals around the circumference plane near the base the ingots. angle deg. from the radii and fired into inner refractory bridge wall which prevents direct flame impingement the ingots. Here the multiple and small burn- ers insure against the localized high temperatures often resulting from the use small number burners. The ingots about central exit port, sufficient size exhaust the waste gases properly. The circular wall tapered back increase the inside diameter the point firing. Reheating Furnaces Reheating furnaces vary even more widely design. They may the simple in-out type the single double chamber continu- ous billet heating furnace type. addition, there are endless special- ized types, such the walking beam furnace used spring leaves, shown Fig. the tower furnace, used for bright annealing, shown Fig. spite the great divergences type, both soaking pits and re- heating furnaces can subdivided, follows: (1) Roof, which may lid lids, (2) side walls, with which are included burner blocks and fireboxes, (3) hearths, (4) flues, including slag pockets, any, and (5) recuperators regener- ators. With small gas fired furnaces, the exit gases often exhaust at- mosphere through the doors and other openings, which case there are flues and recuperators regenerators. Table gives the refractories layout for three furnaces, namely, coal fired soaking pit, continu- ous slab reheating furnace the type used material for car body sheets, and walking beam furnace used spring plates. The refractories used will discussed more under the sub-divisions of: Roof, side walls, etc., but interest note that even with.the rather primitive coal fired soaking pit considerable range refractories required. The bricks used the various positions have mostly been arrived for example, siliceous fireclay brick roof may have given trouble and been replaced more alu- minous grade. With furnaces like Fig. 3—Electrically driven slab mill. Fig. 4—Withdrawing collared forging from reheating THE IRON AGE, July 16, 1942—37 ‘ ° ° t Fig. 5—Circular type soaking pit. (Courtesy Salem Engineering Co., TABLE Selected Arrangements Refractories Reheating Furnaces and Soaking Pits Section Roof Doors Hearth Flues Soaking Pit, Coal Fired, Waste Heat Boiler Arches: Low alumina table Continuous Slab Reheating Furnace Low temperature zone: Medium alumina fireclay, such High temperature zone: high alumina, per cent, fireclay, such Top: Low alumina fireclay, Slag line: Magnesite, chrome, chrome- mag- nesite, chrome-silica, such X.1 X.2 Firebox: Medium and low alumina fireclay bricks, such F.2, F.5, and F.3 See Low alumina fireclay, such F.3 Low alumina fireclay, such F.3 backed with 38—THE IRON AGE, July 16, 1942 Medium alumina fireclay, with low temperature insulation Entry: Insulating concrete Exit: Medium alumina fireclay, such F.2 Chrome plastic medium alumina fireclay, such F.2 Medium alumina fireclay, such F.2 Walking Beam Spring Heating Furnace Medium alumina fireclay and low temperature insulation Medium alumina fireclay backed with low temperature insulation Medium alumina fireclay with asbestos backing Sillimanite, such X.14 and medium alumina fireclay, such F.2 continuous slab reheating furnaces, where the whole production mill may depend the output one unit, the use the more dur- able super-duty fireclay brick considered worth while. walls, fireclay bricks are normally employed but basic refractories are desirable the slag line soaking pits avoid undercutting the wall. The doors may fireclay brick, but the temperature and either brick cement form can used give lighter door, fuel economy, and more even heating the charge. The choice hearth brick likewise depends the precise conditions. 1832 2012 deg. serious attack mill occurs, but higher temperatures basic hearths may required contamination the product molten scale and fre- quent shut-downs are avoided. Roof Construction: Both soaking pits ing furnaces are fitted with great variety roofs. With the soak- ing pit, most the roof consists can lifted with crane made slide track. Where lids are employed, there usually some sort sand seal insure more less gas tight fit. This impor- tant both from the standpoint fuel economy refractories, since poorly fitting lid leads rapid destruction the brick the point where the flame escapes. The sand used should not sinter too readily since otherwise will not perform its true function. both soaking pits and furnaces, the roof lid may pended steel hangers. Particu- larly with reheating furnaces, the suspended type offers many advan- tages; particular the possibility using complex roof shape and yet maintaining stability. The Detrick type roof, shown Fig. used the continuous slab re- heating furnaces, offers good ex- ample this type construction. The individual bricks can made with side corrugations, ample, the Detred tile, which pre- vent cracked bricks from falling away and render the furnace more gas tight. The use this type roof enables the contours the furnace adjusted meet the fuel engineers’ conception the most efficient combustion space. first, sight would appear ° ° f side ally are ing the ‘lay and can ‘uel ing her the fre- led. eat- reat ists are ome por- ries, pes. nter will sus- the van- ility and The Fig. pre- ling nore the the the pear that roofs built this way, using many special shapes, would result high overall cost; but the fact that such slab furnaces operate with total refractories cost only about two cents ton com- pared with say $1.00 per ton for open hearth furnace shows that the roof costs cannot Where sprung arches are used, sim- ilar considerations apply those already discussed connection with basic open hearth furnaces. The general design problem has been ably discussed Spotts, Dowell, and Gill their article “Refractory Arches.” They sug- gest that fireclay roof arch should have rise least in. and not more than in. per ft. span, the higher figure being recommended for roofs subject unusually high temperatures soaking heat, such those heated both from above and below. The gas port arch certain types soaking pits are examples such. The rise somewhat greater than that usually recommended for sil- ica bricks and this not surpris- ing since the latter withstand very much greater temperature under load than the clay brick. Where high temperature insulat- ing brick are used roof construc- tion, rise not less than in. per ft. The thick- ness the arch function the span and suggested that should not less than in. for spans ft.; in. for spans between and ft.; and 13% in. for spans over ft. Arches that are relatively flat, in- sulated, subjected extremely high temperatures severe cor- rosion, should thicker. These authors also point out that where conditions are particularly severe, for example when spanning opening through wall, advan- tageous use two more sprung arches, one above the other, the lower arch serving withstand the brunt the severe furnace conditions while the upper re- lieving arches support the weight the wall and facilitate repairs and renewals the lower arch. Materials: The properties number reheating furnace and soaking pit roof brick are given Table II. general, soaking pit lids are lined with medium clay brick type similar that given under the code No. Fig. beam type furnace used for heating spring plates. TABLE Properties Reheating Furnace Roof Bricks Special Firebrick Normal Firebrick (Suspended Roof) Medium Alumina Fireclay Code No. F.8 Apparent porosity,* per cent 26.7 31.5 21.7 Bulk densit gm. per 1.96 1.82 1.98 per cu. ft. 122 114 124 Apparent specific gravity 2.67 2.65 2.53 Crushing strength, end, per sq. in. 790 n.d. 4140 Permeability air c.g.s. units, perpendicular 9x3 in. face, skin 0.46 0.03 0.013 After contraction, hr. 2570 deg. 0.0 (contraction) (contraction) Pyrometric cone equivalent (Seger) /34 n.d. 30/31 (3164 deg. F.) deg. F.) Refractoriness under load Rising temperature, per sq. in. Initial softening: 2228 deg. 2318 deg. 2228 deg. Fail Temperature: 2786 deg. 2696 deg. 2804 deg. Thermal shock resistance 30+ 30+ 30+ Thermal expansion 248 1832 deg. per cent 0.41 *The methods test were described IRON Feb. and 13, 1941. THE IRON AGE, July 16, 1942—39 ces, 4 ° ° | 5 i | | will seen that this brick has fairly high bulk density, good crushing strength, moderate meability, and reasonable stability reheating 2570 deg. Its ever, cheaper bricks, such Table III, give quite good re- sults. This brick “potty” brick the bloating type and has only average thermal shock resistance. q Fig. 7—A Siemens-Schukert tower furnace used for bright annealing strip. melting point 3056 deg. while shows signs softening even 2228 deg. under load Ib. per sq. in. shock resistance excellent, de- sirable property view the tem- from repeated opening and closing soaking pit lids. This general purpose type firebrick finds works. can used quite suc- cessfully open hearth furnace doors and ladles. With many installations, how- 40—THE IRON AGE, July 16, 1942 glazes readily and because its low softening temperature the brick the roof lid soon become mono- lithic, least the working face. For special purposes, such the suspended roofs the multi-zone slab heating furnaces, grade refractory, namely, the “super-duty,” “high-heat duty” fireclay brick used the United States, employed. Great Brit- ain, bricks the type and have been found give good service. will seen that these are more aluminous grade hav- ing melting point 3092 deg. over and considerably higher porosity, “play” and accounts part for their freedom from spalling. The thermal shock resistance these brick, tested the laboratory, always reversals over. The difficulty with this type that unless has been particularly hard fired, say 2642 deg. over, shows after contraction service. This leads open joints through which the flame can pene- trate and attack the brick the sides well the end, leading stress concentrations the in- terface between the vitrified face and the cool end, and consequent spalling losses. Such shrinkage said more severe with bricks whose alumina content has -been artificially raised adding baux- ite medium alumina clays. With some furnaces possible build the roof high tempera- ture insulation, failing that insulating fireclay brick normally high porosity, about per cent, but much less porous than the proper high temperature insu- lating brick, per cent porosity. For annealing boilers for the heat treatment large blooms, furnaces built entirely high tem- perature insulation, except for the firebrick hearth, have proved very useful. Their durability con- siderable, there are appreciable fuel and time savings due the low heat capacity the brickwork. most soaking pits and reheating furnaces, however, insulation, used all, limited thin layer placed outside the firebrick. Another type brick that gives excellent service reheating fur- nace roofs the semi-silica sand-clay brick. This glazes read- ily, particularly the presence coal ash, and tends show ex- pansion rather than contraction re-firing. Thus, recently constructed bogie type ingot re- heating furnace which patch the roof had built with semi-silica brick due porary shortage the normal fire- clay brick, Table II, the semi-silica brick were found have glazed far better than the fireclay brick and, unlike the lat- ter, showed signs open joints. Where absolutely essential that the sheets other product C SECTION (Super 8—A Detrick roof construction for triple fired, two-zone continuous slab heating furnace. TABLE Ill Properties Fireclay Bricks Used Reheating Furnace Side Walls Code No. F.3 F.4 F.14 F.17 Apparent porosity, per cent 20.8 20.8 26.9 34.5 23.7 23.7 18.9 22.0 | Bulk Density gm. per 2.09 2.09 1.93 1.79 2.00 2.00 2.05 1.99 per cu. ft. 131 131 121 112 125 125 128 125 Apparent specific gravity 2.65 2.65 2.64 2.74 2.63 2.63 2.53 2.56 per sq. in. 1690 4510 3130 1740 6910 3320 1890 2940 9x3 in. face, one skin 0.027 0.0033 0.0097 0.0036 0.0098 0.40 0.029 After contraction: hr. 2570 deg. —4.0 (Exp) —8.7 (Exp) —5.1 (Exp) 3.0 —3.6 (Exp) —3.5 (Exp) —1.1 (Exp) —0.06 (Exp) (Contraction) (Seger) 2912 deg. 2948 deg. 2840 deg. 2966 deg. deg. 2840 deg. 3200 deg. 3110 deg. Refractoriness under load: Rising temperature, Ib. per sq. in. Initial softening, deg. 2264 2228 2012 2318 1850 2120 2318 2156 Rapid softening 2534 2462 2372 2444 2588 2516 2570 2498 Fail temperature 2768 2732 2642 2660 2768 2714 2912 2804 Thermal shock resistance 30+ 26+ 30+ 30+ THE IRON AGE, July 16, 1942—41 SECTION B SKID LINE Gta Yj, AA fy Aff ° ° Re... ‘ 3 - \ | | | | — kept free from brick dust, silli- manite may employed the roof spite its high initial cost. Causes Failure Spalling responsible for great deal the damage re- heating furnace roofs, but only serious problem with furnaces used intermittently. What appears thermal shock spalling may due initially after shrinkage which exposes the brick heating from the sides well the ends. already stated, the risk such brick ends coming away can re- duced the use special corru- gated shapes such the but undoubtedly the greatest hope improvement lies the choice brick having less tendency vitrify together with insulation the roof where this practical. most reheating furnaces and soaking pits, actual slag attack the roof slight. exception the coal fired soaking pit where considerable amount ash may come over from the fire boxes. Much the trouble that experi- Ryerson alloys steels the Ryerson Son, Inc., has been an- nounced. alloys, the new alloy steels established the WPB help conserve nickel, chromium, vanadium, and other scarce alloys, will carried Ryerson six different analyses hot rolled rounds sizes ranging from in. diameter. While, hereto- fore, these steels have not been available for experimentation, man- ufacturers may now obtain small lots for treating and testing specific applications. The six analyses that will car- ried stock are: (1) Carburizing alloys, 4023 and 8620; (2) medium hardening alloys, 4042 and 8744; and (3) high hard- ening alloys, 4047 and 8749. Properly selected and heat treated, expected that these alloys will satisfactorily re- place the higher alloy content steels formerly used except very spec- ial applications. Table indicates 42—THE IRON AGE, July 16, 1942 enced, particularly with pit lids, the result imperfect fitting the bricks the lid the furnace walls, allowing gases escape and causing local over- heat, erosion, and eventually spall- ing. This accentuated the scaling that occurs when the steel cast iron frame comes con- tact with the escaping gases. where great care exer- cised, ingots periodically fall from the dogs onto soaker lids against the side walls and cause serious damage. The problem accentu- ated where alloy steel ingots are being reheated, since their hard- ness temperature makes good grip more difficult. With forge furnaces, considerable damage can done vibration from adjac- ent hammers the impact the charge the hearth. Lines Improvement would appear that the most encouraging line for improvement lies with design. Thus far, better results have been obtained from Stocks Alloy the SAE and American Iron and Steel Institute high alloy steels that can replaced the six grades steels listed. The SAE and American Iron and Steel Institute Grades Steel Replaced the Alloy Steels SAE and AISI Steels Steels Replaced Carburizing grade: 4023 and 8620 2300 2500 3100 4100 4600 5100 6100 Medium hardening grade: 4042 and 8744 2330 2335 3130 3135 4130 4135 5130 5135 6130 6135 High hardening grade: 4047 and 8749 2300 3100 3200 4100 4600 6100 soaker lids where mechanical de- vices have been installed enable the lid first lifted and then traversed laterally dragged from position purely sideways pull. Thus, there projecting brickwork adhesion between the roof and the brick- work, the ordinary withdrawal the lid will result tearing the top the side walls. The recent development the super-duty brick reached more advanced stage the United States, due the avail- ability the Missouri diaspore deposits which provides brick that will stand extremely se- vere conditions without undue vit- rification. Further development along these lines will much reduce the trouble present ex- perienced spalling and slag at- tack. Editors Note: Next week the author concludes this investigation with dis- cussion the refractories used soak- ing pit and reheating furnace side walls, hearths, and flues. Steels Because, the past, alloy steels have been developed meet specific requirements without regard the type quantity alloying ele- ments, now necessary sub- stitute steels lower alloys order conserve dwindling stocks these vital elements. The new steels are the result this conservation program and contain minimum alloying elements. They are, however, composi- tion balanced produce required and adequate physical properties. The metallurgical section the War Production Board anxious know how the new steels perform service and what ex- tent they conserve scarce metals. Users the new steels are urg- ently requested report detail each operation, such forging, machining, heat treating response, and tool life, well the resuits any physical application tests made these steels. This will en- able correlation information concerning the steels, which will made available other users. ° ° SULLIVAN Associate Editor, IRON AGE ° ° ° HEN newly designed air- craft engine cowling ready for experimental pro- duction, there are three ways which can made: Hand form- ing, stamping and spinning. The first slow, not easily duplicated and poorly streamlined; and the second too costly for experimen- tal work. But spinning has proved quick and inexpensive solu- tion the problem. Furthermore, when the design finally accepted and frozen, initial production can started matter days while high production dies are under construction. Spinning not, and probably never will be, competitor stamping, for both have their eco- nomic limitations. But least two distinct processes has been used complement stamping drawing. One these case which described detail later on, where three different shapes are spun from single stamping. The other the removal taper from drawings, for wooden spin- ning chucks require very little taper, and metal chucks need none. article this application ap- peared THE IRON Nov. 21, 1940. recently spinning emerged from the field small decorative pieces the point where industry beginning appreciate its possibilities. The spinner para- phrases Archimedes, “Give lever long enough and will spin the world.” Practically, means that many job undreamed years ago has been licked within the last few years. There more limit the potential size spinning than there that stamping drawing. Nor the shape limitation tight used be; the old assumption that the process applicable was Industrial Metal Spinning Spinning one form metal working which the theory and practice have never fully been set down black and white. This article outlines some the operat- ing principles little known craft that playing ever increasing role industrial metal working. spherical, parabolic similar shapes has gone the board. article the Jan. 30, 1941, issue THE IRON AGE there descrip- tion method forming the unusual curvatures stream- lined oil truck body cutting spinning into number pieces and selecting only the ones desired. Spinning for re- search and work. When peace rolls back the veil censorship, this little known indus- try will credited with playing important role experimental and production work radio, sonics, aircraft, and even shipbuilding. The economics spinning com- pared with stamping are clearly set forth previously mentioned article, and will not discussed here. But should remembered these days when time precious, that since the spinner can swing into production few days, die press breakdown need not completely halt production any vital item, whose shape and thick- ness lends itself the spinning technique. Pewter, silver, copper and brass were the earliest spinning mate- IG. the second operation the manufacture aircraft propeller The first operation, consisting spinning steel sheet the shape shown here, was carried out another lathe. THE IRON AGE, July 16, 1942—43 n n n e Se Ss n aluminum gave the industry boost, for considerably easier spin than either brass copper. These latter two more mechanical skill than alumi- num order avoid scratching, with attendant risk breaking deep spinning; and they require frequent annealing and more form- ing operations than aluminum. 44—THE IRON AGE, July 16, 1942 Several ago IRON AGE article (Aug. 24, 1939) reported Stainless still very difficult metal spin; work hardens quickly and requires frequent and careful annealing 2100 deg. The trend today appears cold rolled steel, for many re- spects, including cost, ideal material for spinning. requires 2—Half way through the sec- ond, and final oper- ation, the steel assumes this shape the operator spins the flaring metal the shape the cast iron chuck. next applies the tool the area about the tailstock verts what appears excess metal into blunt nose. The finished prod- uct shown the right Fig. little more work than aluminum, but somewhat less than brass. Fig. illustrates the difference the forming properties steel, brass and aluminum. The comparatively high tensile strength cold rolled steel enables take more work- ing without tearing, and naturally makes for stronger finished prod- uct. Annealing unnecessary, ex- cept for deep spinnings. 3—Frying pans, ampli- fier housing, lamp reflector and aircraft propeller illustrate the range indus- trial spinnings. Un- usual the helmet left rear, ec- centric shape and therefore spun elliptical chuck. | annealing copper, brass and nickel, they need only brought red heat. Aluminum alloys, like stainless, require careful anneal- ing between operations; dural, for instance, annealed 550 650 deg. Tools plants the country that Edward Young, Brooklyn, The data and illustrations this article are based the work his plant, which considered among the most progressive the industry. Despite the apparent simplicity the spinner’s lathe, Mr. Young has made several improvements permit the production larger pieces with less operator fatigue. The principal feature 30-in. lathe which recently designed the substitution 250-lb. tool rest for rest. The lighter tool support better braced, easier Approximate, and varying depending on the contour being formed. Not including annealing between spin- ning operations. tools shape al- most every conceiv- able contour. Drilled holes the handles two cate they are used the lever type holders shown the accompanying trations. The others are hand tools, held against the opera- tor's chest. Operations Ist. 4th. 4—The wide ALUMINUM difference the forming properties steel, brass and aluminum ically illustrated sketches the operations (or chucks) required for STEEL typical spinning. Further data this piece are given the table. BRASS Comparative Data for the Piece Shown Fig. Assuming Spun Three Different Materials Tool Pressure Material Labor No. Material, Material Gage Cost Cost Operations Lb. per Sq. Aluminum ..... 40c. 20c. 400-500 Cold rolled steel...... 5c. 40c. 3200 3 THE IRON AGE, July 16, 1942—45 oa ° ° ° > ly S 6—Spinning tools, and the shapes they form. The two the right are for beading; the plain one for steel, the wheel for brass, copper and aluminum. 7—Turning wooden chuck for 72-in. diameter parabolic aluminum spinning. The lathe 110-in. swing, gap type machine, which will also used form the spinning. %, IRON AGE, July 16, 1942 handle, and permits the operator exert more force the work. The gap type lathe preferred for spinning since permits the production larger pieces. Fig. made the Young plant, shows gap type lathe with 110-in. swing. Forming tool tips, Figs. and are improvisations based years experience, and are often shaped especially for the operation hand. The method applying the forming pressure, operator through the tool the work, recent development. Fig. clearly shows the dual lever type forming tool used the Young shop. The principal force ex- erted right angles the axis the lathe through the long lever. This lever pivoted the tool rest the lathe and moved the operator’s left hand. tool holder is, turn, pivoted this lever. The operator’s right hand guides the tool holder direction more less parallel the axis the lathe, though apparent that any curve can described the tool tip through judicious use the two arms combination. The lever handle used 110-in. lathe generally least ft. long. addition the threaded tool tips illustrated Fig. brass bar stock, in. diameter and foot long sometimes attached shorter holder. Several these are shown Fig. This arrange- ment means less time out for re- placing tips, and the bar can easily ground the shape desired for the job hand. Wheels are made wide variety sections, with diameters ranging from in. up- ward. The coefficient friction the forming tool tip and the piece spun must different; hence brass tools are used spinning steel, and steel tools are used brass, aluminum and copper. The wheel often used the softer metals because there less dan- ger scoring the metal, fault which would produce crack the metal was spun out. Flowing the metal evenly, the crux good spinning, skill that takes years acquire. The lubricant used practically all jobs the Young plant ordi- nary borax soap. dry cake simply held against the revolving work infrequent intervals. The oil pumps and drum storage the machine shop are replaced car- tons soap the Young plant, | where petroleum lubricants are rarely used. Forming place dies, the spinner uses wooden chucks, which generally turns his own shop. Maple, dog- wood, birch mahogany are the preferred materials, though Ma- sonite can used for aluminum spinnings because they not heat like those the other metals. Large wooden chucks are attached the lathe screwing them threaded metal adapter, which turn screwed the lathe spindle. Small wooden chucks are directly threaded. Chucks used for remov- ing taper and drawings are made metal, gen- erally cast iron, specifications call for complete removal taper, though wooden chucks require con- siderably less taper than drawing dies. Metal chucks are also used for pieces requiring polished in- terior finish. Spinning resembles drawing that number chucks may required produce the desired shape. The physical properties the various materials determine the number operations required, indicated Fig. The first oper- ation involves cutting circular disk from sheet stock. Its diam- eter and thickness are determined the thickness the piece turned out, coupled with the spin- ner’s knowledge the flow prop- erties and characteristics the metal specified. This circular disk liberally dry soaped, hand the center the chuck, and clamped position the chuck follower mounted the tail- stock. Thin gage stock, say from 36, spun shaft speeds ranging from 2200 2400 r.p.m., regard- less the material. Heavier stock, which may run in., spun shaft speeds low 200 r.p.m. Typical Applications Spinning’s usefulness product development may illustrated the peacetime problem manu- facturer soda fountain equip- ment. required only five spin- nings perfect the design part for which the drawing dies will cost several thousand dollars. The total cost the five spinnings was approximately $100. manufacturer lamp reflec- tors has worked out nice com- 8—Components, left, the collapsible chuck used spin the decor- ative aluminum piece the right. The sectioned chuck, mandrel, was cut into eight pieces with carving knife. 9—The possibilities spinning conjunction with stamping are illus- trated these three reflectors, spun from the plain stamping shown with them. huge frying pan for the armed forces. wooden disk the same diameter the base the pan fitted between the heavy steel spinning and the tailstock. clamps the bottom the pan and speeds the operation. manufacture the steel amplifier housing illustrated the left Fig. THE IRON AGE, July 16, 1942—47 bination spinning and stamping. which solved making one stamping and having three differ- ent necks spun on. The threads, course, were applied later. Fig. shows the sequence operations forming the housing for amplifier, where the quan- tity required comparatively small. This particular unit sub- jected very severe service, and originally spun aluminum lacked strength. The second design the sound-directing part involved two spinnings cold rolled steel, with the flange and the flared sec- tion spot welded together. This de- sign was tested and rejected for lack strength the welds, the final product being made sin- gle sheet cold rolled steel. The hemispherical part, simple spin- ning, remained the same all de- signs, and not included the above discussion. Trend Industrial Spinning takes three four years train man the point where can considered capable doing ordinary spinning. Mr. Young, who has been spinner for feels that takes most lifetime before man can con- sidered proficient the craft. Only about 3000 men are engaged spinning the entire country, and many cases their experience decorative objects, lamp bases, lighting fixtures and_ Hence, one expects the group grow leaps and bounds. The trend the industry today to- ward greater utilization its facilities the manufacture in- dustrial and war products, and expected that this change em- phasis will continue industrial- ists become more familiar with its potentialities. Conserving Alloy Steels Flame Hardening means oxy-acetylene flame- hardening, the new (Na- tional Emergency) steels can often used alternates for the standard alloy steels for such parts dies, shear blades, pump liners, and piston rods. Flame-hardening imparts maximum hardness the surface quench-hardenable steels without changing their chemical composition affecting the tough- ness and ductility the core metal. Parts can furnace treated, necessary, for special core prop- erties and then flame-hardened produce the desired physical qual- ities the surface. Flexibility the process and careful controls that may exercised permit the hardening effect restricted only those surfaces where needed, and the degree and depth hardness can accurately con- trolled. While urged upon every user alloy steels use wher- ever possible the mediate manganese, carbon-molyb- denum, manganese molybdenum, grades steel, flame-hardening widens the range uses for these low alloy types. Flame-hardening equipment light and easy operate, con- sisting one more heads which furnish oxy-acetylene heating flames, oil water quench, and means propelling the heating head and quench set speed turning the part being hardened. 48—THE IRON AGE, July 16, 1942 flame-hardening machine for hardening shafts was made from up-ended lathe. During hardening, the shaft rotated and the flames progress upward, followed ring quench. Photo courtesy Linde Air Products Co. Care Flux Light Alloy Welding GREAT deal the welding the light alloys the aluminum and magnesium series performed the flame process, which the two compo- nent parts are homogeneously united with the aid stick metal similar composition that the components themselves, suitable flux, and oxyacetylene flame. The aluminum and magnesi- alloys are strongly electroposi- tive and, given the right conditions, are prone rapid deterioration from corrosive influences. welding, and, unfortunately, all useful fluxes are strongly corrosive and moisture-absorbing chemicals. evident, therefore, that how- ever correctly weld may ex- ecuted give homogeneous mass the compositional and metallo- graphic senses, every care must taken using flux the proper required when wanted, that its functions are properly fulfilled, and that when the welding operations are completed flux remains the metal cause later cor- rosion. corroding, the flux does not become exhausted but continues eat away the metal progres- sive manner, often with increasing rapidity. The magnesium alloys being ap- preciably more electropositive than those the aluminum series ex- hibit failures from flux corrosion even more rapidly than the alu- minum alloys. With both series, however, troubles can completely avoided exercising care all the factors involved. The same The dangers corrosion the fluxes used welding aluminum and magnesium and their alloys have the past been well known, but welding these metals now be- ing undertaken many whom the difficulties are new. Therefore, the practical information herein, summariza- tion article that appeared Metal Treatment, Lon- don, handling fluxes particularly timely. principles apply, but for clarity the two groups will dealt with sep- arately. Aluminum Base Alloys The welding flux has two primary functions fulfill. Firstly, has cater for the natural oxide film that inseparable from aluminum alloys. has take this into solution rapidly and completely over the areas joined be- fore welding can satisfactorily achieved. Secondly, has pro- vide blanket over the heated metal order prevent minimize oxidation during welding. any oxide formed, the molten flux must available and capable removing dissolution. The function weld flux sometimes compared with that solder flux, but will noted that, where their roles coincide, the require- ments for the weld flux are the more stringent, and that has additional purpose. consequence, the formulation weld critical, proprietary brands are almost invariably used, and these are marketed concerns who have specialized aluminum alloy weld- ing. Generally, fluxes comprise uniform mixtures alkaline hal- ides, usually the chlorides and flouorides potassium, sodium and lithium. All the constituents the flux tend corrosive towards alum- inum alloys, and actively under damp conditions. The latter inev- itably arise due the deliquescent nature the flux mixture. Contact therefore rapidly followed attack, the primary reaction being towards the production alkali aluminate and Aluminum halide hydrolized the presence moisture alumi- num hydroxide basic halide and with the libration halide acid, either hydrochloric fluoric acid. This immediately attacks more aluminum, forms halide, which turn again hydrolized acid. the cycle goes on, corrosion pro- ceeds progressively until the alu- minum consumed. not un- THE IRON AGE, July 16, 1942—49 — nly ind es, to- its al- its . = ° ° usual for welded joints that have not been effectively freed from flux corrode through and fail completely within few weeks. Complete removal from welded joint not simple would appear first sight, and effective treatment can only result from the proper observance number principles. The flux should used sparingly, applied the proper manner, contamina- tion adjacent surfaces splash- ing handling avoided, and the junction, designed minimize flux inclu- sion. Washing treatments should follow immediately after comple- tion the welding operation. The standard technique for ap- plying flux heat the end the weld stick, dip the flux and withdraw tuft the powder. Then, inverting the stick and warming it, the flux forced run down the stick and provide glaze extending about six inches. flux applied directly the job, the reservoir flux the stick feeding where required during the actual welding process. this way only possible provide adequate flux for the pur- poses required, yet conserve its use, minimize splashing and spread over surfaces, and keep the amount driven between mating sur- faces low possible. There are, course, restricted number specific instances when application flux the job itself cannot avoided, for example, joining very thin gage sheet. Incidentally, should not necessary stress that work for welding must clean, free from oil, grease, corrosion products and extraneous degreasing sufficient most cases, but scouring with stiff wire brush additionally useful for dirty work. The most favorable design for welding the butt joint, although again this not always practicable. The aim should achieve pene- tration the weld metal through the thickn