The Iron Age 1933-12-28: Vol 132 Iss 26

1-Oxi- 7 ntact } pot, and re of ly or nto a > die. arily f the vhich | the the this the » the nger r, a 1 for This frac- illow 2 air olid- nent new tage com- ting. ark- ob- eth- | @X- ‘on da per ina- sing per flec- ised The ect- cent ally ent, ‘his ent It ; in Lwn hed ga- ( INTH YEAR OF SERVICE TO THE METAL WORKING INDUSTRY MANAGEMENT DECEMBER 28, 1933 PROCESSES ye THREE MORE CARDS ON THE TABLE NDER the caption “All Of The Cards On The Table” The Iron Age recently published, on this page, facts concern- ing 39 reader-interest investigations conducted by advertisers among their own customers. Three additional tests of reader-interest by a cutting tool manu- facturer, a belting manufacturer and an oil refiner have been made lately, in each of which The Iron Age was first, bringing the total number of such investigations up to 42. In fact, only 3 papers rose to first position in the 42 separate investigations by 42 different manufacturers. The Iron Age was in first place 30 times out of 42. Publication “B” was first 11 times, and publication “C” was first one time. The 42 investigations represent 10,500 replies from prominent production, engineering, administrative and purchasing officials of which The Iron Age polled 7,537 votes. There was no close second publication in the estimation of this large body of metal-working executives. In every industry there is one publication which stands out above all others. In the metal-working industry the results of 42 investi- gations point the way as clearly as a highway sign-post—to The Iron Age CONTENTS INDEX PAGE 5 -:- NEWS 1933 THE IRON AGE...DECEMBER 28, Page 2 Ae ee ft ase Se At your service ... THE NEW DEPARTURE ENGINEERING LIBRARY There’s more than bearings to bearing performance ANUFACTURERS are depending more and more on New Departure’s engineering experience and ingenuity for economical manufacture and assured performance. » » » New Departure has never been satisfied just to make a bearing — and let it go at that. » » » New Departure’s product is ideas as well as bearings — and its ideas have pioneered new bearing practice since the industry began. » » » And New Departure will continue to research and originate for the benefit of the industry. The results are always available upon request. The New Departure Mfg. Co., Bristol, Connecticut; Detroit, Chicago, San Francisco and London, England. — ——_—_————————— —_ = ee THE IRON AGE, published every Thursday by the TRON AGE PUBLISHING CO. Publication Office: N. W. Cor. Chestnut & 56th Sts., Philadelphis, Pa Executive Offices: 239 W. 39th St., New York, N. Y., U. S. A. Entered as second class matter at the Post Office at Philadelphia under of March 3, 1879. $6.00 a year in U S., Canada $8.50 Foreign $12.00. Vol. 132, No. 26 ..- THE IRON AGE .. December 28, 1933 J. H. VAN DEVENTER G. L. LACHER W. W. MACON r. H. GERKEN R. BE. MILLER Editor Managing Edito Conaulting Editor News Editor Machinery Edit« F. J. WINTERS G. EHRNSTROM, JR BURNHAM FINNEY GERARD FRAZAR Pittsburgh Detroit Boaton I I PRENTIS Kk. A. Fisk? A. I. FYNnDLeyY L. W. Morrer1 k. G. MecInrTosH Cleveland Chicago Editor Emeritus Washinaton Cincinnati Contents Determining Upper Critical Points of Steel Malleable Casting by Duplex Method ee ee Methods of Rolling Sheets Collective Bargaining or Government Wage Fixing? Products and Processes Steel Supersedes Wood in Beer Barrels Artist Joins Engineer in Design Die Casting, or Stamping? New Equipment News Personals and Obituaries Washington News Automotive Industry Markets Construction and Equipment Buying Products Advertised Index to Advertisers THE IRON AGE PUBLISHING COMPANY F. J. FRANK, President G. H. GRIFFITHS, Secretary Cc. S. BAUR, General Advertising Manage PUBLICATION OFFICE: N. W. Corner Chestnut and 56th Sts., Philadelphia, Pa. EXECUTIVE OFFICES: 239 West 39th St., New York, N. Y., U. §. A. Member Audit Bureau of 0 1DVERTISING STAFF Member Associate usines Emerson Findley, 311 Union Bldg., Cleveland B. L. Herman, 675 Delaware Ave., Buffalo, N. Y H. K. Hottenstein, 802 Otis Bldg., Chicago ription Price Peirce Lewis, 7338 Woodward Ave., Detroit Cuba, $6.00 Charles Lundberg 4 Kent Rd Upper Darby €12.00 Del. C Pa ( H. Ober, 239 West 39th St New York W. B. Robinson, 428 Park Bldg., Pittsburgb W. C. Sweetser. 239 West 39th St New York PD. C. Warrs P. ©. Box 81, Hartford, Conn sigr eign OF SERVICE TO THE METAL WORKING INDUSTRY _ el hiladelphia, under Ac THE IRON AGE DECEMBER 28, 1933 Page 6 4 by . ry & ae % Ser “S 7 s rind Wea piel \ oe ANE “Caen SINCE 1842 Now is the Time To Buy§Immediate Steel Immediate steel makes it possible to take advantage of every sudden change in vol- ume—to gear purchases to fidgety produc- tion schedules—and it frees profit from the drag of slow material deliveries. Immediate steel—ready to use—is quick- ly available from ten strategically located Ryerson plants. It includes the full range of sizes and kinds of steel products, making it easy to concentrate purchases and save time, trouble and money. Unparalleled facilities for cutting, handling and _ ship- ping, developments of almost a century of steel-service, assures accuracy and de- pendability. @@ Buy immediate steel just as you need it for your job or shop and keep capital free for the operation of your busi- ness. @ There is no order too large for im- mediate shipment nor too small for personal attention. Bars Refined Iron Boiler Tubes and Babbitt Metal Concrete Reinforcing Structurals Turned Ground and Fittings Bearings Floor Plates Rails Polished Shafti Mechanical Tubing Billets Copper Plates wren eee Rivets and Bolts Tool Steel Brass Sheets, Blk. & Galv. Screw Stock Welding Rod Alloy Steel Small Tools Sheets, Full Finished JOSEPH T. RYERSON & SON, INC. Strip Steel Forging Bars Stainless Steel Machinery, etc. Plants at Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City L Y) © & E ESTABLISHED 1855 ... THE IRON AGE ... DECEMSER 28, 1933 Vol. 132, No. 26 Upper Critical Temperature (Ac,) of Steel as Affected by Various Elements By. LT. COL. ROBERT R. ABBOTT Metallurgical Engineer, White Motor Co. LL heat treaters must of necessity know the upper critical temperatures of steels in order to secure optimum physical properties upon quench- ing. The higher the quenching temperature above Ac, the more coarsely crystalline will be the resulting steel, and the finest possible structure fol- lows from quenching as close to Ac, as possible. With the usual routine chemical analysis of a steel at hand, a treater can now quickly determine the quenching temperature by using the equa- tions developed in this article, or by employing the simplified and self- contained tables on the accompanying insert. The small shop should profit from this information, for by the elimina- tion of the guessing factor, it will be possible to produce a superior and more uniform product. This work, presented Dec. 11 at a joint meeting of the Cleveland chapter of the American Society for Steel Treating and the Cleveland section of the Society of Automotive Engineers, represents the most pretentious effort of its kind, and probably transcends the cor- responding determination of the effect of impurities on the position of Ac, and Ar, by Howe, Osmond, and others. O PROCURE the most efficient heat treatment of steel, it is ex- tremely important that the upper critical temperature be known within narrow limits. It is of industrial im- portance that, by a chemical analysis, the critical point (Acs) can be de- termined. The following report gives complete data regarding the elevation or depression of the upper critical point as a result of usual additions to steel of carbon, phosphorus, sulphur, chromium, manganese, nickel or sili con, For investigation, the approxi mately 400 bars of steel were obtained Ww from various manufacturers in the United States and foreign countries. » far as possible, ob % -in. These tained sizes. repeated varieties were, S¢ annealed In all cases the annealing was The samples of s in teels included obtainable, diamete) all ana each variety group contained sample with various carbon contents. Samples from each bar were exam ined microscopically and, if this was normal carded. each analyses end, amoun Drillings and were ts, the we found bar ‘re taken exhaustive made = é for all for segregation, in more than dis [rom was chemical possible elements. If excessive differences were found in the two ends, the bar was discarded. By means of a differ- ential pyrometer, heating curves were made on each steel, and the upper critical point determined within about 10 deg. C. A 10-in. section was then taken from each bar and machined down 1S in. in diameter and notched with 16 sections. The notch- ing facilitated breaking off of sections at various points throughout the ex- periment. to Accurately Annealed in Lead The otched bars were all thor- oughiy annealed by very slow cooling in lead until a microscopic examina- tion of the samples showed good pearlite structure well separated from the ferrite. The lead annealing pot contained about two tons of lead, and was fitted with a platinum resistance pyrometer accurate to within less than 1 deg. C. over a range of 200 deg. C. The notched bars were grouped in accordance with their upper critical points and placed in the furnace, which was heated at a rate of about 2 C. deg. an hour. At a temperature 10 deg. below the critical point, as determined previously with the dif- ferential pyrometer, the bar was drawn from the lead, quenched in water, and one section broken or sawed off. It was then replaced and another section removed at 5 deg. below, another near the assumed crit- ical point, and others at 5 deg. and 10 eg. above the‘assumed critical point. ‘*hese five quenched buttons were ex amined under the microscope, thereby finding the last absorption of ferrit« ( T within a 5 deg. range, or, in othe established the Ac, point ; words, vithin 5 C. deg. After this determination was made the same process was repeated within the narrowed limit of 5 deg., and six buttons were quenched 1 deg. apart, and by microscopic examinations the Ac, point was determined to within 1 C. deg. Effect of Various Elements In order to find the effect of diffe: ent elements upon <Ac,, the mass experimental data had to be analyzed squares, e- by the method of least cause of the number variables and ize of figures involved. Only the re ults are of value; therefore n tempt will be made to p ray the mathematical complexities leading to the final solutions. \ preliminary determination wa made of the effect of carbon on Ac,, using 36 plain carbon steels of various carbon contents, and pnoring tne effect of sulphur, manganese, silico! and phosphorus. The experimenta lata reduced mathematically t T—90 » 20 ¢ where 7 is the centigrade temperature of Ac., and C the carbon content ex pressed in hundredths of a per cent. For the preliminary determinatio! f the effect of manganese upon Ac 24 earbon steels were used containing only normal amounts of silicon, phos- phorus, and sulphur. These steels were selected with a fairly narrow carbon range (0.14 to 0.34 per cent), but with a manganese range from 0.17 to 1.61 per cent. When the effect of the carbon A depression is mathematically elimi- nated, the equation is found to be (2) T—903—0.2 manganest 725 Mn The preliminar y determination therefore indicates that 0.01 per cent manganese lowers the Ac, point 0.27 C. deg. No corrections have been made for phosphorus, sulphur or silicon in therefore, thes« these steels, and, equations are merely a step toward the final solutions. Following the same experimenta and mathematical procedure, the fol owing additional tions were found: preliminary equa a, aos 0.428 where . phosphoru 1/1000 of a per cent; the equation in licates that 0.001 per cent raises the Ac, point 0.4282 C. deg. expres a in phosphorus (4) T=—910-+1 where silicon is expressed in 1/100 of a per cent; the equation indic: 8—The Iron Age, December 28, 1933 0.01 per cent silicon raises the Ac point 0.3705 C. deg. The preliminary examinations of the effect of manganese, phosphorus, and silicon upon the upper critical point, and the mathematical equations are so far determined. Ewtensive sul- phur determinations show its effect to be negligible upon Ac,, and it is consequently omitted from further calculations. Since correction factors for phos phorus and silicon are now available, a more accurate determination otf equation (2) can be made by using Ac, temperatures corrected for phos phorus and silicon in accordance with equations (3) and (4). The result is (5) T=—898—0.3508 Mn (compare with equation 2) Using equations (3) and (5) on 35 steels, a second and more accurat« value of the influence of phosphorus is obtained. It is (6) 7 906+0.4506 P Correcting for manganese and phos phorus according to formulae (5) and (6), it is found that (7) T=—912+0.3570 Si A third determination of the effect of manganese after correcting for phosphorus and silicon according to (6) and (7) gives practically the same results as given in equation (5), and therefore, equations (5), (6) and (7) will be used as representing the effect of manganese, phosphorus and silicon on the Ac, point of carbon steels. Correction Factors Determined Three correction factors for the effect of manganese, phosphorus and silicon upon the Ac, temperature are now usable. These are as follows, from (5), (6) and (7): 0.01 per cent manganese lowers Acy by 0.8508 C. deg. 0.001 per cent phosphorus ratses Ac, by 0.4506 C. deg. per cent silicon raises Ac, by 0.3570 C. deg [These are not final figures, but wil be used to correct for the determina tion of the effects of chrome, nickel, and vanadium. The reason these are not taken as final is that they were determined only from plain carbon steels, and later many alloy steels will be included to obtain more veneral (and accurate) influences. Careful comparisons of the Ac. ¢o) rected temperatures of various steels with uride ly varying chromium de finitely showed that this amounts of clement has no appre ciable effeet upon the Ae The Ac, temperatures of 31 chrome- vanadium steels were corrected for manganese, phosphorus and_ silicon, and the effect of vanadium was de termined. The result can be expressed te mt pe rature. (Ss) 0.01 per cent vanadium raises As 0.2862 C. deg. This vanadium correction is an average. A great deal of work done upon it, however, indicates that vana- dium usually occurs in. small quan- tities in most steels, and the above value can be satisfactorily used for all steels with carbon contents below 0.54 per cent. In all the preceding work no dis tinction was made (or found, except as noted for vanadium) in low or high-carbon steels up to 0.54 per cent carbon. When nickel steels were ex amined, however, it was found that the effect was different, and consisted of two parts. The nickel determina- tions were consequently made in two sections and the final result was, (4) O.0OL per cent nickel lowers Ac, 0.23 C. deg. If the steel has a carbon content ubove that given by the equation C = 0.54 — 0.0006 Ni, subtract 2 C. deg. for each 0.01 per cent of carbon above that shown by the equation. For example, a 3.50 per cent Ni steel is first tested by C = 0.54 — 0.0006 Ni. [his gives carbon as 0.33 per cent. If the steel has less than 0.33 carbon con- tent, the correction applied is that of equation (9), but if it has more than 0.33 per cent carbon, subtract from this correction 2 deg. for each point r« the carbon is above 0.33 per cent. Final Solutions All the correction factors are now finished, and the basie effect of carbon on pure iron must be determined to give a point from which to start. About 236 steels were used for this, and their Ac, temperatures were cor- rected for all the affecting elements present, and the final equation for pure carbon-iron alloys was found to be (10) T=308—2.323 where carbon is expressed in hun dredths of a per cent. When carbon is 0, 7 = 908. This means that the Ac, point for the first trace of carbon is at 908 deg. C. This gives a basis to make a more accurate determination of the influence of the various elements given in the previous equations, since it can be assumed that 908 deg. C. is the fixed point fcr pure iron. All of the preceding determina- col Feels oT this (pon yme- for icon, dc sseqd At an done ana- uan- bove for ye low dis xcept Ww 6OI cent ex that sisted nina- 1 two ACs ntent ation Se arbon . For eel is 6 Ni. nt. If 1 con- at of than from point t. now arbon ied to start. this, e cor- ments n for ind to nun This e first !. This curate of the ‘evious d that r pure rmina- TABLE I Carbon Basic Temp. In 1/100 per cent Deg. C. 0 908 1 906 2 904 3 901 4 899 5 897 6 895 7 892 8 890 9 888 10 886 11 883 12 881 13 879 14 877 15 874 16 872 17 870 18 868 19 866 20 863 21 861 22 859 23 857 24 854 25 852 26 850 27 848 28 845 29 843 30 841 31 839 32 836 33 834 34 832 35 830 36 827 37 825 38 823 39 821 40 819 41 816 42 814 43 812 44 810 45 807 46 805 47 803 48 801 49 798 50 796 > | 794 52 792 53 789 54 787 C. Deg. Correction Nfaueswne © om -~CSoee Stet ttt tt Ne OoOweoemnnues WwW WW uu S IN NNN WN w wwwwwwwewntwnt WN Ww aOwnekr wnree OVO D ~s w @ 39 40 41 42 43 44 45 46 47 48 49 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 Determination of Upper Critical Point From Ch Pho-«c .orus .000 Add) So eoomeoonnnsn Oke On UN © oo — & 93 - 95 97 100 102 104 107 109 111 113 116 118 120 123 125 127 129 132 134 136 138 141 143 145 148 150 152 154 157 159 101 103 106 108 110 112 115 117 119 122 124 126 128 131 133 135 137 140 142 144 147 149 151 153 156 158 160 TABLE Il Silicon In 1/100 Add nNnoawn Oo Un WN NN | = = ow tN Ccwewenmremeenntnrtanqnaaua4n#h & & WS Ww aes eh ee Dee Dee OU OHM OU cn) 101 104 107 110 114 117 120 124 127 130 133 137 140 143 146 150 153 156 160 163 166 169 173 176 179 183 186 189 192 196 199 103 106 109 113 116 119 123 126 129 132 136 139 142 145 149 152 155 159 162 165 168 172 175 178 182 185 188 191 195 198 201 Vanadium In 1 100 Add) Manganese In 1 100 102 105 108 110 112 115 118 121 124 127 130 133 136 138 141 144 147 150 153 156 159 162 - 165 168 170 173 176 Subtract 104 107 109 111 114 117 120 123 126 129 132 135 137 140 143 146 149 152 155 158 161 164 167 169 172 175 178 C. Deg. Correction Sn PuekwneK oO 177 181 185 337 - 342 346 350 355 359 364 568 72 377 381 385 390 394 $98 403 Nickel In 1 Subtract BSD BD ES SS et tt tt Se ODSODPDIiAAHS n ne w& bo a te NN WN ND a NN 0 tte BN NS tN i Vs 2 a WWW ewWwweweww = one : ritical Point From Chemical Analysis IRECTIONS for using the convenient tables for a quick determi upper critical point of steel from the chemical analysis: From 1 TABLE III ; ; . mine the basic temperature from the carbon content of the steel. Il and Table III determine the number of degrees to be added to « inganese C. Deg Nickel In 1 100 ; : : a ; n 1 100 Correction Subtract from the basic temperature for the phosphorus, silicon, vanadium patract and nickel contents of the steel, noting from the signs under 1 0 1-2 whether the correction is added or subtracted. From Table IV ( 4 i 3-6 steels containing nickel) make an additional increase in te mperat 7 3 1 . sary. To use Table IV observe the following procedure: Find nick 10 : > 3 steel in first column. If the corresponding figure in second colun 13 , « “- . : : : ar a .Z 6 24-28 than the carbon content of steel this correction is not used. If it is 7 29 — 32 : . 18 8 33 — 36 it from the carbon content of the steel and add double this amour e 9 37 - 41 sa - “ 10 2-45 temperature, ; - a 46 - 49 Example: Find the upper critical temperature (Ac;) of a st 27 2 50. 54 . ° . ; . ~ . » - 30 13 55 - 58 following chemical analysis: C, 0.40; P, 0.017; S, 0.23; Mn, 0.74; 33 . 4 o- 0.37; Si, 0.20. Sulphur and chrome have no effect and are ignot 36 7 68 - 71 shows basic temperature of 40 carbon to be 819 deg. C. From Ta . 72-76 : ; aa ; ¥~ 30 18 77 - 80 deg. for phosphorus, 6 deg. for silicon, and subtract 25 deg. for 42 : = ie a : 3-4 > i. a From Table III, an additional 70 deg. must be subtracted for the 1 46 47 = o 7 a net temperature of 737 deg. C. Since the steel contains nickel T; 48 - 50 23 98 - 102 also be used. From Table IV, carbon corresponding to 3.03 pei 24 103 - 106 on ke 2 , . —— 25 107 a is 36. This is less than the 40 carbon of steel, therefore subtract 4-56 ; s ; ; ested | 7-9 ++} oom and double the result which gives 8 deg. Add this to 737 deg., whi 50 — 62 28 120 - 123 deg. C. as the final Acs temperature. 29 124 - 128 B3 - 65 30 129 - 132 56 - 68 31 133 - 136 e171 32 137 -141 TABLE III TABLE tv a 33 142 - 145 2-74 7 34 146 - 149 ; Sed ; 5-76 35 150 - 154 C. Deg. Nickel In 1 100 Special Nickel Correct 7-79 36 155 —- 158 Correction Subtract For High Carbons) , 37 159 - 163 BO - 82 38 164 — 167 : B3 — 85 39 168 -171 94 407 - 410 Nickel In 1 100 Carb BG _ 88 40 172 — 176 95 411-415 o 41 177 - 180 96 416-419 BS 91 42 181 184 97 420 -423 0-8 p2 94 43 185 - 189 = le = 9 25 : 44 190 - 193 ‘ 2 2 pe - 97 45 194 — 197 100 433 - 436 26 - 41 B8 - 100 46 198 — 202 101 437 - 441 42 -58 2-104 47 203 - 206 102 442 - 445 59 - 75 107 48 207 - 210 103 446 - 449 76-91 5 49 211 -215 104 450 - 454 : 8 - 109 50 216 —- 219 105 455 - 458 92 -108 0-111 51 220 - 223 106 459 - 463 109 - 125 F 52 224 - 228 107 464 - 467 aa pe 53 229 — 232 108 468 - 471 126 -141 5-117 54 233 — 236 109 472 - 476 142 - 158 8 - 120 55 237 - 241 110 477 - 480 159 - 175 3 56 242 - 245 111 431 - 484 176 -191 1 - 123 7 246 — 249 112 485 - 489 4-126 58 250 — 254 113 490 - 493 192 — 208 7-129 59 255 - 258 114 494 - 497 209 - 225 9 60 259 - 263 115 498 - 502 226 241 0 ~ 132 61 264 — 267 116 503 - 506 226-2 3-135 62 268 — 271 117 507 - 510 242 - 258 6 — 137 63 272 - 276 118 S11 -515 259 - 275 64 277 — 280 119 516 -519 27 291 6 - 140 65 281 — 284 120 520 - 523 276 ~ 2s 1-143 66 285 — 289 121 524 - 528 292 - 308 146 67 290 - 293 122 529 - 532 309 — 325 68 294 — 297 123 533 - 536 326 - 341 “eee 69 298 — 302 124 537 - 541 < 152 7 303 - 306 125 542 - 545 342 ~ 358 155 71 307 - 310 126 546 - 549 359 - 375 72 311-315 127 550 - 554 376 - 391 6 - 158 73 316-319 128 555 - 558 9-161 74 320 - 323 129 559 - 563 392 - 408 ~ 164 75 324 - 328 130 564 - 567 409 - 425 76 329 - 332 131 568 - 571 426 - 441 167 77 333 - 336 132 572 -576 8-169 78 337 — 341 133 577 -- 580 442 —- 458 172 79 342 -345 134 581 - 584 459 - 476 . 80 346 - 349 135 S85 - 589 477 - 491 175 81 350 — 354 136 590 - 593 . 178 82 355 — 358 137 594 597 492 508 83 359 — 363 138 598 - 600 509 525 84 364 - 367 526 541 85 368 371 pede 86 372 -376 542 558 87 377 - 380 559 - 575 88 381 - 384 576 ~591 89 385 389 a 90 390 393 092 - 608 91 394 397 92 398 402 93 403 - 406 The Iron Age, | juick determination of the lysis: From Table I deter- of the steel. From Table be added to or subtracted yn, Vanadium, manganese igns under each column Table IV (only used in in temperature if neces- e: Find nickel content of second column is greater sed. If it is less, subtract ie this amount to the Ac Acs) of a steel with the }; Mn, 0.74; Ni, 3.03; Cr, nd are ignored. Table I C. From Table II, add 7 25 deg. for manganese. ‘ted for the nickel, giving 1ins nickel Table IV must r to 3.03 per cent nickel ‘fore subtract 36 from 40 rar 737 deg., which gives 745 TABLE (tv 1 Nickel Correction High Carbons) Carbon In 1 100 54 53 52 51 50 49 48 47 46 45 44 43 2 41 40 39 38 37 36 35 x SNS NNN WN NS wueoeuann tS tw e Iron Age, December 28, 1933 rs] tions were then repeated and the fol lowing represent final effects. Ac, for pure iron is 908 deg. C. (first trace of carbon). 0.01 per cent carbon lowers Acs by 2.237 C. deg. 0.001 per cent phosphorus raises Ac, by 0.4385 C. deg. 0.01 per cent silicon raises Ac, by 0.3049 C. deg. 0.01 per cent vanadium raises Ac, by 0.3792 C. deg. 0.01 per cent manganese lowers Ac, by 0.3443 C. deg 9.01 per cent nickel lowers Acs by 0.23 C. deg. (but increases it by 2 (C — 54 + 0.06 Ni) nrovided the quantity in the bracket is positive). All of the above can be expressed as a single equation as follows: Temperature of At 908—2.237 ¢ 1.4885 P + 0.3049 Si 0.3792 V 0.3443 Vn 0.23 Ni 2 (¢ 54+-0.06 Ni) elements are ¢ where all the in hundredths of a pe rpresse¢ d cent, ¢ ree pt phosphorus which is in thousandths. If the quantity in the last bracket is negative it is omitted. Example: What is the Ac, tem- perature for a steel with the analysis, C, 0.40 per cent; P, 0.017; S, 0.23; Mn, 0.74; Ni, 3.08; Cr, 0.87; Si, 0.20? The sulphur and chrome have no effect and are therefore neglected. Ac; temperature = 908 2.237 x< 40 0.43885 «* 17 0.3049 «x 20 — 0.3443 74 0.23 «x 303 2(40 54 + 0.06 X 303) 745 deg. C The actual Ac, temperature found by experiment on this steel was 748 deg. C. For heat treatment this steel] should be quenched from slightly above 745 deg. C. Additional example: Consider the heat treatment of steel such as S.A.E. 3135. This steel has a range of ele ments instead of a definite analysis, and to get the correct heat treatment, all of the equations must be applied Performance of Cutting Fluids When Sawing Metals UTTING fluids appreciably affect the rate of dulling of tungsten- steel hacksaw blades. Consequently they affect the time necessary to cut a given cross-section when operating under a given feed pressure. A cut- ting fluid giving a short sawing time with a sharp blade does not neces- sarily give relatively short times after the blades become dull. Shorter saw- ing times and least wear on the saw blades were experienced when using sulphurized oils. The 1 to 50 emul- sion was found to be better than a straight mineral or a mineral-lard oil. The foregoing observations were made in progress report No. 5 of the subcommittee on cutting fluids of a special research committee on cutting metals of the American Society of Me- chanical Engineers. The report, which was prepared by Prof. O. W. Boston and C. E. Kraus, College of Engi- neering, University of Michigan, Ann Arbor, Mich., was presented to the annual meeting of the society in New York, and was in part as follows: Tests were conducted on a Peerless high-speed 9-in.-capacity power hack- saw at the University of Michigan. The time required to saw off a 114-in. Square section of Bessemer screw stock was recorded. The conclusions arrived at are based on fixed condi- tions; that is, a specific saw blade op- erating under a constant tension with the feed lever in the twelfth notch, giving a maximum feed pressure of 119 lb. and with a constant cutting speed of 120 strokes per minute for the 6-in. length of stroke. S.A.E. 1112 steel, cold drawn to a 1%-in. square section, was used in the tests, An emulsion of 1 part solu- ble oil to 50 parts water was first used with a high-speed-steel hacksaw blade, 17 in. long, 1 in. wide, 0.065 in. thick. It had six teeth per inch, with a set of right, left, two straight, and cut a kerf of 0.082 in. The sawing time of this blade was found to in- crease uniformly from about 1.3 to 1.4 min, in the first 30 cuts (67% sq. in. of metal), after which there was no appreciable change in cutting times. The test was stopped after the sixty-fifth cut, and the blade showed no visible indication of wear other than polished tooth points. Further tests were then run using tungsten steel blades to reduce the time of the wear tests. These blades were 12 in. long, % in. wide, 0.049-in. gage, hav- ing 14 teeth per inch set right, left, straight. The four cutting fluids used were the 1 to 50 emulsion, a light mineral oil, a mineral- (10 per cent) lard oil, a sulphurized mineral oil. For the tungsten-steel blade with the 1 to 50 emulsion, a marked in- crease in sawing time was found up to the fifteenth cut and a more gradual and non-uniform increase to the sixty- fifth cut, after which the time in- creased rapidly for each successive cut. The teeth at the end of the test were worn down about one-fifth of their height so that very appreciable flats were visible. One tooth was broken out. When the mineral oil was used the cutting time was increased more rap- idly than with the emulsion. At the end of the test nearly one-third of the height of the teeth were worn off and three teeth were broken out. The gereatest rate of dulling was found with the mineral-lard oil, which The Iron Age, December 28, 1933—I1I in such a manner that there is found the lowest and highest Ac, which is possible to get if the elements occurred first so that everything tended to give a low Ac,, and second if they tended to give a high Ac, If they are grouped according to lowest and highest effects, there is found: Basic temperature (908 and 908), carbon —89.5 to —67); phosphorus (0 to 17.5); silicon (4.5 to 9.0); manganese (—27.5 to —17.0); nickel (—34.5 to —23). The Ac, temperature is, there- fore, 761 deg. C. for a minimum, and 827.5 deg. C. for a maximum. Since it is extremely improbable that a steel would have a combination of elements to give either the high or low Ac., the quenching temperature could be taken as midway between the two extreme temperatures. It is often advisable to add about 15 C. deg. to the calculated quenching temperature in order to allow for inaccuracies in furnace pyrometers and metal analyses. showed a low sawing time for the first cuts, but was more than doubled in the 65 cuts taken, increasing from 1.5 to 3.3 min. The blade showed some- what more wear than with the min- eral oil and had six teeth broken out. The sawing time when using the sul- phurized mineral oil increased slowly up to the twentieth cut, after which it increased more rapidly. At the end of the test, however, very little wear was apparent on the teeth. The time per cut for the first, fifth, twentieth and sixtieth cuts for the four cutting fluids is as follows: The emulsion, 1.7, 1.8, 1.9 and 2.2 min.; the mineral oil, 1.9, 2.1, 2.3 and 2.9 min; the mineral-lard oil, 1.5, 1.8, 2.2 and 3.2 min.; and the sulphurized -nin- eral oil, 1.4, 1.5, 1.7 and 2.1 min. Using a new high-speed-steel blade and a given cutting fluid, three series of cuts were taken on each of eight metals tested. The metals were a cast aluminum alloy, S.A.E. 33; a rolled leaded free-cutting brass; cast iron; malleable cast iron; and four S.A.E. steels, 3150, 1020, 1035 and 1112. The 11 cutting fluids were dry cut- ting; 1% per cent borax in water; 1 to 50 emulsion; 1 to 10 emulsion; No. 1 lard oil; light mineral oil; heavy mineral oil, mineral, (10 per cent) lard oil; a 5 per cent oleic acid-min- eral oil; a sulphurized mineral oil; and a sulphurized-lard mineral oil. The time for the first cut in each metal was low and varied most from the average of the three cuts. This was particularly true for the brass and free-cutting steel. Considerable differences in the time required to cut with the different cutting fluids were noticed, and their effectiveness varied with the metal sawed. The cutting fluids had least effect on the alumi- num, malleable cast iron, cast iron and brass, and most effect on the steels. The two sulphurized oils con- sistently gave shortest cutting times. HE malleable castings process with which the author is familiar uses the cupola and the electric furnace by which is regularly ob- tained castings having a minimum tensile strength of 70,000 lb. per sq. in, of cross section by maintaining an annealing cycle of approximately 24 hr. It would seem that a small plant desiring to produce, for instance, 35 tons of salable castings daily might entertain the installation of a small continuous melting cupola from which 60 per cent of the charge of the elec- tric furnace might be provided. The introduction into the mixing ladle of a de-sulphurizing agent will eliminate the high sulphur content of the cupola metal, making it even possible to use gray iron machinery scrap = and briquetted ferrosilicon in lieu of pig iron to be mixed with the returned sprues in the cupola. The cheapest steel scrap available is perhaps structural steel or boiler plate rivet hole punchings. Forty per cent of this steel or shearings du- plexed with 60 per cent of molten cupola metal in an electric furnace should not consume over 250 kwhr. per ton poured into the molds. If the metal is all melted cold in the electric furnace, the product per day is limited to a smaller tonnage per hour and an electric current con- sumption of nearly 600 kwhr. per ton poured into molds is to be expected. An appreciable amount of electric current is consumed in heating up an electric furnace. Utility companies selling current (to offset an unbal- anced load through the 24 hr.) offer inducements to make it mutually de- sirable to operate electric furnaces through the night as well as during the day. This would require 24-hr. cupola service, and, if necessary, hav ing the molds made during two or three molding shifts to take this in- termittent product of the electric fur nace. The Case of a 60-Tons-a-Day Output An ideal arrangement would be the casting of a certain tonnage daily of gray iron as an auxiliary product to the malleable iron to be produced. Thus in the event the electric furnace 12—The Iron Age, December 28, 1933 By CLARENCE B. TEETER cannot take the accumulated con- tinuous flow from the cupola, this ex- cess would go into the gray iron cast- ings. As this discussion deals entirely with the production of malleable cast- ings, we shall assume that only a small amount of gray iron castings is desired. If a large amount is likely, a larger cupola diameter should of course be anticipated. Assuming that we shall wish to pour 60 tons daily into malleable castings and 8 to 10 tons daily into gray iron castings, we would consider a cupola lined down to melt 2 tons an hour and capacity for a product from the elec- tric furnace of 3 tons an hour. Two such cupolas would be required, one being cooled off and repaired while the other is running during the 24 hr. As utilities companies have heavy peak load periods in the larger cities, many of them offer special rates to plants using considerable current, if these ease off the load during the peak periods. For this reason, it would be well to arrange an operating schedule whereby the electric furnace would not be used during the hours of 6 a. m. to 8 a. m., or from 4:30 p. m. to 6:30 p. m. This would mean 20 hours of actual operation of the electric fur- nace, or 60 tons turned out in the 24- hr. day. The cupola properly slagged can operate for 22 hr., furnishing no cupola metal during one of the two electric furnace shutdown periods. The cupola melting from 6:30 p. m. until 4:30 p. m. the following day would hence turn out 44 tons of gray iron, 35 tons of which would go into the electric furnace to make the 60 tons for malleable iron molds. The sprues (gates, risers and defec- tive castings) from 60 tons of mal- leable iron molds would be approxi- mately 25 tons daily and from the gray iron castings would come an ad- ditional remelt of about 3% tons, both of which added to 15% tons of pig iron or gray iron foreign scrap and ferrosilicon would produce the desired 44 ton daily product of the cupola. To 35 tons of this molten cupola metal would be added 25 tons of steel scrap to result in the 60 tons of molten product from the electric furnace in 24 hr. From the above practice we would then obtain about 35 tons of salable malleable castings and about 5% tons of salable gray iron castings in a period of 24 hr., by using 15% tons of gray iron machinery scrap with a little ferrosilicon and 25 tons of the cheapest steel scrap. Certainly that should result in a very low cost per ton for raw materials and melting fuel. The Labor Personnel Required Now let us consider the labor per- sonnel: <A cupola tender at the spout, an electric furnace attendant, two cupola and electric furnace chargers, a man to distribute molten metal by trolley ladle to the molding floor, and a straw boss over this gang, who would also pour a few gray iron molds intermittently as required. These six positions throughout 24 hr. would call for a total of 24 men, each working 6-hr. shifts. Add to these one 6-hr. shift of two men employed for cupola and ladle repairs and we find that 26 men or 156 man-hours will supply the 40% tons of salable castings each 24 hr. It will readily be seen that with this continuous melting operation requir- ing perhaps two or three molding shifts during the 24 hr. day, an inex- pensive installation of mechanical equipment for continuous molding, pouring and sand conditioning might later be entertained. The author knowingly risks the disapproval of many readers in this premise, for such a layout of mechanical equipment is 4, Malleable Castings by the), - a_i. nak “Se aie Gated | 4 eee 6 Oe lhe helDuplex Method . . » to 60 C- 1. i- ne d- th ig od al \p n ye of it p 1s st iz z ~~ ae eV oS as unorthodox to the average mal- leable foundryman as would be a pro- posal at this time to the more progres- sive minded that we perhaps install a set of photoelectric cells and arrest some of the energy of the cosmic ray and abounding planes to run our foundry machinery and furnaces in the future. We will accordingly put discussion of this possibility aside for the next few years, but the matter should not be disposed of without stating that we surely have plenty of good engineers who should have the ability to devise a very simple, practical and inexpen- sive mechanical layout that would be adaptable to the changing nature of the trade catered to, and even to short order jobbing work, as well as to a strictly specialty shop. A _ specialty shop layout should and could be avoided as well as a too elaborate investment which would not function with good results in, God forbid, fu- ture periods of depression with the plant more or less idle. Such a revolutionary equipment installation should make possible a foundry opera- tion whereby 35 tons of salable cast- ings daily would be produced with less than 2 man-hours per ton to cover all molding, pouring and the _ inci- dental foundry labor required. An Annealing Cycle of 24 Hr. Castings from this electric furnace process may be annealed in a complete cycle of 24 hr., leaving the annealing oven at a temperature of about 1100 deg. The tensile strength of these castings should be a minimum of 70,- 000 lb. per sq. in. of cross section and, with an added treatment after leaving the annealing oven, it is possible to increase the tensile strength in excess of 90,000 lb. with no great amount of added time interval, labor or other expense. To accomplish this daily anneal on a relatively high or normal production per day, a specially design- ed continuous oven should be contem- plated. It has been found that cast- ings from this metal were thoroughly annealed by following a regular rou- tine of holding them at annealing temperature for a period of only 4% hr. and cooling as rapidly as 40 deg. per hr. It is therefore safe practice to di- vide the 24 hr. of the cycle into five parts of 4% hr. each. The first period of 4% hr. would be consumed in rais- ing the castings to annealing tem- perature, the second 4% hr. would be devoted to soaking the castings at an- nealing temperature, the third and fourth periods of a total of 9% hr. would be consumed in cooling the castings from annealing temperature to a temperature approximately 300 deg. lower, and the final 4% hr. period would be consumed in continuing the cooling to approximately 1100 deg., when they may be removed from the oven to cool as rapidly as possible in the building or out of doors. The 24-hr. cycle being divided into five parts, it follows that the oven should be divided into five units or chambers (four chambers, as the first cooling chamber would be of double the length of the others). To de- termine the length of these chambers it must first require that the daily tonnage be considered. Assuming an average daily annealing requirement of 25 tons and considering a twin oven or two parallel integral tunnels served by a common flue between them, this would mean that each of the twin compartments would be re- quired to handle 12% tons. Size and Design of Annealing Oven These 12% tons split into five parts would mean 2% tons for each unit of length of the oven, so that a length of 12 ft. and a width of 5 ft. would be required to anneal a layer of cast- ings averaging 83 lb. per sq. ft. of surface. This would be a fairly shal- low layer of castings, which might with safety be slightly increased if needed. A 25-ton daily anneal, 7 days a week, would take care of the 35-ton daily production of castings from the foundry operating five days per week. This twin oven consisting of two compartments, each representing five 12 ft. lengths, would then have each compartment length loaded and un- loaded every 4% hr. of the 24-hr. day. An oven of a trifle ove? 60 ft. in length would then be the requirement. As different degrees of temperature are to be imparted to the castings traveling at those intervals through the oven, it becomes necessary that each unit of the compartments be di- vided by counter balanced sliding doors into chambers. After a unit to be annealed is prop- erly loaded with castings, the several doors of the compartment would simultaneously be raised. The auto- matic clutch to the drive from a com- mon motor for these twin compart- ments would move the several units of castings through the entire length of The Iron Age, December 28, 1933—13 B* operating a small electric furnace in connection with a small cupola, the author suggests how low-cost malleable castings can be made. Notable in the equipment he proposes is a con- tinuous annealing furnace provid- ing for a 24-hr. annealing cycle. The items of labor and material are calculated in some detail. Mr. Teeter is a resident of Chicago, not now connected with the mal- leable iron industry nor interested in the sale of foundry equipment or supplies. His authority for writing on the subject appears to be based on an experience as an operating executive in a malleable iron foundry. the compartment. This would carry the castings just loaded into the first chamber to be heated to annealing temperature, and so on through the several stages for each unit of the load; the lot cooled to about 1100 deg. in chamber No. 4 would move entirely out of that compartment, and the un- loading would be started, with the hot castings remaining under a hood to arrest the rising heat while being unloaded. All doors simultaneously would then be closed and another period of the annealing cycle again repeated. With thermocouples permanently in- serted in these various chambers and leading to a recording pyrometer, the process of annealing through the manipulation of burners and cooling doors could be made a routine of exact performance. If fuel be used for heating, a muffled chamber would not be required to prevent oxidization of the castings as the contact with hot gases and excess air would be a short interval of time, but a combustion chamber with ports to distribute the heat evenly to the castings would be desirable. Economics of Continuous Annealing Oven An estimate of the cost of con- structing such an oven and its me- (Concluded on Page 64) N the office of a consulting engi- neer an inquiry regarding the manufacture of sheets may come from any point in the world. It may come from countries where sheets have been made for years; it may emanate from countries where steel plants now exist and the question has been brought up regarding the pos- sible profits to be derived from sheets; or it may originate from some coun- try where there is no existing steel plant but where it is thought that a steel industry could be established and include in it the manufacture of sheets; it might even have been thought possible to buy sheet bars from other countries and through governmental protection, be able to build up a local and _ profitable industry. In connection with the problem of manufacturing sheets many factors including the following must be con- sidered: i—Tonnage. Size, gage, and quality -Markets available within competi- tive distances. {—Source of raw materials from which to make sheets. 5—Whether there already exists a go- ing steel plant. 6—Whether there is an existing sheet mill, and if so, of what type, capac ity and physical condition, and what is the investment in the same Does any skilled labor exist local- ly; and what are the rates of wages for labor of all kinds; what is the quality, physically and in- tellectually, of local labor; and can it readily be trained into the vari- ous degrees of skill necessary for successful and economical manage- ment and operation of the plant. 8—-How much foreign supervisory and operating force must be imported at a high wage premium, for what positions, and how soon can it be dispensed with. 9—Cost of power. 10—Cost of fuel. 1i—-Can governmental protection be secured; if so, for what amount and for how many years. 14—The Iron Age, December 28, 1933 12—If it is a Government project, do they wish to be entirely independent of other nations. 13—What facilities exist for properly housing the employees. 14—-How much total money must be made available to cover: (a) Plant cost. (b) Interest during construction. (c) Losses during initial operation. (d) Working capital. 15—-Will the proposition pay, making proper allowance for interest and depreciation and in how many years can the initial plant cost be amortized. All of the above factors are im- portant and have quite a bearing upon the type of plant and equipment which should be proposed for the tonnage and quality of sheets under consid- eration. Plant Size to Insure Profit It is very difficult and usually im- possible to show a profit on produc- tion as small as 15,000 to 20,000 tons per annum. If the tonnage should range from 40,000 to 60,000 tons, the problem is at once simplified, as the cost of plant per ton of production would be less and the overhead and fixed charges lower; if the capacity be up to 100,000 tons, the prospects of profit are still more favorable, as the plant overhead could just as read- ily be spread over 100,000 tons as over 40,000 tons. If the tonnage involved should be above 100,000 tons per annum up to say 200,000 tons, the consideration of the type of equipment necessary would be much along the same lines as for 50,000 to 100,000 tons. On the other hand, however, if it can be definitely and conservatively deter- mined and agreed upon that, in the comparatively near future after the initial operations, the market would absorb an increase to 300,000 tons or more per annum, then the problem immediately takes on a different out- look and must be considered accord- ingly. ‘olling Sheets By FRANK L. ESTEP Vice-President, Perin Engineering Co. Methods of New York The question of gages, the percent- age of ordinary grades for galvaniz- ing purposes, and particularly the tonnage required for deep stamping purposes also have a very material bearing on the whole proposition. In certain cases it may be found that the percentage of ordinary black sheets from No. 12 to No. 16 gage is a considerable amount of the total tonnage; in many cases it will be found that the primary question to be considered is the manufacture of gal- vanized sheets of ordinary grades. The type of equipment for these two classes falls within the same range of mills and accessory apparatus. The Cases of Special Quality When you come to the question of deep stamping sheets and particularly to the question of the very highest grades, such as are necessary for auto bodies, then the equipment must be more carefully and differently con- sidered than for the case of ordinary black and galvanized sheets. In the manufacture of many grades of deep stamping sheets and the man- ufacture of practically all auto body sheets, the question of surface be- comes of paramount importance along with the deep stamping qualifications; hence the layout should embody every known facility that will reduce handling to the absolute minimum and the equipment provided be such as will prevent to the greatest degree the possibility of marring or scratch- ing, or otherwise impairing the sur- face of the sheets. We would like to say that even with the best sheet mill plant that man and money could build, you would not be able to make the latter mentioned deep stamping quality of auto body sheets without being able to either make or buy the proper steel neces- sary for the purposes intended. Great attention has been paid during the past 10 to 20 years to the making of high-quality steel for such purposes and mai the pro for not oth eac anc Qu iz- he ng ial In at ck ge al be be i1- vO of of st to be ry es n- ly 1e- 8; ry .e ch ee h- th id od ly or at 1e of eS and marked improvements have been made. What we are trying to point out is the fact that what might be the proper plant and process to propose for one company or country. might not be the proper one at all for some other company or some other country; each is a specific individual problem and must be treated accordingly. Quality and Quantity Demands of the Automobile Until comparatively recently in this country the old type of hand mills were in existence and in full opera- tion when the demand for sheets war- ranted their running at capacity. They employed a large number of men who received very high wages, particularly the roller, heater and doubler. In practically all such mills there was an extremely large amount of man- handling of materials throughout. When the automobile manufactur- ers began to demand sheets to increas- ingly severe specifications regarding deep-stamping qualities and surface, certain of the old-type mills were mod- ified in order to produce sheets of a quality and finish suitable for the automobile trade. The increase in the automotive industry called for a further increase in tonnage of sheets to even m