The Iron Age 1935-10-17: Vol 136 Iss 16

CHESTNUT AND STREETS, PHILADELPHIA, PA. Sales Offices 239 WEST 39TH STREET NEW YORK, Owned, Published and Copyrighted CHILTON COMPANY (Incorporated) Executive and Publication Offices, President FRITZ FRANK, Executive Vice-President FREDERIC STEVENS, Vice-President JOSEPH HILDRETH, GEORGE GRIFFITHS, EVERIT TERHUNE, ERNEST WILLIAM A. BARBER, Treasurer JOHN BLAIR Secretary FRANK, President VAN DEVENTER MILLER Bditor Bditor Emeritus Washington Chicago Cleveland Managing News Editor Pittsburgh Detroit Boston Cincinnati 17, 1935 What Are You Willing Size and Its Influence Steel Wire............. Aluminum Modern Commercial Steel............... Manufacture and Finish Golf Shafts............... 34-A Rate Activity Capital 34-C Construction and Equipment Buying.................. BAUR, Advertising Manager DIX, Manager, Reader Service Member, Audit Bureau Circulations Member, Associated Business Papers Emerson Findley, 311 Union tion Price: United States and Pos- : G \ AY j ¥ x q BEAMS AND HEAVY STRUCTURALS CHANNELS, ANGLES, TEES AND ZEES RAILS, SPLICES, SPIKES, BOLTS, ETC. PLATES—SHEETS STRIP STEEL, FLAT WIRE, ETC. STAINLESS STEEL HOT ROLLED AND BANDS COLD FINISHED SHAFTING AND SCREW STOCK EXTRA WIDE FLATS ALLOY STEELS—TOOL STEELS HEAT TREATED ALLOY STEEL BARS BOILER TUBES AND FITTINGS WELDING ROD—MECHANICAL TUBING RIVETS, BOLTS, NUTS, ETC. REINFORCING BARS AND STEEL BUILDING PRODUCTS COPPER AND ERA BABBITT METAL AND SOLDER PERMITE LEADED BRONZE BARS 14—THE IRON AGE, October 17, 1935 Write for the Ryerson Stock List Key Immediate Steel steel every shape and size standard and alloy grades stock for immediate shipment. Allied lines such non-ferrous metals, welding rod, bab- bitt, boiler tubes and fittings, etc., are also included. Shears saws and special flame cutting equipment quickly cut any length special shape. Prompt ship- ment assured. For more than years Ryerson Steel-Service has been meeting the steel requirements industry. Ten strateg- ically located plants make this service quickly available your territory. Draw the plant nearest you. JOSEPH RYERSON SON, INC., Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City == - q 4 q | 4 THE IRON AGE ... OCTOBER 17, 1935 ESTABLISHED 1855 Vol. 136, No. What Are You Willing Pay? VERYONE who has anything pays tax, because taxes are either collected from, passed to, all who receive income and all who spend. recent striking example hidden indirect taxation the processing tax meat, grains and cotton. The government paid the processor, but actually the tax paid the customer. Now get only two pork chops for the price which formerly bought three. The government has taken the third chop the extent that the processing tax has increased the cost. Normally, about 50,000,000 people are gainfully employed the United States private industry, business and agriculture. Various estimates place those still unemployed private pursuits, 10,000,000. these estimates are correct, 40,000,000, per cent, are employed. These gainfully-employed receive more that four-fifths the national income, that they—the 40,000,000—they and their families—who carry most the tax load. The present rate taxation cannot taken basis for estimating what the load will the future. Additional taxes will required pay expense already incurred, and one can guess what the next Congress will spend. the last Congress failed, billions dollars, provide the taxes necessary cover appropriations, sufficient taxes must levied later unless, repudiation currency inflation, the government fails pay what has bor- rowed government bonds and notes. These taxes must bear heavily the 40,000,000 who pay. The four billion dollar relief bill alone $100.00 for each the 40,000,000. true that the last Congress appropriated ten billion dollars, the 40,000,000 will pay the rate $250.00 each. not suggested that, avoid taxes and payments from wealth, have govern- ment. not suggested that have army navy. not suggested that fail give adequate relief those need. suggested, however, that every individual who has job and who has property, and, therefore, who pays, review what the government has done and plans do. one the 40,000,000 who pay, you should tell your congressmen, state legislators and local officials how much your wealth you want them spend whether you want gov- ernment expenditures increased decreased. President, Link-Belt Co. 4 | | q | | | | 4 3 q j q | a | 5 3 A UCH has been written and heard about the wood the Lindbergh lad- der. But practically nothing has been said about the nails that held together. Yet these nails were identi- fied with uncanny positive- ness through the research the author, Stanley Keith. His testimony for the State New Jersey was not pre- sented the trial Bruno Hauptmann, because the col- lapse the defense alibis made quick closing desirable the prosecution. Here, for the first time, present- ed, with the consent At- torney General Wilentz. most interesting story identification which traces the ladder nails directly back the nail keg Haupt- garage. ° attempting give accurate résumé the technological phase the investigation the nails the ladder used the kidnapping the Lindbergh baby, the author confronted with the necessity giving precedence, article this nature, the technical considerations involved. The opinion that the 8d. com- mon wire nails used the assembly the rungs the side mem- bers, were components the origi- nal contents the keg found have been partly used Haupt- mann constructing his garage, inescapable conclusion one thing; the laborious citation de- tailed circumstances, one one, IRON AGE, October 17, 1935 leading this point quite another. the ordinary layman, nails are nails, the absence any positive occasion regard them otherwise. Any references fur- ther characterizations are apt construed theoretical. Nor does the carpenter’s practical contact with them serve develop cor- respondingly more intimate knowl- edge nails except for type and size. interesting contrast the criminal’s well defined respect for finger-print evidence distinction the highly systematic technology overlooked the nails. The striking analogy will become more and more apparent when regard the grip marks left the parallel effect grasping article with the thumb and fore- finger. However, the impression that “nails are nails” and hence without individuality prevailing one. Even the nail producer considered hopeless identify these ladder nails with the criminal, because their utter promiscuity the raw material and handling phases the production, and the overwhelm- ing numerical factor involved annual marketing during the pre- vious year 1931 almost eight mil- lion kegs wire nails, per cent which were the specific type and size found the ladder. This means field increment annually units, 20,000,000,000 items this class! hasic similarity, all the lad- der nails were observed bear the letter the obverse side directly below the head and just above the grips, shown Fig. which subsequently reduced rephoto- graphing for publication. The significance this index letter trade mark became once obvious, means fixing their mill source. Steel being syn- onymous with Pennsylvania, and specifically Pittsburgh, prompt reference directory dis- closed the fact that the nail mill the Pittsburgh Steel Co. lo- cated Monessen, Pa. This plant produced approximately per cent all the nails this type and size marketed during 1931, thus serv- ing detail, reduce the field from 2,000,000 kegs 200,000 kegs. This was far too general much help independent circumstance. While all these ladder nails were similar respect their common letter they fell systematically within eight characteristic grip mark types, the first sub-classifi- cation, viz: The numerals within the parentheses beneath each such grip mark type designated, show the number ladder such group values. Even cursory observation the series will serve refute the lay impression that nails are nails, constituting they the actual ladder nails themselves. Thus singled out, they are distinctive viduality. series 100 speci- mens provided definitely from dif- ferent assemblies while produc- tion, for such study, through the Monessen plant the Pittsburgh Steel Co., showed two alike after | | | | | | | | | | | 9 | ‘ | q f | 4 q 4 4 STANLEY KEITH Metallurgical Engineer, Montclair,N.J. Steel Technologist for the State the Trial painstaking study the author, and incidentally approximately 5000 involved comparisons. While this study was advisable from lego-technical standpoint, the con- clusion was also obvious the basis mechanical experience. For die maker can duplicate his handiwork absolute detail. the Ladder Nails Returning the more detailed comparison the macrophoto- graphic series Fig. Type Flattened loop section the which extending down- ward, tends shorten the stem. The three upper barbings curve up- ward their extreme right, while the rest terminate horizontally. Type Relatively new die, the well defined and normal typographic form. All eight barb- ings are clearly defined distinctive themselves whole. The sharp upward termination the right, the third and fourth barbings, and the characteristic horizontal wrinkle fold all but the first two, serve distinguish this type further. Type The flattened loop sec- tion this while extending downward, does not tend shorten the stem which broad con- trast that The eight barb- ings show extended production this die assembly, and are char- acterized common declination the right below horizontal. preciably larger size, and located farther below the head than the others. The barbings are dis- tinctive their hooked contours, that this type once dis- tinguished from all the rest. Type The letter declines the right slightly from vertical, and badly emaciated typo- once. Overworked barbings show extended breakdown die. Curious moon face form the fifth and sixth barbings, respectively outlin- ing the eyes and mouth. Type Here the loop deficient its upper section, ob- viously resulting from the use broken stencil stamping the die. Head particularly thin, and there are characteristically wide bars between the second and third, and between the third and fourth barbings. Type The stem the quite pointed. The barbings are singularly horizontal, with well rounded extremities the right. The head thin. Type The letter declines appreciably from vertical the right, with broad and singularly oblique terminating stem. Its barb- ings generally resemble those but with convex curvatures the first while the sixth and seventh barbings have singularly lipped sections. With this classification the ladder nails taken basic start- ing point, the problem resolved it- self into research Hauptmann’s normal nail contacts with view toward the possible paralleling these overwhelmingly singular fea- tures, his work-a-day world. Nail Keg Among his effects brought State police headquar- ters there was included ordinary nail keg with the head removed, ex- cept for small segment having TANLEY KEITH, who made the investigation the nails the Lindbergh ladder for the State New Jersey. with the Smith Co., East Orange, hem and later was charge metallurgical research for that company. three letters red stamped there- on, part word terminating with ECT. This keg contained remainder 8d. common wire nails the same size and type found the ladder. They all bore the common symbol indicating the same mill source those the ladder. this connection, was sub- sequently established, when this keg was taken personally the Pittsburgh Steel Co., that the seg- ment letters were part the word PERFECT, and careful compari- son their details clearly showed them have been stamped the same die that used Monessen the prepara- tion their keg heads. These keg nails were thus established the obvious balance from the original keg lot, without reference this point specifically the ladder nails. painstaking examination and classification one one, these keg nails was made with recorded results shown Fig. They were found identical the THE IRON AGE, October > at 3 : q id 4 — 4 k & 4 LADDER GROUP TOTAL (7) (2) (5) (8) showing the various peculiarities the ladder nails, caused the die grip marks. (5) (6) 18—THE IRON AGE, October 17, 1935 wT KEG GROUP 2—Macrographs the nails found nail keg. minutest detail, type for type, with those the ladder group; and multiples shown parentheses underneath. Further research among Haupt- mann’s miscellaneous effects of- fered additional units, four which were removed the writer from pair his overalls. Their investigation, shown part recorded Fig. disclosed five the total eight die types, viz.: within the parentheses underneath. Nails From Garage Extending this research still further order evaluate the quantity factor involved herein the original keg’s status, what would more apt than investi- gate the nails used Hauptmann the construction his garage some time during the fall preceding the kidnapping? Such normal nail demand would account for large proportion the keg’s origi- nal contents, and from reasonably sized recovery there could estab- lished the group characteristics these nails packed Monessen. Unfortunately, the garage struc- ture had been wrecked during the early stages the search for addi- tional ransom money, but detective Bornman recalled questioning that considerably sized heap had been knocked out the lumber him recovering the boards for investigation purposes. Accord- ingly, 275 units were recovered from this spot respading and sieving the ground. They were naturally covered with rust, but special chemical means were de- veloped clean them with mini- mum amount wear and tear the grip markings. The result their investigation are shown anticipated, they too coincided pre- cisely with the previous type for type, and without tion. order proceed with the phase this investigation, the keg was logically taken the legiti- mate source supply for Haupt- mann’s normal nail demands purely within the innocent province his calling carpenter. Accepted such, and without reference the ladder group for the present, the other nails were figuratively re- turned their known original and the resultant strength thereby attained, made basis for further extended analysis j = q f q « 2 their common die-type status, into coil entities the ultimate sub-division their unit char- acteristics, and for the more subtle group characteristics which ensue. Wire Coil Identities Careful micrometer measure- ments for diameter and length, and accurate gravimetric determina- tions the use analytical baiance, together with servantly constructive microscopic examination each these nails subjectively treated units with respect their wire drawn char- acteristics, constituted the detailed work necessary assign the values given Fig. indices these technological details possessed the lot the premises. The coils fed each the respective die as- semblies were thus revealed. way interpretation, worthy note that the length func- tion the die assembly adjust- ment, and the same within each die type, irrespective the coil used. The diameters, functions the wire drawing die, were par- ticularly interesting that they disclosed the ellipticities common each. The weights, being func- tion both the wire drawing die’s orifice and the machine assembly die’s adjustment, tend show con- sistently the effect within each die type the variations diameter. The fidelity with which, without ex- ception, each unit revealed its coil characteristics, was surprising. Coil No. 11, having double pick up, showed unit after unit, for ex- ample, the two microscopic chan- nels grooves always equidistant, and always diverging the same angle the head and terminating precisely the same location the facet the pointed end; while coil No. 12, when magnified suf- ficiently, showed its broad channel groove have the same char- acteristic contour and depth all the specimens alike thus confirming the fixed form the accumulated metallic die particle generating this defect the common cause for each. The group characteristics this combined sample 320 units ac- cordingly reflect those the technological lot from which they were packed, and the size this packed lot that determines the final limit which these ladder nails may restricted in- verse function their criminologi- cal GROUP GARAGE CONSTRUCTION GROUP THE IRON AGE, October 4—Macrographs nails used garage structure. a) | DIE TYPES STRUCTURAL VALUE PROPORTIONS STRUCTURAL VALUE GROUP INTEGER COIL ANGLE DIE ANGLE 6 group classification, the original contents the Hauptmann nail keg. All the ladder nails were found into these classifications. mathematical factors involved the procedure followed the au- thor ultimately attain this end. structural value meant their total composite value the basic group; while its reciprocal, group integer, the index the probable \ numerical strength the group, required develop this particular . detail. Coil angle and die angle are notations used the graphic representation all these factors, Fig. whereby their propor- tional values the group are shown degrees along the total circumference the circular graph group unity. their size, that there nounced variation their probable ~ ~ ~ ~ ~ ceived when spun roulette. The magnitude. develop therefore intimate mixture nails from this group will have least equal 7—Technological pattern variations coil proportions the basic group strength less than this minimum, with numerical strength 320. Die—Types Length Numbers 2.63 2.63 2.54 2.54 2.54 2.58 2.58 2.58 2.56 2.61 2.61 Weights Gms. 5.00 5.06 4.87 4.90 4.91 4.96 4.88 4.91 4.93 4.83 4.98 Double Heavy Smooth Smooth Smooth Smooth Smooth Smooth Smooth Smooth Smooth Smooth Pick Up| Pick Smooth Smooth Pick Smooth Wire—Die 20—THE IRON AGE, October 17, 1935 + 5 | | AVERAGE q | Be i225 | | 4 ‘ i 4 q | | q | i | i i i i | { for example 44, their mathematical probabilities will shown, their prominence. Having thus analyzed their prob- abilities, may now construct graph this lot, without the de- tails magnitude, order make comparable with fractional groups numerically too weak justify anything like dependable resolution such degree. Fig. represents such graph this basic lot, showing the related coils within their specific die type symbols, and may taken the pattern the original mixture the keg’s contents packed Monessen. the unit and group char- acteristics this lot that shall now refer the ladder nails, show their complete identity. Ladder Nails Coincide With Basic Lot Without tabulating here the de- tails diameter, length, weight and wire die conditions these ladder nails, will suffice an- Fis. 9—Technological pattern specific lot nails premises. WEAKER MEMBERS, COIL SELECTIVITY ONLY 8—Where the number nails less than 64, for example the case the taken from the ladder, the probable distribution above expectable. (Compare this with Fig. exception, with the values found for the basic lot, indicated Fig. thus establishing their re- motest degree comparison, their complete unit identities therewith. The fidelity with which they showed their group identity this same nounce that they coincided, without lot, perhaps the most singular factor the entire investigation. The missing coils shown dotted lines locations Fig. for the ladder group, when com- pared structurally with that the basic lot Fig. actually follow the predicted probability for the numerical strength nails postulated Fig. will ob- served comparing the order prominence with that actually fol- lowed the ladder nails indicated Fig. 11. This equivalent saying that not only every posi- tive way, but even negatively virtue the absence certain coils the ladder nail group, this ladder group was identified component the keg lot. Figs. and are graphs the two lesser components this basic pattern the nails the Lindbergh ladder. THE IRON AGE, October 17, STRONGER MEMBERS, CONSISTENT DIE TYPES pattern the nails found nail keg. lot, viz: The keg group nails, and the personal group nails. The low numerical strength the latter involves the absence even die types, shown dotted loca- tions. new units occur, will observed. The inescapable that these ladder nails hail from the same technological lot that the contents the keg used Hauptmann. was determine the size this lot, means the size their tumbling barrel, that the writer took occasion this point visit the Monessen plant, and the same time make check the findings whole. Investiga- tion mill practices relating the use die assemblies fre- quently such 8d. setup, and the size and handling coils, to- gether with the tote box charges into the buggy feeding the keg tumbler, amply confirmed the de- tails disclosed the investigation basically correct. the same sense that approximately every hr. there new die introduced 22—THE IRON AGE, October 17, 1935 into the series replacement, too there new coil added the setup every min. Since tumbling serves, unintentionally course, integrate such composition every hour, into transient mechanical mixture these varying and progressive phenomena, follows that each successive discharge from the tumbler strikingly individual after hour’s tumbling into composite mixture coil combina- tions within the closed series die types. corollary, there could not therefore more than these kegs such nails, ever produced before, ever produced sub- sequently. Even the same state repair the dies observed common property this lot. The remarkable degree ex- nological lot undeniably borne circumstance, shown its re- lationship the total production this type and size nails. the order only half one thou- sandth one per cent! The care with which the State (CONTINUED PAGE 71) pattern the nails found overalls. COIL ENTITY \ the ladder nails. Compare this with Fig. 8.) q \ we te / / \ Grain Size and Its the Manu acture Steel Wire ° ° McCARTHY survey McQuaid-Ehn grain size control applied the making steel wire was presented the author last week's issue. addition general discussion the subject grain control, was demonstrated how grain size may used, both the melting basic open-hearth steel and the selection steel for wire drawing purposes. this concluding article, the author reviews the influence hot and cold work the McQuaid-Ehn grain size, discusses grain coarsen- ing temperatures, reaction rates and dissolved oxides. Also included are descriptions the plastic deformation wire drawing and the patenting operation. show the effect hot and cold working the size the grain developed the Mc- Quaid-Ehn grain size test the fol- lowing samples were employed: Coarse grain steel, in. billet. C-2 Coarse grain steel, No. rod (hot rolled). C-3 Coarse grain steel after per cent reduction drawing. C-4 Same C-3 after patenting. C-4 after drawing per cent. Fine grain steel, in. billet. Fine grain No. rod (hot rolled). Fine grain steel after per cent re- duction drawing. E-4 Same E-3 after patenting. E-5 E-4 after drawing per cent total reductions. All the above samples were car- burized according the McQuaid- Ehn test. Fig. shown the structures developed the coarse grain steel and Fig. shows the structures developed the fine grain steel. While there some variation the structures result- ing from these treatments the dif- ference not great enough importance. The fine grain steels remain fine grain, while the coarse grain steels remain coarse grain. McQuaid-Ehn grain size some- times referred “inherent grain size.” This incorrect, for while indicates inherent prop- erty inherent tendency to- ward the development certain grain size under the condition the test, the grain size can changed heating higher temperature hot working above the upper critical When steel cools from the molten con- dition the primary crystals grains that form are much larger than indicated the grain size test. The reason for this lies the fact that the austenitic grains formed solidification, form temperature well above the grain coarsening temperature. Coarse Grains Large Sections the hot rolling steel the austenitic grains which existed time heating are continually broken due pressure and the grain size the hot-rolled mate- rial represents the size which the grains developed after hot working had The size the hot-rolled bar determines the amount time permitted for the grains grow after hot working, viz., the larger the section the coarser will the grains. If, how- ever, the rolling continued until the material has cooled tem- perature the neighborhood 1700 deg. the grain size, de- termined the test, will exert influence the size the austenitic grains developed. steel cooled below the new set grains develop inside the old austenitic grains; this particularly noticeable low-car- bon steels. The grain size noted the hot-rolled low-carbon No. rod example this secondary actual grain size. high-car- bon material the same condition exists and the grain size the patented rod wire indicates the actual and not the austenitic grain size. Fig. shows the structure patented No. rod eutectoid composition—note the actual grain size. If, however, the structure contains any pro-eutectoid ferrite the boundaries the austenitic grains—this shown Fig. THE IRON AGE, October 17, 1935—23 ° ° ° 2 { 3 | | ° McQuaid-Ehn grain size test taken 200 diameters—note the grains that have formed inside the au- stenitic grains. The size the austeniitic grains exerts influ- ence the size the actual grains, and therefore neces- sary coarsen the austenitic grains obtain coarse patented grain size. The temperature which the austenitic grains coarsen has been the subject much investigation. Coarse grain steels will coarsen shortly after the critical tempera- ture passed, but fine grain steels may remain fine considerably higher temperatures. However, whether the steels are coarse fine grain, determined the Mc- Quaid-Ehn grain size test, heated high enough they will all coarsen. The temperature which the grains coarsen termed the grain coarsening temperature. The fact that steel fine grain 1700 deg. F., determined the test, indicates that its grain coarsening temperature excess 1700 deg. Gross- has shown that the coars- ening temperature can lowered No. A.S.M., Vol. XXII, 24—THE IRON AGE, October 17, 1935 steel special treatments such heating and quenching number times. However, only the influence hot and cold work the coarsening temperature important the manufacture wire. Grain coarsening proceeds over range temperature and, result, steels heated within this range will show marked non- uniformity grain size. For this same reason some steels will show non-uniformity when carburized 1700 deg. Aluminum Influences Grain Coarsening Grain growth develops the _uniting fine grains reduce surface tension. Very often when fine grain steels are heated above their grain coarsening temperature extremely large grains develop. The amount aluminum added the steel control grain size seems influence the grain coarsening temperature, and this probably due the added obstruction grain growth resulting from the formation particles. demonstrate the effect temperature and aluminum addi- tions grain growth, McQuaid- Ehn tests were made one coarse and two fine grain steels E-3 Fic. the effect hot and cold work the McQuaid-Ehn grain size coarse grain steel. All photos 100 diameters. various temperatures. All sam- ples were from the same heat, the fine grain steels having been treated with aluminum the mold. Fig. shows the grain size devel- oped the coarse grain steel carburizing various tempera- tures. Fig. shows the results carburizing fine grain steel various temperatures. This sample was treated with 6.5 oz. alumi- num per ton. Fig. shows the effect the same temperature fine grain steel which oz. aluminum per ton was added. The fact that all the above structures were obtained the same heat steel serves dem- onstrate the influence aluminum additions the coarsening tem- perature. The coarse grain steel which aluminum has been added was coarse 1600 deg. and continued coarsen the tem- perature was raised. The fine grain steel treated with 6.5 oz. alumi- num per ton began coarsen 1800 deg. and was almost com- pletely coarse grained 1900 deg. While there was some enlarge- ment the grains the case the sample which oz. alu- minum per ton was added, the coarsening temperature was ex- cess 1900 deg. Fic. 7—Showing the effect hot and cold work the McQuaid-Ehn grain size fine grain steel. All views 100 diameters. Sis 4 demonstrate the influence cold work the grain coarsening temperature the following samples from fine grain steel were Sample Hot-rolled No. rod. Sample After reduction per cent drawing. Sample After reduction per cent drawing. All three samples were carbur- ized for hr. 1700 deg. F., 1800 deg. and 1900 deg. Photomicrographs these sam- ples show that 1700 deg. there was little difference, but the temperature was raised 1800 deg. and 1900 deg. sample coarsened greater extent than the influence cold work the coarsening temperature more work will required. Indications, far determined, are that amount drafting seems cause the grains coarsen lower temperature than that required for the hot-rolled rod, while heavier drafting seems raise the coars- ening temperature. The structures developed were very erratic. some instances the sample would fine grain the edge and coarse the center and others reverse condition would exist. The samples used here, however, represent the genera! trend far determined. Vol. 100, Variations coarsening tem- peratures are important con- nection with patenting. The ence cold working the coarsening temperature indicates what might expected process patenting. fact keep mind, BELOW IG. Patented No. rod eu- tectoid composition lightly etched show actual qrains. Photo 200 diame- ters. RIGHT Ehn size test taken 200 diame- ters showing actual inside aus- tenitic however, that while these encing factors affect the coarsen- ing tendencies both coarse and fine grain steels, the coarse grain steels will continue coarse grain above 1700 deg. regard- less hot cold working. therefore desirable employ coarse grain steel avoid the non- uniformities that may exist result variations the coarsen- ing temperatures associated with fine grain steels. Reaction Rates Fine grain steels show quicker reaction rate than coarse grain steels. reaction rate’ meant 9—Patented No. rod, 0.70 carbon, 0.84 manganese, with coarse grain. Ferrite markings austenitic Photo diameters. the time required for the austen- ite>ferrite and carbide reaction which takes place the slow reaction rate will transformation lowering the position the while fast reaction rate will cause occur higher temperature. slow reaction rate will increase the hardness and the hardness pene- tration and result deep harden- THE IRON October 17, vu 3 ra | McQuaid-Ehn grain size test taken 200 diameters—note the grains that have formed inside the au- stenitic grains. The size the austeniitic grains exerts influ- ence the size the actual grains, and therefore neces- sary coarsen the austenitic grains obtain coarse patented grain size. The temperature which the austenitic grains coarsen has been the subject much investigation. Coarse grain steels will coarsen shortly after the critical tempera- ture passed, but fine grain steels may remain fine considerably higher temperatures. However, whether the steels are coarse fine grain, determined the Mc- Quaid-Ehn grain size test, heated high enough they will all coarsen. The temperature which the grains coarsen termed the grain coarsening temperature. The fact that steel fine grain 1700 deg. F., determined the test, indicates that its grain coarsening temperature excess 1700 deg. Gross- has shown that the coars- ening temperature can lowered Transactions, A.S.M., Vol. XXII, No. 10. 24—THE IRON AGE, October 17, 1935 steel special treatments such heating and quenching number times. However, only the influence hot and cold work the coarsening temperature important the manufacture wire. Grain coarsening proceeds over range temperature and, result, steels heated within this range will show marked non- uniformity grain size. For this same reason some steels will show non-uniformity when carburized 1700 deg. Aluminum Influences Grain Coarsening Grain growth develops the _uniting fine grains reduce surface tension. Very often when fine grain steels are heated above their grain coarsening temperature extremely large grains develop. The amount aluminum added the steel control grain size seems influence the grain coarsening temperature, and this probably due the udded obstruction grain growth resulting from the formation particles. demonstrate the effect temperature and aluminum addi- tions grain growth, McQuaid- Ehn tests were made one coarse and two fine grain steels E-3 Fic. the effect hot and cold work the McQuaid-Ehn grain size coarse grain steel. All photos 100 diameters. various temperatures. All sam- ples were from the same heat, the fine grain steels having been treated with aluminum the mold. Fig. shows the grain size devel- oped the coarse grain steel carburizing various tempera- tures. Fig. shows the results carburizing fine grain steel various temperatures. This sample was treated with 6.5 oz. alumi- num per ton. Fig. shows the effect the same temperature fine grain steel which oz. aluminum per ton was added. The fact that all the above structures were obtained the same heat steel serves dem- onstrate the influence aluminum additions the coarsening tem- perature. The coarse grain steel which aluminum has been added was coarse 1600 deg. and continued coarsen the tem- perature was raised. The fine grain steel treated with 6.5 oz. alumi- num per ton began coarsen 1800 deg. and was almost com- pletely coarse grained 1900 deg. While there was some enlarge- ment the grains the case the sample which oz. alu- minum per ton was added, the coarsening temperature was ex- cess 1900 deg. Fic. 7—Showing the effect hot and cold work the McQuaid-Ehn grain size fine grain steel. All views 100 diameters. demonstrate the influence cold work the grain coarsening temperature the following samples from fine grain steel were studied Sample Hot-rolled No. rod. Sample After reduction per cent drawing. Sample After reduction per cent drawing. All three samples were carbur- ized for hr. 1700 deg. F., 1800 deg. and 1900 deg. Photomicrographs these sam- ples show that 1700 deg. there was little difference, but the temperature was raised 1800 deg. and 1900 deg. sample coarsened greater extent than the influence cold work the coarsening temperature more work will required. Indications, far determined, are that small amount drafting seems cause the grains coarsen lower temperature than that required for the hot-rolled rod, while heavier drafting seems raise the coars- ening temperature. The structures developed were very erratic. some instances the sample would fine grain the edge and coarse the center and others reverse condition would exist. The samples used here, however, represent the trend far determined. Vol. 100, Variations coarsening tem- peratures are important con- nection with patenting. The ence cold working the coarsening temperature indicates what might expected process patenting. fact keep mind, BELOW IG. Patented No. rod eu- tectoid composition lightly etched show actual Photo 200 diame- ters. RIGHT Ehn qrain size test taken 200 diame- ters showing actual inside aus- tenitic qrains. however, that while these influ- encing factors affect the coarsen- ing tendencies both coarse and fine grain steels, the coarse grain steels will continue coarse grain above 1700 deg. regard- less hot cold working. therefore desirable employ coarse grain steel avoid the non- uniformities that may exist result variations the coarsen- ing temperatures associated with fine grain steels. Reaction Rates Fine grain steels show quicker reaction rate than coarse grain steels. reaction rate’ meant 9—Patented No. rod, 0.70 carbon, 0.84 with coarse grain. Ferrite markings austenitic grains. the time required for the austen- ite>ferrite and carbide reaction which takes place the slow reaction rate will transformation lowering the position the while fast reaction rate will cause occur higher temperature. slow reaction rate will increase the hardness and the hardness pene- tration and result deep harden- THE IRON AGE, October 17, 1935—25 a : rei ; t > ¥ ing. fast reaction rate will, increasing the rate which the transformation takes place, result shallow hardening. The temperature which the lowered determines the type micro-structure developed ‘In given steel. the cooling slow enough may occur slightly below the phase-boundary tempera- ture (line PSK—see Fig. 1). How- ever, the cooling rate in- creased the transformation takes place lower temperature (line P’S’K’). Slow cooling results the formation coarse pearlite, while faster cooling will result pearlite varying degrees fine- ness, depending the position ered about 950 deg. the micro- American Iron and Steel Institute, New York, May 24, 1934. Transactions, A.S.M., XX, No. November, 1932. # 26—THE IRON AGE, October 17, 1935 structure will consist fine pearlite. Below this temperature martensite will develop until, temperature about 250 deg. the structure will all martensite. quench fast enough produce martensite termed critical quench, while rate cooling slown enough produce pearlite may termed slow, medium fast, depending the position the considering reaction rates should remembered that the analysis the steel and the rate which cooled will influence the position the Also, analysis and rate cooling being the same, difference the grain size the steel will influence the temperature which the transformation takes place, thus influencing the micro-structure. fine grain steel heated above arain carburized 1600 deg. (on left), 1700 deg. (middle) and 1800 deg. for are No. No. and No. from left respectively. its grain temperature and coarse austenitic grain developed, its reaction rate ing will change from fast slow, the influencing factor being the size the austenitic grain. The study reaction rates deals mostly with fast critical quench, when oil water employed quenching medium. However, similar effect can noted less rapid cooling and may with 6.5 oz. aluminum per ton carburized for hr. 1700 deq. (on 1800 deg. (middle) and deg. (right). Grain sizes are No. No. and No. from left right respec- tively. influence the fineness the ite formed patenting. Micro- scopic variations the metal may cause microscopic variations the reaction rate does the presence non-metallic inclusions and dis- solved oxides. Influence Dissolved Oxides Bain has shown that oxygen dissolved influences the rate which the carbide diffuses.” IG. with oz. aluminum per ton, carburized for left), J800 deq. (mid- and 1900 dea. (on right). Grain sizes are No. No. and No. from left re- spectively. | ° ° The structure which results due fast rate diffusion. The cementite diffuses the boundaries the austenitic grains and there results poorly developed peariite. Grossmann presence increased solubility cementite ferrite which de- lays carbide precipitation after the passed. This shown diagramatically Fig. the dotted line GPN represents the solubility cementite ferrite, the position changing with the dissolved oxide content and the cementite solubility resulting from it. That dissolved oxides ence the micro-structure shown the following examples: Fig. shows the structure McQuaid- Ehn test made hot-rolled rod which originally contained seam but which, due high tempera- ture, the iron oxide has become dissolved the metal. Note the massive cementite. This similar abnormal structure, yet the steel question was not abnormal. demonstrate this point further sample 1%-in. billet was pre- pared cutting groove in. deep and 1/32 in. wide parallel with the axis. The piece billet was then heated 1800 deg. and forged round. was then reheated 2300 deg. for min. and forged %-in. round. McQuaid-Ehn test was made the %-in. round, and Fig. shows the structure developed 1000 diameters. The solution iron oxide the metal has resulted the formation massive cemen- tite and ferrite similar the other structure shown Fig. 14. This tendency form massive cementite the expense the pearlite indicates the presence, steel high iron oxide, in- fluence which would interfere with the development fine pearlite patenting and tendency form coarse particles cementite which would delay solution. The solution the excess con- stituents which takes place above requires time. heating for the general run metallurgical operations heating rate hr. for each in. section gen- erally employed. the patenting operation heating dope much less time than this. accomplish solution this increased rate heating, temperatures considerably Bulletin 64, Mining and Metal- lurgical Advisory Board. presence large fer- rite-cementite particles the ma- terial patented delays solu- tion and may result what termed slack patenting. areas pearlite, massive cemen- tite and excessive ferrite re- quire time for solution, and therefore desirable for the parti- promote the quick solution desired. Herty, Lightner and McBride” have shown that fine grain hypo-eutectoid steels there greater tendency toward the pre- cipitation free ferrite than associated with coarse grain steel. This would indicate slower rate solution for this type mate- } ry » IG. showing influence dissolved oxides developed structure. Ehn test sample which iron oxide had been dissolved. rial. The tendency toward the formation massive cementite steels high oxygen may also in- fluence the solution rate. The com- plete solution the constituents essential the production good wire, both because the ne- cessity complete solution for subsequent recrystallization and because grain growth cannot take place until solution complete. Deformation During Drawing When wire being drawn the size the die determines the di- ameter. However, does not fol- low that the strain set evenly distributed throughout the cross- section. are all familar with the fact that steel hardens being cold worked. The hardening which takes place progressive that the more plastic areas harden first and, their hardness increases, other areas, which offer more re- sistance plastic deformation, are affected. this manner the re- sistance the various areas overcome. Sometimes, however, even with heavy total reduction, there are areas that will not de- form. Areas which not deform. because their resistance great, place the burden deforma- tion other areas and may result overworking. The speed drawing and the use too heavy reduction each draft can, not permitting sufficient time for flow, cause excessive hardening certain areas and produce brittle wire. The plastic deformation which takes place the result numer- ous slips planes without the loss cohesion. the deformation certain areas excessive the cohesion may destroyed and brittleness result. Because this necessary that the deformation uniformly dis- tributed throughout the cross-sec- tion produce high quality wire. The microstructure the steel before drawing determines the dis- tribution the effects cold work. Free ferrite, because its plasticity, will deform while areas free cementite will resist deformation. The plasticity pearlite, which consists al- ternate plates cementite and ferrite, depends the thickness the plates and their directional re- lationship the axis the wire. (CONTINUED PAGE 80) THE IRON AGE, October 17, 1935—27 | > a < : & A f q q >} } a the first half this Edward Mille Campbell Memorial Lecture, presented THE IRON AGE last week, Mr. McQuaid pointed out the importance centered this country grain size requirements, particularly for special purpose steels. This attitude was contrasted with the much less interest prevalent Europe. Mr. McQuaid called attention the resent wide use, although carefully concealed, aluminum control grain size, etc., and particularly the combination aluminum addition with improved knowledge and control the basic open-hearth furnace itsel was shown that the status aluminum has changed recent years, and now being recognized users commercia steels most valuable element the steels they use for particular purposes. this concluding portion his lecture, Mr. McQuaid discusses the importance manganese grain size control, points out the connection between the aluminum addition and harden- ability, shows how silicon helps the aluminum, and checks the effects different carburizing agents normality grain size. STATEMENTS have been made the effect that manganese has important relation normality, grain size, hardenabil- ity, ete. Thus, valuable assemble, from the data available, any information which will indi- cate how important manganese this respect. example, consider the characteristics the low manganese, low aluminum heats shown Table IV. Table are heats that are all coarse grained both the Mc- Quaid-Ehn test and actually normalized. These heats are very normal and show grain growth because they are very coarse the Shepherd standard, even low temperatures. The hardness the quenched condition good for steel this analysis. continue, examine some low manganese heats with definite addition aluminum, taking the heats shown Table Here have entirely differ- ent set results. Normalized structures are fine grained and the carburizing test also shows fine structure even after carburizing for hr. 1900 deg. F., and the hypereutectoid zone definitely 28—THE IRON AGE, October 17, 1935 abnormal. The grain growth frac- ture test Shepherd’s shows rela- tively little growth 1900 deg. and the hardness readings are markedly lower than the heats pre- viously examined. This difference can hardly explained charac- teristics variation carbon manganese. the aluminum con- explain the difference between these two groups, until some- thing better shows the differ- ence will have credited the aluminum addition. Now, consider some high man- ganese heats with low aluminum content and see what the charac- teristics this group are (see Table VI). Again, this case there coarse-grained tures, with the grain size after showing coarse hy- pereutectoid zone with normal cementite boundary. Apparently the addition manganese the first group examined does not change markedly the characteris- tics the steel, although the hard- ening effect the increased man- ganese naturally noticeable. The Shepherd fracture grain growth test shows these heats the coarse side 1700 deg. and definitely coarse above this. ° ° Diameter Rockwell Hardness the effects nese and aluminum additions the water quenched in. diameter from 1700 Note that 0.20 per cent 0.39 per cent alumin- hardens than 0.26 per cent 0.42 per cent aluminum. Also that 0.33 per cent 0.44 per cent without aluminum hardens deeper than 0.26 per cent 0.95 per cent with added aluminum. 0.26 per cent steel q Aladded Commercial Steels Now consider some high man- ganese heats which aluminum has been added, such shown Table VII. These heats are inter- esting that they show fine grain structure both the nor- malized and carburized condition and they are the type spite the high manganese con- tent. These results would indicate that manganese itself really minor importance when are interested grain control, re- sponse normalizing, etc. would seem from study these heats examined, that small addi- tions aluminum have very marked effects those character- istics heat steel which are important controlling the heat-treated properties the fin- ished part. This, course, not offered anything new, since exactly for these things that have been adding aluminum steel govern its characteristics after heat treatment for more than years. These results are ° ° IS. the effect in- creasing manganese 0.20 per cent car- aluminum when quenched in. section water from 1700 Note the compar- ative hardness 0.39 per cent 0.80 per cent steel, indicating the relative value car- bon and manganese improving hard- ness penetration. Rockwell Hardness ° ° given simply show how much more important aluminum this respect than manganese. interesting compare the relative importance aluminum additions and manganese additions the hardenability plain car- bon steels. this point exami- nation will given the depth hardness curves made quench- ing diameter round pieces water 1700 deg. and measur- ing the hardness different depths means hard- ness testing. Fig. shows the effects man- ganese and aluminum additions the hardenability 0.25 per cent carbon steel, water quenched l-in. diameter sections from 1700 deg. Note that the 0.20 per cent carbon, 0.39 per cent manganese without the aluminum, hardens deeper than the 0.26 per cent car- bon, 0.42 per cent manganese with aluminum. Note also that the 0.33 per cent carbon, 0.44 per cent man- ° McQUAID Metallurgist, Republic Steel fe) ° ° ganese steel without aluminum hardens deeper than the 0.26 per cent carbon, 0.95 per cent manga- nese steel which aluminum has been added. Now, consider Fig. 10, showing the effect increasing manganese the hardenability 0.20 per cent carbon steel without the alu- minum addition when quenched sections water 1700 deg. Note the comparative hardness 0.39 per cent carbon, 0.80 per cent manganese steel without aluminum, indicating the relative value carbon and manganese improving hardness penetration. Consider now another series steels approximately the same carbon but varying manganese content and containing added alu- minum (see Fig. 11). Note the result adding aluminum, indi- cating the relative effects man- ganese and aluminum hardness penetration. Compare the without aluminum with the other three steels which aluminum has been added, showing this case that the steel with considerably less manganese and without added aluminum will harden compara- tively better. The comparative effect alumi- num added the hardenability steels approximately the same manganese and carbon content shown Fig. 12. While dis- cussed before, there always some