The Iron Age 1945-05-31: Vol 155 Iss 22

inish- ols plus and size all D-150- VAN DEVENTER President and Editerial Directer BAUR General LEONARD Manager HAYES Advertising Manager JOHNSON, Manager Reader Service and Market Research BAUR, Production Manager CLEARY, Research and Prometion Manager Executive Offices Chestnut Sts. 39, Pa., U.S.A. and Advertising Offices Gast 42nd New York 17, N.Y., ° Regional Business Managers New York New York East 42nd 100 East 42nd eveland Pittsburgh Philadelphia Chicago Chilton 1134 Otis Bidg. PEIRCE LEWIS WARREN RAYMOND KAY Los Angeles 2420 Cheremoya Ave. Owned and Published CHILTON COMPANY (Incorporated) OFFICERS AND DIRECTORS MUSSELMAN, President HILDRETH Vice-President GEORGE TERHUNE Vice-President VAN DEVENTER Vice-President BAUR JOHN BLAIR MOFFETT, Secretary JULIAN CHASE CHARLES HEALE ° ° ° WILLIAM VALLAR, Asst. ° ° Member Audit Bureau Member, Associated Business Papers indexed the Industrial Arts Index. Pub- America, South America and Address, HARRY AGE Vol. 156, No. Index May 31, 1945 Editorial Left Hand and Right Hand Technical Articles Weldability High Strength, Low Alloy Steels Indium Plating with Cyanide Caustic Bath. Measuring Efficiency Training Welders Time Allowances for Multiple Spindle Drilling Spot Welding Aluminum With Refrigerated Tips New ° ° ° Features News Front Assembly Line Washington Personals and Obituaries Dear Editor ......... This Industrial Week News Industry News and Markets Procedure Settled for Disciplinary Discharges Regional WMC Directors Get Work-Week Control 102 Construction Machinery Controls Remain 104 Canadian Government Takes Plate Mill 106 Canadian Controls Again Relaxed Cutbacks Reappear 108 Construction Industry Faces Major Tests 110 Machine Tool Market Developments 114 Nonferrous Metals News and Prices 116-7 Iron and Steel Scrap News and Prices 118-9 Comparisons Prices Week and Year 120 Finished Iron and Steel 122-3 Warehouse, Semi-Finished, Steel Prices 124-5 Steel Pipe, Tubing, Wire Products, Prices 126-7 Pig Iron and Coke Prices 128-9 Stainless Steel and Ferroalloy 130-1 184 | | ABE : With the fall Germany realize full well that has been difficult get certain kinds and sizes steel quickly from stock—however, the situation improving. With steel moving from our plants record volume, sizes may not always bal- ance. But Ryerson stocks are be- ing augmented daily and con- tinue the nation’s largest. urge reduction excess steel inventories, which may eduction ess Inventory little value demands change. believe you can this with reasonable safety, and shall glad work with you when- ever you need steel quickly from stock. Joseph Ryerson Son, Inc. Steel-Service Plants: Chicago, Milwaukee, Detroit, Cincinnati, Cleveland, Pittsburgh, Phila- delphia, Buffalo, New York, Boston. Principal Products: Bars Shapes Plates Floor Plates Structurals Sheets Mechanical Tubing Boiler Tubes Boiler Fittings Allegheny Stainless Alloys Babbitt Solder Wire Reinforcing Threaded Rod Tool Steel Welding Rod Chain Nuts Bolts Etc. 34—THE IRON AGE, Mey 1946 RYERSON STEEL A Left Hand and Right Hand ESTABLISHED The navigator sets his course stars and compass and heads straight for his destination. The railway switch system keeps train bound for San Francisco from wandering New Orleans. The 1948 beam brings the flyer home when the ground hidden fog in- tervening clouds. Too bad can’t always follow such fundamentals, rather not DEVENTER so, national policies affecting our economic welfare. President ond Sometimes and sometimes don’t. the latter case the BAUR usual cause that the pursuit detail lose sight relationships and Manager main objectives. there such.a thing main objective which all can agree? think so. Whether left right, liberal, conservative whatever anyone may except plain, unvarnished “nut,” can all agree one thing, namely, the for the most. one will deny that the best for the most, national economy comes when employment good, wages are good and business good. These things are good expanding economy when ideas are en- couraged which will germinate new products and better methods doing things; when new capital flows freely irrigate the new businesses and the old ones and make them grow and thus multiply jobs and pur- chasing power just the rains multiply the harvest. This matter irrigation, capital irrigation, mighty important. You have plant money before you can reap jobs. costs minimum some $5000 buy the tools put one additional man work our mechanized industries and sometimes more than that. Our government wants private industry and business make the jobs that make the things that people buy and sell. But strangely enough, while one hand Uncle Sam stretched out help this pur- Editor ........ OLIVER Associate Editors WINTERS HIGHT ALBIN JOHN ANTHONY BARMASEL Editorial Assistants DAVIS se, his other hand working against it. The injunction: “Let not your 428 Park eft hand know what your right hand doing” not good one for POST government follow. Uncle Sam, with his right hand, petting ready help business finance employment through reduction corporate taxes. The concern DONALD BROWNE that makes million dollars and has $900,000 taken away hasn’t much left make new jobs $5000 per. the tax authorities are National Press pretty much agreed that after Japan licked, the maximum corporate LLOYD profit tax will per cent. That will helpful. But the other hand, matter how much irrigation you supply BRAMS field, you won’t get good harvest government should say you: Detroit “So much shall you raise but more.” And that just what doing and preparing more with respect curtailing jobs, wages and growth through certain international trade agreements. 1355 These agreements are intended fix quotas between nations for the production certain commodities. Wheat, cotton, oil, rubber are the contemplated already executed list. That means inevitably strict division the going business among present producers. And that turn means the prevention new enterprise and the limitation the existing ones. Inevitably, this principle accepted, will extended eventually what you make buy. And is, all the tax reduction that Unele > Milwaukee Sam can make won’t keep out that same state socialism that SANDERSON ruined Germany. Ont. RAYMOND KAY Angeles Jolin McCUNE Birmingham ROY EDMONDS St. JAMES DOUGLAS — { A 4 i rs Both Steel and Engineering Service Shaped Your structural, well all other rolled mechanical equipment you can count Inland steel, Inland engineers are aiding steel work closely with you from blueprint finished with cost-reducing and time-saving suggestions. job. This kind mill service can make big dif- Whether the design for production schedules and profit margins. INLAND STEEL CO. South Dearborn Street, CHICAGO ILLINOIS BARS FLOOR PLATE PILING PLATES RAILS REINFORCING BARS SHEETS STRIP STRUCTURALS TIN PLATE TRACK ACCESSORIES e uct 29, 1945 Present plans are for all light plane manufacturers this country get off start, with limited production beginning September. Cracking arc welded SAE 4130 steel believed caused numerous including chemical composition, hardenability, carbide size and mn, austenite retention, hydrogen absorption and the development internal bling stresses, studies conducted OPRD suggest. Resulting from these researches the crack-sensitivity SAE 4130 test pcedure consisting the deposition circular bead 1-1/4 in. ameter in. preheated specimen held copper jig. breaking the arc, the specimen quenched. The Mare Island Navy Yard will three-shift basis accommodate its work, now per cent heavier than can handled there. Henry Kaiser will able borrow $52,000,000 from private banks provide facilities for making tinplate, light sheet metal, pipe mill other improvements essential reduced costs operation. The Bank believed have tentatively assumed this additional undertaking. Kaiser has already paid RFC $8,600,000 plus $8,700,000 through earnings Kaiser shipyards. steel companies are seriously considering appeal the ergency Court Appeal the recent price increases granted OPA. The increase allowed does not cover their losses brought the high cost raw materials, amortization emergency war facilities and the adjustment inequities. The AAF plane cutback 17,000 units per year announced this week the first "realistic" appraisal post Day needs for one armed services. Layoff 200,000 workers aircraft assembly and 250,000 component production will follow. War Department has held off from announcing forthrightly other munitions which have been effected, and currently involved debate with Administrator Vinson, who feels that heavier cuts should made before new budget submitted. The has abandoned its wartime policy not organizing foremen, and straw bosses. These men, without authority hire and fire, the subject intensive organization drive. big heavy ammunition container program may fill plate schedules which promised evaporate July This program will use about 350,000 tons 3/16-in. plate hermetically sealed welded boxes replace critical lumber, improve the delivered condition material for the Pacific. Allocations companies for the 200,000-plus passenger cars built lis year are expected momentarily. They are based historical production and for the leading producers will approximate the following: General 90,000; Chrysler, 45,000; and Ford, 40,000. First agreement with integrated steel company will with American Rolling Mill. Pricing policies general all such will the basis OPA ceiling prices the negotiating desires, the company can prove that such prices not provide than "fair profit". The RFC steel plant Massilon, Ohio, has been placed the market for that agency. Now operated Eaton Mfg. Co., Cleveland, the plant roducing bullet core steel rods. Interested firms have been given until make contact with the RFC. new method for determining moisture electrode coatings recently adopted the Arc Mfg. Co., Ltd., England, makes results available min. hese tests can carried out unskilled persons. Moisture determinations are carried out and the drying oven used the uct the test contains automatic balance constructed that samples can without being removed from the oven. q 4 a | ns. Improving the Weldability welding the fabrication low-alloy steel the harden- able type has presented problems which did not exist were not seri- ous when welding was conducted the oxyacetylene procedure. The more drastic heating and cooling rates de- veloped the metallic promotes the formation narrow, hard zone the base metal adjacent the weld bead. the case low alloy, high strength steel, this zone ex- tremely hard and especially sus- ceptible cracking. While this type cracking may minimized heating, this procedure involves ad- ditional operations and expense, the results which are not always con- sistent and often lead warping difficulties which cannot tolerated. such situation, the carbon and alloy contents must reduced and BANTA Battelle Memorial Institute weight. Obviously,. lightweight structures high strength are most advanta- geous for many ordnance and espe- cially aircraft applications. For the construction air frames and engine mounts such steels SAE 4130 and 8630 are used. These steels must preheated and sometimes heated prevention against crack- ing which occasionally encountered some lots that are especially crack sensitive. Experience has demonstrated that different lots SAE 4130 steel may have widely varying crack-sensitivity first type jig used for making circular bead test. consists two copper plates in. square in. thick with 134 in. diameter hole tapering located the center each plate. characteristics, that is, the for cracks form and propagate the hard region adjacent the bead. This inconsistent behavior has been more frequently observed this grade largely because the large quantities SAE 4130 fabricated the aircraft industry. the past, one has understood the variation crack sensitivity different lots single grade steel, although numerous speculations have been made, consequently the producers this class material have been unable set all the controls which are required for form, satisfactory response weld- ing. Therefore, appeared that thorough study this problem would assist steel producers and fabricators meet the demands aircraft and ordnance manufacturers. The first step this investigation concerned the development ap- propriate test. This phase the program was substantially aided the availability three pairs com- mercial SAE 4130 sheet stock, each pair quite similar all respects with the exception wide difference crack sensitivity. General informa- tion concerning these steels shown Table Crack-Sensitivity Test After investigating number possibilities, test procedure was veloped which consists depositing circular bead approximately in. specimen held appropri- ate copper jig illustrated Fig. The jig and specimen assembly are preheated 100 deg. F., measured means thermocouple the jig. After allowing sufficient time for the specimen reach the temperature the jig, the bead started, depositing the metal counterclockwise di- rection. The circle completed approximately sec. The electrode selected for the ini- tial test was 5/64 in. Wilson No. 520. Negative polarity was used with volts. Immediately after breaking the arc, the specimen was quenched filling the opening the upper the jig with water. After sec., the come dure the spec the adj thr No 557 ser tit se pr i IRON AGE, May 1945 igh|Strength, Low Alloy Steels tendency compressed air jet and the specimen the weld has this icated tivity culations ntly the material all the for weld- that would bricators raft and stigation ap- the com- ck, each cts with rence shown nber was positing bly are ured the jig. for the iture eted No. with hed sec., the cooling water was removed removed from the jig after another sec. Using the above described proce- dure, tests were made each the two steels Nos. 557 and Within hr. after welding, all the specimens from stéel No. 581 devel- oped large cracks the side opposite the circular bead. These cracks were found originate the hard zone adjacent the weld and propagate through the back the specimen. cracks were found the backs any the specimens from steel No. 557, indicating that the test was sat- isfactory for distinguishing crack- sensitive from relatively insensitive material. meet the need for truly quan- titative test which would distinguish between various degrees crack sensitivity obvious, different ap- proach was tried. The circular bead test was made before and after standing room temperature for hr., the specimens were drawn 1050 deg. for hour. The bead side the specimen was then surface ground removing all the bead to- gether with one two thousandths the specimen. The object the 1050 deg. draw eliminate any possibility producing fine cracks the hard zone during grinding. After grinding, the specimens are Magna- fluxed, and the length the cracks the hard zone measured (see Fig. 2). Results these tests made steels Nos. 557 and 581 are summarized Table II. will noted that the crack-sensitive Steel 581 developed average total crack length 391 deg. per specimen compared with 133 deg. for No. 557. additional work, was soon ob- served that the extent cracking given steel varied from day day, although welding conditions were but results obtained from six more specimens welded consecutively were reasonably consistent. This difficulty was overcome the use control The control was assigned and all unknown arbitrary value, Astudy cracking phenomena SAE 4130 steel suggests that the origin cracks associated with the chemical composition and hardenability, carbide size and distribution, the retention austen- ite and subsequent transformation about room temperature, the absorption, sufficient hydrogen and the development in- ternal cooling stresses. Development crack-sensitivity test described and temperature-dilation curves are analyzed the first part the article, which was based investigation undertaken the Battelle Memorial Institute the instigation the Metals and Minerals Branch the Office Research and Development, War Production Board, and the National Defense Research Commit- tee. identified project No. W-127. steels were compared with the control specimens which were welded along with each group material tested. explanation the mathematical procedure for evaluating the crack- sensitivity test results included the appendix. statistical study large num- ber crack-sensitivity tests leads the conclusion that minimum six tests required order obtain satisfactory degree accuracy. All determination this report was based six more tests, generally six. Table steel No. 557 has been selected the control steel for this 2—(Left) Crack-sensitivity specimen after Magnafluxing. with scotch tape transfer cracks. investigation and assigned rating 1.00. Values lower than 1.00 indi- cate more sensitive steel than the standard; values greater than 1.00 indicate that the sensitivity less than that the control. Jig Design subsequent use this test, was found that the case ex- tremely insensitive lots SAE 4130 steel and especially 8630, the test conditions were not drastic enough produce cracks the specimen. make the test more severe, ice water was used for quenching. The testing procedure was further improved (Right) Record card FILE NO. 30705 THE IRON AGE, May 31, | ° ° ° 3—Hinged water-cooled jig position for welding. The solenoid valve shown above the jig, together with simple control system actuated the thermocouple extending from the lower right the jig, regulates the flow water maintain constant temperature. The specimen dropped from the jig into the quenching water below pulling forward simultaneously the two wing bolts the front the jig. 4—End quench harden- three pairs SAE 4130 commercial steels. Vicker hardness number 0.5 1.0 2.0 Distance from quenched end, inches NOTE: (1) Split Jominy bar (2) Held for hr. (3) Quenched standard Jominy 40—THE IRON AGE, May 1945 the use hinged jig shown Fig. Upon completion the weld, the jig tripped allowing the speci- men fall directly into the quench- ing medium below. This arrange. ment produces more drastic quench addition giving better control the time interval between completion the bead and quenching. order maintain constant pre. heat conditions from test test, the jig kept cool with simple thermo- stat which controls the flow cooling water the jig. This system will keep the jig temperature within deg. the selected temperature. study the possibility adapt- ing the crack-sensitivity test gages other than in. proved that the test was not applicable lighter sections, apparently because they were not sufficiently rigid allow the develop- ment crack producing Work heavier gages revealed that was necessary increase the elec- trode size and current the gage the test specimen increased, or- der obtain uniform degree The procedures finally adopted for making and in, thick commer- cial SAE 4130 steel, are shown Table III. Magnetic measurements made intervals from min. days after quenching specimens SAE 4130 steel from above the critical temperature showed gradual rise 0.34 per cent the ferritic induction. This change presumably indicates the decomposition non-magnetic aus- tenite into martensite. While this measurement not quantitative, does indicate that the extent the transformation quite small. The hard zone welded specimens No. 581 steel was examined with the X-ray using modified Debye procedure. Austenite lines were read- ily found diffraction patterns recently prepared specimens. Since the heat affected zone was narrow and the specimens irregular, the spec- imens could not relocated with sufficient accuracy make any esti- mate the change austenite con- centration with time. Some austenite was observed, however, long hr. after welding. somewhat larger water-quenched found the austenitizing time was all prolonged. When the austenitizing time was reduced few seconds, appreciable amount austenite was retained following quenching. From the information developed this investigation, appears that Temperature, deg.F. HARDENABILITY HEATS 557 AND 400 200 600 HARDENABILITY HEATS 617382 AND 41319 200 70304 7 200 shown the weld, arrange. quench ontrol pre. test, the thermo- tem will thin adapt- gages the test develop- stresses. that the elec- gage or- finally bead 3/16 commer- hown nade days SAE critical rise the tic aus- this ative, the with Debye read- erns Since narrow spec- with esti- con- ustenite uenched was nitizing was loped that Heat 6/7382 1500 Heat 1400 Heat 1500 617382 1400 1200 120 200 SLOWLY HEATED SLOWLY HEATED AND FURNACE AND FURNACE COOLED COOLED 900 1000 800 RAPIDLY HEATED AND AIR COOLED 600 Dilatation 5—Dilatometer cooling curves for steels Nos. 557 900 800 600 sensitive) and (sensitive) (SAE 4130). These curves show how the relative position the temperatures the two have been reversed rapid heating and cooling compared the values obtained the normal procedure slow heat- ing and cooling. addition sufficient hardening ele- ments and restraint, cracking can take place only the carbides are sufficiently small and properly dis- tributed promote the retention austenite the heat-affected zone, which transforms retarded man- ner after reaching the vicinity room temperature. The influence hydrogen upon un- derbead cracking has been pointed out investigators Watertown Arsenal,* and has been suggested *S. Herres, Welding Journal, 1944, Vol. 43; Trans. Amer. Soc. Metals, 1944, Vol. 33, 535. Dr. Lester that the decrease solubility accompanying the aus- tenite-martensite transformation may force the hydrogen out solution. This explanation feasible. view the present knowledge, appears that order for cracks develop, the following conditions must exist: Sufficient hardening elements, and appropriate carbide size and dis- tribution for the retention austen- ite which slowly transforms about room temperature. Cracking will oc- cur under these conditions, provided RAPIDLY HEATED AND ‘AIR COOLED Dilatation 6—Dilatometer cooling curves for steels Nos. 617382 and 41319. both the slow and rapid heating cycles, the crack- sensitive steel No. 41319 displayed the lower Ars temperature. the heat-affected zone has absorbed enough hydrogen from the arc weld metal and cooling lished the needed internal stresses. While little known about the quan- titative relationship these various factors, seems that all these effects are present crack-sensitive material. The results check analyses for the elements commonly determined, together with nitrogen and aluminum contents, are shown Table IV. The values the six elements normally reported, and the nitrogen contents offer explanation for the difference terest note that the insensitive steel No. 557 has appreciably higher aluminum content than the sensitive companion steel No. 581. The same situation, but greater degree, exists for steels 51273 and 70304. the case the other pair, steels Nos. 617382 and 41319, there little difference, the alumi- num content the insensitive steel being slightly lower. TABLE Information Concerning the Three Pairs Commercial SAE 4130 Steels Investigated | Relative Crack Sensitivity Steel No. Ladie Analysis 0.33 0.31 0.285 0.295 0.295 0.31 Sensitive** 617382 41319 70304 Insensitivet Sensitivet Insensitivet Sensitivet 0.026 0.017 0.014 0.018 0.019 0.017 0.020 0.023 0.019 0.016 0.015 0.018 Values obtained check analysis. tests Battelle Memorial Institute. designated the supplier the material. THE IRON AGE, May Heat 4/319 4/319 1400 Heat 70304, Ar. 1300 tometer cooling curves steels Nos. 1200 70304. These curves are agreement 1100 with the data the two preceding figures, that is, the SLOWLY Ars temperature HEATED the crack-sensitive AND FURNACE steel No. 70304 COOLED lower than the cor- perature for the steel when rapidly heated 800 and cooled. 100 AND AIR COOLED 600 Dilatation spectrographic compositional dif- characteristics these alloy steels. ference study also was made which From the tensile properties listed showed the presence nickel, tin, Table will observed that copper and vanadium, but there the yield and tensile strength the correlation between the quantity steel No. 581 appreciably these elements present and the higher than those the less sensitive crack sensitivity. gas analysis de- companion heat. The same also termined the fractional vacuum steels Nos. 617382 and 41319. fusion procedure also failed show However, the case the third relationship with the pair, steels Nos. 51273 and 70304, TABLE Summary Crack-Sensitivity Data Average Total Length Cracks Average Total Length Cracks Crack Sensitivity Steel Per Specimen Deg. Per Specimen Per Cent* Index Steel** 133 18.4 1.00 391 54.3 0.84 Based 720 deg.=100 per cent. See appendix for method cal- culating the Sensitivity Index. Steel No. 557 used the control steel with assigned sensitivity index 1.00. TABLE Ill Procedures for Making Circular Bead Crack-Sensitivity Tests | Time Delay Temperature Specimen Electrode Welding Between Finish Jig Quench Size Time Weld and Quench Temperature, Sec. Sec. Deg. Deg. 18/24 18/24 18/24 42—THE IRON AGE, May 1945 there little any difference the tensile properties. Hardenability Characteristics Since hardening characteristics are with cracking, study was made the relative hardenability these steels. Test bars for end-quench enability determinations were made the sheet material between two thick blocks similar length and width, made from SAE 4330 The two blocks with the specimen tween them were then welded along the longitudinal joints and turned the dimensions the standard Jom. iny bar. The bars were held 158) deg. for hr. followed quench. ing Jominy jig. Vickers’ hard. ness determinations obtained from these bars are shown the curves Fig. The data plotted reveal that two steels widely different sensitivity characteristics may dis. play similar hardening properties; such steels Nos. 557 and 581, also the second pair Nos. 617382 and 41319. the third pair, the crack- sensitive steel No. 70304 developed higher hardness and was somewhat deeper hardening than the companion steel No. From the chemical analysis, Table IV, however, would appear that steel No. 51273 should develop the greater hardness. The grain-growth characteristics each the six steels were deter- mined heating the specimen 1750 deg. for hr. followed nace cooling. These specimens then compared with similar specimens which had been heated 1550 deg. The results were follows: Steel No. Grain Growth 557 grain growth. 581 100 per cent specimen area showed marked grain growth. 100 per cent specimen area marked grain growth. 41319 per cent specimen area marked grain growth. 51273 per cent specimen area showed grain growth. 70304 100 per cent specimen area showed grain growth. Grain growth consistent with the aluminum content, taking into ac- count that only the steels each pair are comparable since the various pairs have received different chanical and thermal while being procesed the gages. However, examination the hard zones adjacent the welds steels Nos. 557 and 581 failed re- veal any appreciable differences, the extent coarsening being about the same each case. While the comparison steels this point has not re- 1500 the yie clu Ter ext ate the ins cal dil the 557 581 Gage In. vs 2x2 330 70 3 33 any one difference that es- pecially outstanding, the results suggest that aluminum content might ristics influential factor and that there ‘istics possibly some correlation between associated tensile properties, especially the made yield strength and weld-crack sensi- tivity. However, additional data are nch hard- needed arrive any definite con- ere clusions. ngth metallic are welding develops 330 rapid heating rates the cimen metal adjacent the bead immedi- turned appeared desirable investigate the relative response sensitive and insensitive steel rapid thermal This phase the work was carried out means temperature- from dilation studies using appropriate curves thermal cycles. The behavior each veal the three pairs steels listed Table were observed when subjected may the following two heating and cooling cycles: 581, also (1) The specimen was slowly heated 1382 and 1800 deg. average rate veloped was furnace cooled average rate somewhat per min. between ompanion (2) The specimen was rapidly heated chemical 1800 deg. average rate 4500 500 deg. per min., and upon reach- would ing 1800 deg. was immediately air should cooled, the rate ranging from 275 425 deg. between the limits 1800 and 700 deg., the cooling rate being in- fluenced the gage. deter- Cylindrical specimens in. di- cimen and in. long were formed from the 0.035 and 0.065 in. gage ma- ens Specimens from the in. stock were made from two in. deg. strips, each strip having in. slot machined from one end the center along the longitudinal axis. The two strips were then pressed together forming X-section in. long. The temperature both types speci- mens was measured means thermocouple spot welded the specimen. The cooling portion each the outlined above illustrated graphically Figs. and The transformation tained means the slow cycle were not good agreement would expected, considering the similarity analysis these six steels. With the exception the slightly lower carbon contents steels Nos. 617382 and 41319, these heats may considered tially identical analysis. The lack good agreement especially no- ticeable the Ar, temperatures. This inconsistency appears due the heating cycle not being sufficiently slow, the time held temperature area showed area showed showed showed showed with the into ac- each pair various rent me- three the welds led re- the about the these not re- * * Steel Steel 581—Crack sensitive 8—Microstructures the two 0.025 in. gage steels showing longitudinal sections after nital etch. These photomicrographs show the carbides are finer and more uniformly distributed the crack-sensitive steel No. 58! compared with the insensitive steel. not being long enough obtain com- plete solution all the carbides. Any variation the proportion the carbide dissolved would reflected irregularities the Ar, tempera- tures. Subsequent work supports this conclusion. Obviously, the dilation curves obtained the rapid cycle not indicate the true critical temper- atures the heating time insuffi- cient for complete solution the car- bides. Although slow compared with heating and cooling rates developed during actual welding, this rapid cycle should indicate any relative dif- TABLE Check Analysis the Commercial SAE 4130 Steels Crack Sersitivity Steel No. 557 §17382 41319 70304 0.020 0.019 0.015 0.011 0.011 0.011 Insensitive Sensitive Insensitive Sensitive 0.30 0.35 0.34 Insensitive Sensitive Acid-soluble aluminum determined. TABLE Tensile Properties the Commercial SAE 4130 Steels Yield Strength Lb./Sq. Steel No. Gage, In. 54,100 53,400 In. Lb./Sq. In. Tensile Strength Per Cent Elongation Yield strength determined from stress-strain curve using load 0.2 per cent offset. THE IRON AGE, May 31, 1945—43 wrt at | 0.50 0.23 0.98 0.20 0.015| 0.006 557 0.125 65,800 94, 100 | 557 0.125 64,800 93,760 581 0.125 79,300 581 0.125 79,700 41319 81,110 41319 0.065 66,000 51273 79,760 51273 0.035 70304 0.035 77,080 70304 0.035 * Steel 617382—Insensitive Steel 41319—Crack the 0.065 in. gage steels showing longitudinal sections etched nital 1000X. The carbide particles are smaller and better distributed the crack-sensitive steel No. 41319 than the companion steel No. 617382. Steel Steel 70304—Crack sensitive the 0.035 in. gage steels showing longitudinal sections etched nital The structures these two steels are quite similar with the exception that steel No. 51273 appears carbon. Steel 557—Insensitive Steel 581—Sensitive obtained spheroidizing treatment obtained alternately heating temperature within and slightly below the critical range. Steel No. 557 partly spheroidized while No. 581 lamellar pearlite. Both these structures were found have low degree crack sensitivity. Nital etch, 44—THE IRON AGE, May 1945 ference the response these the thermal treatment receive faster heating, the temperature most cases were slightly higher while the points were depressed compared with points observed during slower ing and cooling. The most significant fact means the rapid-thermal cyck that each the three pairs steels the crack-sensitive steel has lower apparent Ar, temperature the less sensitive companion fuel. cause the three pairs steels widely gage and hence have re. different mechanical and mal treatment and because there marked difference microstructur each the three pairs, son all six steels with respect crack sensitivity and misleading. The fact that steel No. 41819, for instance, has higher Ar; temperature than the sensitive steels the other pairs without significance. 7 The lower apparent Ar, steels presumably due size may influenced some cases composition. This opinion substan- tiated the microstructures steel under discussion. Effect Microstructure steels the “as-received” marked difference the structure off the insensitive steel No. 557 com- pared with the crack-sensitive steel No. 581, the carbides the latter being much finer and more distributed. Both the steels Fig. are spheroidized but the structure off the crack-sensitive steel No. consists small spheroidal matrix ferrite, while the sensitive companion steel, No. 617382, the carbides are larger and less formly distributed, leaving large islands free ferrite. From these microstructures, obvious why the apparent Ar, atures obtained rapid heating and cooling the sensitive steels, Nos. wl © ‘ q 581 and 41319, are lower than the ence clearly indicated the dilato- Steel 557 Steel 581 characteristics and the results respect circular bead tests. FIG. obtained spheroidizing followed normalizing. Nital etch, Since structure was found important factor with respect nce, has sensitivity, various micro- sufficiently coarse react dur- indicates that the carbon content the structures were developed steels ing heating manner similar austenite formed from the spher- pairs Nos. 557 and 581, using the partly spheroidized steel, No. steels was considerably lower treatments listed below, and both cases, the response that than the normalized steels. then measured: coarse carbide structure, and the carbon austenite, to- (1) Normalized 1700 deg. hr. curves, Fig. 12, gether with the chromium content followed air cooling. the spheroidized steels indicate which increases the sluggishness, the Spheroidized alternately heating evidence the Ar, Ar, transformation does not take place yele, critical range. transformations. will also noted sufficient rapidity produce (3) Spheroidized followed normalizing Table VII that the Ac, and Ac, rate expansion which equal 1900 deg. for hr., then air cooled. (4) Homogenized for 100 hr. 1900 deg. the greater than the contraction re- upor followed from 1900 deg. steels are appreciably higher than sulting from cooling. Therefore, summary the crack-sensitivity the case the normalized stock. This points expansion occurred the The test data from the four lots steel the treated outlined above listed insensitive Table VI. will noted that nor- size slightly decreased the sensi- TABLE cases tivity both steels compared with the “as-received” condition (see Table The Effect Thermal Treatment Upon Crack Sensitivity The microstructures these two res I). Steel No. steels appeared quite similar. The apparent Ar, temperatures ob- 537 ture tained from the cooling portions 581 Normalized the dilatometer curves both nor- 557 similar values the “as- and normalized received” material. These data are tivity indicated the circular bead sensitivity test. the latter both extremely insensitive, Table VI. Fig. also significant note the dif- ructure off ference the structures, Fig. 11, de- TABLE No. 41319 spite identical treatment. This differ- ted treatment appears due the Average Heating Average Cooling Transformation Temperatures, the Variation aluminum content, the Between Rate relatively While the structures were some- Normalized Spheroidized As-received 450/500 450/500 450/500 275/300 what different the two spheroidized 940/830 steels, both reacted similarly the eating appears that the carbide plates the As-received 450/500 275/300 900/800 teels, pearlitic structure steel, No. 581, THE IRON AGE, May 31, 1945—45 . 1400}- 1300 Temperature, Oo 900 800 Dilatation cooling curves the two spheroidized steels. Hardness Surveys order determine the effect structure upon the hardness the heat-affected zone, specimens were made both the normalized and spheroidized material from steels Nos. 557 and 581. Using ° ° ° Dila- tometer cooling curves for spheroi- dized and nor- malized specimens SAE 4130. The ment has eliminated any evidence the and points which are obvious the case the normalized steels. Steel ° ° ° the specimen the “as-welded” con- dition, the bead was ground flush with the surface, and hardness surveys were made the surface across the heat-affected and fused zones point 180 deg. from the start the bead. The results the hardness surveys are shown graphically Fig. steel, the highest 600 STEEL 500 400 300 IG. Hard- ness the eat- NORMALIZED affected and weld- bead the ead was STEEL ground flush with 500 the plate, the speci- men polished and etched nital. Each survey was 400 180 deg. from the w NORMALIZED 200 100 Distance, inches 46—THE IRON AGE, May 31, 1945 start the weld. SPHEROIDIZED hardness was developed the nor- malized specimens, because the more readily soluble carbides the nor- malized specimens produced higher carbon austenite during the short in- terval the steel was above the critical temperature. Upon cooling, this aus- tenite developed greater hardness than was found the similar zone the spheroidized specimen. study the microstructure the hard areas the heat-affected zone sub- stantiated these views. was found that the hard zone the spheroid- ized steel there were relatively large undissolved carbides which contribute little the hardness the structure. the other hand, large carbides could found the hard zone the normalized steels. Following the spheroidizing treat- ment described above, specimens from both heats were normalized heat- ing 1900 deg. for hr. non- oxidizing atmosphere followed air cooling. The high temperature and long cycle were selected with the ob- ject obliterating the effect the previous thermal treatment. The re- sults the crack-sensitivity tests (see Table VI) reveal that the drastic normalizing did not destroy the ex- tremely insensitive properties which were developed the spheroidizing treatment. These data indicate that the case SAE 4130, which reacts sluggishly thermal treatment owing the stability the chromium and molybdenum carbides, the thermal history prior the final normalizing treatment exerts appreciable in- fluence upon the crack sensitivity. The fourth treatment, consisting homogenizing 1900 deg. for 100 hr. normalizing 1900 deg. for hr., produced high degree weld-crack-sensitivity steels, again illustrating that the crack-sensitivity characteristics are strongly influenced the thermal treatment prior the final normaliz- ing. this case, the homogenizing treatment practically insured com- plete solution the carbides result- ing fine uniformly dispersed car- bide structure which contributes high degree sensitivity. The information obtained from this study concerning the effect struc- ture clearly indicates that the sensi- tivity given steel may varied over wide range, depending upon the thermal treatment. And was also found that the structure and thermal history, prior the final nor- malizing, exert influence upon the sensitivity since normalizing does not destroy the effect the pre- vious structure. 1500 Ar; the nor- more the nor- higher short in- this aus- hardness study hard sub- found pheroid- large ntribute ructure. carbides the treat- from heat- non- air and the ob- the re- tests drastic which idizing that and hermal alizing ty. 100 1900 degree both the ermal maliz- com- esult- car- toa this struc- upon Was and 1ence izing pre- INDIUM PLATING With Cyanide Caustic Bath HILE the present day impor- great extent the role plays aircraft engine bearings, the cost the metal, which roughly class with gold, the factor which may discourage experimentation for new uses. There enough indium available the crude form, however, that the price may expected drop with the use larger quan- tities. Experimentation for surface treat- ment will encouraged the im- provement existing plating baths. has been observed recently that lead plating was more rapidly ac- cepted substitute for tin due concentrate place the component chemicals that were difficult con- vert plating bath. lead fluo- borate solution had been available years ago, probable that lead plating would not have been dropped readily following World War There such thing perfect plating bath but there are many practical, easy control baths the two general classes—acid and alka- line. (Some plating baths close 7.0 may regarded neutral.) general, acid baths are charac- terized high cathode efficiency and good anode corrosion whereas the al- kaline baths have good throwing power and inherent cleaning ability allowing greater margin safety the preparation the work plated. The competing acid and alkaline indium baths have been described Whitehead Metal Finishing (July, 1944, 405) and some the disadvantages the cyanide bath de- 19, 1940, issue THE IRON AGE were pointed out. The disadvantages the cyanide indium bath are: Difficulty preparation Bath decomposition Use potassium hydroxide conjunction with potassium cyanide overcomes the difficulties normally encountered bath ‘preparation, halts bath decomposition and eliminates the necessity aging the plating electrolyte before use. Research Chemist, Cleveland Necessity aging before use Insoluble anodes. The first three disadvantages can overcome the use caustic the bath. This bath has not been ex- tensively used but enough work has been done recommend limits and warrant further work test the lim- its and possibly overcome the re- maining objection the bath. The recommended limits are: 15-30 gm. per liter Potassium cyanide 140-160 gm. per liter Potassium hydroxide 30-40 gm. per liter 20-30 gm. per liter Current density ...15-30 amp./sq. ft. Room The bath prepared simply dumping concentrated solution indium and dextrose into concen- trated solution cyanide and caustic, followed dilution. well try this small scale first see just how done there some danger that the solutions are mixed slowly precipitate will form that will not redissolve. The total mixing time should the order few seconds. The cyanide and indium are con- trolled the usual analytical proce- dures and the caustic titration using LaMotte sulfo-orange indicator, although better method caustic control may order. The bath gives good white de- posit immediately ,and will continue tration that indium can re- moved from the bath almost com- pletely simply plating. The bath maintains satisfactory cathode ciencies and does not attack ferrous anodes the extent the cyanide bath. Bath stability very good and only traces precipitate were ob- tained liter laboratory bath used intermittently over period one year. some respects this bath has the characteristics tin. One these the characteristic polarized films formed the anode except that the case indium these are only slowly soluble. With increased bath stability some experiments vated temperatures and with addi- tives similar sodium acetate the tin bath are order develop sol- uble anode and overcome the remain- ing objection this bath. THE IRON AGE, May 1945—47 q 7 ° RAINING new personnel arc welding important and vital part the production all welded ships. Calship, training for welding work production job different from that any other production process. That is, you start out with raw material, process it, in- spect and turn out the product. This production process sarily large scale scope order handle the personnel requirements the yard. Naturally any large production process, the system processing the raw material gov- erned the following factors (all re- lated the economics time, finances, Quality raw material received Use the processed product (a) Consumption (b) Inspection standards Time for processing Equipment, materials, personnel, etc., used convert raw material end product. large scale production nec- Mild stee/ = Ga. sheet NO -------------= = \ 48—THE IRON AGE, May 1945 essary decide upon the method process, with all details worked out, order obtain maximum produc- tion capacity. the training welders the method processing dependent upon the following factors: Minimum production requirements for student welders after leaving "formal" training Money allocated formal training operators Operator qualification The ideal method processing that one which, minimum time, would turn out mechanics who would able normal production work without further training. Practically this objective never reached, since time and money force compromise. The purpose this report not present the method training the qualifications personnel trained, but rather present system measurement efficiency and produc- tion control the training process regardless method end point. Yardstick Needed working efficiently and order know the status each unit pro- duction flow line, necessary have method quantity and qual- ity control well method de- termining quickly and with mini- DATE LEFT Electrode distribution can for stubs. RIGHT 2—Rod issue, stub count and arc time recorded this card filled out for each student. ISSUED RETURNED ARC RODS Measuring Efficiency mum effort the operating efficiency personnel and equipment used the work. All such controls are turn used improve quantity, qual- ity and efficiency. Presented below the method such controls, the use the method and the results obtained its use. person learns are weld translation visual action into manual action, that is, manual manipulation certain results are ob- tained which can seen. There are probably all cases several manual manipulations which might used give identical visual results. There- fore the time used actual burning electrodes and intelligent instruc- tion possible basis measure- ment production quantity, quality and efficiency. Calship system measuring “arc time” use consumed elec- trode count has been devised. This could have been done use arc time meters; however, the simple use electrode count the prob- lem housekeeping was licked, full consumption electrodes and full use available manhours the rod distribution department tained, and incidentally the added equipment expense (installation and maintenance arc time meters) was eliminated. DATE ISSUED RETURNED ARC RODS STUBS TIME ° ° ° 0! s 1 iciency sed are qual- hod nethod use. into ob- are sed struc- asure- uality This arc prob- full full rod added and was ° ° By. ARTHUR Electrode distribution cans were made shown Fig. These cans are all numbered and each stu- dent assigned specific can. Cans are also colored according shift code, thus facilitating the work electrode distribution clerks issu- ing electrodes students. Initially each student issued 100 electrodes. Stubs are deposited into the can and the can then returned the rod room the end the shift svoner necessary. Stubs are counted and the count entered the form shown Fig. The arc time calculated from the following equation: time, min. No. stubs standard burn-off rate. Burn-off rate expressed min- utes required burn in. off 14-in. electrode. Extensive checks were made and the figures shown below are average and accurate for machine settings used training. These rates are for AWS Class E6010 electrodes, with 2-in. stub loss: Size Electrode Burn-Off Rate In. Time, 1/8 5/32 3/16 in. average length) were returned, This time transferred the shown Fig. The card shown above filled out further from time eards and test records. Calculations for efficiency are made follows: Efficiency, per cent time, min. 100 Training time, min. Thus, assuming 9-hr. shift and full training with 3/16-in stubs re- turned, the per cent efficiency would follows: Efficiency per cent (app.) MacKUSICK Welding Engineer California Shipbuildingg Corp., Wilmington, Cal. ° ° ° After establishing standard burn-off rates for various size arc welding electrodes, use consumed electrode count gives simple gage arc time from which comparative measure efficiency can readily calculated for individual students, teacher effectiveness and length training time vs. tests passed. increase per cent training effectiveness was achieved two months this shipyard the use the system described. All cards are kept daily possible check list varia- clerk for all shifts and all students. tions and possible causes then used From this card monthly averages determine what happening: established give the following fig- Condition High operating efficiency, ures for comparison instructors, average training time, but repeated shifts and students, and also gage failure weld improvement make changes the ANALYSIS: Poor training process: Repetition error Average percentage operating ef- manipulation which has not ficiency been corrected (a) instructors Nervous student (b) shift Incompetent student over all Condition Low operating efficiency and Average arc hours required pass repeated failure weld tests. qualification tests ANALYSIS: Student low Training time vs. arc hours vs. tests All students are compared daily with the standards set above. structor. Any variations from the standards cy. but repeated failure weld tests. analyzed and below average, ANALYSIS: Lazy the student checked the super- intendent and the instructor. The fol- (CONCLUDED PAGE 110) 3—Calculations efficiency are made from the data recorded this form, one for each student. STARTING THE IRON AGE, May 1945—49 Testing Engineer INSTRUCTION: DATE HRS. DATE HRS. DATE DATE RESULT-DATE RESULT PERATION standards for mul- tiple drilling been evolved the Corwith plant the Crane Co