The Iron Age 1937-05-20: Vol 139 Iss 20

FRITZ J. FRANK President . H. VAN DEVENTER Editor Managing Editor Editor Emeritus Vachinery Editor irt Leditor Metallurgical Editor Associate Editors J. OLIVER G. RIcciaARDI MACMILLAN R. G JURASCHEK Consulting Editor Washington Editors MOFFETT Resident District Editors Pittshurgh Chicago Cleveland Detroit Editorial Correspondents RICE-OXLEY London, England Cincinnati Milwaukee San Francisco SANDERSON Toronto, Ontario LeRoy ALLISON Newark, N. J St. Louis 239 GE FRAZAR FIDRMUC Boston Hamburg, Germany MEYER LOREN IRWIN ASA ROUNTREE, JR. Birmingham Roy TURNER Buffalo Editorial ond Executive Offices WEST 39TH STREET, NEW YORK, Owned and Published by CHILTON COMPANY Chestnut and Sts., Philadelphia, Pa. 239 West 39th Street, New York, N. Y. OFFICERS AND DIRECTORS C. A. MUSSELMAN, President FRANK, Executive Vice-President FREDERIC STEVENS, JOSEPH HILDRETH, GRIFFITHS, Vice-President EVERIT TERHUNE, ERNEST HASTINGS, WILLIAM A. BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JOHN H. VAN DEVENTER JULIAN CHASE THOMAS L. KANE CHARLES 8S. BAUR G. CARROLL BUZBY M. FAHRENDORF S. BAUR, General Advertising Manager DIX, Manager Reader Service Member, Audit Bureau of Circulations Member, Associated Business Papers Indexed in the Industrial Arts Index. Published every Thursday. Subscrip tion Price: United States and Pos- sessions, Mexico, Cuba, $6.00; Can- ada, $8.50; Foreign $12.00 a year Single copy, 25 cents. Cable Address “*Ironage, N. Y."' ADVERTISING STAFF Emerson Findley, 621 Union Bldg., Cleveland BR. L. Herman, Chilton Bldg., Chestnut & 56th St... Philadelphia, Pa. H. K. Hottenstein, 802 Otis Bldg., Chieago H. E. Leenard, 239 W. 39th St... New York Peirce Lewis, 7310 Woodward <Ave., Detroit C. H. Ober, 239 W. 39th St., New York W. B. Robinson, 428 Park Bldg., Pittsburgh D. C. Warren. P. O. Box 81, Hartford, Cofin BINGHAM Cont MAY 20, 1937 Building Present Trend Engineering Alloys Centrol and Protection Distribution Lines Flame-Cutting Stainless Steel Scrap Flexible Welder Facilitates Truck Fabrication New All-Welded Armory Rises Statistics Metal-Working Activity Rate Activity Capital Goods Automotive Industry Washington News NEWS CONTENTS Plant and Equioment Buying New Literature Just Between Two Products Advertised Index Advertisers Copyright 1937 Chilton Company (Inc.) 105 109 126 126 154 | d { | od et. Its towers— ictures. feet. Its tru orld. the the | & 7 THE IRON MAY 20, 1937 ESTABLISHED Vol. 139, No. experimental work, the spectrographic analysis al- loy cast iron and steel has been put routine, com- mercial basis the Camp- bell Wyant Cannon Foundry Co., Muskegon, Mich. Through cooperative development work SPECTOGRAPHIC analysis metals not new. has been check for years, and research laboratory technic been known for over hundred years. Any handbook physics and chem- istry gives tables wave lengths various spectra all the com- mon elements. For iron alone, Determinations Cast Minutes FRANK OLIVER Associate Editor, The lron Age part photographic plate manufacturers, high-contrast plates are now available that can developed and fixed rapidly enough make pos- sible the quantitative deter- many minutes. This covers the elements present five six ladle mixtures. there are hundreds known wave lengths. The method regular tool astronomers identifying the elements distant planets. Only the last year, however, have the chemico-physical phenom- ena the variations intensity light emitted incandescent vapors metallic elements been applied the ferrous foundry in- dustry quantitative measure. make this possible took the practical vision foundry execu- tive and the cooperation uni- versity research laboratory put- ting complex theory into practice. was Ira Wyant, secretary the Campbell, Wyant Cannon Foundry Co., who had the vision, and Dr. Vincent and Prof. Sawyer, both the Univer- sity Michigan, who performed the commercial development work Ann Arbor. Sampson, spectographic engineer foundry, commuted back and forth between shop and campus, lending mechanical details and eventually taking charge the laboratory installed Muskegon. The photo- graphs show the apparatus use there today. the spectrographic method, high-frequency spark struck be- IE ° Re H on — | 4 tween two small electrodes the material being examined and the light emitted therefrom passed through the slit spectrograph. This instrument contains spreads out the band diffracted graphed vertical black lines varying degrees density. Each clement present the sample has characteristic line lines which density these lines varies ac- cording the amount the ele- ment present and the variations centage silicon, manganese, chromium, nickel, molybdenum. Carbon determina- tions yet have made phorus which are made only percentage the heats. might explained that copper- silicon steel brake drums are regular production run and heats are checked every min. addi- tion, automotive cylinder blocks and heads, camshafts and cylinder liners, chiefly high alloy material, are regularly poured. Much the metal duplexed the electric Sparking Gap Transformer Rotor Frequency Oscillator circuit the sparking mechanism. Spark tem- perature deg. C., raising all the elements present the iron brilliant incandescent vapors. Only the ultraviolet end the band used making the spectrum analysis. meter. Through calibration charts and special scales the density can standardized spectrographs and converted directly percent the element present. Such cali- bration charts and scales must analyzed the chemical labora- tory. Requirements Laboratory graphic laboratory are therefore: (1) the necessary electrical ap- paratus for producing the spark; (2) the spectroscope (highest cost unit); photographic darkroom with suitable apparatus; and (4) the densitometer, with calculation table alongside. Altogether, ex- vestment such equipment ap- proximately $5000. The spectrographic technic has its practical limitations. ap- plied the Muskegon foundry, used for determining per- 26—THE IRON AGE, May 20, 1937 furnace, and the cupola iron mixed with Bessemer steel make the drums. Samples iron are obtained from the transfer ladles after the alloy additions have been made. The electrical hookup ducing the spark shown the chart, Fig. Primary current 220 and cycles. The oil- immersed transformer steps the voltage 40,000 and the 4-pole in- terrupter (driven synchronous motor) with suitable condensers produces discharge oscillation about 300 the spark gap. About kw. energy consumed. The electrodes are in. long in. diameter and are ‘ast four time permanent mold with plenty metal the common riser. This mold hinged for opening and poured from small hand ladle used dip the iron out the transfer ladles. Fins are trimmed off the electrodes the same pair pliers that used break them off the riser. Only two out the four stubs are necessary for electrodes and these are slipped holder that gives the correct spark gap when the electrodes are clipped the shown that 50-sec. exposure best suited for the plates used, and sufficient give reliable results. The spectrograph proper, Fig. Littrow type, made Bausch Lomb Optical Co., 1820 mm. nominal focal length. holder has been revamped take plate originally designed. Only the light the ultra-violet range (0.224 0.295 wave length) focused the plate, that all the optical elements must quartz. The bilateral slit has fairly large opening (70 mi- crons) get wide enough line work the densitometer and its galvanometer. Spark and slit are about ft. apart. The plate holder pose strip in. high time. spectrographs can recorded single plate, although four six exposures are more nearly aver- team two men operates the equipment. One sets the trodes and starts the action, the second the adjoining spectro- graph room. times the expos- ure and cuts the circuits, then shifts the plate for the next shot. These spectrographic plates may fine-grain plate. Such plate in- herently slow, but high exposure speed not desired this phase the process. What much more essential the time pro- cessing the plate, which should reduced minimum. According the batch and make, time de- velopment may vary from sec. min.; fixing hypo, from min. and the length wash varies accordingly from min. between developing and fixing, there 30-sec. rinse chrome- alum hardening bath, and takes only 1-2 min. dry over tric heating box with fan assist- ing carrying away the vapor. standard Eastman hydro-quinine developer (Formula D-19) usu- ally employed, developing, hardening and fixing trays are all mechanically rocked the elec- tric motor and crank mechanism lack sensitivity red, the plate may loaded and developed under fairly bright red ceiling lights. The plate rinsed and sponged off with | | | i | | | | | | | | | | | | | | i | ! | | | ! + ! | i | | | | | i use, the hinged cover the spark gap swung down, closing safety switch. The slit the spectrograph may the background, together with the electrical controls for the primary circuit. mineral deposits that might affect the density. Incidentally, the dryer “homemade” affair consisting some resistance wire, such found toaster, strung along the bottom shallow box, the cover which the plate dried. ordinary household fan blows across and prevents the plate 3—Charging plate the spec- trograph. The spark- ing apparatus the next room, and the slit under the black cloth. from scorching, besides hastening evaporation. Using the processing plate available, total elapsed time for darkroom work min. Analysis Spectrum Lines Analysis the spectrum lines made the densitometer, Fig. darkness, except for the tube lamp over the computing table. The same team men handles this phase the technic, one reading the densitometer, the other com- puting and recording. This den- sitometer instrument with light source that through the plate narrow beam. means mirrors, the THE IRON AGE, May 20, 1937—27 light thus screened the spectrum line projected photoelectric cell which hooked gal- vanometer the far side the room. From the same light source small beam shot out the back side onto the galvanometer mirror and reflected suitable scale the densitometer proper. This instrument has also been revamped. The frame holding the plate has been rebuilt make the lo- cation the spectrum lines more positive and more accurate. There bring individual spectrographs into position for analysis and the cross movement has three speeds: fric- tion slide for fast manual adjust- ment, rack movement for rough positioning and screw for slow motion spectrum line across the field light. The galvano- meter damping has been increased give period sec. (rather than sec.). The slow motion gives the galvanometer build maximum reading. Readings particular element are always relative adjacent iron line, which there are many since the latter makes about per cent the metal analyzed. Because the variation emul- sions and time development, every plate must calibrated be- fore readings elements can taken. The densitometer itself also varies due changes the light 28—THE IRON AGE, May 20, 1937 4—-All processing trays for the development and fixing the plates are mechanically agi- tated the motor and crank mechanism the floor the right. The fan used for drying the plates over heater coils. sources ages, dust the con- denser lenses and the like. This calibration the work minute and done plotting typical sensitivity curve. explain this process, however, necessary refer back the original calibra- tion the spectrometer and den- sitometer the stepped diaphragm method. This method covered patents taken out Dr. Wolfe and Professor Duffendack the brating plate the method in- dicated, light from carefully con- trolled lamp passed through the graphically band the plate. The slit has stepped sections, each which varies width the proportion 1.5 raised the 1.5 empirical and was deter- mined experiment. Thus, the relative slit widths are (1.5°), 1.5, 2.25, 3.38, 5.07, 7.61, call- ing 1.5 the base logarithmic system, have the logs the (Def.: The log number the power which the base must raised order equal that was simple matter find iron lines the spectrograph corre- sponding depth shade the stepped densities produced the experimental plates the phragm. When the densitometer readings are plotted ordinates and the log slit widths (exposure) abscissa, the shape the curve drawn between the points prac- tically straight for the main por- tion with the ends falling off, some- what like half loop hysteresis curve. This calibration curve graph papers. All analytical readings are re- ferred this curve. obtain reading silicon, for example, the nearest iron spectrum line first read for maximum galvanometer deflection and the point the curve corresponding this reading be- comes momentarily the base line determination. means transparent slider with ruled vertical line, the zero point line with this point. The silicon line then read and the per cent the element present read di- rectly from the scale below the slider hair line which moved the point the calibra- | i - 4 | | 4 3 j | 4 | | | i ' | i i | | j tion curve corresponding densitometer reading. For each ele- ment, empirical scale has been worked out reading directly per cent. These scales were built check through chemical analysis. Once the calibration curve made the percentages for the various ele- ments can read off fast the densitometer readings can called off pairs. Average accur- per cent the amount present, with occasional maximum varia- tion per cent the amount present. Conditions Held Constant Conditions throughout must maintained constant get repro- ducible results. voltage regu- lator necessary keep the pri- mary potential constant sparking machine, because there electric furnace the same line melting cold iron and producing very irregular line load. com- pressed air jet blown across the spark clear gases rapidly they are formed. Furthermore the electrodes are pointed small bench grinder 5-deg. flat angle, giving slightly conical shape and tending center the spark. Whether spark are should used still debatable ques- tion, was brought out the Conference Spectroscopy held last July the Massachusetts In- stitute Technology. Initial use the method proved unsatis- factory the Campbell, Wyant Cannon Foundry Co. and the spark method has been much more satis- factory here. Its temperature 10-15,000 deg. raises the atoms IG. Variations density the spectrum lines are measured pho- toelectric cell this densitometer. The galvanometer shown the far side the room suspended from the ceiling three piano wires and inverted tripod eliminate the effect building vibration. Conversion cent the element present made type scale shown the calculating table. This recent improvement which has proved great convenience and time saver. high level excitation and maintains very uniform condition. For purely qualitative analyses, the low-voltage arc with its 5000-deg. temperature preferred, since will show more elements when present small amounts. There tremendous saving time and apparatus this meth- od. Allowing for time let sample cool sand mold and drill the chips, requires least min. run silicon determination single heat. determine copper content would require large amount plating-out equip- ment, since these checks are made three four times hour. While the silicon being determined chemical analysis, average five elements five different sam- ples can determined quantita- tively the spectrograph, includ- ing the copper content. Carbon content the Campbell, Wyant and Cannon lab- oratory are made fast technic that the results are available simultaneously with the spectro- graphic analyses. Under the pres- ent set-up readily possible have the analyses five ladles different metal back the melter’s hands within half hour—which feat, say the least. Upon first sight, the technic seems ultra-scientific and out place contract foundry. Yet when reduced routine basis, requires only normal amount Sampson, charge the labora- physics, but mechanical engineer who has devoted most his pro- fessional life the design auto- motive engines, then spending year the spectrographic develop- ment work with the research de- his laboratory assistants re- cent college graduate, the other studying nights the local junior college. High school graduates probably could trained the work, once the experimental fea- tures are worked out, they prac- tically are today. clerical detail, the plates are filed days the month half-letter size steel file. Wrapped around each plate slip pa- per giving the order analysis, identifying the furnace from which each heat was poured, and the prod- uct, such cylinder liners, well the sequence spectrographs the plate. The time day also recorded, test samples are gen- erally run hourly. The calibra- tion charts are destroyed, since the light source the densitometer not constant, has been ex- plained. Besides, simple mat- ter calibrate the plate again necessary. After three months, the plates are destroyed, but could trodes are held only day, then scrapped. Complete ports are returned the melters and are filed elsewhere, well running report analyses samples from hour hour. Thus evident that the spec- trographic technic not only whol- practical, but extremely fast. foundry able get closer than ever before that ideal point knowing what the ladle be- fore mold poured. THE IRON AGE, May 20, 1937—29 \ £ age BUILDING FLEET LIEUT. VANGELI, (CC), U.S.N.* THE large building pro- gram the past few years has been gi- gantic task for the materiel bureaus the Navy. The simultaneous construction large numbers some nice problems the prepara- tion and distribution plans, the procurement material, in- spection work and the keeping reasonable peace between the build- ing yards, sub-contractors, financial watchdogs, purveyors competing opinions assertions contained herein are the private ones the writer and are not construed official reflecting the views the Navy De- partment Naval Service large.) materials, prospective operating personnel, and designers, both pro- fessional and amateur. The conception new ship, the detailing its specifications and its suecessful construction repre- sent the dovetaling painstaking efforts the part thousands men representing every trade and every profession, from the ord- nance engineer who designs the in- struments death the soul-sav- ing minister who pronounces the benediction the launching. the main, the intricate mech- anism the building program powered two Bureaus, Construc- tion and Repair, and Engineering. ° ° ° AS After Congress has supplied au- thority and money, and devious preliminary steps have been taken, these two Bureaus issue the detail- specifications and contract plans the new class built and invite shipbuilding firms submit bids based this information. Con- tracts are then awarded accord- ance with the law. recent years, Congress has directed that least half the ships any class must built Navy Yards. How the Plans Are Made every building yard had had prepare its own plans, the sud- den and overwhelming demand for draftsmen would have necessitated robbing engineering cradles sup- ply the required talent. This might have occasioned considerable grief, because competent marine drafts- men become through long ex- perience and not designating them such. The Bureaus them- selves could not prepare the neces- sary working drawings, because their staffs were swamped with the development major ideas, the drawing contract plans, general supervision and answering ques- tions. Furthermore, each yard developed its own plans, sister ships might turn out strangers each other joining the fleet. Under these circumstances, one the successful private bidders each class ship designated prepare tracings working plans for all the building yards, public and private, concerned with that class ship. The Superintending Constructor and Inspector Ma- chinery the designing yard col- laborate approving most the plans, but the most important are sent the Bureaus for final action. Tracings approved plans are sent the other private yards, from which are printed the working drawings. Navy Yards not receive their plans direct from the design con- tractor, because the Government’s lowest-bidder system purchasing often supplies equipment different from that bought the private contractor. This may require modi- fication the private plans suit new dimensions. Furthermore, the Navy Yards received their plans direct from the contractor and pur- chased their own material, they would competition with each other for delivery and the Treasury would the loser. Besides, there would considerable duplication effort, requires little more work purchase identical equip- ment for vessels building several Navy Yards than purchase only for the vessels building single yard. Hence, the plans destined for the Navy Yards pass through cen- tral clearing house called the Cen- tral Drafting Office, located the Brooklyn Navy Yard. Here, mate- rial requisitions are prepared, de- liveries are scheduled, plans are checked and corrected suit Gov- ernment-purchased equipment and tracings working plans are final- issued the Government yards. These tracings are not original pen- and-ink drawings, but are reproduc- tions made special process from master copy the Central Drafting Office. The great mass material for Navy-built vessels purchased the Bureau Supplies and counts requisition from the Private yards let their own contracts. But all materials must accordance with Federal and Navy specifications. The material bureaus maintain highly efficient inspection service located stra- tegic centers industrial areas all over the country. The Bureaus keep their inspectors informed mate- rial being purchased their areas. When purveyor has shipment ready, notifies the local inspector and shipment not made until the material has been passed. Nearly everything inspected the source, but subjected further inspection the point receipt. The Bureau Supplies and Ac- counts does the buying, but the material bureaus the accepting. Private Yards Are Supervised The ships built private plants are constructed under the watchful eyes the Superintending Con- structor, representing the Bureau Construction and Repair; and the Inspector Machinery, rep- resenting the Bureau Engineer- ing. These two officials are assisted group officer assistants, draftsmen, and technicians who live with the ship and inspect daily. All work must satisfactory the Navy representatives. They, turn, are guided the general and detailed specifications, drawings, bureau publications, and common sense based experience. far, everything seems straight- forward. But, naturally, too perfect true. The contract designer establishes fixed sched- ule for finishing the plans. Each the building yards lays its keels its own particular time, dic- tated working load, facilities, erection schedule and date de- livery. Because there only one plan schedule, but variety working schedules, there soon much grumbling about lack drawings. Drafting errors and poor design show occasionally. inevitable. But the lost motion be- tween the designing yards and building yards sometimes delays their correction aggravating degree. Zeal for improvements often prompts the Bureaus au- thorize changes plans already is- (CONTINUED PAGE 108) + le 1- IS | | 4 | Present Trend Engineering Alloys ° ° JONES Manager Research, United Steel Co.’s, Ltd., England ° LTHOUGH chromium steels were among the earliest engineering the author points out that nickel steels belong the credit spreading the gos- pel alloy steels general throughout With but passing mention this early history, the discussion centered present-day alloy steels, their THE importance iron the field en- gineering construction liquid state with many other ele- ments, and particular with car- bon, which the essential com- panion element steel. Further, iron assumes heating, form which dissolves carbon carbide, and cooling, changes some temperature another form, from which the carbide again precipi- tated. The temperature the transformation, which this pre- cipitation takes place, dependent the rate cooling. cooling sufficiently rapid, precipitation delayed such extent that the 32—THE IRON AGE, May 20, 1937 ° qualities and their uses. De- tailed attention given the comparative effects single additions nickel, vanadium, molybdenum, chromium, tungsten and manganese the mechan- ical properties open- hearth steel. Test data also are given for steels contain- ing two and three alloying elements. carbide separates extremely fine state division the iron, while the latter almost rigid mass. Such conditions give hard product. the rate cooling formation takes place higher temperature, when the iron more mobile condition precipitated carbide afforded opportunity coalesce into larger particles, with the result that soft product obtained. ex- tremely difficult, plain carbon steels, depress the transforma- tion yield fully hardened product. However, the addition alloy elements, the transformation tem- perature can much more easily depressed low temperature, and thus much lower rates cool- ing produce full hardening. The importance alloy steels for constructional parts attributed the fact that they are capable, when subjected suitable heat treatment, combining equal greater ductility with greater strength than carbon steels. Chro- mium steels were among the earli- est alloy steels used con- nection with engineering construc- tion, but was from the use nickel steels for the manufacture armor plate, guns, etc., that the utility the typical alloy steels spread through many branches the industry. Nickel steel the type under consideration contained about 3.5 per cent nickel with 0.30 0.40 per cent, and this type has remained continu- ous use since its introduction. the course normal produc- tion, generally difficult secure regularly carbon steel satisfactory notched-bar impact figures sections over in. with tensile strength over tons per Improved regularity impact figures can obtained the introduction 0.50, 1.0 1.5 per cent nickel, 1.0 per cent chromium additional 1.0 per ~ ° \ ae ‘ ~_ | cent manganese, but even with such additions, thorough permea- tion the hardening effect not obtained sections larger than in. square when the hardening medium oil. The efficiency the additions various alloy elements reducing the effect mass during quench- ing may judged the relative reduction the critical cooling velocity the steel. Table gives selected results from list and pre-critical speeds originally published and Majert. The pre-critical cool- ing speed taken the maximum speed which allows the austenite pearlite change complete itself, whereas the critical speed the lowest speed which will allow only the austenite martensite change, with pearlite present. clear from these results that chromium and manganese respectively are much more effective than nickel reducing the critical cooling veloci- steel. The relative efficiency various alloy elements reducing the ef- fect mass during oil-quenching may further illustrated the results Vickers hardness tests taken through the thickness bars in. square, the oil-quenched condition. The analyses the ex- perimental steels and the results hardness tests bars square are shown Fig. the case the manganese and silicon additions alloy elements, the percentage indicated additional that found normally these steels. the case additions amounting one per cent alloy molybdenum the most effective, followed closely manganese and chromium, tungsten and silicon be- ing slightly more effective than nickel. The marked superiority additions per cent man- ganese chromium, compared with per cent nickel very evident from the curves. Effect Mechanical Properties All the mechanical properties 0.40 per cent carbon steel the oil-hardened and tempered condi- tion are improved result the addition nickel about per cent. advantage obtained increasing the nickel content be- yond this limit account the limitation imposed the temper- ing temperature the lowering the Ac, point. With manganese contents the order 0.80 per cent, advantage gained ex- ceeding 4.5 per cent nickel. The improvement properties evi- dent the greater toughness higher tensile strength compared with carbon steels, indicated the results tests given Table The presence small amounts chromium has marked effect modifying the properties nickel steels from the point view improving the mechanical prop- erties and reducing the effect mass. The effect small contents chromium the surface hard- ness after oil quenching in. square billets per cent nickel steel shown the results Table III. After oil hardening and temper- ing, the mechanical properties 600 560 480 To Si 1% Mn 2 Mn Cr 360 Vickers Hardness Number 200 Outside ™m 0.40 per cent carbon steels are markedly improved result the presence chromium about per cent, while some fur- ther improvement occurs chromium content raised per cent. Chromium steels show very marked advantages over steels similar tensile strength respect ease machining. The steels higher chromium contents are susceptible temper brittleness slowly cooled from the tempering temperature. Chromium steels containing over per cent chromium have not been developed commercially any great extent constructional steels, but steels containing ap- proximately per cent chromium are wide demand. Test results representative per cent chro- mium steels containing 0.40 per cent carbon are given Table Alloy addition 1.03 Inches from Outside various alloy elements the hardenability oil-quenched 0.35 per cent carbon steel. These graphs show Vickers hardness values through the thickness 134 in. square test bars, oil-quenched from 860 deg. THE IRON AGE, May 20, 1937—33 it j \ 035 054 | — | | | | | 2 | TABLE Effect Alloy Elements the Pre-Critical and Critical Cooling Speeds Steel Quenching Temperature, 950 Deg. Alloying Carbon, Element, Per Cent Per Cent 0.42 0.55 0.49 1.60 0.35 2.20 1.12 Ni 0.52 3.13 Ni 0.40 4.80 Ni 0.55 0.56 Cr 0.48 1.11 0.52 1.96 0.38 2.64 0.31 0.48 W 0.38 1.10 0.35 4.22 0.35 0.98 0.41 1.44 Si TABLE Effect Additions Nickel the Mechanical Properties 0.40 Per Cent Carbon Steel Section, Inches Carben Steel 0.39, 0.80 per Treatment 144 Diam. OH and T at 585 Deg. C. Deg. Per Sec. 120 26 135 120 60 25 to 30 220 190 Per Cent Nickel Steel 0.41, 0.63, 0.51, 0.04): Per Cent Nickel Steel 0.41, 0.87, 0.86, 0.16): Per Cent Nickel Steel 0.42, 0.76, 3.02, 0.09): Per Cent Nickel Steel 0.43, 0.75, Cooling Speeds— Pre-Critical, Average Critical, Deg. Per Sec. 550 50 8 450 180 85 400 100 10 to 15 650 300 200 800 1,000 Maximum Yield Izod Stress, Point, tion, Area, Impact Tons Per Tons Per Cent Per Figure, Sq. In. Sq. In. In. Cent Ft. Lb. 47.1 32.6 25.0 45.3 30.8 26.5 63 66 44.0 29.2 26.5 66 70 45.0 29.3 25.5 44.0 29.0 25.5 63 47 50.1 35.1 23.0 57 43 48.0 33.0 24.5 47.7 32.3 26.0 62 59 49.6 32.0 24.0 47.0 30.4 25.5 57 26 45.5 29.3 25.5 59 32 52.6 40.0 22.5 59 56 51.0 39.2 23.5 59 75 49.4 36.7 25.5 62 80 49.4 32.6 25.0 55 42 46.2 29.8 27.0 59 52 60.6 54. 19.5 54.8 47 24.5 62 69 53.7 42.4 20.0 52 43 49.9 38.8 23.0 58 68 3.38, Cr 0.17): 61.9 55.9 21.0 60 64 56.7 49.6 23.0 64 75 57.8 51.1 20.0 58 58 54.0 44.0 19.0 50 59 TABLE Ill Influence Chromium Carbon, Manganese, Per Cent Per Cent 0.40 0.57 0.37 0.63 0.37 0.67 34—THE IRON AGE, May 20, 1937 Nickel, Per Cent 3.40 3.34 3.25 Surface Hardness Nickel Steel Chromium, Per Cent 0.06 0.11 0.25 Surface Hardness (Brinell) 316 387 460 IV. the same order those per cent nickel steels for The properties are thus seen Unfortunately, chromium steels are particularly susceptible the development during rolling sur- face markings, generally referred “chrome the removal which necessitates the introduc- tion rough turning the course manipulation. spite the additional cost thus entailed, chro- mium steels are still appreciably cheaper than per cent steels. The development chro- mium steels containing least per cent chromium for construc- tional purposes would appear merit consideration. The presence manganese about per cent has markedly beneficial effect the mechanical properties and tempered 0.40 steel, while the improvement still maintained with 2.8 per cent manganese, al- though this higher content shows particular advantage and may introduce difficulties forging and rolling. Representative results mechanical tests number open-hearth steels containing 1.7 per cent manganese are given Table The mechanical prop- erties 1.5 per cent manganese steel may regarded superior similar content nickel, and for sections in. diameter are not greatly inferior those per cent nickel steel. Steels containing 0.30 0.40 per cent carbon and low percentages tungsten have not received any commercial application construc- tional steels. Similarly, the presence other alloy elements such nickel and chromium, while tungsten exerts beneficial effect the properties steels the type used for constructional pur- poses, its influence not sufficient- pronounced warrant any special recommendation its favor. Role Molybdenum and Vanadium The addition molybdenum carbon steels has marked effect raising the elastic limit, yield point, maximum stress and notched- bar impact figure, while about 0.60 per cent, the figure for percentage elongation remains relatively high. Molybdenum may regarded | | dia A = | R. J. WYSOR who was recently mad . Corp. Portrait John Frew for The Iron } -~ - extremely potent alloying ele- ment, even small amounts greatly increasing the propensity steel towards hardening quenching. This valuable effect greatly in- tensified the presence other hardening elements, and this field that molybdenum finds its main application. Vanadium, the same manner other alloy elements, exerts beneficial effect the properties heat-treated steels. Plain vana- dium steels are used only very limited extent for constructional purposes, but vanadium steels containing about 0.15 per cent vanadium have found wide field application for small and medium size sections. The difficulty obtaining di- rect comparison the effect equal additions single alloy ele- ments the mechanical properties open-hearth steel will readily realised, many such steels are not commercial steels. Compara- tive tests can obtained, however, small casts such steels pre- pared the laboratory, and some these results are given Table VI. These results indicate that for content per cent alloy ele- ment, the highest tensile strength after oil-hardening and tempering obtained the molybdenum steel. The chromium and the man- ganese steels are next order tensile strength, followed the tungsten and silicon steels, with the nickel steel showing the lowest values. would appear therefore that both from the point view eliminating the deleterious effect mass and obtaining optimum me- chanical properties, molybdenum the outstanding alloy element among those examined. Commer- cially however, considerations cost militate against the use simple alloy constructional steels containing molybdenum high per cent. Nickel, chromium and medium manganese steels thus con- stitute the chief classes simple constructional alloy steels contain- ing single alloy elements which are used service constructional steels the oil-hardened and tem- pered condition. will evident, however, that the properties obtained from the best such steels can only satisfy limited demand. Further im- proved properties when required large sections, may obtained result combining certain pro- portions two more alloy ele- TABLE Mechanical Properties Oil-Hardened and Tempered Per Cent Chromium Steels 0.40, 0.70, 1.09 Per Cent) Reduc- Average Stress, Point, tion, Area, Impact Section, Tons Per Per Figure, In. Diam. Treatment Sa. In. In. In. Cent Ft. Lb. and 650 Deg. 47.7 38.4 24.0 TABLE Effect the Presence Per Cent Manganese the Mechanical Properties 0.40 Per Cent Carbon Steel Average Maximum Yield Elonga- Reduc- Izod Stress, Point, tion, tion Impact Section, Tons per Tons per Per Cent Area, Figure, Inches Treatment Sq. In. Sq. In. Ft. Lb. 0.36, 1.40 per cent and 650 deg. 32.6 28.0 106 and 650 deg. 43.2 30.0 28.0 0.38, 1.57 per cent square and 600 deg. 48.1 35.2 25.0 0.38, 1.67 per cent diam. and 620 deg. 55.1 46.6 23.5 square and 620 deg. 48.0 36.0 25.0 TABLE Effect Additions Alloy Elements the Mechanical Properties Oil-Hardened and Tempered 0.35 Per Cent Carbon Steel Experimental Steels (Analyses Given Fig. 1); 18-Lb. Ingots Forged In. Diameter Bars; Oil-Hardened 860 Deg. and Tempered Indicated Vickers Average Tempering Hardness Maximum Yield Elonga- Reduc- Izod Alloy Tempera- Number, Stress, Point, tion tion Impact Addition, ture, Tons Per Tons Per Cent Area, Figure, Per Cent *Quenched Sq. In. Sq. In. In. PerCent Ft. Lb. 600 248 43.2 26.5 63.6 640 42.9 30.6 28.0 66.0 2Ni 600 414 47.4 $7.1 25.5 63.6 640 45.8 35.6 27.0 63.6 600 536 47.3 25.0 60.4 640 48.0 42.1 28.0 61.6 600 348 49.1 35.1 28.5 61.6 640 48.0 29.0 61.6 600 284 42.9 23.5 59.2 640 48.5 25.5 61.6 1Mn 600 611 55.0 46.9 22.5 60.4 640 50.1 42.0 25.0 63.6 2Mn 600 557 58.3 50.9 22.0 54.8 640 54.6 47.1 24.0 59.2 1Cr 600 479 55.0 47.9 20.5 61.6 640 51.8 43.6 23.0 63.6 2Cr 600 66.6 60.6 19.0 55.2 640 62.1 56.1 19.5 640 63.2 60.8 21.0 69.2 *Additional steel: 0.85, 0.50, 0.16, 3.01 per cent. THE IRON AGE, May 20, 1937—35 | | | ; | | ~ | j | | ing } | 4 te Wee < | 1.25 per cent, the properties are least equal those obtained 3.0 TABLE 3.5 per cent nickel chromium Susceptibility Nickel-Chromium Steels Temper-Brittleness Air-Cooling From the steel. This illustrated Table Tempering Tempcrature (Sections In. Square, Oil-Hardened 820 Deg. and Tempered 610 Deg. C.) Substitution part the nickel steel manganese re- sults reduction price with ANALYSES (casts arranged order phosphorus content). Carbon, Manganese, Sulphur, Phosphorus, Nickel, Chromium, Steels Per Cent Per Cent Per Cent Per Cent Per Cent Per Cent improvement mechanical proper- 0.033 0.031 3.32 0.72 ties. The combination nickel and 0.32 0.60 0.042 0.032 3.30 0.77 manganese particularly effective 0.32 0.53 0.037 0.033 3.17 0.80 reducing the deleterious effect 0.60 0.086 mass. Two types steel developed 0.31 0.60 0.041 0.034 3.30 0.76 0.33 0.59 0.035 0.035 3.63 0.76 analyze follows: carbon 0.35 0.34 0.57 0.042 0.036 3.23 0.72 0.40 per cent, manganese 1.0 1.2, 0.34 0.64 0.042 3.25 0.78 nickel 1.0 per cent; and carbon 0.35 0.33 0.62 0.039 0.038 3.20 0.77 0.40 per cent, manganese 1.25 MECHANICAL PROPERTIES per cent and nickel 1.75 per cent. The former type generally used Max. Yield Izod for meeting specifications calling Per Cent Area, igure, strength, while the latter type Steel Medium Sa. In. Sa. In. In. Per Cent Ft. Lb. used for 123,000 lb. per sq. in. The Oil 61.5 55.5 22.0 63.6 Air 61.0 66.0 nickel-manganese steels suffer from Oil 59.9 54.6 21.5 61.6 temper brittleness the same Air 59.5 54.6 22.5 63.6 manner steels oil 55.0 and this may overcome the Air 59.8 54.1 22.5 61.6 Air 59.0 53.8 22.5 57.2 denum. Air 51.6 22.0 61.6 ked eff . y Oil 60.4 54.4 20.5 57.2 marked effect, particularly the Air 60.0 54.2 20.0 57.2 presence other alloy elements, Oil 69.4 55.6 20.5 57.2 improving the properties heat- » 9 . Air 60.6 treated steels, has found wide ap- Oil 63.4 57.6 29.5 61.6 the development molybdenum- Air 62.7 58.4 21.5 59.2 bearing steels has made rapid Air 61.4 57.0 21.5 61.6 The addition molybdenum chromium steels results marked effect two alloy elements such for medium-size sections, air-cool- machineable even when hardened nickel and chromium, quenching, ing after tempering not suf- and tempered high tensile considerably greater than that ficiently rapid prevent ap- strength. Molybdenum has either element alone, and conse- preciable drop impact figure, effect reducing tendencies quently sections larger size can indicated the results obtained wards incomplete hardening during heat-treated give high tensile from various casts open-hearth oil-quenching and also reducing strength and uniformly good prop- steels, Table VIII. the softening effect tempering. Steels containing approximately ties throughout the mass. work per cent carbon, 1.0 per cent have been carried out the chromium and 0.35 per cent molyb- time, with view determining Improvement the properties the suitability the nickel the 3.5 per cent nickel steel was chromium ratio 3.5 per cent sought the first instance the nickel-chromium steel for the structional nickel-chromium steels, steel give optimum properties. like nickel steels, were developed Steel containing approximately originally for the manufacture per cent carbon, 2.0 per cent guns, but their applications rapidly nickel and 1.25 per cent chromium widened. The improvement was one the early types Molybdenum-bearing steels find properties obtained the addition adopted alternative the application steam service 0.75 per cent chromium 3.5 steel higher nickel content. elevated temperatures where high per cent nickel the same carbon showed definite advantages. Even creep-resistance required, ac- content given Table VII. Un- the nickel content reduced companied complete immunity fortunately this type 1.6 1.8 per cent without increas- embrittlement due chromium steel normally sus- ing the chromium content beyond longed exposure service temper- Two Alloying Elements 36—THE IRON AGE, May 20, 1937 improvement mechanical proper- ments the steel. The combined ceptible temper brittleness and ties, while steels are very easily ‘ | | | atures. considered that the full potentialities the higher chromium-molybdenum steels have not yet been fully developed, but rapid progress being made applying the results research this field commercial practice. have now been commercial use for number years, and must regarded established steels with reputation for reliability. Development proceeding along the lines investigation the effect slight modifications manganese denum contents with view pro- ducing steels with optimum me- chanical properties, but already wide range analysis covered present day commercial manga- nese-molybdenum steels according quired. The development the higher manganese molybdenum steels has proceeded gradually to- wards maximum contents man- ganese and molybdenum, limitation being placed the higher limits manganese troubles mani- pulation and treatment. These dif- ficulties become evident with about 1.7 per cent manganese when the carbon the order 0.40 per cent, but suitable adjust- ment carbon and manganese, with additions molybdenum, practically any combination mechanical properties normally specified can met. The air-hardening type steel warrants mention. present the nickel-chromium mium-molybdenum steels contain- ing higher nickel than chromium contents hold supremacy. this field, investigation still required TABLE VII Effect the Addition Per Cent Chromium the Mechanical Properties Oil-Hardened and Tempered Per Cent Nickel Maximum Yield Section, Stress, Tons Point, Tons Inches per Sq. In. per In. per cent nickel steel diam. 52.9 45.5 diam. 48.0 37.5 414 diam. 48.0 85.1 per cent nickel-chromium steel diam. 61.6 56.6 diam. 61.1 66.1 diam. 54.6 47.9 Elongation, Reduction Average Izod Per Cent Area, Impact Fig- In. Per Cent ure, Ft. Lb. 24.5 26.5 59 75 25.5 55 65 21.5 62 60 21.0 61 58 find the most appropriate nickel chromium ratio with the view improving the properties and re- ducing the cost. Mention should also made the subject controlled inherent grain size. The tests given are all taken from casts which were not subject during manufacture any process involving grain size con- trol. Fine inherent grain size im- proves toughness carbon and low alloy steels. Experience would indicate that greater degree improvement from this point view may obtained from the manganese-molybdenum steels than from the higher alloyed steels type. The major portion these ma- terials manufactured either acid basic open-hearth processes, both which are capable pro- ducing large quantities steel good quality and the whole the tests quoted, with one exception, have been carried out material produced the open-hearth fur- nace. Steel slightly superior character regards freedom from non-metallic inclusions produced the electric are furnace, while steel even greater cleanness with maximum uniformity quality produced the high frequency electric furnace. This latter method steel manufacture recent origin and its very nature the steel produced must inherently homogenous and very free from foreign matter. The company with which the author associated pos- sesses the largest high frequency electric furnace the world, name- one five tons capacity. possible this furnace produce steel the finest quality, free from contamination, under definite and accurate temperature control, while the well-known movement the liquid bath ensures complete uniformity the charge. further advantage the conservance alloying elements remarkable degree, the regularity routine production being outstanding. TABLE Comparative Mechanical Properties Ni-% Cr, and Steel Size, Analysis, Per Cent Inches Diam. 0.33 0.57 3.20 Diam. 0.38 0.60 1.48 Diam. 0.31 0.55 3.08 Diam. 0.39 0.62 1.62 (Open-Hearth Casts, Oil-Hardened and Tempered) Maximum Tempering Position Stress, Temperature, Tons Per Deg. Test Sq. In. 0.79 600 0 61.1 ( 59.5 650 52.7 Cc 62.1 1.16 600 O 63.2 ( 53.3 0.80 600 0 54.4 M 53.2 ( 1.25 610 Oo 54.5 M 54.6 Cc 52.8 Average Yield Izod Point, Red. Impact Tons Per Per Cent Area, Figure, Sq. In. In. Per Cent Ft. Lb. 42.4 21.0 41.2 20.0 42.6 24.0 41.1 23.0 42.2 23.0 42.2 22.5 46.2 21.5 45.0 21.5 45.5 21.5 59 56 44.0 23.0 43.4 22.5 41.8 23.0 THE IRON AGE, May 20, 1937—37 fa — | > > | | | | i The Control and Protect THERE are two dis- tinct phases the prob- lem electrical control the industrial plant. One applies specifically the elec- trical distribution system, and the other directly the machines apparatus operated. Both are tied closely together, however, that they must considered connec- tion with each other. For the pur- poses logicai discussion the con- trol and protection the distribu- tion lines will considered first, order effectively establish certain principles common both matters. Broadly speaking, industrial elec- trical control equipment includes: Means which operator can safely open and close circuit. Means which operator can safely regulate the flow cur- rent. Means which circuits can safely opened closed auto- matically under certain prescribed conditions. Means which current, volt- age, power, any other desired value may maintained, regulated, varied automatically and with safety. Note that the first two statements cover manual control; that is, con- trol the will, and the effort, human operator. The last two cover automatic control inde- pendently the human operator, mechanisms set certain jobs when certain prescribed condi- tions service are met, exceed- ed. These four statements are given ascending order complexity because each succeeding statement involves the use some the prin- ciples utilized the preceding statement. Thus explanations may made simple and logical or- der. Likewise will simple consider first the control the distribution system, then apply the ideas expressed describing such control consideration 38—THE IRON AGE, May 20, 1937 the electrical control individual machines. The simplest means manually UTLER-HAMMER ard duty direct cur- rent motor starter, with cover and oper- ating moved. Compare with typical wiring diagram. power circuit the knife switch. Low-powered lines, such ordinary lighting alarm circuits, may operated directly push-button, alternating current oil cir- cuit breaker, closed, mounted panel. Rated for 2500 volts, 800 terrupting rating, 25,000 — ( ‘ 4 L. q Ow, am. <> snap tumbler switches, and heavier power lines may control- led through relays similar switches operating local low-power alternating current air cir- cuit breaker, open. Equipped with two inverse time delay devices. Rated for 250 volts, 400 am- peres. Distribution Lines circuits. All these are, however, more complicated mechanisms than the knife switch. Knife switches may have any speed lating slip ring motor rheostat, with auxiliary control switch for interlock- ing magnetic line switch. Compare with typical wiring diagram. ° ° FRANCIS JURASCHEK Consulting Editor, The Iron Age ° ° number “poles” blades ac- commodate the number lines the circuit opened closed simultaneously, and may single double throw. Single throw knife switches (closing one di- rection only) are used open close single circuit. Double throw switches (closing either two opposite directions) are used when current come from either two points application, where the flow current re- versed. Knife switches are used for manually opening closing both direct and alternating current cir- cuits when not more than two switch positions are required. They should not used alone the manufacturing plant interrupt current voltages above 250, higher voltages than these cir- cuit breaker should connected series with the knife switch, some other means interrupting the current employed. For more than two switch posi- usual provide drum dial switches, contactors. motor starting, for instance, throwing the full current into the motor wind- ings while the motor state rest, may result burning out the motor windings (except cer- tain types motors specifically de- signed for across-the-line start- ing). type starting switch embodying the principles the rheostat therefore used, choke off the full flow current through heavy resistance first, then, the motor gains speed, cut out more and more this resistance successive steps until, full motor speed, all the resistance cut out the circuit and the current flows directly the motor windings. rheostat type dial switch. drum switch, contact-fingers mounted revolving drum make contact electrically with stationary THE IRON AGE, May 20, 1937—39 | | fingers plates successive posi- tions the drum open close various combinations operating circuits, including those which con- tain resistances. familiar ex- ample t