The Iron Age 1940-02-29: Vol 45 Iss 9

Managing Editor Machinery Editor Art Editor OLIVER CAMPBELL VAN DEVENTER President and Editor BAUR Vice-President and General Manager Editor Emeritus News Editor Associate Editors PHAIR Washington Editors Resident District Editors Pittsburgh Chicago Cleveland Detroit Editorial Correspondents London, England Cincinnati MEYER Toronto, Ontario Leroy ALLISON FRAZAR Boston Hamburg, Germany CHARLES Milwaukee San Francisco SANDERSON Birmingham Newark, N. J. St. Louis TURNER, JR. Buffalo DIX, Manager Reader Service Publication Office Chestnut and 56th Sts.. Philadelphia, Pa., U.S.A. JOS. HILDRETH, GEORGE GRIFFITHS, EVERIT TERHUNE, ADVERTISING STAFF B. L. Herman, Chilton Bldg., Phila. H. K. Hottenstein, 1012 Otis Bidg., Chicago H. E. Leonard, 239 W. 39th St., New York Peirce Lewis, 7310 Woodward Ave., Detroit C. H. Ober. 239 W. 39th St., New York D. C. Warren, P. O. Box 81, Hartford, Conn. Don F. Harner, 1595 Pacific Avenue, Long Beach, Cal. 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. Annual Num- ber $1.00. Cable Address, ‘“‘Ironage, Owned and Published by CHILTON COMPANY (Incorporated) Editorial and Executive Offices OFFICERS AND DIRECTORS MUSSELMAN, President Vice-President Vice-President Vice-President VAN DEVENTER, BAUR, Vice-President WILLIAM A. BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE, THOMAS KANE, HARRY DUFFY Metallurgical Bditer RICCIARDI BINGHAM CLYDE ENNIS Roy 239 West 39th St., New York, Y., U.S.A. Vice-President Contents February 1940 Good and Bad Inventors Industrial Radiography Theory and Practice Slag Control Automatic Lubrication Production Machines Engine Founding the Modern Manner New Mill Starts Stainless Production Grinding Cracks Quenched Steels What's New Welding Apparatus Washington News THE NEWS BRIEF Weekly Ingot Operating Rates Rate Activity Capital Goods Plant Expansion and Equipment Buying Free Industrial Literature Products Advertised Just Between Two Index Advertisers Copyright, 1940, Chilton Company (Inc.) r d f ‘4 - r ae - 27 40 46 8 98 | 109 134 : Consider Labor hen most jobs, shop labor costs are the biggest single factor—and they depend large degree the steel used. bars are too hard for bend- ing forming—or have hard spots break dull tools—if some shapes are not straight—or the case alloy steel the required proper- ties are not developed the first heat treat- ment—then costs, down profits. Purchasing steel that uniform and has the properties most desirable for your particular use Principal products stock for mediate Shipment include— Bars, Structurals, Plates, Iron and Steel Sheets, Tubing, Shafting, Strip Steel, Alloy Steels, Tool Steels, Stainless, Babbitt, Welding Rod, 24—THE IRON AGE, February 29, 1940 Costs Steel often pays big dividends the form decreased shop costs. You not have pay any more why not get it? for this kind steel For several years Ryerson has been building stocks these better, more uniform steels. Careful selection, checking, testing and inspect- ing assure the uniform high quality necessary for Ryerson Certification. Try Ryerson Certified and check the labor Steels your hardest job costs. Many have told that pays. Joseph Ryerson Son, Inc. Plants at: Chicago, Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City. 2 | W 4 ESTABLISHED 1855 THE IRON AGE ... FEBRUARY 29, 1940 Vol. 145, No. Good and Bad Inventors HIS week marks the culmination the local and national celebrations honoring the inventors America whose work has contributed most effectively American life and living during the past quarter century. Modern pioneers, these, who have dis- covered, surveyed and opened new paths progress, new avenues employment and who have charted the course new levels comfort and high living standards for their fellow citizens and the world large. The 500 American inventors who have been honored with awards and the thousands other practical men not included this necessarily incomplete category may aptly described composing the mainsoring American industry. And what industry? twentieth century economy, which our geographical frontiers have been fully explored and conquered, industry the one all men for better living. Agriculture depends industry and upon its employees for markets. Merchandis- ing depends upon industry and agriculture for the products which sells. Banking depends upon industry for the creation new markets and new wealth well for the main- tenance existing financial demands. Government depends upon this vital creator national wealth because the primary generator tax revenues from profits and wages. Investors, large and small, depend upon industry because its state health the criterion values. matter who you are, doctor, train conductor, mechanic, laborer interior deco- rator, your welfare tied fast the prosperity American industry. And you hap- pen relief, that goes double, for industry and its dependent, agriculture, are paying your wages. are doing significant and appropriate thing, this month February, honor- ing these 500 inventors and their thousands equally deserving associates. But don't let stop that. From self-interest, well from desire for the good all our people, let's learn distinguish the good from the bad inventors. Good inventors, like the men who have been selected for signal honors Modern Industrial Pioneers, have contributed the health and growth American industry. Bad inventors, the other hand, spend their time and devising ways pro- mote class hatred, dissipate wealth, and obstruct the normal and legitimate progress American enterprise. : BES 1 ul Competition does not begin point sale—that where ends. Competition starts when idea conceived—and cannot separated from design, selection materials, production cost, and service tests. Therefore, matter what results you may have had the past, you cannot afford disregard the competitive advantages offered today’s steels. Inland has file case after case faster produc- tion, fewer rejections, finer finished products, and thousands dollars added profits the use SHEETS STRIP TIN PLATE BARS PLATES FLOOR PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS ARE YOU MEETING COMPETITION with Today’s Steels? the more recently developed Inland Ledloy that saves from few dollars $50.00 more per ton steel Hi-Steel that builds stronger yet lighter—and, cessed sheets that help users meet competition their superior workability and finer finish. The expert assistance Inland Metallurgists your command show you how can help you meet competition. Your inquiry will receive immediate attention. ARS announced the world the dis- interest note that his pre- liminary communication mentioned having six photographic shadow pic- tures. these, five were industrial nature. One was described show- ing the lack homogeneity piece metal. From this beginning, indus- trial radiography has grown into vital tool for the non-destructive examination materials. 1895, Wilhelm Konrad Rontgen’ Tremendous strides have been taken since the original industrial radio graphs were made, and many factors have contributed the growth. One the outstanding dates associated with the growth this country was the adoption the boiler code 1931. The thickness material which can satisfactorily penetrated di- rectly related the kilovoltage capac- ity the X-ray generating equipment. The equipment manufacturers have progressively increased the scope their machines from 100 200, 300 and now 400-kv. capacities. do- ing, the practical thickness steel penetration has been increased from The size and weight industrial units have been reduced that 220-kv. New Kind Rays,” Nature (London), 53, 274, Jan. 23, 1896. Translated Arthur Stanton from the Sitzungsberichte der Wiirzburger Physikmedic Gesell- schaft, 137, December, 1895. important practice X-ray inspection metals undergoing constant change and improvement. What the latest advances equipment for industrial radi- ography are, technique continuous and planar inspec- tion, types protection nec- essary, etc., are all treated the author herein. machines are easily portable, and even larger sizes the flexibility move- ment permits considerable manipula- tion. The portable machines are usu- ally mounted either small trailer type truck equipped with pneumatic miniature flat car for use steel track. Most industrial equipment manu- factured today shock-proof and ray- proof. Fig. shows recent 220-kv. portable industrial X-ray machine. The control panel ground the transformers and valves are im- mersed oil contained grounded steel shells. The high voltage de- livered the X-ray tube insulated flexible cable incased grounded metal. The X-ray tube itself housed grounded metallic tube head. The cooling and insulation the tube maintained forced circulation oil. Controls are conveniently grouped lead-protected cabinet. The mounting the tube ex- tremely flexible and counterweighted for easy movement ball and roller bearings. The tube shielded that X-radiation can emerge the port provided, which greatly facili- tates the adequate protection per- sonnel and film. Operation such unit simplified automatic con- trols, which operate the oil cooling system, shut the X-ray machine off should any part the cooling system fail, gradually build selected tube voltage means motor-driven rheostat, operate lead shutter built the tube head that the exposure not started until full voltage applied the tube and con- clude the exposure after pre-set time interval beginning simultaneously with the shutter operation. Fig. illustrates another recent port- able industrial X-ray unit somewhat different construction. this case, all the high voltage equip- ment including the X-ray tube, con- tained single grounded metal tank, from which the radiation emerges through cone. Minor changes the arrangements can easily made fit particular applica- tion. Fig. shows 400-kv. unit capa- Continuous Inspection The continuous X-ray inspection small items has been successfully ac- complished industries manufactur- THE IRON AGE, February 29, 1940—27 ? JT ; a | | 4 he ° ° per ilds ill ati ing materials low absorption. This has been done means fluoro- scopic units. For fluoroscopic inspec- tion the X-ray tube usually mounted below behind moving belt which carries the articles between the X-ray tube and chemically treated screen. The chemicals the screen have the property emitting greenish-yellow light intensity depending the X-ray energy reaching Therefore, shadow image box candy, for example, would clearly indicate, dark spot, any foreign body such wire, stones, etc., which might accidentally have been included. The operator, watching the screen, can No. and Handbook No. the National Bureau Standards, Superintendent Documents, Govern- ment Printing Office, Washington, Price 10c. each. Taylor, “Industrial X-Ray Pro- tection,” A.S.T.M. Bulletin, No. 99, 23, August, 1939. 28—THE IRON AGE, February 29, 1940 operate mechanism which rejects any questionable items for further inspec tion. This method inspection has been used for inspection canned goods, packaged candy, tobacco and citrus units are commercially avail able which may require minor changes conveyor and rejection methods adapt fluoroscopic inspection ent applications. The capacity X-ray tubes has been increased that some tubes for continuous operation 220 kv. rated milliamperes have effective focal-spot size 10x10 mm. order accommodate such large energies, the actual focal spot has been enlarged and usually made rectangular elliptical shape. order that the effective focal spot may still remain small, the target face the tube formed such angle that the use- ful X-ray beam arises focal spot which square circular shape. Self-rectifying, X-ray tubes 200 and 400-kv. capacities are being marketed. Effective focal-spot sizes small 5.5x5.5 mm. are avail- able for work requiring high defini- tion. Focal spots small this may carry 220 kv. continuously, The efficiency oil cooling has been increased studies oil and metals with the object mind increasing backing and cooling oil. Self-rectifying high voltage tubes near the cathode offer interesting pos- sibilities increasing the capacity well improving the useful quality the radiation. The action such grid similar that the simple three-element radio tube. Tube (plate) current does not flow until the voltage has reached high value the and, therefore, the production use- less low voltage X-rays materially reduced. From the quality standpoint, the effective wave length the radia- tion shortened, and the maximum energy shifted toward the shorter wave lengths. Thus, the radiographic efficiency the tube increased be- cause the target the tube relieved the load associated with the produc- X-ray tubes are the subject con- increased voltages and capacities with decreased effective focal-spot size may ex- pected. Protection Practice the penetrating power X-rays has been increased and the use the gamma rays radium has become more common, has been necessary give more attention the problem adequate protection personnel and photographic materials. The effect X-ray and gamma ray radiation cumulative, biologically well photographically. planning start X-ray inspection extend its original kilovoltage range would well consult the National Bureau Standards Handbook, No. 20°. similar handbook, No. deals with the safeguards needed when radium work undertaken. The economies that may observed planning adequate protection have been studied and results tabulated for easy reference. has made comparison lead protection for 100- kv. 600-kv. X-rays, and for gamma rays, with equivalent thicknesses concrete, barium concrete, building \—Portab e qhouse X-Ray | | | blocks and brick, indicating the rela- tive cost installations made during construction and installations made after completion. Radium protection have been reported article These papers indicate the lead protection equivalents iron, barium plaster, concrete, and red brick. Precautions handling radium are discussed which can made assure the personnel. Various techniques are employed produce radiographs the widely different materials encountered in- dustrial refinements and additions knowl- edge technique have been made re- Pullin’ have investigated the problem secondary radiation industrial When X-rays strike matter, some their energy re-emitted the form X-rays similar longer wave length. The various types these X-rays are included under the term “secondary Since sec- ondary radiation spreads all direc tions, non-image forming and merely acts produce general fog over the film, lessening contrast and detail the radiographic image. See mann’s findings indicate that the pro- portion secondary radiation from aluminum and steel, when radiographed direct X-ray technique, increases almost linearly with thickness, and that nearly half this secondary radiation can removed the use lead-foil screens contact with the film. Sec- ondary radiation increases somewhat with the voltage applied the X-ray tube, but important reduction secondary radiation possible range necessarily used for subject. When the object radiographed does not cover the whole film, the areas film outside the shadow may receive very intense exposure, giving rise halation from the and light dif- fusing into the image. protect these outer film areas, customary Some Bell, X-Ray and Gamma-Ray Pro- Values Building Materials,” Brit. Journal Radiol., 11, 676, 1938. SE. Quimby, “Radium Protection,” Journal Applied Physics, 10, No. 604, 1939. Seeman, “Secondary Radiation the Aluminum, Steel, and Proceedings, 38, Part 284, 1938. pect Non-Destructive Jour- neers, 84, No. 509, May, 1939. *C. Moriarty, “The Use Metallic Shot X-Raving Steel.” General Elec- Review, 109, June, 1938. cover them with lead, plastic barium clay, X-ray absorbing solution. use very fine metal shot for this purpose, which has the advantage freely that may readily filled around irregular objects. Fig. illustrates this method would applied round bar stock, one the most difficult applications for which may used. has been suggested that lead mask used retain the shot and reduce the quantity needed. keeping the volume shot the total material contribut- ing secondary radiation reduced. \nother application fill the surface irregularities such exist welded joints. otherwise may confusing the radiograph and have little any diag- nostic importance. The composition the shot may selected suit the material under examination. Moriarty personal communication suggests that practice has found advis- able use copper shot about 0.010 diameter. This size shot pro- and less susceptible adhesion due oil moisture picked from the subject than the smaller size previously recommended. Use Penetrameter evidence the radiograph that suitable exposure technique has been used, penetrameter may placed the subject point representing the ereatest thickness material shown that particular exposure. The penetrameter device, made the used, having thicknesses represent- ing small percentages thickness the subject. The details limitations their use are the subject considerable research and discus- sion. General considerations indicate that the penetrameter should always located the tube side the sub- ject which position most accur- rately indicates the ability the radio- graphic technique show small dif- ferences thickness X-ray absorp- 2—A 220-kv. portable X-ray unit for inspection industrial materials. Photo cour- tesy General Electric X-Ray Corp. THE IRON AGE, February 29, 1940—29 cd tion, for example, defects small depth. The image the penetrameter cannot taken index the minimum size flaw detectable rather arbitrary estimate the quality the radiograph. Les- has discussed some aspects radiographic sensitivity which pene- trameters receive considerable atten- tion. Doan and Young” have pointed out certain geometrical simi- larities between graphy and solar eclipses and from these observations derived equation concerning the penumbral This formula makes possible calcula- tion the minimum source film distance which will give satisfactory penumbral shadow registry and flaw Although the penumbral shadow density gradually into the density the true shadow, within the limits set this equation, the penumbral shadow will safely indicate the flaw. using the penumbral shadow rather than the true shadow, the distances source flaw, Lester, “Some Aspects Radio- graphic Sensitivity Testing with Rays,” A.S.T.M. Bulletin, No. 100, 33, October, 1938. Doan, and Young, “Gamma- Ray Radiography,” A.S.T.M. Proceedings, 38, Part 292, 1938. 30—THE IRON AGE, February 29, and therefore exposure times may substantially reduced. The advisability small source diameter shown, and for sharp shadows, the angle sub- tended between source and flaw should not exceed two degrees. Pullin’ reports that placing radium lead “focusing tunnel” in. long with aperture %-in. diameter appears project scattered radiation into the main beam rays, and doing increases contrast. the use this tunnel was able show hole 1/16 in. diameter, in. deep through added thickness in. metal. Without the tunnel reports being able show the hole through only in. added metal. the same paper Pullin illustrates the experimental use planar radiog- raphy. the name planar radiography method producing radiograph particular plane within solid object. During ex- posure, the specimen and the film are moved parallel the axis the X-ray tube, the same direction, but dif- ferent rates, the film traveling slightly faster than the specimen. For par- ticular difference the rate travel the film and specimen, specific plane within the specimen will remain stationary relative the film, and will FINE METALLIC SPECIMENS > therefore recorded sharply, while other planes within the specimen are moving relative the film, and will indistinct due blurring. suitable provision for choosing the correct dif- ference rate travel the film relative the specimen, any plane may recorded more sharply than other planes the subject. Ed. Note:—Next week the author will conclude this discussion with data the use low voltage radiation, flexible cal- cium tungstate intensifying screens, new type developing solution, etc. 3—A 400-kv. indus- trial X-ray machine capable penetrating in. steel. Photo cour- tesy Kelley-Koett Co., Inc. X-RAY FOCAL. SPOT LIMITING OIAPHRAGM SHOT LEAD MASK FiLmM 4—Metallic shot technique for mask- ing round bars. A q | N 4 4 | MX WY MW Ht NS MR YY | | ° ° PHILBROOK Assistant Superintendent Metallurgy and Inspection, and Research Metallur- gist, Respectively, Wisconsin Steel International Harvester Co. intelligent and accurate slag control goes the credit for the greatly im- proved steel uniformity today. Therefore, most timely are the simplifica- tion and clarification these control problems. Last week the authors dealt detail with the functioning the basic open hearth, and gave data slag formation, transfer iron oxides, and measurements oxidizing power. Herein, the second section this four-part article, the authors describe the elimina- tion carbon from the bath, departure from equilibrium, rate oxidation slag and bath, and the effect temperature. ° LIMINATION THE Batu: The FeO present the steel bath reacts with carbon accordance with the following re- action The formed escapes gas, giv ing rise the “carbon boil,” and, *While this reaction strictly reversi- ble, can proceed only one direction the open hearth furnace because dynamic sense, but FeO constantly in- troduced into the system and with- drawn the flame. 1C. Herty, Jr., Christopher, Freeman, and Sanderson, “The Physical Chemistry Steel-Making. The Control Iron Oxide the Basic Open- Hearth Cooperative Bulletin (1934), Mining and Metallurgical Ad- visory Board, Carnegie Institute Tech- nology, Pittsburgh. ° previously stated, aids greatly the oxygen transfer cycle its stirring action both bath and slag. This reaction goes continuously with the removal both carbon and FeO. further oxygen were introduced from the slag, the reaction would eventually reach equilibrium, and the elimination carbon would cease. impossible stop the transfer oxygen from the slag, and there- fore impossible reach equilibrium the bath long any carbon present react. slowing down the rate trans- fer oxygen from the slag the bath means slag control, possible permit the carbon-FeO re- ° action proceed more nearly equilibrium, and thus reduce some- what the oxide content the bath. The application this principle slag control must handled with caution because the transfer oxygen from the flame the slag not easily slowed down, and any decrease the rate transfer oxygen from the slag the bath will therefore re- slag, which under certain conditions may rather suddenly transferred the bath and not only thus defeat the purpose the manipulation, but may even result higher content oxygen the bath than would other- wise have existed. The reaction between carbon and FeO the bath reversible chemical reaction*, and such obeys the laws chemical equi- librium. This reaction the equilibrium expression are fol- lows: Peo (Fe) (C) (FeO) THE IRON AGE, February 29, re ° ° a and and others, the pres- sure approximately con- and has been estimated slightly over one atmosphere. The activity iron may likewise assumed constant and ap- proximately unity for practical pur- poses. Combining these two terms the constant, simpler expres- sion may written: (C) (FeO) = m Independent determinations the value et. al., Chip- man and and Schenck, Riess and have placed this constant about 0.011 open hearth temperatures, where the concentrations carbon and FeO are expressed weight per Equation (III) and the others derived from are not entirely correct, because known that some carbon dioxide also formed the reaction between carbon and FeO. However, the amount of CO, the gas equilibrium with the steel less than per cent the content above 0.05 per cent and will way af- fect the application these equa- tions for the purposes this paper the formation CO, disre- garded. Departure from Equilibrium The latest calculations the equi- librium value, Chipman’, to- gether with the average curve re- sults obtained from actual heats, are shown Fig. The points for this curve were all obtained from quality killed steels just before the heats were blocked and after attempt had been made approach equilibrium condi- tions. The oxygen content the bath, calculated FeO, was obtained method sampling now known the industry the “bomb de- The curve obtained from actual heats approximately parallel the theoretical equilibrium curve and displaced from amount corre- sponding about 9.04 per cent FeO 0.30 per cent carbon and above, and 0.06 per cent FeO 0.10 per cent carbon. This displacement the curve actual results represents the oxygen excess the equilibrium Chipman and Samarin, “Effect Temperature upon Interaction Gases with Liquid Steel,” Transactions the American Institute and Metallurgical Engineers, Iron and Steel Division, 125, 331-45 (1937). Vacher, “The System Liquid Iron-Carbon Oxides,” Bureau Stand- ards Journal tesearch II, 541-51 (1933). Briiggemann, die Geschwindigkeit und die Gleichgewichtskonstante der Koh- lenstoffreaction bei der Herstellung chemie 38, 562-8 (1932 McCutcheon, “Bath Samples for Determination,” 1938 Open Hearth Proceedings, 143-49, American In- stitute Mining and Metallurgical neers, 32—THE IRON AGE, February 29, 1940 0.60 0.50 IS. tion between carbon and FeO steel. Data from 300 heats quality killed steel just before block- ing. Per cent carbon steel 0.10 0.05 0.10 0.15 0.20 0.25 Per cent FeO steel value which required force the carbon-FeO reaction, the carbon boil, take place rate great enough keep pace with the slowest rate of. introduction oxygen from the slag which can attained practice. The effect upon the rate car- bon elimination this excess FeO, or, stated different way, the difference between the actual (C) (FeO) product and the equi- librium value, expressed mathe- matically the equation derived chemical laws governing rates reaction: ac/dO [(C) (FeO) (VI) where —dC/dO represents rate change with time (negative cause carbon lost), rate constant for given temperature, (C) and the actual weight percentages these constituents the bath any in- Since and are constant for given temperature, the rate carbon drop therefore linear function (C) (FeO). the rate oxygen transfer from the slag the bath greater than the practical minimum, the FeO con- tent the bath will increase. The higher FeO content will cause crease the rate reaction between carbon and FeO, more violent carbon boil. This, turn, will re- move oxygen from the bath more rapidly and will partly compensate the increased rate transfer FeO from the slag. However, since higher value for the (C) (FeO) prod- uct necessary sustain more vigorous carbon boil, impossible the bath, means the carbon re- action alone, with rapid transfer oxygen from the slag with slower rate oxidation. just explained, slowing down the rate transfer oxygen from the slag the bath slag control leads because the rate oxidation the flame continues nearly constant rate. iron oxide accumulated the slag this way, additions ore mill scale, suddenly released enter the bath, the rate transfer oxygen the bath will become greater than the rate oxygen the slag from the flame. This will cause the iron oxide the slag decrease, and the same time the FeO thus introduced into the bath very rapid rate will continu- action. other words, the iron oxide con- tent the slag will reduced the carbon the bath. This the means action the bath mill scale, which dissolves slag. | | | ° | | ° | | | | ° ° ° ° ook Th Gog ° | S ‘ o | < Ping, 4 | 0.50 4—Rela- tion between and total content slag. £0.30 Data from heats killed fore blocking. 0.10 5.0 Lump ore probably reacts partly this way, but primarily direct solu tion the bath. The same effect which reacts sluggishly with the bath thinned the addition spar. Addition silica slag will reduce the basicity and decrease the viscosity with the same effect spar, but addition will release some which may have been held ferrites excess lime, resume active part the oxygen cycle. increase the active iron oxide content the slag this way has the same effect the addition ore corresponding the amount thus liberated. When FeO transferred bath faster than formed the slag, the rate transfer must slow down the iron oxide content the slag diminished, until eventually the rate again reduced the rate Velocity carbon elimination will likewise slow down keep pace with the rate transfer FeO the bath. The FeO introduced into the will have been removed the carbon value which “equi- librium” for the rate carbon-drop prevailing. The net result that the active iron oxide content the slag determined the carbon content the bath the slag sufficiently fluid 10.0 15.0 20.0 25.0 Per cent total iron slag give proper convection and uniform rates oxygen transfer. Due the formation inactive compounds highly basic slags, previously stated, the total iron content such slags will not directly dependent upon the carbon content the bath the same extent lustrated the scattering points where total iron content the slag plotted against carbon con- tent the bath, compared with the curve for the relationship between carbon and FeO the bath given Over any period time, the aver- age rate removal oxygen from the bath must somewhat less than the rate introduction oxygen from the flame, because carbon removed irreversibly from the system carbon monoxide gas, the level necessary for further removal car- bon accordance with equa tion (V), and Fig. and part the oxygen introduced the flame any instant must remain permanently the system fulfil this requirement. carbon content drops below 0.20 per cent, the concentration FeO re- quired cause further carbon elimi- nation increases rapidly until comes appreciable percentage the FeO formed per unit time, and consequently the rate carbon drop diminishes markedly, until below 0.05 per cent carbon very slow indeed. Rate Slag Oxidation Much has been said about rates oxidation the slag and rates transfer FeO the bath, and several assumptions have been made with regard these rates, without any extensive presentation the govern- ing conditions. Consideration the chemical principles involved will show, first, that the rate oxidation the slag the flame dependent directly upon the partial pressures oxidiz- ing gases, O,, CO,, and H,O, and in- versely upon the concentrations reducing gases, and H,, the fur- nace atmosphere the slag-gas inter- face. The total concentrations oxidiz- ing gases comparison with inert nitrogen, and the relative proportions CO, and H,O, will vary with the fuel burned, and one example, has been found experience that mixed blast furnace and coke oven gas flame less highly oxidizing than flame obtained from fuel oil atomized steam. has already been stated that the temperature level necessary open-hearth operation requires com- plete combustion the fuel, that the concentrations carbon monoxide and hydrogen are limited the small amounts formed dissociation carbon dioxide and water vapor the temperature the flame. Ordinarily slight excess air carried insure complete combustion the fuel and from bath reac- tions, but good practice limits this per cent oxygen the waste gas. could even shown that the com- position the flame directly the slag-gas interface somewhat de- pendent upon port design, manner injection the fuel, drafting, and pressure within the furnace, and actual experience indicates that rate oxi- dation some extent character istic individual furnaces, even with the same fuel. effect then, given particular furnace and fuel, the open- hearth operator has very little control over the oxidizing power the flame The rate oxidation the slag the flame is, secondly, directly pro- portional the concentration the slag the slag-gas interface, and inversely proportional the con- which also im- plies rate diffusion from the interface into the lower layers the slag and its replacement more has just been shown, the THE IRON AGE, February 29, 1940—33 thine ° | | +— — -+— - ° oY jolo oo ° 220 ° ®o ap! o 8° 9 ° % | ni | | | | 2° | ity Wes Se concentration active iron oxides the slag determined the carbon content the bath, where the slag sufficiently fluid: The fluidity the slag and the degree agitation, which closely related the fluidity, like- wise control the rapidity replace- ment more FeO the slag-gas interface, and thereby govern the ratio FeO Fe,O, for given concentration total iron active condition the slag. may seen, therefore about the only control the furnace operator has over the iron oxide factor rate oxidation the gas through the regulation cosity. fluid slag will give rapid change iron oxides the slag sur- face exposed the flame, and thus give rapid rate oxidation, with resultant shortening the refining time, but will not permit any excessive accumulation iron oxide the slag. viscous slag, the other hand, will permit the Fe,O, content the upper surface the slag build up, and this will have very slight retarding effect the rate formation more rough qualitative indication that this retarding effect can only very slight obtained follows: From the equations below may ob- tained. adding ex- pressions [12] and [14] and also subtracting [15] from and, adding [14] and [16]: 34—THE IRON AGE, February 29, 1940 Through the relationship —4.574 log the equilibrium constants for these reactions may computed. 4451 (FeO) 2.30 (IX) (CO) (FeO) 3.65 (X) The mol fraction FeO active the slag can probably tuted these expressions without appreciable error, least for the present purpose. At 1600 deg. C the constant for reaction (VII) 1.19, and the ratio steam hydrogen, librium with 0.1 mol fraction the slag 0.119; with 0.2 mol ratio FeO, the steam-hydro- gen ratio 0.238. Likewise, the constant for reaction 0.287, and the ratios (CO;)/(CO) equilibrium with 0.1 and 0.2 mol fractions and FeO the slag are 0.029 and 0.057 respectively. Since the actual ratios the with complete large whole numbers, the order for the condi- tions are far from equilibrium and variations FeO content within the usual range would have little effect the oxidizing power the gas. These figures should not construed any more than qualitative indication because, while equations (VII) and (VIIT) represent the net reactions for the through the cycle previously de- scribed, they not express the reactions the slag-gas interface. Oxidation Bath The factors affecting rate trans- fer FeO from the slag the bath are roughly analogous those govern- ing the oxidation the slag the Bomb test mold and test. The rate oxidation the bath directly proportional the oxidizing power the slag, the concentrations FeO and available for the oxygen cycle, the proportional the concentration the steel. course necessary that iron oxides able move freely from the hody the slag the slag-metal in- terface replace those entering the steel, and that FeO the interface transferred into the lower parts the steel bath that the concentration the interface may not become great enough slow stop the proc- ess solution from the slag. fluid slag necessary for proper convection the slag, and will pro- mote rapid solution FeO the steel the interface. Rapid solution the steel gives rise more violent carbon boil, which agitates the bath and helps carry the FeO down convection. The area the interface also increased the disturbance caused the rising bubbles carbon monoxide. The viscosity the slag, therefore, exerts the major influence the rate oxidation the bath the slag. Effect Temperature Temperature very important factor open hearth operations be- cause influences both the limiting equilibrium conditions and the rates which reactions proceed the direc- tion such equilibria. The effects temperature open hearth reactions are understood only qualitatively most practical furnace men and are very difficult demonstrate apply | x | | 4. 1 it Bomb test molds ready for use. exact manner the present time, because there still reliable way determining the exact temperature level the steel the furnace. Sev- eral very promising methods measur- ing bath temperatures the open hearth furnace, employing both tion and thermo-electric effects, are now process development, but they are yet neither common use nor readily available the industry. The effect temperature the (C) (FeO) equilibrium product, has been calculated reliably Chip- man and who showed that increasing increases words, the temperature increases, the reducing power the carbon the bath toward the dissolved de- creases. This effect rather small, amounting only about per cent per deg. (90 deg. F.) rise tem- perature, and far overshadowed the influence temperature other reactions that may ignored for practical purposes. The solubility FeO the steel increases rather rapidly with rising temperature, and Herty! found that the value the FeO distribution coefficient increases markedly with temperature. The in- creased FeO transfer the bath from this cause would more than offset the the rate carbon elimination from the bath. Inspection the equations and thermodynamic functions for the oxi- dation the slag the flame (small type indented) will show that the values the constants become smaller with increasing temperature. This means that the ratios CO,/CO and H.O/H, equilibrium with given oxygen content the slag decrease, conversely, the oxidizing power flame rich CO, and H,O increases the temperature rises. Higher tem- perature would also increase the fluid- ity slag given composition. All all, then, may seen that higher temperatures the slag and bath should increase the rate transfer oxygen from the flame the slag, thence the bath, and thereby in- crease the rate carbon elimination. From the standpoint practical open hearth operation, more perti- nent view the question tempera- ture from different angle. Successful operation requires that comparatively high temperature level, depending somewhat upon the carbon and alloy- ing content and the type steel, attained before the heat may tapped. The melter much more interested knowing how attain this necessary temperature level most rapidly, than knowing the effect temperature upon the furnace reactions. Heating the open hearth furnace done most inefficient manner, namely, from the top down and through insulator, the slag. Every effort should therefore made facilitate the process. has now been firmly established, both prac- tical operation and theoretical compu- tation, that the greater part the heat transfer from the flame the bath after the heat “under cover” through radiation from the flame. luminous flame high. radiating power therefore advantageous dur- ing the refining period. Methods for obtaining such flame with various fuels are beyond the scope this paper, but are generally understood the industry. Application the Stefan-Boltzmann law the open hearth furnace pro- vides that the transfer heat from the per unit slag surface area proportional the difference be- tween the fourth power the tem- perature the radiating body the flame and the fourth power the tem- perature the upper surface the slag. Rapid heat transfer requires that heat transmitted readily from the upper surface the slag the body the slag and the bath, order keep the temperature differential be- tween flame and slag surface great possible. Heat transferred through the slag and bath tion and conduction, with convection being the more important, especially the slag where thermal conductivity low. Establishment rents requires mobile, fluid, slag. This also gives rapid FeO transfer, thus creating vigorous carbon boil which stirs both steel and slag and thereby assists tremendously the convection process. Aside from regu- lating flame luminosity, the most po- tent means the melter’s control promoting rapid heat transfer from the flame the bath the mainte- nance fluid slag for much the refining period possible. Ed. Note:—Next week the authors con- tinue with summary the process carbon elimination, elimination silicon, elimination manganese, and removal phosphorus. THE IRON AGE, February 29, 1940—35 | > e | of. j 1 | | | » Pi ke 4 \ OST the manufacturers products utilizing centralized pressure-lubrication, automat- ically metered, also employ lubricating scheme for the production machines making the haps the experience with automatically- lubricated production machinery may have induced the manufacturer in- corporate automatic lubrication the product design. Or, perhaps the re- sults obtained automatically lubricating the product resulted specifying similar lubrication for the production machines. Somewhat HEWITT like the chicken-and-egg sequence, hard determine which came first. Most such manufacturers are the opinion that automatic, metered-feed oiling systems take lubrication out the hit-or-miss category and place under positive control. remov- ing the human worries are minimized. many instances automatic force- feed lubrication has ous economies into machine use. Oper- ating efficiency and machine life are raised, and shutdowns for machine re- grinder lubricated Bijur system. 36—THE IRON AGE, February 29, 1940 pair are decreased along with mainte- nance costs. Many speed precision machine now requires part design. And, manufac tured product, such lubricating sys- tem eliminates servicing the prod- uct many cases, and, makes servicing much easier and less wasteful time—where, for example, service men call regularly custom- ers check installations. One plant using automatic lubrica- tion production machines and prod- ae J . . " 2—Single ram surface broaches Machines Corp., Endicott, surface grinder 1), used ma- chining parts for models and experi- mental machines, has unobtrusive automatic lubricating system—it shot” lubricator. simple movement the lever raises the pump piston and compresses spring. With the automatic return the piston, pre- determined volume oil delivered under pressure the distribution system—a single feedline type automatic lubrication. branches various junctions. Meter- units the branched line then appor- tion the bearings the exact quantity oil each bearing requires, according its size, speed and load. This metered feed entirely automatic, without lag, and any changes the temperature and viscosity the oil are automatically compensated Some bearings (for the entire ma- chine except the spindle) thus are served its own individual meter- unit, which needs adjustment any time. plant, pair 5-ton single ram sur- face broaches (Fig. are employed broaching magnet yokes used all electric accounting machines and elec- Each broach lubricated “con- tinuous” type automatic lubricator. sorting machines. both “continuous” and “high- cyclic types, the lubricator pump operated automatically simple mechanical drive from ciprocating rotating part the ma- chine. The lubricating cycle for FIG. 3—Thread grinder provided with automatic lubricating system. THE IRON AGE, February 29, 4 | FIG. grinder equipped with Bijur automatic lubrication “high-pressure” lubricator controlled postively driven cam. (Hydrau- lically-driven also are now available for hydraulically operated machines. Another “continuous” type auto- matic lubricator utilized the thread grinder (Fig. which grinds worm threads from the solid shafts for electric sorting machines. The machine which grinds triple thread worm, has from operating bearings and slides lubricated its automatic system. the apprentice school, where high school graduates are trained for jobs the plant, all kinds turn- ing are done lathe which must withstand lot abuse. Its bearings are protected, however, two auto- matic lubricators the “continuous” type. One, driven from the bull gear, 38—THE IRON AGE, February 29, 1940 lubricates the spindle bearings the headstock. The other, installed the apron, lubricates apron, bed ways and cross slide dovetail. Where intervals oil-feed and other lubricating re- quirements (including the isolated po- sition some machine parts) differ quite widely, usually advisable use more than one lubricator, although ordinarily any number bearings are served one automatic lubricator machine—no matter what the loca- tion the bearings may be, their difference size type. The success automatic lubrica- tion the Alphabetic Inter- preter, where some bearings are made standard equipment for the In- terpreter 1936—led directly the automatic lubrication many special production machines the also encouraged the repair department embody such lubricating equipment all production machinery being re- built—as, for example, the surface grinder shown Fig. which the installed “one-shot” lubricator takes care bearings automatically. In- stallation the automatic lubricating systems proved relatively simple pro- cedure, although for greatest efficiency desirable have the original ma- chine designed with cation view. Ease handling and the neatness and compactness installation possi- ble, are suggested Figs. and the board, and the latter sub-assembly operation connection with the instal- lation automatic lubricating equip- ment electric accounting machines, The actual time required for this in- stallation hr. The lubricator pump-and-reservoir unit may installed any level the machine, relative the positions the bearings. Feedlines are incon- spicuous, requiring little space. They readily are concealed within the cas- ings streamlined machines, for in- stance—and with automatic lubrica- tion there need make adjust- ment any parts the system, hid- den otherwise. Used production machinery, auto- matic lubricating equipment provides safety for the operator well for the machine. Bearings even the most difficult, remote parts the ma- chine are oiled automatically while the machine operation—which the time when machine really needs its lubrication. Since the automatic lubri- “closed” system, there drain FIG. 5—Tube bending board for preforming feedline tubing. fee = FIG. sub-assem- bly used electric accounting machine. oil from the line create fire risks hazards from oil-slippery floors. Automatic lubricating systems elimi- nate many wastes, for instance the following machine starting; slowing-up ma- chine speed; shut-downs that throw production schedules and deliveries out kilter. Waste lubricant. Waste power. Waste materials and parts—used machine repairs caused directly indirectly bearing seizures and freeze-ups. Waste through spoilage (on ma- chines carrying paper fabrics that may come contact with unregulated Also machine operators, rid the task hand oiling, are able con- centrate productive work and often are spared considerable fatigue. Large Tanks Rubber Lined OUR large pickling tanks for use the manufacture steel are currently being rubber lined Plioweld process the Goodyear Tire Rubber Co., Akron, Ohio, factory. The completed tanks will ft. long, ft. in. wide, and ft. Problems handling and in. deep. shipping require each tank built two 40-ft. sections. The rubber lining, which will pro- tect the steel tanks from the corrosive effects chemicals used the pick- ling process, involves use 3300 rubber for each the four tanks and 1600 rubber for the cover sections each tank. After the rubber lining has been ap- plied the tank sections, illustrated the accompanying photograph, each section vulcanized large 15-ft. diameter vulcanizing heater installed the Goodyear Akron Plant No. expressly for large jobs this type. The vulcanizing operation entire unit thus carried out with uniform- ity. Delivery completed sections be- ing made tractor-trailer, each unit with its cover sections comprising complete load. THE IRON AGE, February 29, | | | | | ae | | \ ‘ - 4 é castings are born this raw material yard, located adjacent railroad siding. IG. the cope has been . . h . . e< Beneath the coke and limestone bins seen the foreground merry-go-round carrying charg through series cooling ing buckets past the loading stations located beneath the bins; Thence into the plant where the shown this photograph. The castings charges are deposited the cupola via mechanical chargers. hours slowly moving conveyors bring dowr pushes drags onto shakeout Note ENGINE duction castings achieved foundry, part the company's new $7,000,000 motor truck plant that city, produces all the castings used International trucks. One the outstanding features foundry the high degree dust 2—The core sand mixing platform contains Beardsley Piper Speedmuller and Baker- Perkins mixer. Sand mixtures are delivered the mixers through automatic weigh lorry and the mixed product distributed hoppers carried overhead monorail cranes. 1G. 3—High production cylinder-block barrel cores are made sandslingers, smaller cores 4—This Osborne unit equipped with knocked out core blowers and bump-roll-over machines take care miscellaneous cores. produce small castings snap flasks. Illustration shows barrel cores being made Beardsley Piper slinger. around the oval takes place > » } 7—The chipping room, shown above, designed keep casting handling castin are overhead conveyor and spend about three Filter Rotoclone precipitator. Hagen annealing furnace can seen the down handling heat. Air cylinder left Note the number exhaust hoods. % THE MANNER elimination which has been realized. tons each; floor area, 215,795 sq. ft.; total length conveyors, bins, 22,820 tons. cupolas are tapped continuously into five-ton reservoir ladles. From these ladles the iron moves molding floors covered and insulated hot metal carriers such shown this illustration. The iron then transferred small ladles for pouring into the molds. ° ° ° Champion jolt-squeeze molding machines used castings, such these engine pistons, are rammed Milwaukee asks, the index type which moveme