Iron Age 1937-10-07: Vol 140 Iss 15

President ‘Editor Managing Editor News Editor Emeritus Consulting Editor Washington Editer Resident District Editors Pittsburgh Chicago Cleveland Detroit Editorial Correspondents London, England Milwaukee San Francisco Toronto, Onterio Birmingham Buffalo Owned and Published CHILTON COMPANY Publication Offices Editorial and Chestnut and Offices 239 West 39th New York, OFFICERS AND DIRECTORS MUSSELMAN, President FRITZ FRANK, Executive Vice-President Philadelphia, Pa. FREDERIC STEVENS, Vice-President JOSEPH HILDRETH, GRIFFITHS, EVERIT TERHUNE, ERNEST HASTINGS, WILLIAM BARBER, Treasurer JOHN BLAIR Secretary JOHN VAN DEVENTER JULIAN CHASE THOMAS KANE CHARLES BAUR CARROLL BUZBY BAUR, General Advertising Manager DIX, Manager Reader Service Member, Audit Bureau Circulations Member, Associated Business Papers Indexed the Industrial Arts Index. Published every Thursday. Subecrip- tion Price: United and Pos- sessions, Mexico, Cuba, $6.00 Can- ada, $8.50 Foreign, $12.00 year. Single copy, cents. Address, ADVERTISING Findley, 621 Union Cleveland Herman, Chilton Chestnut 56th Sts.. Philadeiphia. Pa. EB Leonard, 239 W. 39th 8t.. New York Peirce Lewis, Woodward Ww. B. Park Bidg., Pittsburgh D. ©. Box $1, Hartford, Coan. . Warren. OCTOBER 1937 Revealment, Not Concealment Today Metal Finishing Economics D.C. Drives for Runout Tables and Coilers Reasons Governing Use Extreme Pressure Lubricants Lubricating Oil Flooded Roll Neck Bearings ............ Protective Atmospheres for Annealing Furnaces Corrosion Proof Tank Lining .......... Steam Generation from Gas Engine Welding Economics and Application Selection Insulated Cables for Steel Mills Fundamental Characteristics Gear What the Machine Doing for Your Community Automotive Industry .................. Statistics Metal-Working Activity Rate Activity Capital Goods Washington News ............ New Industrial Literature Products Advertised Index Advertisers ........... (Copyright 1937 Chilton Company | Plant Expansion and Equipment HERE’S reason why VisControlled steels have won high favor where parts must heat treated. lies their uniformity. Uniform reaction heat treatment depends pri- marily two factors—uniformity analysis and uniformity grain structure. Analysis the prin- cipal factor affecting strength. For any particular analysis, grain size, more than anything else, de- termines depth hardness. The VisControl process for making steel, used exclusively Bethlehem, goes long way toward producing absolutely uniform steel—as both BETHLEHEM 30—THE IRON AGE, October 1937 analysis and grain structure. largely removes variables from open-hearth furnace conditions— composition slag, oxidation bath, and other technical considerations which have never hereto- fore been under such complete control. Practically all Bethlehem steels—for forging, machining, heat treating other processing—are now made under VisControl. Discuss your specifications with Bethlehem will show you how get the full benefit VisControl processing the steel you buy. q | | | THE IRON AGE October 1937 ESTABLISHED 1855 Vol. 140, Revealment, Not Concealment, Today CTOBER the the metal-working industry well other industries. This the time when men similar occupation pro- fession meet groups discuss their common current problems and contribute from their experience the common fund knowledge. This week, chronicle the doings and accomplishments the Association lron and Steel Engineers, which has just completed its annual meeting Chi- cago. Starting out formerly the and Steel Engineers, this associa- tion has been broadened take the vertical section professional interest, mechanical, electrical well executive, having with steel mill equipment and operation. Today, electricity and electrical apparatus put work are much part the modern steel mill are the furnaces and the rolling mills. True, the electrical problems encountered steel making are specialized ones, just are the mechan- ical problems the industry. But knowledge both the electrical well the mechanical technique essential the success the modern steel production ex- ecutive and plant engineer. Hence the value this association allied interests. During the remainder this month, our convention calendar shows, the in- dustrial paper editor will hard pressed keep with the convention pro- cession. Far from regretting the effort, however, welcome it. For the best sort proof that are establishing progress the firm foundation mutual help and the interchange ideas. Some remember the old days trade secrets our industry. those days was unthinkable that engineer, his company had financed him some im- portant research, would permitted share the knowledge gained with his competitors. That day has passed and never will return. The technical and professional as- sociation sounded its death knell. have come know that revealment, not concealment knowledge, means progress for all. 4 f STIMULATING THs chart, prepared Al- bert Byers, Benjamin Franklin Paint Varnish affords easy means identifying contrasting colors. the so-called warm colors are preferred women and the cool colors men. trait the preference for bright color against drabness. This fact has been recognized the decorative trades from the time their inception, but the utili- tarian field progress use color has been slow. Only within recent years have such unpreten- tious items wrenches and thrashing machines begun re- flect the designer’s gradual real- ization that the human preference for color extends into all branches industry—even into the foundry, the machine shop and the mine. Thus, when industrial designer thoroughly awake the uni- versality color response, his only reason for not introducing color into the finished appearance almost any product must Finishing Metal Products—Simonds. 32—THE IRON AGE, October 1937 one economy. Often when sell- ing expense considered, how- ever, the saving production cost through elimination color proves manufacturer having decided use color once confronted with two problems: first, what color use; second, how apply it. series articles which ran IRON AGE about year ago described many methods used for coloring iron, steel, copper, brass, and other metals indus- try. Organic coatings were not considered, the subject was the coloring metal distinct from the application color coat the metal. Four methods were de- scribed: heat treatment, chemical treatment surface, alloying and plating. one the articles brief reference was made new color-by-electrolysis process. Quot- ing from that article: “It has been found that alkaline solutions copper lactate produce cathodic deposits low current density which are highly colored. The color the deposit, according Dr. Fink, function its thickness and thus plating time. Violet, blue, green, yellow, orange HERBERT SIMONDS Vice-President, Metal Products Exhibit, Inc., Rockefeller Center, New York and red with intermediate shades appear successively with each cycle. The deposit, which appears primarily cuprous oxide, stable both chemically and me- chanically and can applied large variety metals.” the purpose this article describe the actual application the proc- ess the shop. process, which covered patents owned the Kansas City Testing Laboratory, now being marketed United Chro- mium, New York, exclusive licensee. The trade mark “Elec- trocolor” has been registered United Chromium designate ar- ticles finished this process. its plant Waterbury, Conn., the company has been carrying de- velopment work this particular field for several years and now introducing the process along the same lines has used heretofore connection with chromium plat- ing. the new process, all colors are produced bath uniform composition, which need not modified order effect change color. Cost Color Plating Because the nature color plating, takes its place the established field electroplating, and expected that much the color work this method will done existing plating shops. Because the low current con- sumption and the comparatively simple equipment, the process relatively inexpensive. The throw- ing power the bath sufficiently good plate recesses without special anodes and insure uniformity color many pieces simultaneously plated. Articles finished Elec- trocolor are most applications coated with clear lacquer give wear and corrosion resistance. Exact duplication color one the big advantages claimed for this new process, for stated, color every case factor plating time. With proper time- controlling device possible accurately match colors daily regular production, and further- more possible duplicate the color any other plant employing the same timing and base metal. This perhaps the first time that such statement could made. Color matching and color reproduction has always presented difficulties. Color experts have gone great trouble establish master color cards which are kept light-insulated containers in- sure them against fading. Such master color standards with uni- form designating numbers have been shipped different countries and different industrial centers attempt establish uniform color language. This method, while marks long step forward standardization colors, de- pends its final analysis the color stability the master plates and addition has the disadvan- tage difficulty when comes accurately describing intermedi- ate colors and new color mixtures. course, there have been some attempts made describe color Color Industry new finish for metal. applied electroplating technique and, aside from its eye appeal, has many in- teresting advantages, one which accuracy color specification and color re- production. this fourth article series metal finishing Mr. Simonds, more detailed description color plating presented than has been pos- sible heretofore. mechanically. One the best em- ploys color analyzing machine, known photoelectric spectro- photometer, invented Arthur Hardy, Massachusetts Insti- tute Technology. Its operation depends chiefly upon the ability the photoelectric cell turn light waves into electrical energy. claimed that three minutes after sample any colored ma- terial placed it, the apparatus produces chart showing pre- cisely how much each wave length light reflected. Each color shade, and there are mil- lions them, thus represented its own peculiar graph. means these graphs pos- sible check the matching possi- bilities two samples mately the same color, but difficult reverse the process and reproduce color from its graph. Metallic Color Cycle trocolor article almost any color simple number (represent- ing the time factor) and have that color accurately reproduced any time and many times desired any industrial center. The process has developed for use industry such metal- lic parts shown some the accompanying illustrations. These merely indicate the extent some its applications. While must not confused with ordinary electroplating, such chromium plating, properly finished Electro- color articles which are subse- quently lacquered have good cor- rosion and and the colors are said ac- tually light fast and free from fading. addition, the articles have transparent metallic luster. The actual color produced without pigment dye and light in- terference phenomenon. Light passing through the semi-trans- parent electrodeposited coating refracted and reflected give the resultant color. the thickness the coating increases, the color changes through complete spec- trum cycle. This cycle repeated the plating builds up, but each succeeding cycle the colors become darker. Finally, the plating continued long enough, deeper and darker shades, tending toward reddish brown, are pro- duced. The length plating time may range from min. hr. more, and since the rate change color relatively slow, the control shades can readily handled the usual careful com- mercial practice controlling plating time. The gloss brilliance the resultant color depends large extent upon the nature the finish the surface before plat- ing. highly polished surface gives color finish, while scratch-brushed surface may like manner color. Most any base metal THE IRON AGE, October a if in} ii | may used, although for accurate reproduction given color the same base metal should used that the original sample. course, color has been plated copper one instance, and the same color desired steel, simple matter first copper plate the steel and then color plate the copper coat. Plating Technique The process relatively fool- proof, and the plating solution readily maintained for continuous operation adjusting the essen- tial constituents based chemical analysis. standard tank water solution complex copper ions. Parts color plated are introduced into the solution cathodes and may hung standard cathode bars. Anodes are pure copper. The bath oper- ated low voltage (approxi- mately 0.5 volts being recom- mended) and current density approximately 0.3 amp. per sq. ft. piece left the bath beyond the time required produce the desired color, the col- ored deposit may dissolved off and the process started again without injury the articles be- ing colored and without removing them from the rack. There difficulty such dissolving, claimed, nor there any danger etching the surface. Many Colors Produced Preparation the article plated similar that called for standard electroplating prac- tice. Articles must thoroughly cleaned and, course, must polished high gloss desired. For color plating, any base metal which functionally best suited may used. With some base metals intermediate step electroplating with other metals may indicated for improving the wear and corrosion resistance the final surface. Such plating may alsc required give exact match color. For ex- ample, steel piece may copper and then nickel plated for the pur- pose applying the color over the nickel secure the desired shade, the same time producing finish more resistant cor- rosion. Each the color plating bath runs through practically the 34—THE IRON AGE, October 1937 EARLY all decorative metal articles, such this water bottle, offer good opportunity for the use new process employing elec- troplating technique. entire range the spectrum, with the basic characteristics deter- mined the finish the under- lying metal and the color there- of. If, for instance, the shade green produced the first plating cycle nickel too light, darker shade can obtained continuing the plating time successive cycle. the character the color may altered using different base metal giving the surface different pol- ishing treatment. When any par- ticular definite effect has been se- cured, may given number which will specify the surface fin- ish, the nature the base metal, and the length time the article has remained the color plating bath. Thus, this exact shade and character can reproduced any future time without color charts color samples. Switch plates may colored either match trim contrast pleasantly with it. the same way the color lamp bases may determined the lamp shades other room decoration, and for any one product production basis series colors may produced practically the same cost were the same color. Thus one batch may put through the color bath 5-min. schedule, and the succeeding batch combinations are also possible. For instance, two-tone effects may produced masking part the area for portion the plating time. Masking may also used prevent color plating pre- determined design. Another meth- mask part through chromium plating process, and then render passive the design thus plated and put the part through the color plating process. Rapid advance the lacquer industry has greatly aided the table lamps may finished several contrasting colors and the actual hues may accurately specified the customer. commercial development color plating—as has also aided the usual forms electroplating. Electrocolor light fast, but relatively thin plate and thus subject abrasion. Added protec- tion against abrasion afforded some the new transparent lacquers without loss appear- ance, the same way resistance alcohol and other solvents may secured. Importance Color Some the ways which color used industry lower selling costs have been discussed the author recent book.* the metal industry the intro- duction colors first was limited the simpler hues because the difficulties involved the use % 4 £ | | | | ii the more complicated shades. Now with Electrocolor available, and also with the greatly increased facilities for metal color finishing question what colors can ap- plied but rather, what color will have best sales appeal. Sales wide variety metal products have been increased ma- terially through the use differ- ent colors color combinations finish. Even such humble products LEASING colors combination with aluminum center band have creased sales this item. HIS shows typical case where metal luster color finish, such Elec- trocolor, increases attractiveness while still maintaining the quality metal. hack saw blades have shown surprising sales response color finish. The Glidden Co. has made interesting study color re- lation sales and recent publication called “The Age Color” has specified various color reactions the part the public. Quoting, never was time when color meant much the social and industrial interests this nation.” fact, the appeal color has become important not only home decoration but also nearly all merchandise. The reactions men various colors differ considerably from the reac- tions women the same colors. Thus men prefer blue about per cent all instances, and wo- men prefer red their first choice about per cent all instances, general women pre- fer the warm colors such orange and yellow, while men prefer the cooler colors indicated the graph. Concrete Joist Design Tables twelve concrete joist and rod spacing scales with design tables, just being announced the Universal Atlas Cement Co., will prove valuable the drafting board and designer’s table the architect and the concrete designing engineer because the time-saving features which these scales and tables include. The architect who desires draw the joists sectional drawing will find all the stand- ard spacings for joists-cast-in- place over in. and in. wide steel forms. The depths the forms vary from six in., and the widths the joists from four seven inches. 16-in. spacing included for four in. wide joist with which four-, six- and eight-in. depths in. clay tile can used fillers between joists. Four standard spacings are pro- vided for use with precast concrete joists. Scales are included for rod spac- ings solid concrete slab con- struction, There are many ways which these scales for rod spac- ings (which vary from in. in. with in. increases) may used the drafting room addition the uses for which they are primarily intended, just the in. spacing for concrete joists with clay tile fillers may used for spacing wood joists equally well the concrete. The tables these scales show the necessary design data make computations depth joists and slabs, and the bar sizes re- quired for the sections selected. Tables are based the latest approved code recommendations the American Concrete Institute, viz., Ib. per sq. in. and f’c=3,000 Ib. per sq. in. Joist loading tables for metal forms are courtesy the Con- crete Reinforcing Steel Institute. Precast joist loading tables are from the “Precast Joist Concrete Floor Construction Details” the Portland Cement Association. Clay tile filler and one-way solid concrete slab floor tables were spe- cially prepared for this set scales and are accordance with the provisions the American Concrete Institute building regula- tions for reinforced concrete for in. ft. in. with spacings totaling ft. in. and ft. respec- tively. They are printed tough, stiff stock having very durable wearing surface. Seales are along the edges in. 14% in. sheets with design tables between. general, tables apply the scales the same sheet. Cross references with promi- nently displayed scale numbers make easy locate any desired scale table. Sets these “Concrete Joist Spacing Scales and Design Tables” will furnished any architect, en- gineer general contractor the Universal Atlas Cement Co., 208 South Salle Street, Chicago, when requested business station- ery. THE IRON AGE, October ad Drives For Runout this and following pages are presented abstracts some the papers read before the 33rd convention the Association and Steel Engineers, held Chicago, Sept. Oct. Abstracts other papers the group, but not all them, will appear succeeding issues. The papers cover wide range engineering problems the steel mill, including such subjects runout table drives, lubrication both plain and roller bearings, protective atmospheres for annealing, pickling tank construction, welding techniques, maintenance electrical systems and combustion engineering problems. Steam generated from gas engine exhaust phase the last named that discussed. writer believes the ad- vantage d.c. motors for driv- ing the rollers runout tables and coilers modern, wide, hot- strip mills. Under this system each roller pair equipped with individual mill-type d.c. motor, ranging capacity coilers. These motors are more, and each group supplied with power from d.c. generator. Ward-Leonard control used. The writer suggested this sys- tem late 1936 connection with the then proposed 98-in. hot strip mill—in preference the squirrel cage induction motors and adjust- able frequency M-G sets. Since that time not only the 98-in. mill, but 44-in. and 80-in. hot strip mill were laid out and ordered with d.c. motors for tables and coilers. The idea individual drives for table rollers more than years old. The mills considered the earlier years were either narrow strip hoop mills, merchant bar mills. The table rollers were light and narrow. Each required motor of, say, hp. hp., and the aggregate capacity sel- dom exceeded 200 hp. Table rol- lers were ordinarily kept running continuously, and was most logi- use squirrel cage motors, and control their speed 36—THE IRON AGE, October 1937 unit raising lowering the supply frequency. Size Units Increasing With the advent and growth the wide strip mill, the capacity the table and coiler drives grew leaps and bounds. some cases the total capacity motors has been over 2000 hp. for single table. The several table sections and the coilers had individ- ually started and stopped. The converting plant consisting d.c. cluded six more sets, aggregat- ing well over 3000 kva. became apparent some that the very capacity the apparatus made the otherwise good system unwieldy, uneconomical efficient. Its first and inherent handicap that any adjustable speed a.c. drive. The only means ad- justing the speed squirrel cage motors varying the applied able means providing commer- cially source adjustable fre- quency, except rather crude way, means d.c. a.c. set. Since the power supply usually a.c., this means that another con- verter set used somewhere the system provide power run the adjustable frequency Thus, the power converted through five machines succes- sion. Low overall efficiency and high first cost the converting plant, per unit power, can hard- neglected when the power involved becomes large. Likewise, squirrel cage motor not par- ticularly well adapted for rapid start-and-stop service. Losses Are Cut the proposed d.c. system, each group motors, say per table section, connected generator, having Ward- Leonard control. start the table, the generator voltage built up: stop it, the voltage rapidly brought zero, and the table motors pump their energy back. There are losses similar rotor losses squirrel cage motors. With motor heating reduced markedly, obvious that smaller continuous motor capacity With this system there are three, instead five, transformations power from a.c. supply table rollers. The con- version losses are cut half. Space Motor Room ordinarily necessary ad- just separately the speed each section the mill runout table— and there usually are five more such sections. Independent start- ing and stopping each table section and each coiler are also order. Therefore, a.c. drives are employed, seldom less than five motor alternates are used, not counting the M-G set. against this, the sev- eral generators for the d.c. table and coiler motors can con- veniently grouped into one two sets driven 2200 6600-volt motors.. The control equipment elementarily simple and compact. Only small contactors are used | | | | | | ° ° | { | | | i} | | | | ir} control the generator field. One building bay instead three often sufficient. D.C. motors cost more than the squirrel cage motors. the other hand, the a.c. d.c. M-G set and control equipment less ex- pensive than the adjustable fre- quency motor-alternators and cor- responding control usually required for wide strip mill. Taking the equipment whole, the two types drives are quite competi- tive. Tables and Coilers Maintenance the d.c. drives likely higher than that the squirrel cage motors, due wear brushes. The mainte- nance the controls much simpler and much easier work- ing with d.c. drives that ques- tionable whether the total main- tenance expense will higher. For years the engi- neers have selected the mill type d.c. motor for such tough applica- tions blooming mill screw- down, sideguard, charging ° ° UMANSKY General Electric Co. machine. The choice made be- cause the d.c. motor and control will better job than a.c. motor and control. The writer reasonably certain that the runout table and coiler drives will not prove exception this rule. still believes, however, that when the amount power involved relatively small, and when start- ing and stopping not very fre- quent—a.c. motors will hold their own. Cost analysis will decide the issue specific cases. Steel Mill Lubrication and Lubricants for Anti-Friction Bearings UBRICATION plays impor- tant part the modern roll- ing mill, which complex organization offering the lubrica- tion engineer perhaps range problems than any other industry. All degrees speed are encountered and loads range from light extremely heavy. Wide temperature variations must handled and water, dirt and scale still further complicate the situa- tion. the case anti-friction bear- ings, the lubricant must act to: (1) Form film between the operating metal parts, thus preventing metal- to-metal contact and still further reducing the already slight internal friction the bearing; (2) dissi- pate heat; (3) aid keeping out foreign matter such water, scale, ete., and (4) prevent rust and cor- The film lubricant essential, metal-to-metal contact quickly produces scuffing, galling exces- sive wear, any which will soon ° MAAG Lubrication Engineer The Timken Roller Bearing Co. ° ° ruin bearing. When equipment properly designed from the lubrica- tion point view, which means that the bearing load and operat- ing speed are not excessive, this vital film lubricant will estab- lished oils various viscosities. the viscosity, body the oil, becomes heavier, the load carrying capacity the oil film increases, unless extreme pressure products are used, when viscosity becomes secondary factor. Heat Due Many Causes Heat anti-friction bearing may due number causes. the bearing over-loaded, dis- tortion the races and rollers they enter and leave the load zone may cause serious rise tem- perature. The use too much, the wrong consistency lubricant, may cause rise temperature. too much too heavy lubricant used, there bound some increase temperature when the machine starts, usually followed leakage. attempt stop this tightening the closures will in- crease the friction, thus still fur- ther aggrevating the condition until extreme cases the bearing fails. some cases, the surround- ing atmosphere may reach tem- perature actually injurious the bearing, due poor ventilation. some steel mills expected that the lubricant will aid keep- ing foreign matter out the bear- ings. This course mainly done the closures, but the use the correct kind and grade lubricant will make the problem easier and the whole operation more efficient. When the lubricant expected THE IRON AGE, October | | it il sential that the lubricant should not thin out too much service. The highly polished steel sur- faces anti-friction bearings are easily attacked rust and corro- sion. During shipment and stor- age, bearing surfaces are carefully protected with petrolatum oil coating; after installation the function the lubricant maintain rust and corrosion proof coating the operating sur- faces all times, necessitating close watch lubricant specifica- tions. Since temperature affects the vis- cosity lubricant and therefore its film strength, essential that keep the bearing and lubricant cool possible. This can done preventing churning, using large volume lubri- consistent with good practice, installing water jack- ets around the bearing, pass- ing the lubricant through cooling system. When steel mill bearings and lubricants are maintained uniformly low temperature, oper- ators find that easier main- tain uniformity gage and quality the product being rolled and likewise that the lubricant does not break down quickly, and lasts longer. Water-Free Greases High temperature conditions are likely cause foaming and separa- tion soap and oil, particularly when the grease has high mois- ture content. The oil may drain out, leaving only the heavy soap the housing. quite likely that the near future all operators will insist upon having grease that has less than per cent water. the grease bearing not renewed for long time, deposit lime soda soap may form the housing, reducing the space available for the effective lubricant and the same time tending insulate the housing and reduce heat dissipation. And finally, there the situation which develops when grease used that too heavy flow into and around the bearing. When this occurs, bear- ing failure results. Steel mill equipment frequently includes high-speed units where oil lubrication desirable. Ordinarily such equipment carries compara- tively light load, but the high speeds have tendency develop over-heating unless light-bodied oils are used. Sight feed, constant level, and wick feed oilers are commonly 38—THE IRON AGE, October 1937 used equipment this nature, the last two being the most eco- nomical. With the sight feed oil- ing systems, oils compounded with from per cent soaps adhere better the bearing sur- faces and feed more slowly, afford- ing degree economy worth consideration. Recent work along this line has indicated that partial- oxidized oils and certain the newly developed chemical com- pounds and oily products have shown merit. Advantages Circulating Systems Circulating oil systems offer number advantages lubricat- ing gear drives and the bearings connected with them. The outstand- ing advantages circulating system are: (1) Ample lubrication; (2) cleansing action; (3) absence churning and hence lower oper- ating temperatures; (4) provision for settling, filtering centrifug- ing the lubricant, cooling it; and result (5) reduction oxidation and breakdown, thus in- creasing its life Gears and bearings are often lubricated with the same lubricant. this case, mineral oil that satisfactory for the gears usually entirely satisfac- tory for the anti-friction bearings. essential that the mill op- erator make sure that the lubricant being used does not contain any corrosive abrasive material. This particularly essential when any copper bronze bushings are lubricated the same lubri- cant used for the gears and anti-friction bearings. Likewise, when circulating oil system used, important that the lubricant, particularly the type, free from mate- rials which will emulsify the presence water and scale. Any emulsions will thrown out the filtering centrifuging equip- ment and there danger that the load carrying capacity the oil may dangerously reduced with- out warning. Due the design equipment and the conditions under which must operate, grease widely used. Various types greases are available and care should exer- cised their selection. soap products are ordinarily lowest price and have the widest use. they are not particularly affected water, these greases well those compounded with aluminum stearate are widely used for lubri- cating equipment where moisture may encountered and where op- erating speeds are comparatively low. High operating speeds and high temperatures, but without the presence moisture, call for the use soda soap lubricants general rule, since their melting point higher. all cases where grease used best results that ample space provided the housing. Normally, the housing should not filled more than half full. This permits the grease expand without being forced past the closures, avoids churning and assures adequate lubrication without waste. When applying grease bearing, spe- cial care must used see that applied directly the bearing and not merely placed housing. Lubricants Recommended There can question but that lubricants are here stay, and safe say that most greases tomorrow will that type. Bearings course must designed with due regard fer the type lubricant used, for some extreme pressure lubricants compounded today have ten- dency cause abrasion corro- sion unless proper precautions are taken. Nevertheless the Timken Roller Bearing Co. now recom- mends the use extreme pressure lubricants for all types bearings steel mill heavy duty service. general, cold worked milled grease should used avoid the possibility the lubricant thinning out too much service. Experience indicates that the various types sulphur-saponifiable, lead-soap-sul- phur, chlorinated and phosphorous types combinations, are satisfac- tory when properly compounded. Some greases have the ability hold considerable water before thinning out too much, which times desirable feature. The average lime soap emulsify with between and per cent water, any additional water appearing the form free globules. This free water chiefly responsible for etching corroding bearing surfaces. Oper- ators may expect some trouble from emulsification and scale even when using greases. However, since water, and grease containing water the form emulsion, | it hit | i} i} 1 | ij i] i} i | | | | | | | | 2 are lighter than fresh lubricant, the addition new grease will serve force the thinner ma- terial out the bearing. Provision should therefore made the housing closure design per- mit the removal emulsified contaminated grease while fresh lubricant added. the selection lubricants the bearing size, speed, temperature, load and general operating condi- tions must all considered, with the most adverse conditions being chosen the governing factors. speeds above 1000 r.p.m. oil considered more satisfactory than grease, although the smaller size bearings grease successfully used. For bearings over in. outside diameter, medium consis- tency and medium soft con- sistency greases are recommended only speeds 500 r.p.m. Conditions high operating temperature require special recom- mendations. lime base grease will usually tend melt ap- proximately 150-175 deg. Soda base greases will usually hold over 200 deg., and are therefore more suitable for the higher tem- perature applications. Above 200 deg., better results are generally secured using steam cylinder oil the proper degree refine- ment. Bearings exposed extreme cold are best lubricated oil with low viscosity and low cold test. highly refined mineral oil with viscosity 500 sec., Saybolt Universal, 100 deg. recom- mended, depending upon the appli- cation. Reasons Governing the Use Extreme Pressure Lubricants RALPH WALTERS Penola, Inc. tion extreme pressure lubri- cants steel mill lubrication mental application one the early 4-high continuous hot strip mills when load conditions both roll neck roller bearings and mill drives became too severe for ordi- nary lubricants handle. was evident from these tests that lubri- cants were available which would hold under high tooth and bear- ing pressures and only remained develop technique for ex- tension their application. The application extreme pres- sure greases the roller bearings for roll necks now quite fully developed and can almost con- sidered standardized. Although present general applica- this grease was developed marily for large, heavy-duty roller bearings, definitely general purpose grease, working equally well either plain anti-friction bearings and speeds and tem- peratures generally encountered mill operation. This characteristic offers many possibilities for sim- plified mill lubrication. There are today several mills operating with this single product every grease lubricated bearing, plain, anti- friction, sliding, from furnace table and slab return coiler. The factors determining the use extreme pressure lubricants mill drives are, course, loads and operating conditions. First, have the comparatively simple case where changes product re- quirements operation have in- creased the loads equipment point where old methods lubrication are result- ing drive failures. RALPH WALTERS Next have the case where structural limitations determine the size drives, such the pinions driving the work rolls 4-high mills. The loads applied may approach the strength the material the pinion teeth. Op- erating and experimental data in- dicate that good gear lubricant will satisfactorily maintain pro- tective film tooth pressures about 3500 Ib. per in. face. pressures above this figure extreme pressure lubricant defi- nitely required. (In the full paper, the author presents graphical method pinion load conditions directly from tachometer and motor ammeter readings.) The manufacturer furnishing drives with precision cut gears curately alined and lapped per- THE IRON AGE, October fect contact and they must kept this condition nearly pos- sible. The alinement particu- lar importance. Any deviation will, general, affect the proper tooth contact. With proper ex- treme pressure lubricant use, with the gears proper alinement and tooth pressures below the limit strength the material the gears, have never seen gear failure from pressure alone. are all familiar with the more less general difficulty from contamination experienced with mill drives using gear lubri- cant the gears and lighter oil the bearings. extreme pres- sure offers ideal solu- tion this problem, for its KROGH gots preparatory rolling being closely scrutinized now- adays for possible improvement fuel economy, metallic loss, even heating, increased production, and general all-around efficiency. number new pit designs have been made, with the designers out- doing one another showing in- creased efficiencies. The results have been highly gratifying, and are, fact, revolutionizing prac- tices many mills. The soaking pit graduating into heat-treat- ing furnace. While various designs pits differ many respects, there universal agreement that complete automatic control sys- tem requisite. process reheating in- 40—THE IRON AGE, October 1937 high film strength viscosity light enough suit the bearing clear- ances and speeds will still give adequate tooth protection well perfect bearing lubrication. While extreme pressure lubri- cants have less variation viscos- ity different temperatures than the ordinary gear shields gear lubricants, advisable where gears are operating pres- sures the danger zone provide cooling for the lubricant during the hot weather when the drive unit subject heat radiation from the mill, and provide heat- ing the extreme cold weather order maintain the lubricant its highest operating efficiency. The viscosity should checked regular intervals product adjusted the proper viscosity. addition this check, the lubricant, used circulating systems, should periodically fil- tered centrifuged, the frequency depending upon operating condi- tions. far circulating systems are concerned, the same general standards capacity, pressure, quantity flow, etc., apply for extreme pressure lubricants for circulating oil systems. With these precautions being taken, full ad- vantage the extreme pressure lubricants can realized and long life the product assured. Control Systems For Soaking Pits ° KROGH Market Development Department, Brown Instrument Co. important remember that tempted, should complete and unified. For instance, the best con- ceivable pit pressure control could not accomplish the desired ends the furnace were being fired with “feast and famine” type tem- perature controller, nor can satis- factory economy secured temperature controller the pres- sure the fuel ahead the valve allowed Agreement seems general that complete control soaking pits involves the following: Control and indication pit pressure draft. Control atmosphere fuel- air ratio. This frequently also in- volves control fuel and air pres- sures ahead the controlling valves and control air preheat temperatures. Preferred forms record and integrate fuel flow and record waste gas analysis. Control temperature. Control reversal periods for regenerative pits. Control fuel limit. Shut-off control fuel and air when pit opened. The desirability pit pressure draft control need hardly stressed. saves fuel prevent- ing air infiltration, and tends maintain the furnace temperature more constant. The control equip- ment must very sensitive, inde- pendent temperature tions, anti-hunting, and quick- acting type order respond quickly and correctly the many upsets that occur while the pit being charged and drawn. number installations, in- volving bark pits, have been made wherein the pressure the base the stack was controlled for all pits. This can success- fully done only when the proper means are taken assure that the damper does not hunt any posi- tion. Control pit atmosphere one tHe! ; | ph Ht i! ii i} : i | | 4 the chief contributing factors the remarkable evenness heating and reduction metallic loss which has resulted from these new pit designs. keeping the atmosphere surrounding the steel desired values, washing the ingots can practically eliminated, especial- when atmosphere control com- with temperature control. again important that the sensitivity the control system satisfactory, both for the heating and the soaking periods. The radi- cally differing amounts fuel needed the two instances require control system adapted avoid hunting all rates fuel flow. selecting temperature control equipment for soaking pits, the first problem determine suitable point temperature mea- surement. The use radiation pyrometers sighted directly upon the ingots has been discouraging due the flame conditions within the pit. Generally, temperature measurement must confined temperature sensitive device, thermocouple, measuring the tem- perature within refractory tube built into the wall the pit. Ex- cellent results have also been secured installing thermocouples the outlet flues. The control reversal periods regenerative soaking pits has long been practiced some plants with excellent results. Generally the reversal determined the lapse definite time intervals which may, some instances, made differ for the two sides pit. Since the temperature con- troller will adjust the fuel main- tain given temperature the pit, differing consumptions fuel will required, depending upon which checker used for preheating the air, and recording flow meter, which part the atmosphere Lubricating Oil Flooded Roll Neck Bearings ° WOOD Engineer, Morgan Construction Co. enclosed oil film bearing whose inner and outer races are separated unbroken oil film. was developed primarily for use roll necks rolling mills where, due its high load carrying capacity and freedom from fatigue and wear, has quickly made place for itself the ferrous and non-ferrous mills. Morgoil bearing total- The bearing parts proper con- sist the roll neck sleeve inner race with taper bore and cylin- drical outside surface and with integral thrust flange. The sleeve rotates with the roll neck inside steel bushing whose inner surface coated with comparatively thin lining special bearing metal and the sleeve and bushing are sepa- rated the oil film. The thrust bearing, which double acting, consists the thrust flange the sleeve, the rotating element, and two stationary steel thrust shoes with the surfaces adjacent the flange the sleeve also coated with comparatively thin section the same special bear- ing metal used the bushing. The taper bore roll neck sleeve, whose taper non-locking, held position the roll neck lock nut. Oil retained the bearing seals conventional type both inboard and outboard ends. further protection, water guard seal applied against the end the roll barrel. The Morgoil bearing has very low coefficient friction the range 0.0015 0.003, which control system the fuel limit control, will clearly indicate the need for changes time periods between the two checkers. Modern pits are being equipped with control instruments that defi- nitely limit the rate fuel input. The resultant saving fuel easily pays for the initial investment short period time. The addition- saving avoiding ingot wash- ing pure profit. incidental but important fea- ture modern control systems for soaking pits the use safety shut-off system which automatical- shuts off fuel and air the burners soon the cover lifted, preparatory opening the pit. These controls appear some- what formidable, but when all are combined and engineered into unified whole, the result will effi- ciency and satisfaction high order. WOOD par with the coefficient friction anti-friction bearings. obvious that with almost per- fect surface journal and sleeve that the oil film can extremely thin and still prevent metal metal contact, and this results uniformity load carrying capac- ity throughout the speed range the mill. The oil enters the Morgoil bear- THE IRON AGE, October 3 ing through hole the chock parallel the axis the roll. The drilled hole meets two annular extending from slightly above the horizontal cen- ter line top bearing around the bottom the chock and point above the center line the opposite side the bore. bettom bearings the annular grooves are reversed and are the top the chock. these grooves the oil delivered through holes oil pockets the bore the bushing, one each side cen- tered the horizontal center line. These oil pockets are kept full oil under slight pressure. there oil pocket each side, does not make any difference which way the bearing runs. oil the bearing parts proper. The end leakage from the inboard end drains oil sump the chock. The end leakage from the outboard end lubricates the double- acting thrust bearing and drains the outboard oil sump. The oil sumps are connected the re- tank the circulating system. The lubricant supplied Mor- goil roll neck bearings must high-grade straight mineral oil free from acid and other impuri- ties and must have high resis- tance oxidation and the for- mation sludge when subjected hard service. must separate rapidly from water and other liquid impurities and must, there- fore, type oil which shows excellent demulsibility test. great importance that the oil type which has high viscosity index. The viscosity the oil used determined the minimum speed opera- tion the rolls and also con- sideration the unit loading the projected area the bearing. condition maximum load, minimum speed and minimum vis- cosity oil that will support the load makes for lowest possible co- efficient friction. Bearing Meters Oil The quantity oil needed based complete replacement the oil film specified num- ber revolutions. Therefore, given size bearing operating high speed needs more oil than the same size bearing low speed. Oil factors have been developed for each size bearing, which, when 42—THE IRON AGE, October 1937 multiplied maximum r.p.m. the oil which the bearing ap- plied, gives the maximum gallons per minute oil required. each side the mill, there flexible supply riser and drain riser with flexible lines the chocks. the top the supply riser pressure gage and pressure switch with low- limit alarm contact and light. This pressure switch set pressure below the normal op- erating pressure. Usually the red light circuit tied actuate siren. Sufficient pressure carried the riser cause the required quantity oil flow through the bearings when the mill operat- ing absolute top speed. any speed below the maximum, the bearing acts somewhat mea- suring valve and takes less oil. OTIS protective atmospheres the mills today for annealing bright sheets and strip. But even though these equipments are used widely, there appears some confusion the requirements, particularly the permissible desirable moisture content for bright annealing steel. Some specify the use absorption dryers re- move the moisture content very low value, others specify re- frigerated coolers, while others get largest single application Morgoil the supply riser. general, the lubricating sys- tem equipment consists re- ceiving tank the oil cellar from which two rotary pumps, take the oil through the floating suctions. Either pump adequate supply the maximum amount lubricant required. The pump delivers the oil through filters from which the oil goes into the main supply line and the mill. Beyond the filter there lead from the main supply line pressure tank with three pressure switches. Two are for the purpose starting and stopping the service pump and the spare pump and the switch used ring alarm gong if, for any reason, the pressure the main supply line below standard. Protective Annealing Furnaces OTIS General Electric Co. entirely satisfactory results with- out the use either. The laws governing the reactions these complex gases were out- was shown that some gases, too dry, will etch bright steel, pro- ducing gray matte finish, par- ticularly the content high. was also shown that for the gases tested considerable moisture content permissible; that could varied over fairly wide range; and, some mixtures, was made high per cent without change appearance bright steel. Coke Oven Gas Favored For bright materials, coke oven gas purified oxygen and water | | | | iii | i]