The Iron Age 1930-11-27: Vol 126 Iss 22

THE IRON ACE New York, November 27, 1930 ESTABLISHED 1855 VOL. 126, No. Twenty Alloys for Gray Iron ETALLURGICALLY, this the age alloys. usual, steel leads the way. first, small additions nickel, chromium, copper, etc., were made. the greatly enhanced value the metal became apparent, progress became rapid, and today everyone familiar with the wonderful stain- less irons and steels. beautiful example the glistening tower the Chrysler Building. Some years ago attempts were made add various metals gray iron, with view increase its strength corrosion resistance. Not until the last decade has there been any great commercial prog- ress. During this period, the use alloys gray iron has been systematically and successfully intro- duced and many have read with surprise the statement EMAND for alloy gray iron castings grow- ing. What the foundryman wishes know that alloy gray iron was produced 1928 the enor- mous amount 700,000 tons. (Cone, THE IRON AGE, Aug. 1929, page 282). Despite this staggering total, the authors feel safe stating that alloy cast iron its infancy, tech- nically and commercially. Alloy steel did not really come into its own until the austenitic steels were de- veloped and precisely parallel manner much work being done present toward the development austenitic gray irons. Mr. Coyle pointed out recent technical session, “gray iron simply steel interspersed with graphite.” are all familiar with the terrible ravages rust. seems highly probable that within few years this enormous economic waste will greatly what alloys may use and how should use them better his product. The case each fourteen alloying elements here set down, and the compilation becomes compendium in- formation not easily otherwise obtainable. 1583 s 4 | im. 4 reduced, large proportion the steel and iron will either completely non-corrosive least partly so. Where now the housewife takes pride stainless cutlery, possible she may soon rejoice polished non-rusting cast iron stove furnace. the foundryman now engaged the manufac- ture gray iron castings, the subject alloys comes with increasing frequency. particular, confronted two questions: Will incidental alloys his various raw materials detrimental the in- tegrity his product? What alloys can use successfully and how can use them the betterment his product and the en- hancement his profits? The literature this subject voluminous and widely dispersed make impractical for the busy foundryman obtain quickly the pub- lished information any given alloy. This paper attempt give that information. many gray iron. (Below) cases data are very incomplete only preliminary in- vestigations have been made. some instances, investigations are now under way, and the results are not available. Aluminum LUMINUM active deoxidizer and with cer- tain restrictions acts degasifier. (Keep, Trans., and E., Vol. 18, 1889). has strong softening effect, breaking carbides and form- ing graphite. 0.10 per cent, aluminum has defi- nite softening effect (Piwowarsky, Stahl und Vol. 45, Feb. 26, 1925, page 289), and 0.5 per cent continues separate out graphitic carbon. From 0.5 per cent, graphitic carbon decreases being only 0.20 per cent graphite with 11.8 per cent aluminum. 1584—The Iron Age, November 27, 1930 ERY soft gray iron. Ferrite and Graphite. (Right) Deoxidized with Aluminum. Etched. X500 (Above) Molybdenum 0.65 Per Cent. Unetched. and Waldron, Journal (British) Iron and Steel Inst., Vol. 1900.) Aluminum may also used turn white iron gray, although this respect about half effec- tive silicon. From 0.50 0.75 per cent aluminum will usually change white iron gray. also de- creases shrinkage and chill and increases fluidity. (Payne’s Founders Manual, page 266.) using aluminum softener, two difficulties are usually encountered. Almost invariably film aluminum oxide formed the surface the iron and carried into the mold, causing wrinkled sur- cases the sand shakes off from the surface, leaving practically clean cast- The other difficulty, found the authors and others, was due heavy evolution gas from the iron pouring. This will often result badly honeycombed casting. (Hogg. Journal Iron and Steel Inst., No. 1894, page 104, and Hamasumi, Science Reports, Tohoku Imperial University, Series No. 13-2.) IGH test molyb- denum Effect High Percentages Additions aluminum per cent result soft machinable gray iron. From per cent, the metal becomes hard and brittle, carbon being com- bined. From per cent there another rela- tively soft series alloys. (Everest, Foundry Trade Journal, Aug. 25, 1927, page 169.) High aluminum irons showed non-magnetic, anti-corrosive and non- oxidizable properties, but were unstable moist air. (Everest, Foundry Trade Journal, Jan. 17, 1929, page 46.) Aluminum small percentages decreases magnetic induction, permeability, and residual magnetism, but coercive force and hysteresis loss, according Airplanes use alloy gray iron Piwowarsky, Hochwertiger Grauguss, 1929, page 190. There some uncertainty the actual com- bination aluminum cast iron, although pos- sible that enters into solid solution (Gwyer, Zeitschrift fiir Anorganischen Chemie, Vol. 57, page 129.) Melting loss varies but stated about per cent. would seem that aluminum has three distinctly valuable possibilities the foundry: Addition not more than 0.10 per cent softener and deoxidizer. Additions 0.5 per cent order turn white iron gray. corrosion resisting alloy austenitic type with about per cent aluminum. Antimony and Arsenic ERY little information available the effect antimony cast iron. stated that the separation primary austenite and the solidification the eutectic are both lowered and that its action similar that tin, which hardener. (Goerens and Elligen, Revue Met., No. 5.) well known that iron ore various parts the world carries small percentages arsenic. This probably acts hardener but amounts found are insufficient have notable effect. normal iron, arsenic 0.1 per cent had deleterious effect. (Piwowarsky, Hochwertiger Grauguss, 1929, page 288.) Bismuth and Boron HERE are results the effect bismuth cast iron. series experiments way the present authors would seem indicate that bismuth may used ad- vantage some types cast iron. The general opinion seems that boron increases hardness and makes the metal brittle, preventing formation 0.4 per cent made the iron dif- ficult machine while 0.8 per cent made decidedly brittle. (Stahl wnd Eisen, 1914. ceo 1530.) Another investigator found increased shrinkage but brittleness. (Campion, Pro- ceedings, British Foundry- men’s Assoc., 1917-1918, page 81.) Calcium and Cerium ALCIUM about 0.2 per cent was found strength, transverse strength, fluidity, shrinkage. (Smal- ley, Engineering, Vol. 114. 1922, page 277.) Calcium sili- cide employed one company graphitizer for white iron. the subject cerium cast iron, there has been little published and this mostly contradictory. Dr. Moldenke states that cerium active deoxidizer; that when added 0.15 per cent, increases trans- verse strength about per cent with increased that the iron more fluid. (Moldenke, A., 1919, page 368.) Prof. Piwowarsky, his recent book high strength cast iron, says that cerium has effect cleaning the iron, shrinkage, tensile strength. (Piwowarsky, Hochwertiger Grau- guss, 1929, page 286.) Chromium use chromium cast iron usually con- nected with nickel. However, chromium itself, has certain advantages, and, reason its low cost, will find many applications. general, chromium increases chill, carbides, hardness (Merica, Handbook, T., 1930, page 340) and shrinkage. (Campion, Proceedings, Brit. Foundrymen’s Assoc., 1917-1918, page 81.) forms double iron-chromium carbides, remaining eutectic. Hatfield, “Cast Iron the Light Recent Research,” page 109.) Probably the matrix also hardened gray iron may steel. (Arnold and Read, Jour. and Steel Inst., Vol. 1911, and Hanson, Foundry Trade Jour., Nov. 1928, page 337.) Graph- ite made much finer. Difficulty machining often encountered when chromium reaches 0.4 0.5 per cent, owing carbides. However, the carbides can Alloy iron factor ships — - | The Iron Age, November 27, 1930—1585 TABLE I—EFFECT CHROMIUM STRENGTH AND HARDNESS GRAY IRON* Chromium, Tensile Strength, Combined Carbon, Mark Per Cent Tons per Sq. Brinell Per Cent 16.6 223 0.68 Cr. 0.20 17.0 235 0.70 Cr. 0.39 18.4 248 0.93 0.66 17.8 255 Cr. 0.78 15.8 262 1.25 0.90 13.4 277 *Donalds June 27, 1929, 489 Hardness.—Small amounts chromium harden gray iron, little one two-tenths per cent being noticeable machinability, and increased hard- ness. Hardness increases with chromium, and per cent chromium the iron permanently white. (Edwards, Journal, Iron and Steel Inst., 1920, Vol. 1.) The typical effect chromium hardness shown Table Strength.—Chromium additions increase strength about per cent chromium, then decrease slowly. (Keep, “Cast Iron,” 1916, page 212; Campion, Foundry Trade Jour., 1918, Vol. 20, page 467, and Smalley, Proceedings, Inst. Brit. Foundrymen, 1922-3, Vol. 16, page 495.) Another investigator reports that 0.4 per cent chromium raised tensile strength from 33,000 per sq. in., 45,600 with little change structure, and embrittlement. (Hamasumi, Foundry Trade Jour., 1925, Vol. 32, page 71.) Another finds that 0.5 per cent chromium increases Brinell hardness per cent and shock resistance per cent. (Piwowarsky, Foundry Trade Jour., 1925, Vol. 31, pages 331 and 345.) Table shows effect chromium strength, silicon being about 1.42 per cent. Growth and Corrosion.—At high temperatures, chromium cast iron has decided field usefulness, account its resistance oxidation and growth. increases the stability the carbides, least 1022 deg. Fahr. (550 deg. C.), and improves the strength all temperatures, probably due the chromium carbide the cementite the pearlite. (Donaldson, Foundry Trade Jour., June 27, 1929, page 489; Westgren, Phragmen, Negresco. Jour. Iron and Steel Inst., Vol. 1928, page 383, and Donaldson, Proc., Inst. Brit. Foundrymen, 1924-5, Vol. 18, page 89.) repeated heatings the same tempera- tures, ordinary gray iron grows, which property often detrimental, but similar iron which chromium has been added (0.20 0.39 per cent), contracts (ac- cording Donaldson, above). higher tempera- tures (1652 deg. Fahr. 900 deg. C.) 1.5 per cent chromium retards growth, but does not entirely pre- vent it. (Andrew and Hyman, Journal, Iron and Steel Inst., 1924, Vol. page 451.) Small amounts chromium make gray iron slightly corrosion resistant, especially sea water and weak acids. (Kotzschke and Piwowarsky, Arch. 1928-9, Vol. page 333, and Hud- son, Foundry Trade Jour., Aug. 1929, page 100.) used without nickel, chromium best added the form crushed ferrochromium (65 per cent), added the ladle. The ferrochromium must crushed and the iron hot, solution will incomplete. Carefully used, loss may per cent. Chromium added the cupola charge oxidized, with heavy losses, this method not practical. Chromium, itself, would seem have wide field alloy for cast iron, and even broader field when used combination with other metals, such nickel and possibly aluminum. There also strong possibility valuable cast alloys for high heat and corrosion resistance, with per cent chromium. Cobalt ITTLE has been published the effect cobalt give useful results. apparently reduces graphitic TABLE II—CASTING TEMPERATURE, 1350 DEG. FOR GRAY IRON CONTAINING MANGANESE* Analysis Physical Tests Total Graphitic Combined Maximum Test Carbon, Carbon, Carbon, Silicon, Manganese, Stress, Brinell Machina- No. Per Cent Per Cent Per Cent Per Cent Per Cent per Sq. No. bility 3.01 0.74 1.79 0.38 27.65 191 Very soft 3.01 2.18 0.83 1.73 0.40 28.25 191 Very soft 2.82 1.90 0.92 1.89 0.45 28.39 207 Very soft 2.94 2.16 0.78 1.86 0.51 29.92 205 Very soft 2.82 1.97 0.85 1.54 0.61 28.58 203 Very soft 2.84 2.07 0.77 1.78 0.9 31.88 217 Soft 2.86 1.99 0.87 1.65 1.10 34.35 217 Soft 2.82 2.07 0.75 1.91 1.45 33.46 227 Soft 2.73 1.81 0.92 1.80 1.69 34.51 235 Soft 2.78 2.04 0.74 1.85 2.20 35.05 235 Good 2.88 2.18 0.70 1.76 2.79 37.43 254 Good 12 2.80 1.77 1.03 1.83 3.15 37.18 262 Good 3.06 1.89 1.17 1.79 3.83 40.77 275 Very hard *Hamasumi, Science Reports, Tohoku Imperial Univ., 1924, two tests Iron Age, November 27, 1930 Vol 13 pages 133 178. carbon slightly, reduces strength, and increases Brinell hardness (Bauer and Piwowarsky, Stahl und Eisen, 1920, Vol. 40, page 1300.) Copper MALL amounts copper readily enter into solution the matrix cast iron, but without very strik- ing results physical properties. per cent, there slight in- crease strength, transverse strength, and Brinell hardness. (Hama- sumi, Sci. Reports, Tohoku Imperial Univ., Vol. 13, pages 133-178, and Die Giesserei, 1929, No. page 179.) There noticeable effect the carbon, but the iron appears 4.9 per cent copper was used. (Lupin, Stahl Vol. 20, pages 536 541, 558, 590.) Investigators dis- agree the max- imum solubility copper iron. Lupin uses 4.9 per cent, Hamasumi, 4.0 per cent (as above), while Sahmen states the limit solubility 3.0 per cent. (Sahmen, Zeit fiir Anorg. Chemie, 1908.) Copper appears confer appreciable corrosion re- sistance cast iron, especially under acid conditions. Resistance reaches maximum per cent copper. (Michailoff, Messenger Metal Industry, Moscow, 1926-9-10, 5-22.) Lead and Magnesium has been repeatedly attempted alloy small amounts lead with iron, but without success, lead and iron are almost completely immiscible. (Isaak and Tammann, Zeit fiir Anorg. Chemie, 55, 59, 1907.) more recent experiments, additions lead were apparently followed tendency toward higher car- bides the iron. Even connection with copper additions, lead could found the iron. (Lentze and Piwowarsky, Dissertation Aachen, 1928.) Where lead accidentally introduced into the mixtures, completely lost. (Williams, Sims, Newhall, Foundry, Jan. 1924, page 5.) Little work has been published the addition magnesium cast iron, although would seem have decided possibilities. Its introduction into the iron accomplished strong reaction, would expected. There little effect physical properties, but the iron left decidedly harder. (Piwowarsky, Hochwertiger Grauguss, 1929, page 286.) Manganese effect manganese proportions ordinarily found cast iron well understood that not considered alloy. However, when manganese Alloy iron castings important locomotives found proportions over per cent, may thought alloying element. There firmly rooted belief that manganese, say above 0.75 per cent, drastic hardener gray iron, but ordinary irons this belief does not seem well founded. Coe made series bars with manganese from 0.55 per cent, finding great reduction graphite until manganese was over per cent. (Coe, Journal, Iron and Steel Inst., No. found little differ- ence combined until man- ganese was over per cent, although Brinell hardness in- creased steadily. (Hamasumi, Science Reports, Tohoku Im- perial Univ., 1924, Vol. pages 133- 178.) Other investiga- tors added manga- nese gray iron, 2.5 per cent, find- ing little effect tensile strength, de- flection, hardness. (Wiist and Meiss- ner, Ferrum., Vol. Jan. 1924, page 97.) The effect manganese the iron carbon system has been studied Wiist. Metallurgie, Vol. Jan. 1909, page 3.) Keep, his book “Cast Iron,” and also West, have published the results numerous practical experiments the effects manganese cast iron. (Hatfield, “Cast Iron the Light Recent page 93.) The effects manganese per cent have been recently reported. (Krivobok, Report Car- negie Inst. and Bur. Mines. Foundry Trade Jour. Dec. 13, 1928, page 428.) Molybdenum general, molybdenum acts strengthener and hardener gray iron. produces fine grain, and resistance wear, the graphitic carbon taking char- acteristic hook whorl forms. Investigators found decided increase tensile and transverse strength with little reduction machinability, with 0.5 per cent molybdenum. (Piwowarsky, Stahl und Feb. 26, 1925, page 289; Smalley, Foundry Trade Jour., 31, 1922, Jan. 1923, and Smith and Aufderhaar, THE IRON Dec. 1929, page 1507.) Molybdenum has been successfully used rolls, and where wear resistance important. (Anderson, THE IRON AGE, Jan. 1925, page 65.) Molybdenum can obtained ferromolybdenum (62 per cent). the crushed form, readily soluble gray iron. Where wear resistance and strength are desired, this alloy will probably find enlarged field. Recent work molybdenum gives promise combining the remarkable strength prop- erties molybdenum with those other alloys. (To coneluded) The Iron Age, November 27, 3 PHILLIPS XPERIMENTS with steel containing per cent chromium and 0.25 per cent carbon leads the conclusion that steel this composi- tion subject relatively rapid grain growth the lower temperatures, 1290 1830 deg. Fahr. and extremely rapid growth higher tempera- tures, 1830 2550 deg. Fahr., according parer “Grain Growth High-Chromium Heat-Resisting Steel,” delivered the National Metal Congress Chicago this fall, Arthur Phillips, associate pro- fessor metallurgy, Yale University, and Ralph Baker, research metallurgist, Republic Steel Cor- poration. Furthermore, the grains approach the maximum size after comparatively short periods elevated temperatures. This observation regarding the rapid grain growth this alloy agreement with the experience the mill operators who report that develops extremely coarse grain during short annealing periods moderately high temperatures. processing the anneal important, therefore, use the lowest effective temperature order avoid the brittleness associated with the coarse- grained structure. For the grain growth work, 5-lb. ingot the following composition was prepared: Chromium 27.82 per cent, carbon 0.26 per cent, silicon 0.34 per cent, manganese 0.39 per cent. was melted 35-kilovolt-ampere nace, using Armco iron and low-carbon ferrochrom- ium the base materials. After homogenizing the casting annealing for several hours 1650 deg. Fahr., followed furnace cooling, seven pieces were cut from the central part the ingot. Each specimen was then given per cent reduction thickness cold working. One specimen was used for each the tempera- tures chosen for the annealing schedule. After an- nealing given temperature for hr. the sample was furnace cooled, ground and polished, and grain count made. was then annealed for another hr. the same temperature and grain Iron Age, November 27, 1930 Grain Growth RAIN growth certain types the high chrome-irons high tem- peratures often the cause serious trouble. This paper offers the results certain investigations some types these alloy steels. demonstrated that some such steels are subject count obtained. This procedure was followed until each specimen had been annealed for total time hr. other words, this method permitted the ex- amination and grain count each specimen for cumulative annealing period and including hr. How the Grains Were Counted The grain counts were obtained counting every grain included within rectangular area, 314 in., outlined ground glass plate. With the exception the specimen annealed the highest temperature, magnification 100 dia. was used. the case the extremely coarse-grained struc- tures, magnification dia. was employed and the counts obtained were evaluated terms the higher magnification. was noticed that the structures resulting from the prolonged annealing were free from austenite only virtue consid- erable decarburization produced the several hours elevated temperatures. Work Other Investigators Checked Other investigators studies iron-chromium- carbon alloys found austenite quenched samples 600) Grain Count Fig. 3—Grain count curve the relatively rapid growth the lower temperatures and extremely rapid tremely coarse structure respon- sible for brittleness, whether from service. per cent chromium steel containing 0.32 per cent carbon. order obtain further information this point the authors melted, the high-fre- quency furnace, three 5-lb. heats the following composition: No. NO Per Cent Per Cent Per Cent 28.81 27.00 27.82 Manganese ........ 0.40 0.38 0.39 After the castings had been homogenized, speci- mens 3/16 in. were cut from the central por- tions the castings. Pieces 3/16 in. thick were se- lected, instead the thinner strips used other investigators, order minimize and determine the extent decarburization associated with the heating this alloy high temperatures. liminary work indicated that the treatment thin strips led chemical alterations serious na- ture. fortunate this connection that the phase transformations this alloy are sluggish permit the use reasonably thick specimens. One specimen each composition was quenched water after heating for hr. the following tem- peratures, 2100, 2280, 2370, 2460, 2570 and 2640 deg. | Coordinates Initial Grain Count inGrain Size Fig. 4—Grain count curve BAKER Fahr., requiring total specimens. Pieces from the three castings were heated together each common temperature. all cases, the steel was heated slowly the desired temperature and then held that temperature for the time specified. The heat treatments were carried tightly sealed platinum-wound resistance furnace, the atmosphere which approached near neutral atmosphere may conveniently realized. Examination disclosed that film oxide cov- ered the specimens quenched from the lower tem- peratures. Specimens heated the higher tempera- tures, however, were covered scale approximate- 0.02 in. thick. The scale and decarburized under- surface were removed from all surfaces the pieces. general, the samples for chemical anal- ysis and structural studies contained carbon con- tents equal those the same specimens prior the heat treatment. Austenite Found All Specimens all the specimens the presence austenite varying amounts was observed. the case the steels quenched from the lower temperatures, large amount the austenite was retained the form broad grain boundaries and spherical intergrain globules. the specimens quenched from the high- temperatures, small amount austenite was visible the form thinner grain boundaries and smaller intergrain globules. The pieces heated 2640 deg. Fahr. showed evidences liquefied metal. Supplementary examinations specimens subjected the prolonged anneals, referred the grain growth experiments, disclosed surface free from austenite. The experimental results this study confirm the belief Bain and others that carbon soluble appreciable extent delta iron, and since alpha iron elevated temperatures becomes delta iron, evident that the solubility carbon (Concluded page 1665) The Iron Age, November 27, 1930—1589 é w o , € “ IQ ® = i i?) =) Conveyor lines are supported Girls transferring work and from conveyor and edgers. edging tables are extreme left Spraying work (below) and hanging conveyor, which can seen passing and out dryer, right. 1590—The Iron Age, November 27, 1930 = CONVE YOR Vitreous Enameling Process Semi-Automatic NEALEY ONTINUOUS and automatic enameling fur- naces, with traveling conveyors projecting from either both ends, and about which are located the dip tanks, edgers, etc., have completely changed the process vitreous enameling iron and steel products. new unit this kind has been installed the plant the Detroit Michigan Stove Co., Detroit, where supplanted seven periodic-type furnaces. The instal- lation flexible that can adapted almost any kind enameling, and now doing per cent the work the plant steel. This department run two-shift basis, the ground coat being applied and burned night and the white coats day. Dip tanks wheels are rolled into position along the outside the moving conveyor. Operators dip the stove parts and place them the tools suspended from the conveyor. The work carried through the drying oven and then through the length the furnace, where makes complete turn and travels back, picked off just before reaching the point from which started. The following shift rolls the dip tanks out the way and places the spraying and edging units opposite sides the conveyor. The parts are sprayed and hung one side the conveyor, which takes them into the drying oven. the con- veyor makes complete turn and brings them out the side opposite where they were first hung on. The operators then remove the work, edge brush the edges and return them the conveyor which car- ries them through the furnaces and return, com- pletely vitrified. Furnace and drying oven are set opposite each other, shown diagram. The loop conveyor makes complete turn the further end each. There considerable space between the two units for loading and unloading. the parts with the first white coat emerge from the furnace they are removed and dipped for the second white coat and then hung back the conveyor. From one four coats are used this plant. The furnace ft. long, and the dryer ft. The overhead chain conveyor operated mo- tor-driven sprocket the back end the dryer, and held suspension idler the back end the furnace. The distance between these two sprockets 193 ft., leaving ft. double conveyor chain free between the two units, for loading and unloading. 2-hp. motor drives the conveyor through speed-reduction gears, which permit wide range burning time. the muffle type, the furnace ft. wide and ft. high, inside dimensions, and built brick, steel incased. The heating chamber, roughly the back half the furnace, ft. wider, while the walls are firebrick and have ft. insulation added. The remaining wall sections are thinner in. Vertical channels along the sides the fur- nace support the roof and conveyor. Heat supplied through ten gas burners, lo- cated the heating chamber portion, five firing from each side. These fire into muffle under the hearth and the products combustion from this muffle pass out into stack through duct. Proper temperature automatically maintained endless conveyor, one end which the burning furnace, while the other the dryer, company making gas stoves has solved many problems connection with operating its enamel- ing plant low cost and producing uniform product. The space be- tween furnace and dryer, which are line with each other, used for dipping, spraying and edging, the equipment for these purposes being movable and handled and out between working shifts. The Iron Age, November 27, American Gas Association, New 7 7 Mn 7 through three thermocouples within the furnace, which are wired automatic temperature control. One couple located the back end and the other two the entrance and exit portions the heating chamber respectively. The valves the gas supply lines are motor-operated and chart the heat fluc- tuations kept means recording pyrometer. The furnace thus divided into two zones, pre- heating and heating. Its design the counter- flow order, i.e., the outgoing hot work imparts some its heat the coming cold work, they pass parallel each other and opposite directions. The chain conveyor runs just above the roof the furnace, the carrying fixtures hanging from intervals ft. The shanks these travel through slots the roof. Narrow metal strips these fixtures ride two metal bands the roof, one each side the slot. These effectively seal the furnace. Gas premixed with air for complete combustion and proper furnace atmosphere, and this mixture delivered the burners under pressure. The heat- ing chamber the furnace maintained approxi- mately 1600 deg. Fahr. The speed the conveyor regulated that the ground coat remains the furnace about min., while the white coats are allowed only min. and their highest temperature 1400 deg. Fahr. The dryer kept 600 deg. Fahr. sheet steel chamber placed the point where the hot work emerges from the furnace. Here considerable hot air collected and blown, through duct, into the dryer, which partially warmed this waste heat. Adjoining this chamber hood and more warm air removed suction, which helps cool the work that can handled the operators. The dryer also sheet metal, insulated depth ft. long and ft. high. The main heat supply for this unit comes from long gas pipe burner laid close the floor. Each spray unit consists three-rope, motor- operated, traveling conveyor about ft. long, which runs through spray booth. One operator places the stove parts the conveyor, another puts the enamel under pressure and the third removes the parts and hangs them the furnace conveyor. The process edging speeded the use unique round tables light weight which can revolved hand. The brushes with their wheels are located close these tables, but the side away from the conveyor. Operators remove the parts they emerge from the drying oven, place them the tables and revolve them within easy reach the edgers, who brush the white coat from the edges, leaving the black ground coat exposed. They then return them the tables that the other operator can replace them the conveyor. For putting the white coats the crew consists operators, while that employed the ground coat process totals only 18. Approximately 50,000 sq. ft. white coat can burned daily, with gas consumption about 10,000 cu. ft. This concern also applies and burns enamel cast iron, the wet process. Here the first coat sprayed wet, air dried and then burned furnace 1200 deg. for from min. The work then removed, the second coat sprayed wet, and dried and burned with the same tem- perature and time period. Work entering and emerging from furnace. Sheet steel chamber and hood gather heated air from the outgoing work and this blown into the dryer. 1592—The Iron Age, November 27, 1930 a 4 of é | — a =." ANY interesting problems the design plant for the die-casting industry came solution when the Allied Die Casting Corporation, Long Island City, put its new building ago. Efficient grouping departments that control operations was easy, inexpensive handling materials, avoidance crossed lines movement, ventilation—of particular importance both foundry and die-casting departments—heating, lighting, con- servation water and many other items had considered. Each these was taken up, not only itself, but its relation the entire layout. The resulting plant perhaps one the best arranged and equipped which can found. Engineering Heart System OUR floors, with daylight all around, comprise the plant. The heart the operation lies the en- gineering department, the eastern end the third floor. Die-casting preeminently engineering proposition. high type engineering required the design the dies and the design the ma- chines which use these dies producing the castings. All this work done here, and the casting machines themselves are made right the plant. Immediately the north the engineering depart- ment the die-making room, with heat-treating de- partment adjoining. This combined unit occupies about one-fifth the total floor space the plant. Immediately above the engineering department and occupying most the fourth floor the die-casting room. Immediately below the engineering department the trimming and finishing department, again using dies and requiring close engineering supervision. Die-Casting Plant Laid Out Engineering Basis SIDNEY KOON IRON ACE COG NUN AUC, Similarly with handling materials. The die stor- age the basement closely adjacent the freight elevator, which almost the geographical center the building. Dies are removed from their racks means elevating truck, are carried the elevator and quickly delivered the machine where needed. The location the freight elevator central point means that the average haul minimum. means also the smallest possible amount cross hauls taking material from one place another. Closely adjacent this elevator vertical pipe shaft, fully inclosed, with two access doors each floor, which all piping for all floors traverses the building from top bottom. This includes air pipe, gas pipe, oil pipe, steam pipe and water pipe, and the case air there are two sets piping, for differ- ing air pressures. This element accessibility and short movement carried out the relation between the tool makers’ benches and their machines. Each bench has two elec- tric outlet plugs and flexible lamp bracket. The lathe other machine which the man working im- mediately back him when works the bench, and only step away. Die storage worked out common-sense sys- tem, upon racks heavy oak shelving set steel frames located the basement. Successive stands racks are labeled “A, C,” etc. Each section rack between the supporting steel members has number and each shelf has another number. Thus, means one letter and two digits the location every die indicated the cards kept the foreman’s office. There space between the steel supports these racks for about four five dies. Each die has its The Iron Age, November 27, 7 q a > J ACHINES casting room, showing splash guards and long operating handles. Ventilating duct appears top, carrying away the exhaust gases. General room ventilation aided the large windows, which also furnish ample light. department. This occupies large part one entire floor the four-story build- ing. Wood blocks set mastic are used for floor- ing, for the double purpose minimizing vibra- tion and making easy install move ma- chines. 1594—The Iron Age, November 27, 1930 number painted upon large white figures. From the card the man getting the die can locate immediately which section shelf on. has then only select from among, say, four dies that shelf the one called for and transfer the die-casting room. Providing Suitable Working Conditions ATURAL ventilation depended upon large measure taking care heat generated the die-casting room. Skylights generous size, ft. from the outer wall the building, receive and dispose heat carried them natural flow from the windows alongside the machines. For tak- ing care the fumes and hot gases from the melting pots the machines, however, exhaust system operated. There are two fans convenient locations, each fan handling the exhaust from considerable battery machines and discharging through the roof. central station for compressors for air and gas and pumps for oil maintained the first floor. Here oil pump running pressure 1000 lb. the square inch, and governing its pressure means accumulator take pulsations. This pressure used hold the dies position during casting. this same central station are air compressors giving the pressure used injecting metal into the die, and 100-lb. pressure used for cleaning the dies and for other purposes. gas compressor puts pressure the gas mains which are led the various furnaces, including both the melting furnaces the foundry and the pots the base each die- casting machine. Much water cooling employed the plant. f A ENTERING around the engineer- ing department, which the heart the whole system, the plant described here has grouped the differ- ent departments such manner render them easily accessible from one the other. the same time many factors entering into modern industrial plant were studied and the problems solved connection with the erection this unit. The article shows what some these problems were, how they were attacked and how well they were met. cooling tower ft. high, erected upon the roof, has paid good dividends upon its cost through cutting down the monthly water bill mere fraction what otherwise would be. This tower, the way, will give water only deg. above the wet bulb thermometer reading the hottest day summer. Water used cool the compressors the first floor. Water circulated through the die-casting dies OURING alloy into water-cooled re- versible mold. page 1593 the operator using band saw trim gates from die-casting. The Iron Age, November 27, { | 7 7 , gi the machines. Water used cool the molds which the alloy ingots are made. All this water closed system, speak, and the only industrial water required from day day the make-up take care evaporation, leaks, spray blowing away from the cooling tower and other minor losses. Heating the building accomplished very satis- factorily unit heaters suspended from the ceilings the various departments. This under good con- trol, steam heat for these heaters being supplied means oil-burning boiler the Along- ATTERNS are stored and shelves. The locations are cified the order cards, mak- ing easy get the die wanted. side this boiler the pump which elevates water the cooling tower, drawing from the tank into which this water drains after passing through the various cooling operations the manufacturing processes. Definite Production Control Installed LMOST without exception the features mentioned above were new the new building. There were other new features introduced,. however, entirely aside from these physical factors. Previously there was controlled planning operations. Orders were put through pretty much they came in, and machines were loaded accordance with the foreman’s judg- ment. Today all this changed. The production control department makes use two visual charts the walls, one which shows glance the location and progress every live order the books, while the other shows, also visually, what each machine doing the moment and how long dated up. Every day about the foreman each de- partment receives schedule the work ahead for his 1596—The Iron Age, November 27, 1930 department during the following day. This specifies what each machine and goes into such details description the die, what the particular alloy which cast the die, how many are made, and other pertinent facts regarding the order. Thus, fully competent run his department its eco- nomical best, without having worry about the added factor routing work and seeing that machines are kept busy. Considerable new equipment was purchased the time the new plant was occupied. All the new machines are individuaily motor driven. course, many the old machines had this characteristic, also, but was not universal, the new practice. Flooring and Machine Foundations NOTHER the new plant lies the flocring the die-making and place- ment machinery everywhere, but particularly where vibration would serious factor. The die-making department has floor wood blocks set base cold mastic the concrete floor slab. This mastic plastic, which makes easy remove parts the floor any time for the purpose installing new machinery. The blocks are not fastened down any way. the same time, there enough suction the mastic that the floor keeps good surface condition with- out attention. The wood blocks not abut the con- crete walls. They are separated from the walls layer the mastic, that vibration elsewhere the building cannot affect the floor this room and allow for expansion and contraction. This form — “ A + floor was adopted this room for the double reason avoiding vibration and easing the conditions under- foot for the men working it. Foundation emplacements for machinery, particu- larly for such machinery the compressors the central station the first floor, consist sand bottom with cork filling all around, absorb such vibration the machines make and prevent from being transmitted the building structure. some cases, foundations have been laid out for future ma- chinery. every such case this same manner avoiding, all possible means, the incidence vibration transmitted operating departments. Control heating the pots the die-casting room centralized battery Brown Instrument Co. indicating recorders. This pyrometric control maintains temperature within about deg. Fahr. that called for specifications. Machines casting aluminum alloys are being maintained about 1400 deg., while those casting zinc are run about 800 deg. Approximately one-third the dollar volume work going through aluminum and its alloys, the re- mainder being zinc and zinc alloys. Factors Safety Carefully Worked Out 1000 per sq. in. operates the hydraulic ram, pressing one half the die against the other half. Air, about 450 pressure, forces the metal from the container through jet and into the die. The factor safety holding the two halves the die the work may roughly estimated the ratio between these two pressures, about Each die water cooled both halves. Air pres- sure about 100 used cleaning the dies, such occasions they not clean themselves when the casting stripped from them. Safety devices have been well thought out that there have been only three lost-time accidents the last six months. Perhaps the most dangerous work the plant that around the die-casting machines themselves. There are splash and spray guards be- tween machines and front machines, that drops molten metal accidentally thrown out any time the heavy pressures exerted will fall harmlessly. The lever means which the operator releases the air pressure back the metal jet far away from the place where molten metal flows, and such direction from that place, that the operator position hit any these missiles. interesting kink was seen the foundry, where the alloys are cast into small pigs ingots water- cooled mold. Each one the three melting furnaces has two mold stands front it, the operator work- ing between the two. These molds are reversible, hav- ing capacity for about the small pigs each side. They are made cast iron and are given daily French chalk wash prevent the metal from sticking. The procedure here for the operator fill the mold one side, thus making about pigs. then fills the mold the other side his working position, which time the first lot will have cooled sufficiently dumped. That mold then turned over—it swivelled central axis—thus expos- ing its other side the third pouring pigs. There- upon the second mold dumped and its heretofore unused side receives the fourth lot pigs. This procedure carried from one mold the other indefinitely, the water keeps the molds cool enough for this treatment. Alloys are melted under careful grade control oil-fired furnaces, with pots carrying about one ton metal. Waste gases from the oil burners and fumes from the pots are drawn off through the hood the top, and carried means fans the outer air above the roof, the same manner the exhaust from the die-casting machines the top floor handled. Making its own die-casting machines its own designs, the company has the first floor fully equipped machine shop for this purpose. This gives the same time opportunity for doing such maintenance work required throughout the plant. Manufacture the die-casting machines furnishes certain backlog whereby the machine shop may kept running fairly uniform rate. Some these die-casting machines are made for sale, under certain conditions. 900.000 deg. Fahr., approximately times hot the sun, demonstrated Dr. Slepian the Westinghouse Research Laboratories, East Pittsburgh. The spot, believed the hottest the universe, created electrically nearly perfect vacuum. was developed Ragnar Tanberg while investigating the characteristics electric arcs vacuum. thermometer exists which will measure measuring the velocity the molecules the elec- trode metal, which has been “boiled away” the intense heat. The Iron Age, November 27, 4 ARIABLES such the material; condition the original surface and condition desired the final surface the work; the type, material, density and cushion the polish- ing wheel; the kind and grain size the abrasive and the peripheral speed the polishing wheel; the speed and pressure wheel and machine vibra- tion are among the most important factors which depend the success machine polishing. im- portant provide oscillation either the work the polishing wheel order avoid straight line polishing marks the surface. This was discussed Robert Kent, Divine Brothers, Utica, Y., paper “Success Machine Polishing Depends Several Variables” the National Metal Congress Chicago this fall. General Rule Difficult State difficult lay down any general rule covering the economics machine polishing. Nevertheless, where the machine adapted the work and hand operations can eliminated and where there sufficient production keep the machine busy fair proportion the working day, machine polish- ing will usually prove economical. must recognized the offset that all vari- ables are more less interrelated. For instance, the character the material will determine the character abrasive. Then, too, the condition the original surface influences the size the abra- sive grain that employed. The contour the work will influence the selection the type wheel, for instance, plain surface calls for hard, somewhat rigid wheel. Work that has curved contour calls for softer, flexible wheel that will fit itself the surface polished. The degree finish obtained also influences the speed the work past the polishing wheel—the slower the speed the work passing the wheel the better will the finish. The material which the work composed determines the character the abrasive that must used. What Various Metals Require Steel and brass require sharp cutting edges continuously presented the work. The abra- Iron Age, November 27, 1930 Successful Machine Polishing Metals and Metal Products sive, therefore, should fracture such manner and along such fracture planes, form cutting edges that are always the same character. abrasive that fractures such manner cause splinters and slivers will prove unsuitable these splinters will put scratches the work that will later have removed. soft cast iron, the sharp cutting grains tend dig the iron particles out the softer carbon matrix and roll them along the work under the wheel. solution found the use abrasive that will crush instead fracture it. Turkish emery has been found satisfactory when working aluminum, duralumin and copper. Alundum satisfactory steel and brass and crystolon may used for polishing cast iron. Brass requires several times the horsepower that steel does. Other materials require still different amounts power. Although research has not yet progressed the point where can stated defi- nitely what power required over certain range conditions polish the different materials, can stated with certainty that the size the motor hand lathe that will produce the desired finish absolutely criterion the size motor that should installed the polishing machine. Effect Mill Scale and Pits Mill scale hard and difficult for the polishing wheel break. Furthermore, will clog the wheel and render ineffective short time. Deep pits require that the polishing wheels remove all the surface metal down the bottom the deepest pit and may impose wholly unnecessary burden the wheel. Tumbling pickling may improve both these adverse conditions but, not care- fully done, may enhance the difficulty. The surface may ground may machine finished. either event, the polishing wheel must first remove the metal down the bottom the deepest grind- ing scratch deepest tool mark. axiomatic that the polishing wheel will work best clean, uniform follows then that the better the original surface, the lower will the investment machinery, pol- — Vy ishing wheels, and the lower will the labor cost the polishing operation. Condition the final surface the work dic- tates both the number and character polishing Wheels that must used the machine. Color and the dimensional characteristics the work itself are several points considered. Quite frequently work that susceptible machine polishing all other respects presents considerable difficulty, for the reason that its contour such that the polish- ing wheel will round edges passes over them, drag the edges drilled holes un- til the holes are elliptical. Proper selection the wheel may obviate some these difficulties. change the design fixture may OLISHING metals means machinery has its prob- sewed over the entire surface, wide narrow intervals, they may have two many rows concentric sewing from the center hole out the periphery. Each class sewing dictated the character work that the wheel and wheel that eminently fitted for one job will prove hopeless failure another. Furthermore, the various buff sections which the clothflex wheel composed may glued gether from the center hole clear out the circum- ference the wheel, the gluing may stop in. in., any other distance from the circumference, depending upon the hardness the cushion desired the wheel. very soft wheel re- quired, the gluing may eliminate others. change lems. The polishing rustless omitted altogether, and the the direction rotation steels among recent ones various cross sections hand- the wheel quite frequently introduce difficulties. Robert sewed together with two wheel made trail over the edges with which comes hold the edges square and sharp. Close tolerances call for extreme care setting the wheel and making truly symmetrical operating speed. The wheel should hard density, for soft wheel will flex the work and thereby cause lack uniformity the contour the surface polish. Wheels Should Trued Speed Used make wheel truly cylindri- cal when truing the lathe, preparatory apply- ing abrasive head. However, should borne mind that, the ordinary wheel-dressing machine engine lathe, which sometimes used for the purpose truing wheels, the speed rotation relatively low. When operation the polishing wheel rotates from 1800 2500 r.p.m. depending upon the diameter. The wheel will become distorted these high speeds and the surface that comes contact with the work longer cylindrical. correct this con- dition, wheels should trued the same speed which they are used. Many manufacturers, even today, have the idea that buff buff, and polishing wheel simply collection buffs edge-glued together. illus- trate the fallacy this idea, only necessary state that light different grades cloth are used the manufacture buffs which enter into pol- ishing wheels. Every one these grades selected because particularly adapted one class another class work. Furthermore, the buff made from these different grades cloth may sewed several different ways. They may spirally Kent, the accompanying article, takes some length the vari- ous factors which must receive consideration and states these limitations, for example: Peri- The polishing machine pheral speed the polishing wheels should held closely possible 7500 lin. ft. per min.; different jobs require dif- ferent depths cushion and dif- ferent wheel densities; too much cushion may tend