The Iron Age 1935-12-19: Vol 136 Iss 25

ilo, CHESTNUT AND STREETS, PHILADELPHIA, PA. Sales Offices 239 WEST 39TH STREET NEW YORK, Owned, Published and Copyrighted, 1935, CHILTON COMPANY (Incorporated) Executive and Publication Offices, Chestnut and 56th Sts., Philadelphia, MUSSELMAN, President FRITZ FRANK, Executive Vice-President FREDERIC STEVENS, Vice-President JOSEPH HILDRETH, GEORGE H. GRIFFITHS, EVERIT TERHUNE, ERNEST HASTINGS, WILLIAM BARBER, Treasurer JOHN BLAIR Secretary ———_—_—_— FRITZ FRANK, President VAN DEVENTER Editor Managing Editor News Editor Machinery Editor Washington Chicago Cleveland Pittsburgh Detroit Boston Cincinnati —December 19, 1935 Whose Overcoat Are You Paying For?................ Control Cupola Operation. Manufacture Copper Tubing...... New Carnegie-lllinois McDonald Strip Nitricastiron Cylinder Sleeves Statistics Metal-Working Activity........ Construction and Equipment BAUR, General Advertising Manager DIX, Manager, Reader Service Member, Audit Bureau Circulations ADVERTISING Member, Associated Papers Findley. 311 Union Bidg., Cleveland B. L. Herman, 675 Ave., Buffalo, Published every Thursday. Subscrip- H. K. Hottenstein. 802 Otis Bidg.. Chicage tion Price: United States and Pos- Peirce Lewis, Woodward $6.00; Can- Charles Lundberg, Chilton Bidg., Chestaut & Séth Sts.. Philadelphia, Pa. Cc. H. Ober, 239 W. 39th St., New York W. B. Robinson, 428 Park Bidg., Pittsburgh W. C. Sweetser. 739 West 39th St.. New York D. C. Warren. P. 0. Box 81, Hartford, Conn. sessions, Mexico, Cula, ada. $5.50. including duty: Foreign $12.00 a year. Single copy. 25 cents. Cable Address. ‘‘Ironage. N. Y.” 4 = — |. : 4 16—THE IRON AGE, 19, 1935 ollow-through earb on-bar production the manufacture Bethlehem Carbon Bars staff metallurgical observers, whose responsibility see that the bars possess the qualities the customer requires, follow the steel through melting, pouring, soaking, rolling. They are the agents through whom the division metallurgist en- forces the steel-making practice that has decided upon result careful study the re- quirements—the processing the bars will receive, the service for which they are intended. These observers link together the various stages production. They provide the follow-through es- sential the production any ity steel product. They coordinate the entire process manufacturing Beth- lehem Carbon Bars, directing every toward the single goal cus- tomer satisfaction. THE IRON AGE DECEMBER 19, 1935 ESTABLISHED 1855 Vol. 136, No. Whose Overcoat Are You Paying For? the so-called good old days before the depression, expense accounts concealed many overcoat. What meant this that some salesmen—a small minority course—abused confidence finagling their expense accounts and got away with it. There are not many overcoats today's business expense accounts. The average employer has hard going keep his head above water and make for depression and has watch every penny carefully used watch dollars. Right here you may inclined say, were employer, would too smart let anyone working for get away with anything like Oh, yes? Well, friend, let tell you that you have anything with earning pay envelope spending the contents it, you are employer. For that case, you are one the employers Uncle Sam and such are supposed director the largest business concern the world, measured both income and outgo. And, believe not, you are unknowingly paying for enough concealed overcoats your employee's expense accounts stock all the clothing stores the world twice over. Proof? There plenty it. Next time that you buy package cigarettes, ex- amine the revenue stamp. Does come right out and say bill you from Uncle Sam for Government expenses and the amount six cents, per cent sales Oh, no, the overcoat camouflaged the inscription U.S. A-20. What you don't know may not bother you! The same thing true nearly everything that you buy today. Meats, cotton, potatoes and hundreds other necessities come you with concealed Government expense accounts the price tags. Less than per cent the Government's tax income comes from income taxes. Seventy per cent more Uncle Sam's revenue comes from hidden sales taxes paid the consumers. Our representatives Washington are solicitous that private business shall nothing the American consumers. They insist that all packages shall plainly labeled contents that the buyer shall know what paying for. Even Mr. Heinz has tell you how much benzoate soda puts into each bottle catsup. Shouldn't insist that Uncle Sam shall equally frank with the expense bill that now writes invisible ink nearly every package food merchandise? will not done unless you insist upon it. For the army political hangers-on whose overcoats you are now buying know well that you knew how much you were paving for them there would immediate and indignant insistence upon economy. You would see that the political army was whittled down until least Washington could hold without annexing Baltimore! Because the many requests for reprints editorials appearing Iron the publishers have ar- ranged make such reprints available any quantity desired price representing cost production and mailing. Please address Reader Service Department, THE Tron 239 West 39th New York City. tig 4 4 i F 2 iia 4 4 4 4 H * melting practice the foundry depends more complete control the cupola. pointing the way better control, the authors carefully analyze the different divisions cupola practice. The reactions that occur each the four zones the cupola are explained. The conditions resulting from the combustion carbon are arranged groups based the proportions carbon dioxide and carbon monoxide the gases. The air required burn coke under each combustion condition set forth. The weight iron melted and superheated each three tempera- tures with lb. coke given. The original and operating heights the coke bed for different air pressures are presented. The method finding the weight coke each charge explained and the weights coke charges for cupolas different sizes are given. The weights metal charges for cupolas different sizes are shown. The amount flux used cupola melting derived. shown that the power required deliver air the cupola and the amount coke consumed vary with the speed melting. demonstrated that unnecessary decrease the size the tuyeres bosh the cupola above the tuyeres obtain penetration the air the center the cupola. THE cupola furnace the most widely used melting unit for cast iron, and the best re- sults from its operation can ob- tained only when all divisions the practice are under definite control. the following discussion, at- tention given the combustion conditions within the cupola and the proportioning the metal, fuel, flux and air supply. def- inite amount air may sup- plied the cupola, containing suffi- cient oxygen burn definite weight coke, which turn will produce sufficient heat melt and superheat definite weight metal. Furthermore, definite *Associate professor and **Instruc- tor metal Engineering College, University Michigan, Ann Arbor, Mich. IRON AGE, December 19, 1935 weight flux necessary ob- tain satisfactory slagging condi- tions. When the correct propor- tions air, fuel, flux, and metal are used, reliable and uniform melting conditions are obtained the cupola. The entire shaft the cupola may divided into four sections for convenience examining the operation this furnace. The upper part the cupola from the sill the charging door the top the shell known the stack. This section serves only for the re- moval waste heat and gases from the cupola. Zone extends from the charg- ing door the top the coke bed. Within this volume, the coke and metal charges are preheated the ascending gases. account the deficiency oxygen the gases zone practically combustion the coke takes this section. The heat this region sufficient dissociate the limestone flux into lime and carbon dioxide, and melt some thin pieces scrap metals. Near the bottom zone the temperature the gases about 3000 deg. F., and the temperature decreases the gases travel through the charges. the level just below the charging door, temperatures 800 1500 deg. have been obtained. The bottom the tuyeres lo- cates the lower level zone shown Fig. Maximum com- bustion the fuel takes place within this section. Furthermore, the charges are arranged that most the melting and superheat- ing the metal occurs the upper part zone The lower portion the interior the cupola from the bottom the tuyeres the sand bottom the crucible. Molten metal and slag collect between the pieces coke within this volume. Since practically combustion takes place below the tuyeres, im- possible add heat the metal which retained the crucible. Combustion Conditions the Cupola When the cupola operation, air delivered relatively low pressure into bed hot coke the lower part the cupola. Ad- ditional fuel supplied the coke charges preheat, melt and super- heat the succeeding metal charges. Combustion maintained the chemical reactions which take place when carbon and oxygen are brought together relatively high temperatures. The conditions for supporting combustion are not ideal because the materials used for this pur- | | . lat} 14 pose are not the pure, elemen- tary form. Foundry coke usually contains over per cent weight ash which must removed after the coke has burned, and the nitrogen content the air about 76.9 per cent weight. The in- tensity the heat developed the oxidation the carbon the coke decreased the nitrogen the air supply. However, the heat efficiency the cupola high compared with other melting furnaces because the products from the combustion the fuel come direct contact with the materials being melted, and the counter flow gases and melting stock permits the recovery much the heat produced within the cupola. the high temperatures en- countered the bed cupola furnace, the oxygen the air sup- ply combines with the carbon the coke form carbon dioxide. The chemical reaction for the com- plete combustion carbon follows: This equation implies that carbon will combine with lb. oxygen produce only carbon dioxide with evolution heat. The complete combustion Ib. carbon requires 2.66 Ib. oxy- gen, and develops 14,550 B.t.u. heat. Another chemical reaction which occurs some extent normal cupola operation indicated the following equation: This secondary reaction takes place when the carbon dioxide formed complete combustion comes con- tact with more carbon high tem- peratures. For every pound carbon consumed this way, 5850 heat are absorbed from the reacting materials. Hence, the ° JOHN GRENNAN** conditions which favor this reac- tion are avoided much pos- sible cupola practice. When the cupola blower oper- ating, the air which enters the tuyeres encounters the hot coke the bed and soon becomes heated. Combustion the coke proceeds more rapidly the air passes through the coke the bed. the bed sufficient height, loca- tion reached which the oxy- gen the air completely con- sumed combustion carbon di- oxide according reaction (A). the carbon dioxide thus formed continues travel past more hot coke, some carbon monoxide pro- duced according reaction (B). the height the coke bed and the rate the air supply are prop- erly adjusted, this heat-consuming reaction proceeds only mini- mum extent. Table the conditions result- ing from the combustion carbon are arranged groups based the proportions carbon di- oxide and carbon monoxide (CO) finally produced from the combustion reactions. The anal- yses the gases associated with the different combustion conditions given Table were found transposing the weights the products proportions volume. With condition all the carbon burned carbon dioxide, and, ac- cording the reaction for com- plete combustion, 2.66 Ib. oxygen are required burn car- bon. This weight oxygen 151 cu. ft. air deg. and 14.7 Ib. per square inch. the coke contains per cent carbon, 136 cu. ft. air will necessary burn coke. With condi- tion all the carbon finally burned carbon monoxide and one-half much air needed required for combustion condi- tion With condition equal amounts carbon are finally burned carbon dioxide and car- bon monoxide, and the reactions require 2.00 oxygen (2.66 equivalent 102 cu. ft. air for every pound coke containing per cent carbon. The combustion condition within any cupola can established the analysis the cupola gases. With good cupola practice, the pro- portions volume carbon di- oxide and carbon monoxide the gases just below the charging will about equai. The gas sam- ples from cupolas operating under favorable conditions will contain about per cent carbon dioxide, per cent carbon monoxide, and per cent nitrogen. The carbon monoxide content cupola gases seldom greater than per cent volume. the other hand, the analyses cupola gases seldom show less than per cent vol- ume carbon monoxide, unless auxiliary air introduced above the coke bed. Melting Ratio The total heat produced from the complete combustion Ib. coke containing per cent car- bon B.tu. (14,550 0.90). the conditions are such that only carbon monoxide pro- duced from the combustion reac- tions, the total heat developed from each pound coke will 3915 0.90]. The amounts heat pro- duced from Ib. coke for other combustion conditions are given Table Under combustion con- dition per cent each pound carbon burned initially dioxide with the develop- ment 10,912.5 B.t.u. heat (14,550 and the remain- THE IRON AGE, December ag 4 q wg 4 g a i i ‘ iq TABLE AIR REQUIRED FOR DIFFERENT COMBUSTION CONDITIONS Per Cent Weight Com- Carbon Burned Gas Analysis, Per Cent Finally Con- ally dition Cog CO, co CO, co 100 100 21.0 79.0 78.3 77.2 76.3 75.1 74.0 72.5 71.0 69.3 67.4 65.3 per per ot - - 2.66 11.5 151 136 2.53 10.9 143 129 2.39 10.4 136 123 2.26 9.8 128 115 2.13 9.2 121 109 2.00 8.7 113 102 1.86 8.1 106 1.73 7.5. 1.60 6.9 1.46 6.3 1.33 5.8 ing per cent reacts with the carbon dioxide gas produce car- bon monoxide with 1,462.5 B.t.u. heat (5850 0.25) absorbed result this reaction. Therefore, the net amount heat available from Ib. carbon when burned under combustion condition and from ib. coke 8505 B.t.u. (9450 0.90). The amount heat required melt cast iron and super- heat this metal any desired pouring temperature given Fig. When the iron tapped from the cupola 2550 degrees F., 460 B.t.u. heat will neces- sary for each pound metal. determine the number Hurst, “Melting Iron the Cupola.” Penton Publishing Co., 1929. Refer pages 111-118, Belden, “Foundry-Cupola Gases and Temperatures.” United Bureau Mines Bulletin 54, 1913. pounds cast iron which can melted with one pound coke the cupola, necessary estab- lish the proportion the total heat which used for preheating, melt- ing and superheating the metal. Other uses heat the cupola include heating the gases and the coke addition the preheating and dissociation the limestone. Attempts have been made de- termine the heat balance for the cupola furnace, and the results have shown that about per cent the actual heat produced from the combustion the coke used heating and melting the metal charges.(*) 8505 B.t.u. are pro- duced from Ib. coke under combustion condition Ib. metal can melted and super- heated 2550 deg. with per cent the total heat produced from the coke [(8505 0.50) 460}. When greater heat efficiency TABLE METAL COKE RATIOS FOR DIFFERENT COMBUSTION CONDITIONS Heat Produced per Lb. Coke Combustion (90 Per Cent C.) Condition 12,087 11,259 10,341 9,423 8,505 7,587 6,669 5,751 4,833 3,915 Lb. Iron Melted Per Lb. Coke and Superheated 2250 Deg. 2650 Deg. 2750 Deg. IRON AGE, December 19, 1935 more favorable combustion condi- tions, the ratio pounds melted per pound coke will increased. The heat produced from Ib. coke and the number pounds metal which can melted and superheated each three different temperatures under the specified combustion conditions are given Table II. When steel scrap used the metal charges for the cupola, some carbon absorbed the steel, and the number pounds metal melted for each pound coke will necessarily less than possible when only pig iron and iron scrap are used the cupola charges. The Height the Coke Bed The coke bed made sufficiently high that all melting the metal charges will confined that portion the cupola which there free oxygen. The pro- duction iron good quality this method melting depends large extent upon maintaining the correct height the coke bed throughout the entire heat. When the bed too low, the oxygen the air supply will not completely consumed the coke the bed, and will pass through the metal charges, causing the rapid oxidation the metal. the coke bed higher than necessary for the complete con- sumption the oxygen, the car- bon dioxide formed initially will combine with more carbon the upper part the bed produce carbon monoxide. This reaction will prevent the development the maximum amount heat from the coke the top portion the bed and will retard the melting. extensive investigation conditions combustion within cupola furnace was made 1913 States Bureau Mines.(*) The compositions and temperatures the gases were found many points within the coke bed cupola. From the results these determinations, the area which lo- cated the highest temperatures the fuel bed was found have the shape inverted cone with the base intersecting the cupola lining in. above the top the tuyeres, when the air was supplied pressure 5.3 oz. per square inch. The line A-B-C Fig. locates the cross-section the area | | | i} —CFOHTHC 4 highest temperature the coke bed. Below this area free oxygen present the gases. order melt the metal charges without excessive oxidation, all melting must completed above the level which oxygen present the fuel bed the cupola. The exact location this area, which rep- resented the straight line A-C Fig. dependent upon the velocity the gases indirectly the volume the air supplied the cupola. The investigations that have been made the conditions combustion within the fuel bed the cupola furnace have shown that the oxygen the air supply gradually consumed passes through the hot coke bed. cer- tain amount time required for the oxygen combine with the carbon, and the distance that the oxygen travels before com- pletely burned carbon dioxide depends upon the velocity the gases. This, turn, controlled the volume air delivered the cupola. increase the volume the air supply causes increase the pressure the wind belt, with other conditions constant. Since the air pressure can readily measured, the loca- tion the region minimum oxy- gen the coke bed can estab- lished most conveniently this basis. The line A-C Fig. indicates the minimum operating heights the coke bed for all pressures cupola any size. The points the line A-C were computed the basis the increase the veloc- ity the gases over that used Belden obtain height in. above the top the tuyeres for the location minimum oxygen. important that all melting the metal charges confined above the line A-C Fig. where practically oxygen present the gases. The line locates the top the 6-in. layer coke which will replace the coke con- sumed the development heat for melting and superheating the first metal charge. compensate for the settling the bed, well for the consumption fuel from the time the coke bed mea- sured until the blower started, the bed increased addi- tional height in.; this known safety coke. Under nor- mal operating conditions, the height the coke bed varies between points the line D-E and points the line A-C corresponding with the operating air pressure the wind belt. The coke between these limits replaced intermittently the succeeding coke charges. The Coke Charge The coke the bed which consumed furnish the heat for melting the metal charges re- facture, well the care taken handling this fuel. the rela- tion weight volume for specific coke cannot found trial, may assumed that, occupies cu. in. The weights the coke charges given Table III for cupolas different sizes were calculated this basis. The coke charges are placed level ORIGINAL HEIGHT COKE BED OPERATING HEIGHTS SECOND METAL CHARGE FIRST METAL CHARGE SAFETY N N Ly: N Fic. cupola. plenished the intermediate coke charges. this way, the coke bed maintained the correct level insure favorable tions. decrease the formation carbon monoxide, which lowers the temperature the gases, the coke charges are kept small practical. With the ordinary sizes foundry coke, layers less than in. thickness are not readily ob- tained. Therefore, each coke charge will contain definite weight dry coke which can placed height in. within the cupola. This amount coke can deter- mined experimentally weighing the coke which will fill cylinder having the same diameter the cupola and height in., and dividing three. The volume oc- varies with the method manu- possible over the entire area the cupola that the top the coke bed will remain level during the entire melting period. When large pieces iron scrap large bundles steel scrap are included the metal charges, desirable have the coke charges sufficient thickness that com- bustion will maintained for the length time required for all the metal each charge melted before reaches the region con- taining free oxygen. The Metal Charge The heat from the combustion the coke preheats, melts, and super- heats the pig iron and scrap metals the charges. The ratio the weight metal melted for each pound coke dependent upon number conditions, among which THE IRON AGE, December 19, q q 4 - i 3 TABLE WEIGHTS MATERIALS CUPOLA CHARGES Dia. Area Volume Limestone One Metal Inside In. per Ratio Ratio Ratio Ratio Ratio In. In. Cu: In. Lb. Lb. Lb. Lb. Lb. Lb. Lb. 804 4,824 518 592 666 814 1,018 6,108 648 846 940 1,034 1,385 8,310 896 1,024 1,152 1,280 1,408 1,810 10,860 1,169 1,336 1,503 1,670 1,837 2,290 13,740 211 1,477 1,688 1,899 2,110 2,321 2,827 16,962 261 1,827 2,088 2,349 2,610 3,421 20,526 316 2,212 2,528 2,844 3,160 3,476 4,072 24,432 376 2,632 3,008 4,136 4,778 28,668 441 3,087 3,528 3,969 4,410 5,542 33,252 512 102 3,584 4,096 4,608 5,120 6,362 38,172 587 117 4,109 4,696 5,283 6,457 are: (1) the quality the coke, (2) the relative proportion the surfaces the pieces metal which are exposed the hot gases, and (3) the amount superheat required the metal. The greater the fixed carbon content the coke, the more heat will pro- duced from given weight this fuel. Scrap metals having rela- tively thin sections absorb heat more rapidly than heavy pieces pig iron scrap. Furthermore, the metal which poured into castings with light sections usu- ally heated higher temperatures than the metal which used castings with heavy sections. When steel scrap used the charges for the cupola, some carbon necessarily consumed carburiz- ing this material. Therefore, the ratio the weights metal coke must established the basis all the operating condi- tions. The values given Table for the pounds iron melted per pound coke are based upon the assumption that per cent the heat produced froin the combustion the coke used melting and superheating the iron. The ratios which are most commonly used are from Ib. metal melted per pound coke. The weight one metal charge found mul- tiplying the weight one coke charge the factor which will give the desired amount super- heat the metal. Table III the weights one metal charge are given for different iron coke ratios and for cupolas different The Flux Charge The non-metallic, non-combusti- ble materials which accompany the cupola charges are produced during melting form viscous slag within the cupola. this slag allowed accumulate sufficient quantity, will interfere with good melting practice. The combustion the fuel and the melting the metal are retarded the presence gummy slag which adheres the surfaces the pieces the stock. Furthermore, slags which fuse high temperatures obstruct some the gas passages through the charges, and this condition will make uniform melting impossible. The viscosity slags lowered the addition fluxes the charges. Limestone (CaCO,) the most important cupola flux, although and soda ash are also used for this purpose. The most satisfactory fluxing material calcium oxide which produced the decompo- sition limestone within the cu- pola. The calcium oxide combines with silicon oxide form calcium silicate slag. This reaction requires 1.66 pure limestone, 1.71 lime- stone containing per cent im- TABLE AIR SUPPLY AND MELTING RATE Lb. Cubic Feet Air per Minute Lb. Metal Dia. per ToBurn Lb. Metal Inside Charge OneCoke OneCoke OneCoke One Coke Melted per Lb. Coke Melted per Lb. Coke Lining In. Charge Charge Charge Charge 7,548 1,887 1,509 1,258 5.0 4.0 3.3 4.4 3.6 3.0 9,588 2,397 1,917 1,598 6.3 5.1 4.2 5.6 4.5 3.8 128 13,056 3,264 2,611 2,176 8.6 6.9 5.8 7.7 6.1 167 17,034 4,259 3,407 2,839 11.3 9.0 7.5 10.0 8.0 211 21,522 5,381 4,304 3,587 14.2 11.4 9.5 12.7 10.1 8.4 261 26,622 6,656 4,437 17.6 14.1 11.7 15.6 12.5 10.4 316 32,232 8,058 6,446 21.3 17.1 14.2 18.9 15.2 12.6 376 38,352 9,588 7,670 6,392 25.4 20.3 16.9 22.6 18.0 15.0 441 44,982 11,246 8,996 7,497 29.8 23.8 19.9 26.5 21.2 17.5 52,224 10,445 8,704 34.6 27.6 23.0 30.7 24.6 20.5 587 59,874 14,969 11,975 9,979 39.6 31.7 26.4 35.2 28.2 23.5 22—THE IRON AGE, December 19, 1935 | ‘ { FF purities unite with each pound silicon oxide. The silicon oxide content the cupola charges derived mainly from the ash the coke, from the products oxidation the metal, and from the sand the iron scrap. assumed that the coke contains per cent ash, and that 250 coke are required ABOVE TOP TUYERES INCHES HEIGHT COKE BED ash will produced the cupola during the melting every ton metal. Since the ash contains ap- proximately 50, per cent its weight silicon oxide, the com- lb. coke will pro- duce silicon oxide. the melting the metal the cupola, silicon oxidized the extent about metal charges. The silicon oxide collects the total metal mixture contains silicon, the normal oxidation 2000 metal will result the formation 9.4 Ib. silicon oxide. When this amount oxide the coke used -melt- ing: the metal, total 21.9 Ib, will obtained. The produce liquid slag combining with the silicon oxide from these two sources alone amounts 37.4 per cent the weight the coke used. Other sources slag are the cupola patching material and the sand the metals which are charged into the furnace. The limestone apportioned ac- cording the conditions oper- ation for every cupola; rule, ABOVE 2700 2800 IS. 3—Heights coke bed for dif- ferent air pressures. per cent the weight the coke consumed melting sat- isfactory proportion for the lime- stone additions, The limestone flux distributed uniformly over each coke charge and kept away from the lining. Since the coke can usu- ally placed more level the cupola than the meta] charges, the limestone can distributed more uniformly over the coke layers. Fluorspar very active flux- ing agent for cupola slags and often supplied with limestone the cupola charges; little per cent the weight the lime- stone sufficient increase no- ticeably the fluidity the cupola slag. Soda ash also used increase the fluidity and the dissolving ac- tion cupola slags. Under favor- able conditions, soda ash valu- (CONTINUED PAGE 84) 2900 TEMPERATURE IRON SPOUT DEGREES FAHRENHEIT 2—Total heat iron cupola Basis Diagram | | j j all | 2300 2400 2500 600 Origin temperature deg Specific solid iron (60 225 deg. deg. B.t.u. per Ib. per Latent heat B.t.u. per Ib. Specific heat B.t.u. per Ib. per degree THE IRON AGE, December 4 | | 3 | AIR PRESSURE WIND BELT at | | | 410 3000 7 OPPER melted tilting type furnace which ox- idation carefully controlled. Manufacture Copper Tubing ALL tube made our company from cast billets extruded vertical press, then drawn specified size and an- nealed. The number drawing and annealing operations depends, course, the finished size tubing and its hardness specifica- tion. Manufacturing operations begin the casting shop where 99.9 per cent copper melted tilting type furnace which oxidation carefully controlled. The molten copper, thus having oxygen content, held the furnace under blanket char- coal briquettes until brought pouring temperature. The charcoal blanket used prevent further oxygen absorption. This paper was presented the author before the non-ferrous section the Detroit chapter the American Society for Metals, Nov. 11, 1935. 24—THE IRON AGE, December 1935 OTTO KLOPSCH Factory Manager, Wolverine Tube Co. When pouring temperature reached, carefully weighed charge phosphor copper added deoxidize the charge. This leaves approximately 0.02 per cent phosphorus the molten metal. The charge then poured directly into the billet molds. author describes the methods used his com- pany producing copper tubing for use the air con- ditioning, automotive, oil burner, plumbing and refrig- eration industries. All billet molds are water cooled and are coated the inside with suitable mold dressing. Water allowed drip into the mold being poured the rate ap- proximately 100 c.c. per minute. The water tends draw the car- bonized mold dressing the center and top the rising column molten metal, well form steam blanket over which keeps oxidation minimum, with the result that clean non-porous billet produced. Incidentally, unless phosphorus maintained the molten metal, the addition water will result explosion. Immediately after casting, the billet shrunk back ladle addi- tion molten copper. Then allowed cool. Upon removal from the mold, the quenched handling temperature and sent the power saw where cut into specific lengths for { } ° ° | | operations extrusion press, consisting mainly container for holding the hot billet and ram having sufficient driving pressure force the billet metal through die and over mandrel form extrusion. (Fig. 2.) After careful inspection, the extrusion length billets are sent oil-fired type furnace for heating sion temperature. high temperatures and the presence air, copper oxidizes very rapidly. the hot billet were thus exposed, hard oxide scale would quickly form all its sur- faces. This scale would become embedded the metal the ex- truded tube cause its prompt rejection. reducing atmosphere the tube itself. therefore held the muffle furnace. The extrusion press consists es- sentially container for holding the hot billet and ram having sufficient driving pressure force the billet metal through die and over mandrel form the tube itself. The heated billet from the muffle furnace placed the press container and upset special device order effect snug fit the container. the same time, center punched. The work end the ram car- ries head with piercing mandrel extending below it. This mandrel punches hole longitudinally through the axis the billet. The mandrel just long enough pro- trude slightly through the die the bottom the container when the head makes contact with the top the billet. During the re- maining portion the downward stroke, the head forces the billet metal through the die and around the lower end the piercing start the draw, one end the large diameter hollow cylinder tube pointed and opposite open end laced over hollow rod which carries the draw pin. This rod serves locate the draw pin the die opening and forms the conduit for the lubricant required the drawing operation. beyond its inner face, where gripped tong. Hook tong drops into link continuous chain which carries forward along bench until entire tube has passed through die. rear end tube die, tension tong relieved and automatically Drawn tube then pushed over into rack side bench and tong returns die means cable and friction clutch. Cycle then repeated. Pointed end tube passed through die extend slightly THE IRON AGE, December 19, = - 4 A f : 4 } — — q ‘ 3 4 / \ 4 J") > i — 3 i ; { fe mandrel. Thus perfect seamless tube large diameter formed. apparent that the hot billet metal actually flows under steady uniform pressure, also that the initial crystalline structure the original billet entirely changed reason the severity this hot work. After the ram has reached bot- tom stroke, the remaining butt metal which approximately in. thick, cut off and later re- turned scrap. The tube formed projects downward into longitudinal pit where straight- ened hand and then water quenched. The quench effectively removes whatever oxide has formed the surface the tube during the few seconds exposed the air after extrusion. conveyor returns the quenched tubes the plant floor level for inspection and transfer the draw benches. comes from the extrusion press the tube large diameter hollow cylinder which must Wire Mesh Furnac Straight Tube Rollers, Platform two three passes through dies, tube annealed continuous belt-type oil-fired open furnace, one high the progressively reduced diameter and wall thickness series drawing operations. order start the drawing, one end the tube pointed and the opposite open end then laced over hollow rod which carries the draw pin. This rod serves properly locate the draw pin the die opening, and also forms the conduit for the lubricant required the drawing operation. The die itself held rigidly the head block the bench. The pointed end the tube passed through the die extend slightly beyond its inner face. There gripped tong. The hook the tong into link con- tinuous chain which carries for- ward along the bench until the en- tire tube has passed through the die. the rear end the tube clears the die, tension the tong relieved and automatically dis- engages. The drawn tube then pushed over into rack the side the bench and the tong returned Heah Fan Units and Cooling Chamber Water Cooled Tubes the die means cable and friction clutch. The cycle then repeated. through the dies, tube must annealed refine the grain struc- ture and annealed grain size approximating 0.050 mm. diameters. This annealing type, oil-fired, open furnace, one high the griddle. Because the open anneal, this operation fol- lowed pickling remove any scale that may have formed. The solution used for this purpose having sulphuric acid con- tent per cent. After pickling and drawing again resumed until either the tube reduced speci- fied dimensions the next anneal required. The subsequent an- neals, incidentally, are what term bright anneals which differ from the open anneal first used. Annealing usually follows re- duction approximately per Tube Wire lengths pipe are self-purged due the stack effect and excess pressure inside the bright annealing furnace 26—THE IRON AGE, December 19, 1935 Diagram illustrates operation furnace. | Unload: - Drive tubing bright annealed this gas-fired General Electric furnace. Furnace atmosphere gas made burning mixture four parts air with one part city gas. cent metal cross-section. The number anneals depends, course, the ultimate tube size desired. Tubing used commercially both straight lengths and coils. After leaving the draw benches, therefore, necessary remove the points and tails and cut the tube into specified lengths, all which done standard band saw. Tubing coiled sent the coiling machines and the re- mainder the straighteners.. The coiling machine consists essentially three more power-driven grooved rolls, one which being offset from the horizontal plane causes the tube take the form delivered the annealing furnace for the final anneal. Normally, twelve-roll straightener used for tubing lengths. For precision tube parts, straightening done the Sutton Medart machines which are very much alike and which accurately maintain roundness during the straightening the straight lengths are meet the specification for hard copper tub- ing, they immediately from the straightening machines shipping room. Otherwise, they are annealed obtain the speci- fied temper. One the plant’s most interest- ing processes the bright anneal- ing copper tubing General Electric bright annealing furnace. Obviously, for use conductor refrigerant, gasoline oil burner fuels, tubing must com- pletely free scale. Annealing must accomplished, therefore, atmosphere free from all oxygen. The atmosphere within this furnace gas made burn- ing mixture four parts air with one part city gas. This process eliminates the oxygen, but introduces sulphur and moisture which must removed before the gas admitted the furnace. Sulphur even small quantities attacks hot copper readily form copper sulphide, which jet black substance and objectionable the surface copper tubing. Some the sulphur removed passing the gas through iron oxide which removes inorganic sul- phur H,S. The inorganic sul- phur-free gas then sent through cooling coils remove the organic sulphur that remains end the form dilute solutions H,SO, and due combining with the moisture. The resulting gas not only free oxygen and sul- phur, but also perfectly dry enters the furnace. This special gas introduced into the furnace (CONTINUED PAGE 86) Some the many uses which copper tubing being applied. THE IRON AGE, December P 4 ¥ Steel Corpn. has announced comple- tion construction the new 43-in. continuous strip mill McDonald, Ohio. This mill, which will produce strip steel in. wide and ranging thickness from No. gage in., has 30,000 tons month. The mill served three natural gas-fired, continuous type heating furnaces, each ft. wide and ft. long inside, with capacity heat tons slabs per hour per furnace. All rolls have wide face, and the mill product finishing stand the rate 2000 ft. per minute. The mill consists the following 28—THE IRON AGE, December 1935 units: horizontal high slab reducer, three high roughing stands with one vertical edger, 4-high rough- ing stand with ver- tical edger, delay and rocking table, flying crop shear, six 4-high finishing stands, fly- ing shear for cutting ft., two coilers and one piler for cut lengths. Hot coils from the mill are conveyed storage area, where they are weighed and View showing mill proper from No. furnace, squeezer shown the foreground. — allowed cool. From there they are either loaded into cars for direct shipment put another con- veyor serving three coil processing units. These units can proc- ess the coils for pre- vention “coil break,” trim the edges slit the coils into many seven multiples, shear into accurate cut lengths. Hot packed mate- rial lengths from ft. from the mill weighed and placed racks coiler building for cooling. They are then trans- ferred either conveyor elec- -tric transfer car three pack processing units. Additional auxiliary equipment includes 4-arm batch pickling unit, natural gas-fired normal- izing furnace, skin pass mill, squaring shear, roller levellers and oiling equipment. The has Selsyn devices which allow mi- crometer adjustment the rolls and guides, and are electrically indicating. They afford silent thickness indication the product all parts the mill. The mill also equipped with pumping equipment and sprays for use THE IRON AGE, December stands from the coiler building. breaking scale the steel passes through the mill, water 1000 lb. pressure being used this purpose. All stands the mill and the major portion its auxiliary equipment are driven individually 765 electric motors, ranging from 3500 hp. For cooling the main mill motors, 600,000 cu. IRON AGE, December 19, 1935 ft. per min. cleaned air re- quired. The buildings are equipped with electric overhead traveling Power for operating the mill generated the Ohio works the Steel Corpn., 44,000 volts means trans- formers and transmitted the LEFT PRAY pumps and mill prop- from No. roughing stand the heating BELOW scale breaker and finishing stand. McDonald mills, where step- ped down 6600, 220 and 110 The above 6600 volt alternating current converted means motor generator sets direct cur- rent, 600 and 250 volts. The ground was broken for the construction this mill Jan. 17, 1935. q Nitricastiron Cylinder Sleeves CYLINDER sleeves are being more widely used bus and truck motors. These are both the dry and wet types. has been found that the ordinary gray iron block does not resist wear for sufficient period heavy duty motors. Frequently cost over- haul considerable, addition tying the equipment. Formerly 25,000 30,000 miles hard oper- ation necessitated overhaul; with alloy sleeves this has been in- creased 75,000 200,000 miles. Tests indicate that Nitricastiron sleeves will further increase this 400,000 miles without any service being necessary the block it- self. will necessary re- place pistons and rings during this period, depending upon the operat- ing conditions, but the block itself needs attention. Hardened cylinder liners present very definite advantages over the gray iron block. The principal causes wear cylinders are be- lieved the following: Corrosion, principally low oper- ating temperatures while the block below the dew point. This corrosion caused carbonic acid, sulphuric hydrochloric acid. The carbonic acid product combustion, carbon dioxide uniting with water. Impurities fuel oil may cause other acids present. Deformation the cylinder due the high pressure explosion and impact the rings. The pressures are highest the top the cylinder and most wear occurs there, causing bell mouth condition. These pressures are particularly high Diesel motors. Deformation cylinders due improper head installation. has been definitely proved that the cold condition cylinders distort when heads are improperly attached. Abrasion the rings, particular- air cleaners are not functioning properly. Lack oil film the top the bore. ° ° COLWELL Director Engineering, Thompson Products, Inc., Cleveland overcome the above conditions essential that the cylinder have high hardness. The cylinder must have strength and soundness, and free from excessive distor- tion during operation. must also corrosion-resistant fair de- gree. Various materials have been tested cylinder liners, hard- ened chrome-nickel iron. being the best the conventional sleeves. This material will Brinell about 500. can rebored the motor several times for oversize pistons and rings. Analysis Nitricastiron Nitricastiron special grade iron which nitrided the Hardness Kil bore surface. The hardness will 800 1000 Brinell for depth 0.004 0.006 in. The iron analysis follows: Per Cent Total carbon...... 2.93 Graphitic carbon......... Combined carbon........ 0.62 Phosphorus ........ Manganese 0.76 Molybdenum 0.24 Aluminum The high hardness obtained the nitrided sleeve overcomes great degree the principal causes wear outlined above. Bores with high hardness introduce high oil consumption the ring installa- Thousandths Inch Test showing that case hardest the very outside. THE AGE, December 650 H ters). RIGHT tion not properly made. Our present experience indicates that dead rings with expanders behind them are best for controlling oil under these conditions. This ap- plies both oil and compression rings. The friction loss very little with such installation, be- cause the coefficient friction the very hard nitrided iron quite low. some installations the rings have been tin plated, and this allows them start sealing oil im- mediately, without the usual loss until they have seated. With ordi- nary ‘installations consider- able time before the rings seat, but with the special installation men- tioned above, very good oil control obtained immediately. Sleeves Centrifugally Cast The castings for cylinder sleeves are centrifugally cast, the original ing finished liner approximate- Ib. will seen that great deal metal machined away, 32—THE IRON AGE, December 19, 1935 this being done reach the dense, perfect material the interior the liner. The liners are tin plated the outside surface after ma- chining, prevent nitriding. They are then nitrided approximately 950 deg. for hr. con- ventional nitriding furnace. case approximately 0.015 in. obtained, the hardness tapering off accordance with the chart. will seen from the chart that the very outside the case the most desirable. For this rea- son, very little material should honed away after installation, and our field experiments indicate that total 0.002 in. honing will clean practically all distortion. There nitriding fuzz the surface which removed before the liners are shipped. The cylinders are honed size the bore and there may some distortion present. Much this distortion disappears when the liner pressed into the block. The liners should installed cylin- LEFT 3—Section outside surface, showing nitrided sur- face and portion core (250 diame- ters). RIGHT 1G. 4—Section nitride case (1000 ders and and then and minimize distortion. slight amount honing after installation will cause the bore clean up. Growth Allowed For There small growth during nitriding, which varies with size and thickness. This may high 0.001 in. and allowed for the size the bore before placed the furnace. Depending upon diameter, the liners are assembled with press- fit 0.0015 0.0025 in. The out- side may coated with linseed oil facilitate the pressing operation. Heating the block boiling water help and chilling the liners dry ice further decreases the re- sistance installation. the or- dinary repair shop liners are satis- factorily installed without either the above refinements. This liner being introduced America Thompson Products, Inc. has been used small extent Europe and reports its ° > * | | performance there are The liners must made with great care and control from the initial casting through the process. Again, during installation, considerable care should exer- cised getting proper fits. When the liner properly made and installed, operates better than any known liner today. With the ring installation mentioned above, oil consumption very low the start and remains for comparatively long time, gradually increasing the piston and rings wear. Practically all wear occurs the moving parts, which saving reconditioning the motor. Experience Use Operators light trucks aver- age replacing piston rings and com- pletely reconditioning cylinders, in- cluding piston pins and rings, follows: 25,000 miles replace rings. 40,000 miles recondition cylinders, replace pistons, pins and rings. 65,000 miles replace rings. 80,000 miles recondition cylinders, etc. 105,000 miles replace rings. 120,000 miles recondition cylinders, etc. 145,000 miles replace rings. 160,000 miles recondition cylinders. 185,000 miles replace rings. 200,000 miles recondition cylinders, etc. cylinder liner which will run from 300,000 400,000 miles will show tremendous saving the reconditioning cylinders. While gray iron blocks and alloy sleeves can reconditioned number times, this not true with Nitri- castiron. The small amount wear makes unnecessary, the en- tire set sleeves being replaced after 300,000 400,000 miles the block worth salvaging. ype Highway Guard Introduced steel for highway guard rails expected in- creased and greater protection pro- vided for the motor car traveling public the bringing out improved type guard the American Steel Wire Co. This cable-type guard which designated the company its Muitisafety cable highway guard. The outstanding new feature this guard, which moderniza- tion the commonly used two- cable guard, the mounting the rail members cables upon re- silient offset brackets. brackets are strip steel ap- proaching circle form, with overlapping ends slotted holes the front through which the cables pass. These slots hold the cables proper spacing and permit the free sliding the cables either direction each post connection. The ends the slotted holes are rounded inwardly eliminate sharp edges. The slots are sufficiently wide allow ample clearance the cables. The cables are held the slots oval stay pin which can readily installed removed prying open the ends the post bracket. For attachment the post, the bracket has either single hole the back two slotted holes which permit the bracket tilted. The method fastening the bracket the post allows the bracket move automobile. Serving buffer between the cables and post and with its efficiency depending the steel used its construction, numerous tests were made determine the material best suited for the bracket, well the best de- sign, order provide bracket that, after heat treating, has de- sired resiliency and the proper toughness withstand severe shocks. The steel chosen most THE IRON AGE, 19, suitable has chemical composi- tion 0.60 0.75 per cent car- bon, 0.40 0.70 per cent man- ganese, 0.05 per cent maximum sulphur and 0.04 per cent maxi- mum phosphorus. For the rail members, three, four eight cables may used and additional cable may at- tached near the top the post. The cables are tightened the adjustment take-up bolts end posts without attention the con- nections intermediate posts. the resiliency provided the cable added the shock-absorb- ing features the post bracket. The guard rail designed de- flect the colliding automobile rather than stop abruptly. The contacting surface smooth, offset from posts and free from obstructions order that may guide car along the roadway. With cables unattached except the end posts, any sag will taken and drawn the point impact cushion the blow, and the stress exerted the force the impact against the cable transmitted tension along the cables the anchorages. With the brackets serving buffers between the cables and posts, the danger the breaking posts when automobile runs into the guard rail reduced. 4 q q 3 4 - 1 : ; 7 a § q High-Speed Crankshaft Milling New Production Miller VERTICAL movement upper and lower cutter spindle arbors, conjunc- tion with horizontal table move- ment, provides the means for se- curing square bottom square cut finished milled locating pad surfaces crankshafts, the de- sign new machine announced the Producto Machine Co., Bridgeport, Conn. tion milling locating pads preparatory the center turning bearings production lathes. The work mounted between centers and additional equaliz- ing device used support and keep the crankshaft properly line for securing the required finish. All cutter and table move- ments are cam controlled and syn- chronized. After the work piece has been positioned, feed lever starts the downward feed the upper cut- ter spindle bearing and the upward feed the lower