The Iron Age 1925-12-03: Vol 116 Iss 23

ESTABLISHED 1855 THE IRON AGE New York, December 3, 1925 VOL. 116, No. 23 segs A sy Savings Follow Study of Equipment Demand for Automatic Telephones Met by Speeding Up Screw Machines, Presses and Other Ma- chinery Without Increase of Floor Space BY ROGERS A. FISKE* rapid growth in the demand for its products, have thee manufacturing facilities, required by been forced upon an industry which in its infancy was so pressed by competition that it extended service without cost to its customers. The industry referred to is that of the automatic telephone, which in its be- ginning was both producer or man- ufacturer, and operator, but which at a later date separated into natural channels so that at present the operating com- panies are either quite widely or entirely separat- ed from the man- ufacturer of the apparatus. The automatic telephone was the invention, in 1888, of Alvin B. Strowger, and the first prac- tical installation was made in 1892 at La Porte, Ind. Extensive appli- cations are being increase output, lower costs and avoid as much as pos- sible any increase in floor space. The products of this company consist of the multiplicity of small parts which make up the automatic telephone and switch- board, these parts being made for the most part on automatic screw machines, drilling machines and punch presses. Typical of the changes made in this plant is that of speeding up a number of the automatic screw machines. In gen- eral four mate- rials are worked, these being hard rubber, Norway iron, ste“l and phosphor bronze. The steel used in this department is stored in the basement in 10- ft. lengths and is pointed befote being sent to the production de- partment. Upon arrival in the machine room each rod is gaged and if found to made of the auto- Fig. 1—By Means of High-Speed Spindles the Speed of Screw Machines be too large it is matic telephone. Hundreds of pri- vate installations have been and are being made and city exchanges, such as in Dallas, Los Angeles, Philadelphia, London, Tokio and Buenos Aires, are doing away with the manually-operated switchboard, thus making substantial savings by the elimination of operators and a reduction in the size of the maintenance crews. This steadily increas- ing demand has made it necessary for the Auto- matic Electric Co., Chicago, to add to its manufactur- ing floor space from time to time and lately to make careful study of machine tool operations in order to *Western editor of THp IRON AGE 1507 Was Doubled brought down to size in order to avoid any outside turning. The ma- chine used for this purpose is a centerless grinder made by the Heim Grinder Co., Danbury, Conn. High-speed spindles applied to No. 2 Brown & Sharpe automatic screw machines increased the speed of those machines from 1200 r.p.m. to 2400 r.p.m., thus cutting the production time per piece from 56 sec. to 28 sec. One of the pieces made on these machines is a phosphor bronze plunger, which may be seen in the set-up shown in Fig. 1. This piece is of %-in. round rod and the operations are: Stop, box tool, center and face drill, drill stop, form and cut off. High-speed <p cca “2 aileron enmenemmne aE FE eres aa . Papa : peas a ativan! es Toten BT Ra Sey Ee ca OE TY a fe. i ea a Se oy POTN OT ee eee ee pats: at Pe ee Ove 1508 THE IRON AGE spindles were also fitted to several No. 00 Brown & Sharpe automatics used for the production of hard rubber bushings, which are made from %-in. hard rubber rods. The speed of these machines was in ereased from 2400 r.p.m. to 4800 r.p.m., thus doubling the productive capacity. The operations performed on Fig. 4 (Below)—Four-Spindle Tap- pers Do the Work Previously Done On Several Drilling Machines. The output has been increased from 750 pieces to 4000 pieces per day these bushings are: Center drill, drill, stop and cut off. In both of the cases of speeding up just cited no additional labor expense for operation of the machines was involved, and the cost of making the changes to the machines was paid out in three months of opera- tion. Further, the increased production was readily December 3, 1925 absorbed by the increased demand for the product so that no reduction was made in the size of the operating force. _ Grinder Increases Output of Magnet Cores Norway iron is used for magnet cores and is faced, drilled, tapped and cut off in automatic screw ma- MTT shevieneennnnne ners Fig. 2 (Left)—Grinding Machine Arranged to Finish Magnet Cores at Rate of 3600 an Hour. By the previous method the output was less than 3600 per day Fig. 3 (Below)—The Installation of a Three-Head Automatic Drill Has Eliminated One, and In Some Cases Two, Operations chines. The outside diameter of these cores is not of so great importance as the length, which must be held to limits of 0.002 in. Formerly these cores were fed one at a time into automatics and were turned to length at one end. Here was found another oppor- tunity to speed up production and at the same time release four automatics and two hand screw machines for other work. This was accomplished by the in- stallation of a Badger Tool Co., Beloit, Wis., grinder, shown in Fig. 2, which is magazine fed and is capable to finishing to size 2400 to 3600 cores per hour, the production by the previous method having been 2400 pieces per 8 hr. This machine is, of course, idle part of the time; the part time of one operator now suf- fices, where formerly two operators were required. The cores are fed from a tray to a chute and are picked up, four at a time, by the vertical-disk feeder. Two abrasive wheels, actuated by a cam motion, move in and trim the two ends of the cores to gage. Several parts are manufactured which require the drilling of several holes at right angles to each other. With drill presses this necessitated two or three sepa- rate operations. With the installation of the automatic drilling machines shown in Fig. 3 made by the Kings- bury Mfg. Co., Keene, N. H., these holes are drilled at one operation. These machines are made up of three drilling heads, one being mounted at right angles to the other two. Each of these machines will complete the drilling operations on 12,000 pieces per 8 hr., whereas but 3000 pieces could be finished on a drill press. One operator now takes the place of four. Three Tappers Replace 15 Drilling Machines Three tappers built by the Anderson Die Machine Co., Bridgeport, Conn., have been installed in place of nam et Ba ch Pt 3% oe enna ee ee sdnoe yy Pe nat a el a th i a Ret eM Nn de acmalattc: se, A ek a December 3, 1925 Fig. 5—Punch Presses Fitted With Automatic Feeders and Scrap Cutters Gave a_ Large Increase in Pro- duction and Re- duced the Acci- dent Hazard. One operator attends four machines 15 drilling machines, the tappers finishing 12,000 parts per 8 hr. as against 3000 pieces formerly finished on the drilling machines. One operator is required on each tapper, whereas one operator formerly took care of four drilling machines. Each operator now turns out 4000 pieces per day, instead of 750 pieces, which was the previous output per operator. These tappers consists of a disk feeder and four vertical spindles, so that four holes may be burred, drilled and tapped at a time, or combinations of these operations may be per- formed. Changes were made also in the punch press de- partment, which was equipped with presses built by the Walsh Die & Press Co., 4709 Kinzie Street, Chi- cago. These machines were hand fed, each machine requiring one operator. Clamping washers and simi lar parts were made on the machines, and increased THE IRON AGE 1509 production requirements necessitated either the in- stallation of more machines or increasing the output of the equipment in use. Four of the presses were fitted with automatic feeders and scrap cutters shown in Fig. 5, furnished by the F. J. Littell Machine Co., 4125 Ravenswood Avenue, Chicago, with the result that production was increased 250 per cent and one operator could attend all four machines... The accident hazard was also greatly reduced. Each press was fitted with a five-roll straightener and two stands of feeding rolls, one stand on each side of the die. Lubri- cating rolls are located between the straightener and the first feeder rolls. After the perforated strip passes the pulling or second stand feeder rolls, it is sheared into short lengths and disposed of as scrap. The second operation on the clamping washers is that of turning the lip at right angles to the face of Fig. 6 — Turning the Lip of Clamp- ing Washers Is Now Done on Presses Equipped with Disk Feed. Compared to hand feeding, the output has been increased more than fourfold ' @ J Tin U \ EST BE SAAS ed oa a pacar ewe or ow erren Des er SS Tee re Lia craStilesrincaslen 1510 THE IRON AGE the washer. This is done in other Walsh presses which are fitted with disk feeders as shown in Fig. 6. The blanked washers are stacked on a rod from which they are ted to a chute which serves as a magazine for the disk feeder. This feeding equipment, furnished by th: F. J. Littell Machine Co., is said to have increased the output of these presses 400 per cent as compared to the previous method of hand feeding separate pieces. Another significant economy made by the manage- ment was in the transportation and washing of ma- chined parts. To lessen the labor and reduce the cost of these operations a spiral chute extending from the top floor to the basement was installed. The tote TO MOBILIZE INDUSTRY Plan to Draft Plants in War Time Outlined by Secretary Davis PHILADELPHIA, Dec. 1.—The manner in which the War Department would mobilize the industries of the ountry in time of war was outlined in an address by Secretary of War Dwight F. Davis before the Union League of Philadelphia last Friday. The secretary pointed out that the National Defense Act makes pro- vision for this plan, and is the first expression of a real military policy this country has ever made. It is based, he said, upon the American doctrine that this country lesires peace, so long as peace can be maintained with honor, and that such a peace calls for reasonable pre paredness for self-defense. An army could not be trained and equipped until it had by actual enumeration some 35,000 varieties of irticles which are indispensable to it as a going con- ern, the secretary asserted. “The procurement and provision of this material, according to proper specification, in proper amounts, at roper price, in seasonable time, and the orderly plac- ng of it at the disposal of troops is the greatest of war problems. This effort requires the services of 17 men to every one on the fighting front It is more lifficult to organize, direct and synchronize the activi ies of those 17 men and to provide the facilities wit} which they must work, than it is to direct the activities f tl he one soldier their consolidated effort manages to keep on the line of fire defending his country’s cause with a rifle.” The United States is now prepared, according to Secretary Davis, to equip any military force up t 1,000,000 more rapidly, more completely and more economically than a new army of that size has ever been equipped before. This, the secretary said, was be- ause of a systematic plan for the mobilization of in- dustry in case of wat The 35,000 pieces of equipment referred to would re- juire 70,000 items, the secretary said, which would have to be traced and provided for the manufacture of the equipment needed. The services of approximately 20,000 manufacturing plants in the United States would be needed by the War Department to equip a large army, he said, and surveys of about 10,000 al- ready have been completed. Explaining that the country has been divided into 14 procurement districts, the secretary said that Phil- adelphia is located in district No. 5, embracing eastern Pennsylvania, southern New Jersey and Delaware. Specifically naming companies in the Philadelphia dis- trict which would be called upon, the secretary said the National Conduit & Cable Co. would supply wir: und cable for the Signal Corps. This was cited as an ‘bvious example. But turning to things not made in time of peace, he said the Baldwin Locomotive Works would supply big guns, railroad and seacoast artillery; Henry Disston & Sons, manufacturers of saws and files, would furnish surgical appliances; the Belmont Iron Works airplane equipment, and the J. G. Brill Co. would mobilize artillery of medium caliber. Several bills now pending before Congress cover details for mobilizing the human and material resources of the nation in war, the secretary stated. What they December 3, 1925 pans containing the work to be washed are now moved down this chute to a washing machine furnished by the Blakesley Washing Machine Co., Cicero, Ill., the tote pans traveling through the washer on a chain conveyor. The parts in passing through the machine are cleansed with a lime solution and steam. As the tote pans come out of the washer they pass over an automatic part counting or weighing machine and then continue down the spiral chute to the nickel plating or assembly department, as required. The increase in production at this plant has been accompanied by a successful effort to increase the serviceability of its products. contemplate is virtually an enabling act authorizing the President in time of war, or when he deems war to be imminent, to establish without delay control of all industrial elements necessary for war as well as the machinery for providing wartime man power and allot- ting that man power to its tasks. “The law should have teeth in it,” said Secretary Davis. . . . “The Government must be able to exer- cise more than mere moral suasion to keep down war costs in material—to prevent war contract profiteering while American boys are called upon to sacrifice their lives, if need be, for the flag.” All Automobile Records Broken Production of 406,569 passenger cars in October, as reported by the Department of Commerce, marks a new high point in automobile manufacture in the United States. The previous record of 391,302 cars was made last May. In total output of cars and trucks October shows a new record at 452,392 vehicles, dis- placing the previous high of 439,125, made last May. For ten months the production of passenger cars, 3,196,067, is within 4% days’ output (at October rate) of the figure for the whole of 1924. It is 120,000 ahead of the first ten months of 1923—the previous record year. Production in November and December at 60 per cent of the October rate will be sufficient to establish a new record. In trucks a new yearly record already has been made, the ten-month production having been 122,587. In all of 1924 the truck output was 377,344; in 1923, only 376,129. No other year reached 325,000. Farm Equipment Made and Sold Production in 1924 of 949 establishments engaged in the manufacture of farm equipment is reported by the Bureau of the Census at $329,170,367. This is a drop of about 10 per cent from the $364,854,106 from the 1135 establishments in 1923. Sales in the United States have accounted for the drop, the export sales having been greater in 1924 than in 1923. In the more recent year exports amounted to $55,319,372, against $49,349,- 294 in 1923. The largest single item in value was trac- tors and traction engines, aggregating $88,581,125 in 1924. Harvesting machinery at $29,751,849 was greater than in the preceding year. B. Nicoll & Co. to Import Steel }. Nicoll & Co., 294 Madison Avenue, New York have been appointed representatives in the United States of “Sogeco,” the Societe Generale pour le Com- merce des Produits Industriels, a Luxemburg company representing French, Belgian and Luxemburg steel mills, blast furnaces, by-product coke ovens and coal mines. B. Nicoll & Co. continue as exclusive represen- tatives in the United States of the Societe Anonyme des Hauts-Fourneaux et Fonderies de Pont-a-Mousson in France, a large maker of cast iron pipe. ' “Sogeco” includes among others the Saar mill Forges et Acieries de Dilling and the Luxemburg companies, Societe Lorraine des Acieries de Rombas and Hauts Fourneaux et Acieries de Differdange. owe a See aN 2 nb cD tt nl era wo eas cancel a aD Differences in Open-Hearth Boils Classification According to Degree and Violence— Consideration of Uses and Characters of Ten Recognized Types BY HENRY D. HIBBARD processes, either oral or written, must necessarily include consideration of the boil (so-called), as perhaps the most important of the phenomena which guide the steelmaker in his treatment of the charge. To aid in the description of the boil, as when and for describing some method, or for comparing one method with another, it may be well to have the differen‘ degrees of boil classified, which is the object hereof. One meets statements that a heat of steel was “wild,” or that it had a “lively action,” which descrip- tions leave much to be told. One assumes of course that “wild” means improper escape of gas from the metal, but what gas and how much? When referring to a heat in the furnace, “wild” presumably means that the boil was unduly active or stronger than brisk (No 6, described later): When referring to a heat in the ladle, that it continued to boil, gas escaping through the slag in considerable quantity: or when to steel in the mold, that it rose after teeming was finished, an indication of inferior quality because of harmful gas- holes in the ingot. If it rises immediately after teem- ing has ceased, skin-holes, which are always injurious, are being formed; if later, deeper-seated gas-holes are the cause. A “lively action” in the furnace means perhaps the same as “wild” but in a milder sense. The term would hardly be used in referring to a boil in the ladle, while it might properly be applied to the action of the gases of good effervescing steel in the molds. But all de pends on what kind of steel is being made. (processes, description of the open-hearth steel Gases in Steel Until we have fuller knowledge of the gases of steel we must not confound those of liquid steel with those of hot solid steel, or with those of cold steel. Further, in each of these three cases we must deal separately with those given out and those absorbed by the metal, in each of these states in different environ- ments, at different temperatures and at atmospheric as well as other pressures. With enough knowledge of these different gases an explanation or theory applicable to them may come but, until then, our knowledge and treatment of them must be largely empirical. At present the facts are mostly lacking. There is little or no coordination, between the gases obtained so far from steels in these different states, by different investigators. The quantities of gases dissolved in steel at the freezing point are perhaps too small to be detected by weight. Hence their effect on the mechanical proper- tiés of the metal may be slight, if not negligible, as the other ingredients which do profoundly affect those properties are in quantity great enough to be deter- mined by analysis. The gases manifest themselves chiefly, if not wholly, by forming gas-holes. Yet in referring to the quantities of non-ferrous ingredients, it must be admitted that a content of oxygen sufficient to give steel some red-short tendency is too small to be easily determined by analysis. It is of course conceivable that gases may concentrate in the interfacial metal between the grains, as do other non-ferrous substances, and so affect the properties but of that we have no knowledge. A charge of steel does not boil, strictly speaking. Actually to boil, that is, to give off bubbles of vapo- rized iron, it would have to be heated to or near the boiling point of iron, or 2450 deg. C. (4440 deg. Fahr.). *Consulting Metallurgical Engineer, Plainfield, N. J. 1511 The non-ferrous elements steel contains may lower the boiling point of unfinished steel, as they do its melting point. The temperature of most steel baths is between 1500 and 1650 deg. C. (2730 and 3000 deg. Fahr.). The action designated as boil, for want of a better term and in accordance with custom, resembles boil indeed, and is the escape from the bath of bubbles of gas, chiefly carbonic oxide (CO), which is generated by the oxidation of carbon in the metal. That is, it is the result of chemical action and is more like effervescence than boiling. It shows the rate at which the carbon is being eliminated from the metal. What the Boil Tells The boil also gives the most information of any- thing—without waiting for an analysis—as to the con- centration of uncombined or free oxide of iron in the slag. The more there is of it, the stronger will be the boil for a given concentration of carbon in the metal, unless checked by the presence of gas-solvents, silicon or manganese, one or both. With the exceptions noted later, some degree of boil necessarily occurs at some stage in every variation of the open-hearth process. The bubbles vary in size in the different variations, and in the different stages of each variation, from those extremely small, say % in. or less in diameter, up to masses of gas thousands of times larger, or equivalent to bubbles 4 or 5 in. or even more in diameter. Each bath at each stage of the operation gives off bubbles of different sizes, within limits. The larger ones, at any certain stage of the operation, are presum- ably those which start to form deep down in the metal, which gives them time to grow as they ascend. This assumption is borne out by the smaller sizes of the bubbles around the edges of the bath, where the depth of metal is least. The smallest of all may be formed along the plane of contact between the metal and the slag. Every steel melter believes it important to give his bath what he calls a “good boil,” it being that which he considers will give the best steel under the con- ditions attending his work and the methods he employs. He may not, however, be able to give adequate reasons for his belief, even though it be well founded. Except as noted, this article relates to basic open-hearth boils. Causes of Boil To cause boil or to increase the vigor thereof, as- suming an ample concentration of carbon in the metal, requires that oxygen be fed to the bath, either from the air or in iron ore or both; or, if too hot, by lowering the bath temperature. Silicon must be almost wholly eliminated from the metal, to have proper decarburizing boils, but it is rarely present in sufficient quantity to prevent or even check such boils, particularly in a basic furnace. Manganese, while not preventing boil in ordinary practice, has a quieting effect on the bath. That ele- ment like silicon, though less eagerly, will seize a part of the oxygen which has entered the metal. To that extent it will check the oxidation of the carbon and hence the boil. Carbon may be slowly oxidized, caus- ing gentle boil, when the bath metal contains as much as 0.5 per cent of manganese, and of course propor- tionately faster when there is less. To obtain a brisk boil with carbon in the metal under 0.15 per cent, the manganese should be below 0.10 per cent, and prefer- ably not over 0.06 per cent. It is but slowly oxidized by oxide of iron and therefore should not be too plenti- pemecaeies ig inns ro m+ = ntl me tant SRN 1512 THE IRON AGE ful in the charge materials, though the proper content depends on whether the steel is to be killed or to be made to “rim in” in the molds. Moderating the Boil To lessen or weaken the boil, when there is plenty of carbon present, the charge may be held molten in the furnace and allowed to boil without further addi- tion of iron oxide; or a moderate quantity (3 to 5 per cent) of pig iron containing preferably about 2 per cent of manganese, or about one per cent of spiegel or other equivalent manganese or silicon alloy, may be added. If, however, the lack of boil is due to lack of arbon, these additions will increase boil, because of e carbon they contain. At or near the end of the heat, further additions of alloys are of course made to finish the steel. The effect of holding the charge as alluded to for quieting the boil is quite different in the acid from what it is in the basic process. In the acid process the oxide of iron in the slag continually combines wit} ie silicic acid (SiO.) of the hearth to form silicates which, under conditions prevailing in the hearth, have little or no power to oxidize carbon. When all the oxide of iron is either reduced to metallic iron by the carbon, or so combined with silicic acid, boil practically ceases. In such a case the slag will be extremely vitreous and contain about 60 per cent of silica. In the basic process the effect of a given addition f ore, in promoting boil, persists much longer than in the acid. There is so little silica in the slag that the calcium oxide, which has stronger affinity for it than iron oxide has, seizes and holds it all in combi- nation, so that the oxide of iron remains uncombined y such, or until reduced to metallic iron, and so keeps ip the boil. th There is another way in which a batch of ore has nereased oxidizing power in the basic process, as ympared with the acid. It may give up a part of its oxygen to the metal, or to the non-ferrous oxidizable elements contained therein, being thereby itself reduced to a lower oxide. Then, when it is brought to the surface by the stirring action of the boil, it takes up xygen from the air in the furnace to replace in part, it least, that which it has lost to the metal. Because of this more efficient action of oxide of iron in the basic furnace, a basic bath will boil more vigorously as a rule than an acid bath having the same composition. The temperature of the metal, as already stated, affects the degree of boil, at least when the carbon is low, in which case the boil is slackened somewhat by an unduly high bath temperature. This seems to be because the solvent power of the metal for the gases increased, rather than that the rate of oxidation carbon is lessened. + Effects of Boil The effects of boil are numerous. It stirs the bath metal and slag, and thereby: 1. It promotes oxidation of the undesired excesses of the oxidizable non-ferrous elements, particularly carbon, silicon, manganese and phosphorus, enabling them to get their quantum of oxygen from oxide of iron contained in the slag and also in small measure in the metal itself. 2. It tends to equalize throughout the temperature of the molten metal, which receives heat only from the top, by bringing up that of the lower, colder strata and mixing it with the hotter metal above. 3. It promotes the absorption of heat from the flame, by bringing up the cooler slag from beneath, so that it may take up more heat. A dead bath with- out boil absorbs heat relatively slowly, because its surface becomes substantially as hot as the walls of the furnace. In that case there is danger that the furnace may suddenly become too hot, and thus damage the brickwork. 4. It favors cleaning the metal of emulsified oxides, particularly those of silicon, iron and manganese; combined, it may be, more or less completely into silicates 5. It may and probably does effect the elimination +} December 3, 1925 from the metal of some hydrogen and possibly also some nitrogen and ammonia (NH,) which have been absorbed by the metal at some previous stage in its history. Some or all of these gases, if not suppressed, might form harmful gas-holes in the ingots. 6. It may in certain cases promote the absorption of sulphur by the slag from the gas, which sulphur may be absorbed in part by the metal from the slag. Degrees of Boil Classification of the various open-hearth boils into ten divisions: 1. Dead Bath; no bubbles. 2. Almost Dead Bath; from one to five bubbles per q. ft. of bath surface at any instant. 3. Incipient Boil; from 10 to 20 bubbles, up to one n. in diameter, per sq. ft. at any instant. 1. Gentle Boil; surface of bath one-fourth covered by bubbles up to 1% in. in diameter. ’ 5. Moderate Boil: bath surface practically covered by bubbles up to two in. in diameter. 6. Brisk Boil: bubbles cover the whole bath and crowd each other. 7. Strong Boil; bubbles crowd so as to raise the surface of the slag 2 or 3 in. 8. Jet Boil: bubbles crowd each other still more, and some throw up jets of slag three to six in. high; slag rises three or four in. 9. Strong Jet Boil; bubbles throw up numerous jets of slag six to 12 in. high; slag rises to door sills, which require to be banked up with bottom stuff. 10. Talbot Reaction; slag jets one to two ft. high, caused by escape of larger masses of gas all over the bath; slag rises and flows out of doors in great quan- tity; flames 20 to 30 ft. high play out of the furnace doors, opened for the purpose. Boils from No. 2 to No. 6 inclusive might be called “settled” boils, as the bath tends of itself to take on some one of them if allowed to work without additions. There are others, however, which, with the decarburiz- ing boils, No. 7 to No. 10 inclusive, might be called transitional. Thus a bath may “foam,” which means that the slag is filled with minute gas bubbles so that it resembles froth, which greatly increases its bulk. A foamy slag retards, or at least accompanies a slowing down of, the rate of progress of the charge, prolong- ing the heat. Such a slag is liable to exist before the charge is wholly melted, or when the silicon is unduly high in the crude iron, say over two per cent, or immediately after an addition of fresh material, including ore, pig and ferromanganese. It sometimes occurs when the cause is not apparent, induced, it may be, by too low a bath temperature. A bath may be covered partly by large bubbles, say one or two in. across, with foamy slag between them; or the whole slag may be in a foamy state, which increases its volume perhaps two or three times. This action of the bath is not con- templated in the ten kinds of boil herein considered, as it is abnormal and transitory and the bath will in due course assume one of the settled boils, though some- times the foamy condition persists in an exasperating way. Another phenomenon sometimes called “boil,” not included in the present classification, is the local in- tensified action which sometimes occurs, usually near the end of a heat, when the metal at some spot en- ergetically surges up from below, so as to rise above the slag, with a subdued fountain effect. This action, which may continue for some minutes or a consider- able fraction of an hour, is due to the admixture with the metal of oxides or oxidized iron in the hearth, which oxidizes carbon at that place more rapidly than elsewhere. Sometimes such action precedes the forma- tion of a hole through the bottom at that point, through which the charge may escape from the furnace and make a bad “mess.” Boils In-Between A boil which does not meet exactly any of the classes into which the subject is here divided, but comes between any two, should of course be so des- ni December 3, 1925 ignated. Before the boil becomes settled after melt- ing it will usually vary in intensity in different places, but will tend gradually to assume a settled boil over its whole surface. The boil of any steel charge varies from beginning to end. During melting the boil in the pools formed locally may be of any activity up to the jet boils. Then comes the boil when the charge is first wholly melted, which may be any up to brisk (No. 6). Next are the variations during decarburization, which come from changes in the rate at which carbon is being oxidized. These may vary from moderate (No. 5) up to the THE IRON AGE 1513 jet boils (Nos. 8 and 9). Finally is the boil at the end, lying between almost dead (No. 2) and brisk (No. 5). Through the progress of similar charges, even though they are to be made into different grades of steel, the boil may follow the same general lines at the successive earlier stages, but at the end, for satis- factory results, it must be right for the kind of steel being made. We will consider in the two succeeding articles each degree of boil and its significance, and then certain particular cases. Impact Values of a Nickel Steel* Effect of Quenching and Drawing Temperatures on the Izod Results BY F. T. SISCO N certain types of airplane construction structural members of a low-carbon nickel steel are welded, brazed or riveted to members of a low-carbon chrome- vanadium steel. It is necessary to heat treat these members as a unit after joining, hence they are quenched from a temperature of approximately 1625 Fig. 1—Low-Carbon Nickel Steel, Quenched in Oil from 1425 Deg. Fahr., Drawn at 1200 Deg. Fahr. X500, etched in alcoholic nitric acid deg. Fahr. and drawn back (tempered) until the de- sired physical properties are obtained. As 1625 deg. Fahr. is at least 100 deg. higher than the proper quenching temperature for the nickel steel, it was con- sidered advisable to run a series of tests using differ- ent quenching temperatures to ascertain if the higher temperature affected the resistance of the steel to impact. Low-carbon nickel steels are usually quenched from 1500 to 1550 deg. Fahr. In connection with the effect of temperatures higher than this on the impact value, tests were also made to determine the effect of tem- peratures lower than usual in the impact value. Material and Methods of Testing . The material used consisted of a %-in. sq. bar of low-carbon (S. A. E. No. 2320) nickel steel of the fol- lowing composition: Per Cent CIOs os 5 << ces eee pans 0.24 ee ee en ee 0.61 EE + os. deaweee eee ee ‘ss 0.016 Preagmorua (Hibs) “o.4s.<. cneee st 0.040 BUNGEE on ove ca ubledh octane hoes 3.52 RELIOCOM 3. . «v0 o:0:ale0s. cede eee «6 pee The bar was cut into sections about 10 in. long. *Published by permission of the chief of air service, War Department. The author is metallurgist engineering division, air service, McCook Field, Dayton, Ohio. These were heat treated according to the following schedule: Quenching Temperature (Oil), Deg. Fahr. } bars marked A... 1425 } bars marked B 1450 3 bars marked C. 1500 3 bars marked D 1550 3 bars marked E... 1575 3 bars marked F 1600 ‘ G } bars marked G.. 1625 One bar of each series from A to G was drawn at 800 deg., one bar at 1000 deg., and one bar at 1200 deg. Fahr. The bars drawn at 800 deg. were stamped 8A, 8B, 8C, 8D, etc.; the bars drawn at 1000 deg. were stamped 10 and the designating letter. The bars drawn at 1200 deg. were stamped 12 and their corresponding letter. The bars were put in an electric muffle furnace, heated slowly to the prescribed temperature, and held 30 min. at heat. The specimens were cooled in air from the drawing temperature. Three standard Izod impact “V” notch specimens Fig. 2 in Oil from 1625 Deg. Fahr., Drawn at 1200 Deg. Fahr. X500, etched in alcoholic nitric acid Low-Carbon Nickel Steel, Quenched (0.394 x 0.394 x 2.950 in.) were machined from each bar, making 63 test specimens. For metallographic exam- ination the end of the Izod impact specimen was used. Transverse and longitudinal specimens were taken from the bars representing the lowest, the middle and the highest quenching temperature for each drawing temperature. Results The results of the impact tests are summarized in the table, which also gives the Rockwell hardness values made with the diamond point and C scale. Each tab- ulated result is the average of three separate tests. ee t oS Sem | Sean ‘pated oot ds ntrememeaal et ; ae enna val aks ee ean ae: wy « we Se stat AY + eas PS Pen Sa eee S| RY ‘ ae ee a ee N 1514 THE IRON AGE December 3, 1925 The Izod values for the three tests representing For a drawing temperature of 1200 deg. Fahr. the each heat treatment were very consistent. The ex- quenching temperature is not of material difference, perimental error is about plus or minus 2 ft.-lb. In all the impact value for the 1425 deg. quench being 94 cases the specimen did not fracture completely, testify- ft.-lb., and for the 1625 deg. quench, 97 ft.-Ib. ing to the ductility of the material. The Rockwell hardness for a given drawing tem- Magnification of 500 diameters was necessary to detect perature was constant and did not vary with the any difference at all in grain size. In the case of the quenching temperature. 800 deg. and 1000 deg. Fahr. draw, very little difference Increasing the quenching temperature does not in structure could be detected between the specimens affect the impact resistance after drawing except pos- quenched at 1425, 1525 and 1625 deg. Fahr. The struc- sibly when the drawing temperature is below 1000 deg. ture of the specimens drawn at 1200 deg. is shown in Fahr. : ‘ ; ; Figs. 1 and 2. Fig. 1 represents a quenching tempera- For draws of 800 and 1000 deg. Fahr. increasing the ire of 1425 and Fig. 2, a temperature of 1625 deg. quenching temperature produces no perceptible coarsen- Fahr. The structure shown in Fig. 2 is just perceptibly ing of the grain size. In the case of the 1200-deg. ‘oarser than that shown in Fig. 1. draw there is probably a slight coarsening when the quenching is 1625 deg. Fahr. This, however, is of little Conclusions importance. ; : Table of Izod Impact Value nd Rockwell Hardness of For a drawing temperature ol R00 de g. and a , I il oA E. 2320 ‘Nickel ‘Steel juenching temperature of 1425 to 1550 deg. Fahr., the Series 8 Series 10 Series 12 impact value is confined to the range of 47 to 51 ft.-lb. Quenched Drawn 800 Drawn 1000 eawe 1300 , . 1 or 2 In Deg. Fahr eg. Fahr eg. Fahr With higher quenching temperatures, up to 1625 deg., On oem coe. eee th i act resistance is ¢ r 41 ft.-lb. Sper Deg Izod, Rock- Izod, Rock- Izod, Rock- e impact resistance i mly 41 ft | ) . _., = nah wat ah ae ok a For a drawing temperature of 1000 deg. and a 4 149° 51.( 5.3 82.0 26.( 93.6 17.5 . - as . . . ° . eA 4Q Ff 9 ‘ -Q °6 7 9 g : uenching temperature of 1425 deg. Fahr., the impact B LS60 49.5 39.9 ba =s 38.2 os e ; ye . — ( I i] 27.0 09.U i ‘ 20.35 v0.4 ~ ie is 82 ft.-lb. With higher quenching temperatures 1550 17.1 26.6 717.4 27.6 95.7 16.7 mpact resistanc nds to be lowered but not ap 157 10.6 37.5 79.8 26.6 97.0 17.5 ‘ impa esistance tends to be lowered but n at 1600 41 56 9 77.9 973 96.6 17.4 la Dly 162 10.9 7. 76.2 27.0 97.1 17.3 Mechanically Charging the Cupola Equipment for Handling Pig Iron and Sprues and Gates in Cincinnati Foundry—Saving in Labor and Improvement in Product BY EARL F. ROGERS HE cupola, as David McLean has said, “is th put them on a platform box, which was handled by T' heart of the foundry.” One of the most difficult means of an electric lift truck. This job was always jobs that we have had in the Peerless plant is done, and still is being done, on a piece work basis. harging the cupola by hand. Through the installation The night man left the platform boxes in the foundry of a charging hoist recently we have been enabled not close to the elevator leading to the charging floor. only to save the cost of several workmen, but also to The day chargers would then place the boxes on the eliminate the type of work that men dislike to do. elevator, from which they were taken to the charging It was formerly our practice to have the night man floor by a hand lift truck and placed in a convenient pick up the sprues and gates from the molding floor and location. At charging time the platform boxes were picked up and put in front of the cupola, their contents *Superintendent, Peerless Foundry Co., Cincinnati dumped upon the floor and forked into the cupola by General View of Charging Hoist at Peerless Foun- dry. Below are conveyors with pans filled with sprues and gates, ready to be hoisted for charging into the cupola WOUEEDEDETEHTLEreancueNNEDETENOHOGO NE cisaeeroeuNRENDENSeEREORDOOOOEDLANOCRCA DOOR CO DONENEDEOGUROOUOERRDOEUORREDEDEREERORREREDENRAON teu ineEEOLETNET VODNUNERONELEANONECHENAOOUEENRDEESLONEVECLORSeDTEreCHHeSEEANEED UDenEHEdtENOOOSRONOEDOEENERENOCEOOOON HOHUHOONDONEDEDOEDATONSHONEDOESRUNN ENS VeaeOeneuenanenenneveanosnnnseunonneensenenensnonnenneiennscunenan iene iisaesnoonen -. sa lit se ed a ee ors Pa Niners Te ela as a a is BP ll ll i an ait a eee December 3, 1925 hand. The empty boxes were replaced on the elevator and sent to the foundry ready for the night man to repeat the process. Our new system is simple, but highly efficient. An iron pan is used instead of a platform box. The night man takes the empty pan from the conveyor, using the electric lift truck, which is equipped with scales. The pan is loaded with sprues and gates and is returned Loaded Sprue Pan (Above) En- tering Cupola in Charging WERTH AENLesoenOOHEOeHCONOFE UNEASE EONNENORENEODOSENEDENEREOOOOORORORHARENDEHONOD to the conveyor. This work is done at the same piece work price as prevailed when the old method was in vogue. The outstanding fact is that the pan is not handled from the time that it is put on the conveyor until it is picked up by the charger and dumped into the cupola. Whenever it is necessary to secure scrap from the yard we run an empty pan on the conveyor to the scrap pile and load it there. We are also enabled to save considerable labor in handling our pig iron by our new method. Empty plates are placed on the conveyor and moved by hand to the pig iron storage yard, where the proper number of machine cast pigs are put on the plates to make up a charge. The plate is then passed over a scale, which is situated in the conveyor, to see if it contains the cor- rect weight. It is moved to a storage conveyor, from which it is picked up by the charger and unloaded in the cupola. This system makes it possible for us to handle the pig iron only once. Before we installed the charging hoist, which is the product of the P. H. & F. M. Roots Co., we em- ployed five men to charge the cupola. Three of them were employed on the charging floor, while the other two prepared the stock and brought it up to the ele- vator. Today three workmen instead ot five are suf- ficient to handle the work properly. One of them is on the charging floor, another operates the hoist, and Charging Pig Iron into Cupola. At left the loaded plate is ente ring : at right, been tripped and the load dropped THE IRON AGE 1515 the third is in the yard to hook up the hoist to the plates and the pans. Thus we are actually making a daily saving equivalent to the wages of two men. Mechanical charging has also secured daily heats of uniform iron. This is just as important as the labor saving feature. In fact, it probably amounts to as much, if not more, in dollars and cents, because regu- larly uniform iron is a major consideration. It means Sprue and Scrap Carrier After Being Tripped and Dropping Its Load into Cupola (Below) it has the elimination of the molder’s wasted time of rejected castings and of oxidized or sluggish iron. Aside from the economy of mechanical handling, as compared with the old method, we are satisfied be- cause we know that we have made a “skull-dragging” job easy and desirable. Any person who has gone onto the charging floor and thrown in pigs in August, when the thermometer is around 100 deg. Fahr. in the shade, will realize what we are accomplishing. Increase in Malleable Castings Production of malleable castings in October, as re- ported by the Department of Commerce, was the larg- est for more than a year. The output of 142 plants, of which five were idle, is given as 68,234 tons, com- pared with 58,573 tons in September and with 50,066 tons in October of last year. The production in Octo- ber represented 60.6 per cent of the capacity operated. This is the first time the figure has passed 60 per cent since March, 1924. Shipments in October at 59,657 tons were the larg- est since May. Orders booked during the month by 132 of the plants reached 65,495 tons, the largest total in 18 months. The gain over September in orders booked was 31 per cent. aste-Heat Boilers in Steel Mills Gas Volumes and Velocities Differ from Other Types of Boiler—Close Contact with Tubes Essential BY F. H. WILLCOX AND J. C. HAYES’ Y UCCESS with some recent installations of fire- s tube waste-heat boilers has revived interest in ‘ the recovery of heat from comparatively low- temperature waste gases. Experience continues to in- dicate that many accepted rules of boiler design for direct firing do not apply in waste-heat practice. Close to 70 per cent of the total heat absorbed in a direct fired standard water-tube boiler occurs in the first rows of tubes, exposed to the radiant heat of the furnace, ordinarily not more than 15 per cent of the total water- heating surface. For this reason one feature common to all successful types of direct-fired boilers is rapid and positive water circulation in the tubes thus exposed. In a boiler utilizing waste heat at 1200 deg. Fahr., the radiant heat available is less than one-tenth of that available in a direct-fired boiler where furnace temperatures of 2700 deg. or over prevail. Therefore rapid water circulation is not a prime requisite in the waste-heat boiler, but it is highly important that it accomplish maximum heat recovery by conduction and comparison is generally taken as the weight of gas in pounds per hour divided by the area of gas passage in square feet. But the draft loss varies as the square of the velocity, so that the boiler arrangement designed for attaining a high heat transfer must be compro- mised, to keep the friction loss within economical limits. Whereas the water-tube boiler at a given mass ve- locity and tube diameter has a higher heat transfer rate than the fire-tube type, nevertheless the friction loss in the fire-tube boiler is much less. Because of its low friction loss, the mass velocity may be raised in the fire-tube type of waste-heat boiler. Consequently the rate of heat transfer may be so increased as to exceed that obtained in the water-tube type, while keeping the friction loss the same. Figures published, comparing fire-tube and water- tube boilers on this basis assume always the heating surface on the gas side in both cases to be perfectly clean. The fire-tube boiler shows up to much better advaritage in practice, on account of the ease with General Arrangement of Waste-Heat Boiler at the Plant of the United Alloy Steel Co., Canton, Ohio. This is one of three sim- ilar units, 80 ft. apart. Instead of going directly \ ye ly from furnace to stack, the gases pass to right through wl) me ~~ 3 boiler to fan and then onvection Consequentiy, it must be arranged to pro duce the most intimate possible contact of gases and water-heating surface. It is essential that the waste gas pass as close to the heating surface as possible, and there must be a positive scrubbing or tumbling action. This can be brought about only by close tube spacing in the case of a water-tube boiler, or the use of small-diameter tubes in a fire-tube boiler. In either case it is neces sary to pass the gas at a velocity higher than usually is possible by natural draft alone. The velocities em- ployed are high enough to break up the definite stream lines along which the gas tends to flow and to prevent the formation of an insulating film of cool gas close to the heating surface, which otherwise would allow a hot center or core of gas to pass on without giving up its quota of heat. Draft Loss Must Be Kept Within Economical Limits Two most important requisites of proportioning boilers for a given amount and temperature of waste vases are high rate of heat transfer and low draft loss. Both depend on mass velocity, which for purposes of *Vice-president and mechanical engineer respectively Frevn Engineering Co., Chicag The paper was presented Ni 16 before the Western Society of Engineers, Chicag It is ere ghtly abridged each stack through the overhead inclined pipe which its heating surface may be maintained practi- cally free of dust deposits and of the difficulty of main- taining the water-tube boiler in the same condition. In direct-fired practice there is a definite advantage in a design that passes the products of combustion across the tubes substantially at right angles to their center lines, as in the vertically baffled horizontal straight-tube types. This advantage in direct-fired practice is largely discounted in waste-heat practice because much greater quantities of gas are passed per unit of heat transferred and a greater draft loss occurs for the same weight of gas passed per sq. ft. of gas passage area, imposing a correspondingly greater load on the exhaust fan. The net evaporation is substan- tially the same for either type of water-tube waste- heat boiler. While a number of water-tube boiler types have parallel flow over a large part of the heating sur- face, the flow at the entrance, cross-over and exit pas- sages is substantially at right angles to the tube cen- ter lines. This latter type is generaly baffled for two passes and has the lowest relative draft loss of any of the water-tube types. No practical combination of tube spacing and baf- fling of water tubes can possibly bring about as close a contact of the gas with the heating surfaces as is possible in a fire-tube boiler for the same draft loss. Obviously, where 2-in. tubes are used, none of the waste 1516 December 8, 1925 THE IRON AGE 1517 4 eavneneaneneiis vereecerenege \ & ~ x > = , x a es § . 4 Sw ON 3 . Sy ~ CS It Is Often Found Ad- F She3°0 ---640 --- > 60-7 OI vantageous to Install 4,4" S . . “_ IT- fz --S3 >| Superheaters in Con- | a7 - junction with Waste- Heat Boilers. These drawings show the gen- eral arrangement at c r f r ouperneare the Melrose Park plant — oder of the National Mal- a a, j leable & Steel Castings y | Co. At top is the plan; two elevations are be- - I low, and the relation of a.Lfxustitg Vanver , pulls Sp Ay fan to flue at bottom. ™ * Cy A superheater is used, nw ° . > as shown in three views . = 1 < $ “4 = . ' > 4 ICIIG ia . i : ” : § : cy \ | Y ee eee eeee, x oe secansfe o 0" . 3 +24 Perf aa