The Iron Age 1915-04-15: Vol 95 Iss 15

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MILLHOLLAND Now that the smoke of battle has lifted to some extent and the war over the merits of Bessemer, open hearth, and alloy steels have to some extent abated, it behooves the manufacturer to profit by the discussions of the controversy and to choose the materials that in his judgment are best adapted to his individual needs. The automobile manufacturer has placed the use of steel in a new light. Heretofore mechanical con- struction has been based on the minimum physical properties of materials used in the fabrication of the machine. Automobile manufacturers came face to face with difficulty at this point. If automobiles were designed and built on the basis of minimum physical properties of material, weight would reach such a degree that it would make motor cars almost an impossibility. In desperation the manufacturers appealed to the steel manufacturers for aid and they n turn called upon their metallurgists for a way out of the dilemma. AUTOMOBILE MAKERS ONCE ALLOY-STEEL MAD The result was the discovery of the virtues of certain metals and their remarkable effect on steel. Nickel, chromium and nickel, chromium alone, and finally the vanadium steels were developed. For a while then automobile manufacturers went alloy- steel mad. Everything imaginable was made of alloy steel. We can all remember the day when motor cars were considered the playthings of the ultra rich, and what made them so? Alloy steels for one thing. When you stop to consider that 60 per cent. of the total cost of a motor car is material and alloy steels are nearly 60 per cent. more costly than ordinary steels, it can be easily seen why the motor car used to be considered such an unattain- able luxury. Of course the sudden demand for high-grade steels naturally set up a wholesome business rivalry among the various steel makers. They gave their metallurgists every facility for bettering their prod- cts. Men of brains and shrewd reasoning powers concentrated their efforts on improving steel for motor car construction. It was out of this intense concentration and effort that the value of heat treat- ‘ng steel gradually rose into prominence. Without attempting to settle absolutely and uncompromis- ne ingly the superiority of alloy steels over the straight rights reserved by R. A. Millholland, who is heat £ engineer of the Lyons-Atlas Company, Indianapolis, or to the builders of the Atlas steam engines and now cturer of Diesel oi] engines and motor cars. The Ss observations are based on five years of experiment, and study. carbon steels, the writer merely desires to set forth what has been his experience in the past with all of the various steels used in modern manufacturing and the heat treatments that will develop the maximum physical and dynamic qualities of each individual steel. Particular stress will be laid on the steel best adapted to the various parts of mod ern machinery. The true purpose of this article is to demonstrate of what real value heat treatment is to steel with the ideal in view of using the most economical steel consistent with the duties required of a given part. Heat treatment is the key to the entire situation. In many cases cheaper grades of steel can be substituted in place of expensive alloy steels, simply by applying scientific heat treatment and commonsense. THE PROBLEMS OF HEAT-TREATED GEARS Up to within the last ten years the hardening of gears had been an almost unheard of operation. True, some forms of gears where accuracy and si- lence were not essential, were hardened, but as a general practice the hardening of steel gears was unknown. Since the advent of high-speed steel and the motor car, the practice of hardening all gears subject to wear has become a recognized practice in a variety of industries. Many manufacturers have plunged into the matter because they saw they must keep up with progress and their competitors. Nearly every steel company and every chemical car- bonizing compound manufacturer has put out litera- ture on the subject. Some steel makers have made valuable suggestions and some of the information passed out so freely by the carbonizing compound people is really of some value, but they all miss the mark, as all of us who are confronted with the modern heat treating problems are aware to our own discomfiture. In the first place, neither of the foregoing industries have even a speaking ac- quaintance, we might say, with gear making and hardening, and any information they get is usually second hand: nor can we censure them in any way for not furnishing us with specific information. Therefore, if we want information regarding gears we must do one of two things, go ask the other fel- low who makes them, and run the risk of being purposely misled or refused, or else experiment in- telligently and find out. TO THE BIT-ONCE-SHY-TWICE TRUTH SEEKERS As every man knows who ever heated a piece of steel red hot, there are no two heating furnaces 835 tO bye RII 5 eng ren Ny re te ee i = 836 that behave exactly alike; in fact, there is so much variation that if I were to start talking in numbers of degrees Fahrenheit or Centigrade there would be a number of us. bit-once-shy-twice seekers after truth who would stop reading right at this point in the article. So listen well to what I now say for my entire article from henceforth is based on this principle, which I find to be the only safeguard. I have discovered in my experience that before ever subjecting a finished gear to a trial heat, hoping against hope that it will come out in a usable condition, it is best to run a series of test pieces through the various operations through which you intend to run the gear. Yes, test pieces are the best means of checking up the correctness of the heats of your furnaces. Whether you have a pyrometer equipment or not, test pieces should always be run to tell you whether your pyrometers are reliable, and just what is the true condition of the steel you are using. The simple inoffending innocent scrap of steel that was cut off the end of your gear stock is more truthful than a furnace room full of pyrom- eters. In other words, the treatment of a given piece of steel should be governed by the behavior of the test piece cut from the bar. OIL-HARDENING GEARS Now let us get back to gears. There are two dis- tinct methods of producing hard gears. One method is commonly known as oil hardening, which really amounts to using a high-carbon alloy steel and heat- ing the gear to the hardening point and quenching the gear in oil. The gear becomes hard as the heart could wish, and in many cases answers very well. The other method is the case hardened or case car- bonized gear as some see fit to call it. This latter method is no doubt the better of the two; though more elaborate and costly, it has proved its supe- riority for heavy duty and strength combined with durability. Since we mentioned the oil-hardening method first, let us give it our first consideration. The steel used in oil hardening gears is usually an alloy steel, either chrome vanadium, chrome nickel, nickel or chrome steel. The carbon content varies from 0.40 to 0.80 per cent. and in a few cases 90 points carbon, depending on the hardness desired. In the chrome vanadium steel the chromium runs about 85 to 100 points, or chemically speaking from 0.85 to 1.00.per cent. The nickel-steel oil-hardening gears run in the neighborhood of 40 to 60 points of carbon and 314 to 5 per cent. nickel. Chrome nickel steel is much the same save that about 1 per cent. of chromium is added. The chrome steel gen- erally runs higher in carbon than the others; fre- quently it is found up to 90 points carbon. It is little used for gears, though in the writer’s opinion it has some admirable qualities where extreme hard- ness is desired. STOCK FOR MACHINING MUST BE ANNEALED The first rule to lay down in making hardened gears of any description whatsoever is: use an- nealed stock in machining the parts. Do not im- agine that because the tools will cut into the stock that it is annealed. This is especially applicable to drop forgings or even hand forgings. Anneal all drop forgings and hand forgings, and also all bar stock before attempting to machine. The metal has been disturbed by violence, and strains result that will show up ir hardening and cause the gears to come out warped and egg shaped if not properly annealed. The simplest way to relieve all forging strains is to heat the forging gently in a furnace up to a THE IRON AGE April 15 19); very soft low red (1400 to 1550 deg. F.). Whey thoroughly saturated with heat, allow the © irnag, to cool until the red is barely visible. Hold «+ th; iiS temperature for a considerable length of ti; erned of course by the size and weight of the fory. ings. Forgings weighing a pound or less «ap | removed after a half hour’s heating. Large forg. ings weighing 5 to 20 lb. are frequently held at ay annealing temperature for 3 to 5 hr. Allow the forgings to cool either in the furnace or in a place that is free from drafts. The writer has tried jy the past innumerable formulas, both secret and otherwise, for annealing these particular kinds of steel, and he has always found this method superior to any other. It is a copy, with a few modifications, of an eastern steel mill’s practice. » £OV- he SHARP CUTTING TOOLS AND THEN REANNEALING The next precaution to take and one the writer urges strongly to observe is: Don’t attempt to “hog out” the gear with dull tools. Keep the cutting tools sharp and free cutting and avoid heavy cuts on thin walls and sections. Between the roughing and fin- ishing operations it is best to reanneal the gear to relieve the strains set up by removing the skin from one side of the forging at a time. Steel, like cast iron, has a surface tension in its skin or scale, and it changes shape when that skin is disturbed. The skin acts as an envelope holding the steel under a perceptible compression, much similar in principle to the bands about a bale of cotton. Breakone band and distortion immediately occurs. Therefore, after the skin has been removed from the forging, reanneal. The second annealing process is much simpler than the first. It consists of heating the gear slowly to a very low red, approximately its hardening tem- perature, and allowing it to cool in the air. The metal adjusts itself to the new condition at a slightly lower temperature than those at which hardening takes place. The gear may then be finished and is ready for the final treatment, i. e., hardening. HEAT TREATMENT WITH THE TEST PIECE If the steel has been treated properly through the operation just described, the greatest difficulty is over and the ensuing treatment will be so simple that the results obtained are surprising. Here is where the test pieces will come into use, as follows: Select the portion of the furnace that has the most uniform temperature, for if you have a uniformly heating furnace you are a fortunate individual in- deed, and if you have a pyrometer which you are reasonably sure is reliable attempt to get the “fire end” as near the spot where you intend to harden the gear or gears. Raise the temperature of your furnace to full red heat (1550 deg. F.) and cast in your test piece and allow it to heat slowly until it attains the temperature of the furnace. Never de- pend on “catching it on a rising heat”; you will fail nine times out of ten. If the steel is chrome vanadium or straight chrome steel, this tempera- ture is ideal; for chrome nickel drop to 1500 deg. F., and for straight nickel drop to 1475 deg. F. After the test piece has soaked up all the heat it can, remove it quickly and quench in a light oil —fish oil, cottonseed oil or a very light automobile cylinder oil. Allow to grow cold in the oil. Why: One word answers that query, “cracks.” The steel is likely to crack, if the density of the cooling m™* dium is materially altered. Now draw the test piece to 360 deg. F. in an oil bath. This can be done very easily with the aid of the ordinary ™e™ cury thermometer. Do not trust an electric pyro™ eter for such low temperatures. When satisfied that 15, 1915 est piece is thoroughly heated, remove it and it to cool off in the air for a few moments hen check in coal oil. Sprinkling sawdust over ece and brushing it off again will absorb any ; of oil and kerosene and make the piece pre- le for inspection. ie next step is the fracture. For gears, the et test is no doubt the most logical. The pro- is as follows: Clamp the test piece in a vise and take a light sledge and commence ng regular blows upon the free end of the test i increasing the force gradually. If your test , : is over %4 in. thick and 1 in. wide, you will strike some pretty hard raps before the test piece breaks. Look then at the fracture; if there is a EDWARD NASH HURLEY A Manufacturer Member of the Federal Trade Commission It has been said that the man who makes his money in the country and spends it in the city is a farmer, but that one who acquires money in the city and spends the country is a mere horticulturist. At any rate, the saying is current in Wheaton, Ill, that neighbor Hurley as a farmer is an Al manufacturer of washing machines. Edward Nash Hurley, whom President Wil- son appointed vice-chairman ‘ the Federal Trade Com- mission, is more distinctly representative of manufac- turing interests than his as- wiates on that body. He been well known in the Middle West as president of Illinois Manufacturers’ \ssociation, a position he is w resigning to meet the re- lirements of his new duties. ivocation Mr. Hurley is gentleman farmer with a te for fancy livestock; by e of habit he is a com- ioner, be it to Panama, South America or at Wash- ngton; by inclination as well habit an _ everlasting In the capacity of a public vant Mr. Hurley made an nded trip through the Americas in 1914, a partial record of which may found in his report to the National Foreign Trade Con- tion held at Washington, C., May 27 and 28, 1914, and in his extended port on banking and credit in Argentina, Brazil, and Peru, which he prepared under the horization of Secretary of Commerce Redfield for Vepartment of Commerce. This latter report in ticular evidences a detailed study of commercial ‘tions, not alone in the countries of South America this country as well. Mr. Hurley was born at Galesburg, IIl., July 31, Having finished the public school course, he took railroading, becoming in time an engineer on the ago, Burlington & Quincy. In 1888 he became a eling salesman for the U. S. Metallic Packing Com- His service in that connection continued for years, in the latter part of which he was man- of the company. About that time Mr. Hurley ight to the stage of marketing a pneumatic drill, to promote its manufacture and sale he organized EDWARD THE IRON N. os we ) ~] AGE fine close grain that has no perceptible crystalline structure in the result, then the temperature is cor rect, provided, of course, that the test piece is the required hardness. You will generally find your test pieces to run 5 to 10 points higher on the sclero scope than the gear will run. If crystals appear in the test piece, try two more test pieces, one 25 deg higher and the other 25 deg. lower, and treat i: identically the manner that the first one was treated When you are thoroughly satisfied with the hard ness, strength and toughness of the test piece, then turn your attention toward the gears, following as closely as you can the treatment given the test piece that proved satisfactory. (To Be Continued) the Standard Pneumatic Tool Company, of which he was president and treasurer. This was in 1896. The Standard Pneumatic Tool Company continued its existence until 1902, when it was absorbed by the Chi cago Pneumatic Tool Company and Mr. Hurley re tired to his farm 25 miles west of Chicago, where he remained for two years without active business con nections. Later the Hurley Machine Company, of which he was the organizer and president, was formed to engage in the manutfa ture of electrically operated household appliances, par ticularly the electrically driven washing Mr. Hurley has been uni formly successful in his en terprises, the result of keen business intuition and untirz ing energy. He has a num ber of interests aside fron his own company and i president of the First Na tional Bank of Wheaton machine Change in Steel Jobbing Business The William J Walker Steel Company, Cleveland, Ohio, which has been incor of $20,000, will take over the business conducted under the same name by William J Walker, who died recenvly H. T. Bradley, formerly of Detroit, ha ated with the company as president and manager Other officers are James T Hunt of the Hunt & Dorman become associ HURLEY Mfg. Company, vice-presi dent, and F. D. Walker, sec retary and treasurer. G. S. Auer, of the Auer Register Company, is a director. The company will continue the jobbing business heretofore carried on in cold-rolled strip steel and flat wire, and in addition will handle grindi: g wheels. It is the intention to increase largely the volume of business, and larger quarters will probably be secured shortly when the lease expires of the quarters now occupied at 1722 Columbus road The Elyria Enameled Products Company, Elyria, Ohio, has been incorporated with a capital stock of $150,000 by Charles E. Wilson, John Murbach, C. E. lslanchard and others. The company proposes to take over the plant of the Enamel Pipe & Enginering Com pany, Elyria, which has been operating under a re ceivership. Its products include acid vats, pickling vats and various other receptacles. It is stated that several Pittsburgh men are associated with Elyria stock- holders in the new company. porated with a capital stock 838 POWER-PLANT OIL FILTER Heating To Facilitate Precipitation of Water and Vertical Filtering A new type of oil filter for power plants has been placed on the market by the Richardson- Phenix Company, Milwaukee, Wis. Advantage is taken of the fact that heated oil has less viscosity than a cooler one and is not so likely to retain water and solid particles in suspension. The oil flows at low velocity over shallow trays where the particles in suspension are precipitated and is afterward filtered before passing into the storage compartment. Special emphasis is laid upon the fact that the only part requiring cleaning are the filter cloths which. can be readily removed without interfering with the continuous operation of the filter. The body of the filter is constructed of No. 12 gauge galvanized sheet. steel reinforced by channel and angle irons, the joints being locked, riveted and soldered. The filter cloth is cleaned by lifting out a unit, setting it in a pan of kerosene and brushing with a stiff brush to remove the sediment collecting on the outside of the cloth. It is poiated out that it is sometimes advisable to remove the cloth from the filtering unit and wash it in gasoline or kerosene. In operation the dirty oil enters the filter through the strainer box a, passing down through removable strainer where large particles of foreign matter, such as waste, etc, are caught. The oil then passes to the heating tray directly underneath where its viscosity is lowered and then flows to the top compartment. It passes down through the funnel 6 and is spread out by the baffle under the bottom of the lowest tray. As the head in the con- ductor funnel increases the oil is forced to take a zigzag path, passing under and above the trays, as shown by the lines of flow. Then the oil passes out through the opening c to the filtering compart- ment. Drawing Showing the Arrangement of the . Precipitation, Fil- tering and Clean Oil Compartments THE IRON AGE April 15 915 The water which separates from the | lects in the bottom of the different trays «4 j, by-passed directly to the bottom of the pre: ipity- tion compartment through the channel surro. the main conduc- tor through n_/* which the oil flows into the fil- ter. In this way it does not come in contact with the traveling oil and is automat- ically ejected by a water overflow tube, d, which consists of two concentric pipes. The water flows upward through the outer tube and falls over the top of the funnel. This is threaded and can the be raised or low- ered to give the necessary adjustment for oils having different specific gravities. The water overflow operates on the principle of a U-tube, the column of water in the outer pipe balancing a column in the filter which is made up of oil and water. As oil is lighter than water, the top of the overflow is located at a slightly lower level than that of the oil in the precipitation compart- ment. With an increased precipitation of water from the oil, the water level in the precipitation compartment tends to rise and the leg of the U- tube which is inside the filter becomes heavier, due to the fact that the proportion of water in it is increased. This causes water to flow over the top of the funnel until the two legs of the U-tube again balance, this arrangement being re- lied upon to maintain the low water level of the precipitation compartment automatically. The skimmer e maintains the oil in the top tray at a constant level. From here it flows through the pipe ec into the filtering compartment which con- tains nine non-collapsible filtering units. The oil passes from the outside to the inside of the units and then out through the nozzles f which project through the wall of the filtering compart- ment to that in which the clean oil is stored. The nozzle on each filtering unit fits into a spring actuated valve so that any individual unit can be withdrawn and cleaned, it is emphasized, without interfering with the continuous operation of the filter. The withdrawal of a filtering unit is relied upon to close the valve associated with it instantly and thus prevent unfiltered oil from flowing into the clean oil compartment. One of the features upon which special em- phasis is laid is that the filtering cloth is arranged so as to be free from folds, thus making every portion active in filtering the oil. No oil can pass to the clean oil compartment until the level in the filtering compartment reaches that of the outlets /. In this way it is pointed out no filtering takes place until every square inch of the cloth is sub- merged in oil. As soon as a slight head builds up over the outlet, the process of filtration com- mences and is distributed over the entire surface, every portion of which is subjected to equal pressure. The filtering medium is a cloth that filters the oil largely by capillary action instead of serving as a screen. The placing of this cloth ing Y Elevation of the Chamber Showing Taken by the Oil That Is Being Filtered Cross-Sectional Precipitation Path 15, 1915 rtical position and having the oil pass from itside to the inside is an advantage, it is sized, as the slime and sediment collecting cloth, continually work toward the bottom rop off, thus automatically tending to keep irface clean. e head of oil over the filtering units is shown indicator at the top of the gauge g which show a level of approximately 3 in. when ter is being operated at its normal rating. A ter hight indicates that the oil is not passing rh the cloth as rapidly as it should and one re of the filtering units need cleaning. The rs are rated at a head of 3 in. above the filter- inits, although space is provided for carrying 6-in. head. In this way it is possible for the ter to handle short overloads of 100 per cent. as might occur if a large batch of oil were 1 Gauges are provided for showing the water el in the precipitation compartment which tuld be as low as is practical and the oil levels in the clean oil and filtering compartments, the ist of which should be kept filled with oil at all nes. Sheet metal guards with white enamel on he inside are placed in back of the gauge glasses vith a view to protecting the glass from break- age and also enabling the oil level to be seen at , distance. The cock on the fitting at the bottom f the clean oil level gauge provides a means for ling cans for hand oiling. Thermometers are provided for showing the temperature of the oil before it enters the precipitation compartment and also that of the oil in the storage compartment, and the engineer adjusts the quantity of heat to aintain the desired viscosity. Graphite and Strength of Castings The deleterious effects of graphite were emphasized Dr. J. E. Stead in a recent lecture in Birmingham, England, on “Some Scientific Features of Cast Iron.” He described graphite as the enemy of the foundryman and likened it to thin plates of mica which can be split along their cleavage planes with the utmost ease. He summarized the results of a large number of tests, indertaken with a view of ascertaining the influence graphite on the strength of castings, in the fol- owing table: Transverse Tenacity, iphite, per cent strength, cwt tons OD Cia ves cee eas oie eee 20.4 8.25 OU 00 Sei Ga ev adscbad hs ceuede 27. 13.24 to 2.55.... howe ee eka ae 31.9 14.54 PeTT TT eee Te ee 40.0 above 17.10 None, with 3 per cent. silicon. 91.0 $8.60 He deprecated the rule-of-thumb practice which has ed foundrymen to adopt a hostile attitude towards ypes or grades of pig iron with which they were un- ‘familiar, citing the case of some irons of superlative iality which were unsaleable and had to be reinserted ecause their fracture presented some unusual features. ‘le argued that any class of iron could be made to yield he results desired if only it were “mixed with brains”; hat even sulphur, sometimes considered the foundry- ‘S worst enemy, could be turned to useful account ntelligently handled. This element should rather be egarded as a friend, said Dr. Stead, because it pre- the carbide from parting with its graphite. eel plates coated with three different thicknesses ement immersed in sea water for three years near irydock at Mt. Hope, Canal Zone, Isthmus of Pana- show that the 1-in. did as well as the 1%-in., that of the coatings afforded sufficient protection to to insure the permanence of structures dependent uch protection; but that the life of such structures d be considerably prolonged by coating with cement ‘e in. thick. THE IRON AGE A New Special 5-in. Slotting Machine A new design of slotting machine having a stroke of 5 in. has been brought out by the Newton Machine Tool Works, Inc., Twenty-fourth and Vine streets, Philadelphia, Pa. The work that this ma chine was especially designed to handle is the finish ing of the breech mechanism on army rifles, al- though it can also be used for toolroom work where a high speed of the cutting bar, ranging from 30 to 120 strokes per min., is required The table measures 12 in. in diameter over the T-slots, while the over-all diameter is 3 in. greater Power feed is provided in all directions and is con trolled by a friction clutch For convenience in making duplicate parts a set of stops is furnished The in and out and the traverse is ll in. The hight under the frame is 9 traverse is 10 in cross A New Design of Slotting Machine with a 5-In. Stroke De signed Especialiy for Finishing the Breech Mechanism on Army Rifles and also for Toolroom Work Where from 3060 t« 120 Strokes per Min. of the Cutting Ram Are Required in. The cutting bar is provided with a relief tool apron and the maximum distance under the apron is 15 in. If desired, a turret tool holder and ram slide that can swivel to a maximum of 10 deg. on either side of the vertical position can be furnished. An Iron-Boron-Carbon-Copper Alloy An alloy that is practically non-corrosive and which, though hard and tough, may be rolled to sheet form or readily machined without being annealed, is covered by a patent recently issued to Edward D. Gleason, Brook lyn, N. Y., and assigned to the Neu-Metals & Process Company, Long Island City, N. Y. It is an alloy of iron, boron, carbon copper. The first incorporated in the copper so as to be in excess of the amount that will combine with copper. As the boron associates with iron as readily as silicon, regardless of the carbon content of the iron, the copper is thus caused to alloy with the iron and carbon, forming a homo- geneous mixture. By taking 80 parts of Bessemer scrap and fusing it in a furnace and adding 20 parts of copper containing boron in excess, an alloy is pro duced which may be cast in ordinary sand molds form ing castings homogeneous and easily machined. and boron is Studebaker Corporation Gray-Iron Foundry Arrangement of the Foundry at South Bend, Ind.—Methods of Handling Materials and Product—The Organization in Brief The Studebaker Corporation of America does at South Bend, Ind., all of the gray-iron foundry work for both the wagon and carriage works and for the Studebaker automobile plants at Detroit. The foundry is situated advantageously on the Grand Trunk Railroad about *4 mile from the main plants of the corporation. The location was chosen for its shipping facilities, together with liberal yard space and an opportunity to spread. The following inter- esting information concerning the design and opera- tion of the foundry has been obtained from R. L. Sackett of the Studebaker Corporation: The part of the foundry yard used for pig iron storage is divided into three parts by two spurs of standard gauge track connecting directly with the is given to the foreman in charge of th: pola loading floor by the superintendent. The erir tendent also determines the amount of steel and cast-iron scrap to be used. At the present time the plant is running about 65 tons daily, th handled very nicely by one cupola. Duplicate equi, ment is provided to guard against accident cupola. Several different qualities of iron are being ryy through the cupola daily, varying from soft gra, iron used in wagon hardware and some of the aut: mobile castings, to iron suitable for automobile cylinders. Information furnished by the chemica! laboratory from test specimens taken daily of differ. ent portions of the run has made it possible to get . Making Sand Molds for Cyli railroad through one of the yard gates. Industrial tracks run down the center of these divisions and lead to the elevator which feeds the cupola charging room. They have been built upon made land and are so graded as to require but little assistance to gravity in moving loaded cars of pig and scrap. The: unloaded cars can easily be moved up this gradient. The industrial railway cars are fitted with dust proof roller bearings, the trackage con- necting all parts of the foundry from the yard to the shipping room. All cars bearing charges for the cupola are weighed by passing over a track scale before run- ning onto the elevator to the cupola charging floors. The proportion of different kinds of pig, the analyses of which have been previously determined, nder C oh stings: Mold Dryer in Background almost exactly the desired analyses for the differen! classes of castings. Test bars are poured off dal) for the physical testing laboratory, which is ated at the foundry itself. Tensile strength and fracture are observed by the superintendent as an immediate guide. Chemical analysis serves to check up Hs conclusions when received later in the day. A check is thus maintained to remove the chanct question that castings made on a certain day Ww up to the engineer’s specifications. The foundry proper is divided into three mé floors. Automobile cylinders, crank cases, flywhee's, manifolds, transmission case covers, pistons, ® are made in the west bay. Wagon hardwar' and such miscellaneous castings as are used in building any special types of vehicles are made in the ce! tral Ost re 840 15, 1915 r Regular wagon boxes and skein work is car- n in the east bay, and the castings are made iding machines of Studebaker design. e western bay of the foundry, taking the most s near the coremaking department, which is in an adjacent building. Raw material is red to the north end of this department and is | into the various kinds of core sand mixtures next room south. The core makers occupy ext room, and the finished cores are taken on n cross tracks to cars on a depressed track , conveys the loaded cars to a point in the next . room south, opposite the ovens. The loaded core : ars are then run directly into the core ovens, no rehandling of cores or plates being necessary. Cores are stored after baking on the west side of the oven , room, and are delivered to the molders only in such juantities as the schedules on which the different s floors are running necessitate. ! On the second floor of the core making depart- . ment are numbers of girls who make light cores. A small elevator running as a dumb waiter conveys sand to this floor and returns the finished cores to the floor below where they are baked. The distribu- tion of sand, plates and all other heavy work is taken are of by a laborer who serves this department. Suitable rest and toilet rooms are provided so that it is not necessary for the help employed in this de partment to enter the factory proper. Adjacent to the core ovens but facing into the bay in which the automobile castings are made, are three large ovens which are used for drying out dry sand molds. A large amount of this work is being done in connection with automobile cylinders and crank cases. Ovens are loaded in the afternoon and part of the morning, heated at night and un- loaded the following morning. In the southern end of the west bay are located the pattern shop and pattern storage rooms. The foundry office, which covers the office of the superintendent, his assistant and the clerical force, s located on the passage way between the western and central bays of the plant about equidistant from points these men have to visit often. The air is turned on the cupola about 1:30 p.m. and the blast is left on until about 4:30. The mold ers pour their own floors in team with their helper, or in two teams on large work, or singly as the case may require, and in every case where possible when through pouring they shake out their own floor and pile their flasks and follow boards. Such castings as cannot be shaken out at once are taken care of the night by a force of men, who shake out molds, pile flasks, wet down and temper sand, etc., prepara- tory to the next day’s work. All castings from each floor are piled adjacent to the industrial railway tracks from which point they re placed on cars and taken to the rattler, if small istings, and to the sand blast room if they are astings which cannot be handled in a tumbling rrel. These men take return car loads of sprues, rates, ete., from the cleaning room to the cupola arging floor, first weighing them in as described. After castings have passed through the cleaning cess and have been inspected for superficial de- ts they are placed on the industrial cars and con- ed to the store room from which point they are pped to Detroit or other points in carload lots, ide up according to schedules. The shipping and rage facilities are excellent, so that it is possible run the toundry on what is found to be the most nomical quantities. The freight cars are backed rectly into the store room and loaded under cover. iis also is a big advantage, as a number of the ‘stings have to have special treatment or inspec- THE IRON AGE 841 tion, such as automobile cylinders, which are given a thorough water test before shipping. Owing to the volume of business and a large variety of sizes and types of skeins and boxes for the wagon trade, a large stock of these parts is carried as a protection that immediate shipments can be made of a reason able quantity of any size or style. Adjacent to the store house and feeding into the portion in which skeins and boxes are stored, is a room in which such machine work is done as turn ing and threading the ends, tapping the nuts, etc The general supervision of the foundry organiza tion is taken by the superintendent. The only other portion of the work to which he gives his personal attention and with which he will trust with no one else, is furnishing the charging-floor foreman the data for his daily run of metal and employing and discharging the help. Directly under the superin tendent is his assistant. The various foremen of the different departments, such as core making, clean ing, automobile castings, box and skein castings, skein machining, stock room, shipping, pattern shop, vard and labor, report directly to the superinten dent, who is thereby kept in touch with the condi tions in all parts of the plant at all times. Each foreman is given a book containing a schedule of the production which is, expected from his particu lar department, the number of men that it is ex pected this production will be obtained with and the prices which may be paid for the different jobs The planning is done for them as far as determining what shall be made and how many; this enables them to devote their entire attention to the problems of production itself. In addition to this a record is kept of the amount of controllable expense in curred by each department monthly. This report enables the superintendent to check and stop many leaks. Nickel-Plating Aluminum The successful nickel-plating of aluminum is an nounced by M. Le Chatelier in a recent communication to the Académie des Sciences. This has not been accom ulished heretofore by ordinary methods. The new proc ess consists in a preliminary scouring of the aluminum in a bath of hydrochloric acid containing a certain por- tion of iron. The iron is precipitated on the surface of the aluminum forming a kind of network. When this is passed into a nickel bath the nickel becomes en- tangled in this network and adheres strongly to the aluminum. This process is based on a physical action and appears to solve the problem, hitherto considered impossible. The Structure of Carbon Tool Steel How Its Qualities Proper Crystalline Refinement—Causes and Remedies BY J. Some time ago the author bought a pocket knife from a large hardware firm. He paid enough for it to insure, as he thought, a good knife. After trial, he discovered that one of the blades was so brittle that large pieces could be broken out of it with the thumb nail, Upon returning it, the knife was at once replaced with another similar in appearance and of the same make. One of the blades of this knife was so soft that it could be bent over at right angles without breaking. The knife being replaced a second time, he received one that has been the best that he has ever carried. An examination of the two defective knives re- vealed that the first had a structure similar to Fig. 1, the long coarse lines of which greatly weaken the steel. The second knife, with the soft blade, had a structure similar to Fig. 2, in which the carbon is all in the form of graphite, serving no useful purpose. This structure is almost exactly like that of ’*hotomicrographs of Carbon Tool Steel Fig Caused by Defective Heat Treatment Depend Upon of Ordinary Defects Vv. EMMONS and forged or rolled to a block, plate or bar, accord ing to the purpose for which the steel is intended This working, which is usually at a lower tempera ture than the previous one, results in a still greater refining of the grain size. The steel is now in the form in which it is re ceived by the tool maker, but before it can be ma- chined, the structure must be still further refined in order to give it softness and put it in proper condi- tion for hardening. This is accomplished by a care- fully regulated annealing. This annealing consists of heating the steel to a temperature above its critical point, usually about 1450 deg. F., and cooling very slowly. This treatment breaks up the coarse network which has been such a prominent feature of the several stages shown before, and substitutes a very fine granular structure like Fig. 4 in its place. Steel in this condition is now ready for machin- 1 Shows the Structure of a Brittle Knife Blade and Fig. 2 of a Soft Blade, Both Fig. 3 is the Proper Structure of Correctly Treated Carbon Tool Steel. Fig. 4 Reveals the Proper Crystalline Condition of Carbon Tool Steel Before Hardening or in the Condition of the Annealed Blocks or Bars malleable cast iron. The good blade has not been examined, but it undoubtedly has a structure like Fig. 3, in which the fine uniform condition shows clearly the quality of the material. Yet these three knives, under ordinary examination, appeared ex- actly the same. Furthermore, the chemical analysis of each is undoubtedly similar, the difference in quality being purely a matter of the different ar- rangement of the various chemical constituents, or in other words, the structure. Tool steel ordinarily contains from 0.60 per cent. to 1.75 per cent. carbon. The principal constituents of hardened tool steel are martensite and cementite. Hardened and tempered tool steel contains two other constituents, troostite and sorbite, which are softer and tougher than the martensite from which they are derived by tempering, but still much harder than pearlite. The process of manufacture of a tool steel product is one of refinement of structure. In the steel mill the ingots are first inspected, graded and the pipe in the top broken off and discarded, then reheated and hammered or rolled to a billet. This hot working breaks up the coarse crystals and refines the structure very appreciably. In the struc- ture of a high carbon billet the grain size is still large, but much superior to that of the ingot as cast. REFINING THE STRUCTURE After the billets have had the surface imperfec- tions chipped or ground out, they are again reheated *From a paper presented before the Cleveland (Ohio) Engineering Society and printed in the society’s March Jour- nal. The author is metallurgical engineer of the Cleveland Twist Drill Company ing and hardening. The last stage in the series of re- fining processes ishardening. The principal structural changes which take place on hardening are the change of pearlite to martensite, the absorption of all ferrite present, the absorption of part of the free cementite and the breaking up of the remainder into smaller sized particles. In the case of a low carbon steel, these changes produce on amorphous mass of martensite in which even the highest powers of the microscope find it difficult to distinguish a structure. In a high carbon steel, the martensite mass is thickly dotted with small particles 0! cementite. The final heat treatment of drawing the temper results in a change of a portion of the martensite to trootsite and sorbite, toughening the tool and re- ducing its hardness, but not affecting the degree 0! refinement. This structure is the one which will be present in all high grade tools which have been properly hardened. In the preceding series of operations for the re- fining of the structure of tool steel from the ingot to the finished tool, each operation may be assumed to have been perfectly done. In the manufacture 0! tool steel products on a large scale, there is oppor- tunity at every turn for defects to creep into the steel and all unseen by the ordinary eye remain to undo the work of the most skilled mechanics. The microscope has been shown to be by far the most useful means of tracing these hidden flaws to their true source. It also, in many cases, points out the cure or the means of eliminating the harmful! con- dition. 842 | 15, 1915 DEFECTS IN TOOL STEEL fects in tool steel may be divided into three e which originate in the casting and hot work- rations of the steel mill. se resulting from annealing. se resulting from hardening. Defects—In the mill, the first structural which may occur in tool steel is the forma- f a pipe or shrinkage cavity in the center of vot. This pipe may be closed over at the top ingot and so not being discovered, rolled down finished bar. In the absence of proper in- tion, it may even progress as far as the harden- peration unsuspected. There it makes its pres- ence known by splitting the tool open along its entire length as soon as it is cooled in the quenching bath. Laps, seams and bursts are other defects caused ‘) the mill and are usually visible to the naked eye. Fig. 5 shows a slight seam which has become a still more serious defect through decarbonization. Segregation of the carbon is a defect which weurs in the mill, either by prolonged soaking in the reheating furnaces or insufficient hot work. The arbon in the form of cementite instead of being uniformly distributed through the steel, becomes collected in large groups or masses. These masses, as the steel is rolled out in the form of bars, are drawn into long streaks or strings which are a To serious form of weakness in the steel. Fig. 6 shows a cross section and a longitudinal section of a bar showing this segregation. loo high temperature of finishing under the rolls or hammers may leave the steel in too coarse a con- dition to be refined by any ordinary annealing or hardening methods. This is one of the commonest defects in steel as it comes from the mill. Steel in this condition, Fig. 7, will harden with a coarse rystalline fracture and will be liable to firecrack. Annealing Defects.—The annealing of tool steel is sometimes done by the mill and sometimes by the ? too] 1 manufacturer. If the heat is not sufficiently gh, or if the time is not long enough, the coarse structure will be incompletely broken up, with a result like Fig. 8. This would make a tool very ely to chip and of poor wearing quality. A very serious defect, which is sometimes caused annealing, is the formation of graphitic carbon. s condition is produced by a prolonged annealing w temperatures. The carbon is thrown entirely combination with the iron and assumes the of graphite. When this change has taken the tool steel is no longer steel, but a very ellent grade of cast iron. Hardening Defects—In considering the defects may be due to hardening, we should not vet that too often the hardener gets the blame all the mistakes which may have been made on steel before he gets it. The most common de- due to hardening, is overheat. When a piece perfectly annealed steel is overheated, the coarse r ice tomicrographs of Defective Carbon Tool Steel. Fig. 5 Shows a Slight Seam Rendered More g. § Shows Both the Cross and Longitudinal Section of Segregated Carbon in Tool Stee! High a Temperature in Finishing Under the Rolls or Hammers Fig. 8 Reveals the of Insufficient Temperature or Time in Annealing THE IRON AGE 8435 crystalline structure which the steel mill has gone to such great trouble to break up, is again given a chance to grow. The larger this structure is al lowed to become, the greater the damage done to the steel. A few minutes’ carelessness by a hardener may thus undo many days’ work of a careful steel maker. Underheat in hardening, of course, results in a soft tool with little change of structure. Un- even heating and heating for too short time result in uneven hardening with great danger of fire cracking. Heating for too short or too long a time may also cause distortion of the tool. DECARBONIZATION OF THE SURFACE One of the commonest defects in tool steel has not been classified above, because it may occur at any time the steel is heated above its critical point. This is the decarbonization of the exposed surface which is commonly known as the bark or skin on tool steel. This defect is present to a greater or less extent on all tool steel and must be removed by machining. It is caused by the exposure of the steel to the air or other oxidizing conditions while heated to a high temperature. The result is the removal of the carbon from the surface and often penetrating to a considerable depth. Taking for ex ample in a 1.25 per cent. carbon steel, the outside of the steel has been reduced to pure iron. Below this is a band of steel or low carbon, then a band of Defective by Decarbonizat Fig. 7 Shows Coarseness Caused Incompletel Broken up Sti steel of about 0.80 per cent. carbon, then the 1.25 per cent. carbon of the interior. This bark or de carbonized surface, if not completely removed, will result in soft spots and poor cutting qualities in the hardened tool. These structural defects are, with a few excep- tions, not visible to the naked eye, yet upon their successful prevention depends the quality of the tool. A finished tool containing such a defect might be likened to a bridge which, perfect in every other detail, is built upon an unsafe pier. The entire structure may be instantly destroyed through the failure of a single member. In the production of finished tools on a large scale, the most constant vigilance is necessary in both inspection of raw material and regulation of heat treatment, to insure that none but tools with a perfect structure may reach the customer. Even those that make and temper a few tools for their own use, find that inspection of the raw material and regulation of their heat treatments, repays many times its cost in the production of tools of increased efficiency. T