The Iron Age 1914-05-28: Vol 93 Iss 22

*UPPUUUNDEUOEUERENT EC ONE ONO OOREO EEO DEO ORG ED EEODEODDONN NICS POEEYUCUOUOLUEOODAREOOUUUUUUTUUODEOOUOU TD PEEEDER ETE E TOUTE SUE EEL The Reclaiming of Waste Foundry Sand What Experiments at Detroit Have Shown with Regard to the Possibilities of Utiliz- ing Material Looked Upon as Refuse A vear or two ago the railroads advanced the a hydraulic classifier, a dry ck ny macnine ana rate of outgoing foundry refuse from the Detroit a system of elevators, chutes, spouts, district, and this made it desirable for the foun- handling the material. drymen to find a method of using as much of the The general arrangement of the plant and some old sand as possible. Experiments had already of the equipment is indicated in the accompanying been run in different parts of the country using illustrations. Fig. 1 shows the base of the ele different types of machinery. They had been more vator tower and the bottom section of the dry or less successful but the experiments had also cleaner. This was also arranged to act as a drye proved that the local conditions governed the for removing a small percentage of moisture fron practice to a larger extent than generally understood. the sand, to fit the material for dry cleaning. The A co-operative ar- elevator boot shown at rangement was finally made in accordance with which a number of man- ufacturers of equipment loaned the necessary ma- chinery and a group of foundrymen were to de- fray the expenses of the tests. An experimental plant was put in in con- nection with the labora- tory of the H. M. Lane Company, Detroit, as this laboratory was centrally located, both for work in the city of Detroit and for rail shipments. The following are some of the firms that supplied appa- ratus: Standard Sand & Machine Company, Cleve- land, supplied a paddle type batch mixer, a ham- mer crusher for crushing old cores, a roll blending machine for re-bonding et for the left received material! for delivery to any one of the machines, the flow of the material being controlled by pipes and chutes extending fron the top ofl the tower, which was something over 40 ft. high On some of the tests a spe cial riddle was fitted up for feeding the material directly into the boot of the elevator Fig. 2 shows a bin in the second story of the main laboratory arranged to receive sand from the elevator. At the right of this is the Osborn wash ing barrel with a series of pipes leading to set tling tanks in the sand cleaning building proper Fig. 3 is a general view of the sand cleaning Sand and a centrifugal room. In the center i mill for disintegrating Wee. hc Silt ot Miimintine tone Cieiiiae Gane ts ene the Dorr washer. Beyond sand; the Knickerbocker “Together with Base of Dry Cleaning Tower the Dorr washer may be vompany, Jackson, Mich., seen the blower which loaned a dust arrester; the American Blower Com- served as an exhauster for the dry cleaner. Over pany, a blower; the Wadsworth Core Machine & the Dorr machine can be seen the cone at the bot Equipment Company, Akron, Ohio, two pan type tom of the dust separator which was used for re roller mills (one was a small experimental mill moving the dust from the air exhausted from the and the other a three-foot mill); the Osborn Mfg. dry cleaner. The dust flowed from the trap Company, Cleveland, supplied one of the Osborn through an inclined pipe and was either caught Washing barrels; Dorr Cyanide Machinery Com- in wheel-barrows or allowed to accumulate on the pany, New York City, furnished a Dorr washer. floor. At the left can be seen some of the parts Later some slight changes were made in this dur- of the hydraulic classifier and some of the settling ing the progress of the tests to adapt it to the tanks. Fig. 4 shows the centrifugal core crusher work. Considerable material was gotten out un- and the roll blending machine supplied by the der the supervision of H. M. Lane, which included Standard Sand & Machine Company. 1315 Established 1855 New York, May 28, 1914 Vol. 93: No. 22 TRE re re manners ee Soha Pcs Mant! Ae " od N 1316 THE IRON AGE Ma) 1914 : Sand was tested for the following firms: Amer- some exteni, the characier of the orj ican Blower Company, Michigan Steel Castings sand used. Company, Detroit Steel Castings Company, Mon- The universal opinion expressed arch Steel Castings Company, Aluminum Castings steel foundries for whom testing has bh Company, Packard Motor Car Company, Michigan that the wet cleaned sand is fully as ¢ Malleable Iron Company, American Car & Foun- Silica sand and that for some work the dry Company, Russel Wheel & Foundry Company, sand is almost as good as new silica s Ford Motor Company, Detroit Foundry Company, As regards the gray iron foundry, Fairview Foundry Company, and the Cadillac Mo- different set of conditions is found. W tor Car Company, all of Detroit, the Michigan Mo- coarse gravel or sand is employed in n tor Castings Company, Flint, Mich., Central Foun cores with pitch compound or flour, th dry Company, Holt, Ala., and the Pressed Steel ing process removes sufficient of the fi Car Company, Pittsburgh. A number of other from the sand and returns a product w! firms have shown an interest in the tests. as efficient in making cores as the o1 The resulta of the teste may be atated brief sand. This is also true where glutri: as follows: The use that can be made of foundry 2% core binder, provided some clay wa sand depends upon the character of tne original ing Sand be used in the mix. sand used, the cnaracter oa binder used and For oil a nd cores made from an ' . : Cases rneé > SePACO? r 7 ce St the stvle of work that. is being turned out. In SES where no seacoal or coke dust ’ : . ; . °7 11Y } ay’ F rYrayv ir F ‘ea ‘ e Ye? steel castings plants where silica sand is em number of gray om foundries hay oe Ey ce a cellent results with wet cleaned sand ployed, a good recovery can be had 0D elitnel the s 5 ilies a have had good results from the dry cle wet or dry process. However, with sand from t} liti li le : : 1e conditions depending more or iess some foundries, the practice had to be varied e acter of the original sand. For pitch cores or dextrin cores for automobile dry cleaning process gives excellent resul! Where very fine sands are employe: the dry or wet process removes the car! ciently to give a high binding ratio fo cores. For brass or aluminum work with } dextrin or flour as a binder, the dry cleaning p: ess returns an excellent product. In all of the experiments the sand coming f: the gangway and cleaning room was, as a genera little choice either as to original cost or cost of rule, put through the machine together regardless operation between the wet and dry processes. The of whether it was molding or core sand. governing features are local conditions, the char- A number of experiments were run in whic! acter of the sand as it leaves the foundry and, to the cleaned sand was made into molding sai 1: } slightly in accordance with the condition in which the sand left the casting cleaning floo1 The dry cleaning process takes less plant in- stallation, but more power for its operation. The cost per ton, however, will be less in the wet process, as far as the cleaning is concerned, but where the sand has to be used again at once it is necessary to install drying machinery, which in- creases the cost per ton and thus of operation to such an extent that in most cases there is very Fig. 2—Osborn Washing Barrel for Washing Core Sand 1914 THE IRON AGE 1317 ndries where a rather fine grade of core’ In fact, the cleaning of the sand removes the pe ised, all of the material from the cleaning bles which have been reduced to dust owing to nd gangways was dry cleaned and then re exposure to heat with clay, the bond being rolled into the The tests indicate that each plant will have to with a roll blending machine. In the be designed to fit the special foundry requirements xperiment considerable difficulty was en encountered in the different plants, but that once tered in getting a suitable clay, but a good these conditions have been taken into considera samples were made which gave excellent re- tion, good returns can be expected from sand the sand heap, and it is undoubtedly true cleaning. There are a few types of cores the sand the case of many foundries the waste prod- from which is not worth cleaning. In some parts be utilized to better advantage as molding of the country 50 to 75 per cent of the material n in any other way. This also opens up used is limestone pebbles. This material cannot lity of making a mixture of cleaned sand be cleaned satisfactorily and it is probable that al bank sand bonded for use as a molding apparatus for either the wet process of cleaning very expensive. For asses of work it has und possible to design e machine for crushing res and re-using the which they contain. side of an account sed of two items, first, new sand, and sec- expense involved in f old sand. In the cases sand can be for less than it can be from the plant and to the dump, and this at the sand is cleaned ng or for a very few ton and is just as effi- ewly purchased sand. t Fig ‘—Core Crushing Machine nd Roll Blending Machine for Using Old Products S. DIESCHER & SONS Mechanicai and Civil Engineers, PITTSBURGH, PA. « Oi oe “2% ee ae ee pa ON i AO me LO ~ ae > 1318 THE IRON AGE May 28, 1914 some other local types of sand may give trouble. In a plant where oil sand cores are being made it will frequently be found advantageous to subject local bank sand to washing so as to remove the loam and reduce the percentage of oil necessary to make good cores. The magnitude of the waste sand problem in the United States is not appreciated by most foun- drymen nor is the advantage in conserving the core and molding sand resources. Such plants as the Commonwealth Steel Company and the Amer- ican Steel Foundrles at Granite City, Ill., Mr. Lane mentions, ship out as much as 200 tons of waste foundry sand per day when the plant is running full. When the foundries in Detroit are operating at the maximum capacity there are some 65 cars of outgoing refuse daily. Of this material, 80 to 92 per cent can usually be recovered and returned to the foundryman in a condition in which it is just as efficient as new sand. This means that a foundry would not have to maintain as many bins for the storage of their winter supply and they would not be as dependant as they are at present upon shipping conditions. Scarcely any foundries are too small to consider the problem, Mr. Lane emphasizes, and no plant which does much core work and melts over 12 or 15 tons per day can afford not to give it consideration. A New Heavy Service Shaping Machine The American Tool Works Company, Cincin- nati, Ohio, has brought out a new shaping ma- chine designed especially for heavy service. An ‘effort has been made to combine ample power, rigidity and a wide range or cutting speeds. Among the features are an improved design of ram and rocker arm, a new type automatic and variable cross feed and a new speed box. The column is deep and wide, with internal bracing and tapers slightly toward the top. A wide deep rib cast integral with the wall provides rein- A Recently Designed Shaping Machine Intended for Heavy Service forcing on the outside, and the top of the column pojects both front and rear, to give a long bear- ing for the ram. The base is of pan construction, both inside and out, to catch the oil drippings, thus protecting the floor and foundation, and means are provided for draining off the oil which is collected on the inside. The table support, which is of an entirely new design, consists of a notched bar supplied with an adjustable nut at the bottom, and is operated throughout the full traverse of the notches are spaced 1 in. apart and are ’ a spring plunger after the rail has be: ite any further adjustment being accomplis| ' the nut at the bottom of the notched . bears on the planed surface of the ba In se. way, it is pointed out, a rigid and eae Rear of the Machine with the Cover Plate Removed to Show Ram Driving Mechanism port is secured, and at the same time the rail is relieved of the weight of the table and the work. The ram and the rocker arm are of an im- proved design, the latter being rigidly connected to a pivot shaft at the bottom of the column which supports all the weight of the arm and the other parts. The connection between the rocker arm and the ram is by a double link, which is arranged to pull down on the ram during the cutting stroke, thus tending to neutralize the upward thrust of the tool. The rocker arm is a complete U-section for its entire length, and is reinforced by heav transverse and cross ribs. The ram is heavy and is reinforced by internal ribs. The length of stroke can be changed at will, without stopping the ma- chine, as the device for positioning the stroke located on the ram near the head and can be oper- ated while the machine is running. The speed box is a complete unit which can be easily interchanged with cone pulley drive units, so that a cone pulley driven machine can be changed over to a speed box drive after shipment and vice versa. Four speed changes are provided, and — are doubled by the back gear drive, so that a to range of from 6.5 to 90 strokes per min. is pro vided. The changes are accomplished while th machine is running by seven heat-treated steel gears and two operating levers, which are Col veniently located. “A The head can be operated at any angle within an are of 100 deg., and can be easily locked in pos tion. The down slide has a continuous taper £!' having end screw adjustment for taking up wea! The down feed is of unusual length, and the scre¥ has an adjustable graduated collar reading to "." i in. A large tool post is supplied for using holders with inserted bits. The cross feed is Tee : and variable and has 32 changes from 0.006 in. Pe’ stroke of the ram upward. A conveniently ere knurled knob enables the feed to be chang ed ete the machine is running. A fiber adjustable oA tion serves as a safety device between the ‘ mechanism and the cross-feed screw. 1914 M: ms New Floor Type of Grinding Wheel Stand Norton Company, Worcester, Mass., has ut a new design of floor type of grinding ind, equipped with special protection and ds. It represents a product of the com- <perience in the use of its grinding wheels types of floor stands now on the market, lesigner has apparently endeavored to in- te into it every feature that will help to ob- iter production and give longer life to the nd the machine itself. Particular attention paid to its general appearance, as indi- its freedom from sharp corners, overed bolts and to provision against too t replacements by increasing the weight and ne large sized spindles and chilled work recesses ough the foundation space occupied by the » is small, it is emphasized that its weight dity permit of overhang of the bearing bed, gives the operator footroom. The portion spindle outside the bearings has been made igh to take taper wheels, having a taper of in. per ft., which have the same face width s the maximum width of straight wheels. The in- ie flanges are fitted loosely on the spindle and are 1 by a key, which it is pointed out makes removal a simple matter. Taper flanges can also e used on these machines if the hole is of the per size, by cutting a spline in the hole of the flange to fit the square key in the spindle. [fhe underside of the overhanging bearing bed machined seat and T-slots, in which bolts are laced to secure work rest brackets, protection ods and surface grinding attachments. All of the tachments are independent and interchangeable ind may be attached or removed quickly. Where ge work has to be ground, and it is necessary to ve the work rest, the work rest bracket can be taken away. The upper surface of the work is chilled, which is relied upon to give longer and has been increased in size to give support r large and heavy work. A belt guard, which en- les any angle from the vertical from 45 deg. to secured, extends 2 in. above the top line of the mum size of wheels. In addition to affording tection to the operator, this also guards the belt en long pieces are being ground on the surface ding attachment. \ specially designed protection and dust hood provided, which is relied upon to guard not only injury in case of accident to the wheel but when the hood is connected with some suitable removal system, against injury to the health. sed hood consists essentially of a heavy band r plate and two heads or side plates which ind about five-sixths of the wheel, leaving a opening. A heavy steel slide which provides ment for wheel wear travels in grooves which entric to the spindle center. This type of vers the end of the spindle, thus preventing dent due to clothing becoming caught in the { the spindle while through the employment ecial lock nut the outer head or side plate is emoved to permit the wheels being changed. ddition to this type of hood, the company placing on the market one adaptable to any floor stand conforming to the general con- the Norton stands. The hood is adjustable the wheel, permitting the grinding to be done it the front or at the bottom of the wheel, necessary for the purchaser to provide a to which the inner head holding the entire may be attached. Both of these heads nged for connection to a dust exhaust pipe. THE IRON AGE 1319 In the hood which is supplied with the machine the bracket supporting the hood serves also as a dust exhaust pipe, while in the other hood the bracket is solid, as is also the inner head, and the exhaust pipe is located on the boiler plate band. \ Recent Developed Grinding Whe Stand of the |! type Equipped witl New Design of Protective Hoo The exhaust pipe is mounted on a steel plate of the same radius as the band and is firmly bolted to it, the opening being cut at any desired point Programme of Supply and Machinery Dealers The programme for the ninth annual convention of the National Supply and Machinery Dealers’ tion, which meets in conjunction with the American Supply and Machinery Manufacturers’ Association at White Sulphur Springs, W. Va., June 15, 16 and 17, is briefly as follows Monday, June 15, 10.30 a. m. nual address of President dler & Farquhar Company, Boston, Secretary-Treasurer Thomas A. ecutive committee. Monday, 2.30 p. m.—Joint session with the Ameri can Supply and Machinery Manufacturers’ Association; addresses by well known speakers on topics of national A ssocia- Upen session. An Charles S. Farquhar, Chan Mass.; reports of Fernley and of the ex importance to dealers and manufacturers. Tuesday, June 16, 10 a. m.—Executive session. Re port of the treasurer and of the committee on the cost of distributing mill supplies and discussions on cash discounts, association work, direct shipments, stock and cost records, standardization of records and other sub- jects of interest to machinery dealers. Wednesday, June 17, 10.30 a. m.—Executive New business, election and installation of officers, ex pressions “ preference regarding place of next con adjournment of business sessions. On Tuesday afternoon there will be no either body, ences on matters of individual busine sessior vention, final session of which will allow time for private confer concern. Enter tainment features have been arranged for each evening and Wednesday afternoon. The National Association of Corporation Schools will hold its second convention in Philadelphia, June 9, 10, 11 and 12. The association was organized in New York, January 24, 1913, “to aid corporations in the edu- cation of their employees, (1) by providing a forum for the interchange of ideas and (2) by collecting, and mak- ing available, data as to successful and unsuccessful plans in educating employees.” Arthur Williams, New York Edison Company, is president. The membership approaches 150 in all classes, covering 32 different in- dustries. The W. M. Pattison Supply Company, Cleveland, Ohio, dealer in machinery and supplies, has increased its capital stock from $150,000 to $500,000. The com- pany plans to erect a new storeroom and warehouse on Rockwell avenue near East Sixth street. —— de See ees - Fue) a... AP 5 oe ree tegen ao map eegaedtengies or o SREt > a ~ as mmrrenrs * — ep eee oy 22 es “ft ce, Re Heat Treatment in the Steel Wire Industry What It Contributes to the Production of High Grade Materials—Details of the Ad- vanced Practice the Laboratory Has Given BY JOHN F. The use in the wire industry of heat treatments in the broad definition of the term is very old. In fact, the development of the wire business has been due primarily to an early appreciation and applica- tion of such fundamental heat treatment processes as annealing, hardening and tempering. In the manufacture of wire, heat treatments take not merely an important position but an indispen- sable one, with a scope of application far broader perhaps than in any other branch of the steel in- dustry. This is, of course, to be expected, not only because of the multiplicity of uses under the most exacting requirements of service to which the enor- mous tonnage of wire is put, and not only because of the extremely small individual parts manufac- tured from wire, but also because of the extraor- dinary amount of work required in reducing steel from the ingot, in which it is orignally cast, to the comparatively small section of the finished wire. A better appreciation of the latter fact may be had TINSLEY* thus making the steel ductile and soft. for this purpose covers principally th wires, those with carbon 0.25 per cent 2. To refine grain—applied principally to carbon rods and wires, those with car! cent. and over. 3. To obtain definite sj the finished material—applied principa higher carbon wires, those with carl cent. and over. REMOVING THE EFFECTS OF COLD \ The first class of annealing to be describe: low carbon steel which, under the microscoy. a structure consisting chiefly of a mass of iron interspersed with dark patches. Thes patches contain practically all of the carbon steel in the form of iron carbide. Fig. 1 shows photomicrograph of a small section of a specime of an 0.08 per cent. carbon steel with a magnit tion of 100. 1—Annealed Fig. (0.08 carbon) steel 2—Steel one draft; Fig. given when it is realized that a 2-ton ingot, when rolled and drawn into the average size telegraph wire, be- comes elongated upward of 20,000 times its orig- inal length. The principal heat treatments used in the manu- facture of wire are: 1, annealing; 2, patenting; 3, hardening and tempering. The object of this paper is to present a discussion of the practical application of these basic heat-treatment processes, which affect by far the largest tonnages in the manufacture of steel wire. THE FUNCTIONS OF ANNEALING In discussing heat treatments of steel wire, that of annealing naturally comes first, because it is the most common of all heat treatments applied to wire, being practically the only heat treatment to which the enormous tonnage of soft or low carbon steel wires is subjected. Annealing serves to accomplish three important functions: 1. To remove the effects of hardening due to cold work in wire drawing or cold rolling, f *From a paper presented at the Sixth General Meeting of the American Iron and Steel Institute, New York, May 22. +Superintendent South Works, American Steel & Wire Company, Worcester, Mass. wire 15 per cent. tion from rod (0.08 carbon) reduc- (0.0% Fig. 3—Steel wire given several drafts; 60 per duction from rod The Effect of Wire Drawing.—When a steel wire rod of the structure shown in this photomicrograph is subjected to the wire drawing process, a marked change in the grain structure takes place. Wit! each successive draft, the grains stretch out in th direction of drafting until a point is reached when the grains have been elongated to the limit of their ductility. If subjected to further strain by furthe! drafting they will part and the wire will brea Before this brittle condition is reached, theretore, it is necessary to heat treat the wire by subject ing it to what is known in the wire business 4s | “process annealing.” The effect of wire drawing in elongating structural grain of the steel may be seen 0) paring Figs. 1, 2 and 3. Fig. 1 shows the stru of the rod before drawing; Fig. 2 shows the su ture after a 15 per cent. reduction from the re and Fig. 3, the structure after a 60 per cent. redu tion from the rod. All of these micrographs rep! sent sections taken from a plane parallel to the = of the rod or wire, not cross sections. The _— for the marked difference in grain shown 12 Figs 1 and 8 may be grasped more clearly when ! chef preciated that Fig. 3 represents a wire reduced | ture tr 1320 1914 lrawing. process to such a degree that it e elongated 2% times the original length fect of Process Annealing.—Process or annealing consists in heating the wire to emperature, maintaining such tempera- the entire mass of steel is thoroughly rough, and finally cooling down. Practi- prominent authorities on the metallurgy of te that the temperature of annealing must the critical temperature, which briefly de- that range of temperature above which the iron carbide are mutually in solid solution. ir authorities, however, seem to recognize that in the most common of all annealing wire—that to remove the effects of cold h as drawing—it is not necessary to reach al temperature, which is 1300 deg. F., or depending on the carbon content. A tem 1100 deg. F. is entirely sufficient to the strained condition of the grain shown in Fig. 4 shows the same wire that is depicted ; after annealing at a temperature below al range. the annealing process the strained and elon grains shown in Fig. 3 break up and re- ge themselves to form a new grain structure wn in the micrograph. The annealed steel of structure shown is now in excellent condition thstand further cold work in reducing it to t ot Steel wire (0.08 carbon) hard Fig ste ritical temperature s; or, if already at finished size, is in good to meet the demands of annealed wire effect of reduction of section incident to drawing on the tensile strength and ductility eel wire, and the marked change brought about ese characteristics by annealing, as just out- shown in Table 1. This table is based on and annealing practice in reducing a low steel rod—in this case 0.10 per cent. carbon ine size of wire. It will be noted that be- ‘0 per cent. and 90 per cent. reduction from or annealed wire can be taken before an- Ss necessary. found in practice that in cold drawing from ‘od or annealed wire, the increase in tensile is a direct function of the amount of cold nost independent of other conditions. An- practically brings the rod or wire, regard- size, back to its original condition with re- E tensile strength and ductility. It will be that the final annealing does not bring the strength as low as previous annealing. This mply to the fact that in annealing the fine is usual, in order to avoid the mechanical THE IRON AGE 1321 sticking of the wire in coils, to anneal at slightly lower temperatures than in ordinary process an- nealing. The Effect of Dead Soft Annealing.—The effect of “dead soft” annealing upon the physical proper- ties of wire is shown below the process annealing column in Table 1. The reason for this difference is that in heating above the critical temperature range the pre-existing structure is entirely obliter- ated, due to the iron and iron carbide going into solid solution and in cooling down forming a new structure. On the other hand, in annealing below the critical temperature the pre-existing structure is simply broken up and re-arranged but not en tirely obliterated, and the deformation introduced by the cold work is thus not entirely removed. In the annealing of low carbon steel wire, the rate of cooling from the annealing temperature is of little consequence as affecting structure, a fact which much appreciated in the wire industry. REFINING THE GRAIN BY ANNEALING The second important function of annealing is that of refining grain, and its practical application in the wire mill covers principally the medium and higher carbon steels. The structure of wire rods with regard to size of grain is dependent upon the temperature at which the rods are finished in the hot rolling mill and upon the rate of cooling through the critical temperature of the steel. In steel of then annealed below the heated low carbon this is not of as much importance as in the higher carbon steels, for the reason that the ordi- nary finishing témperature variations of good roll- ing mill practice have less effect on grain structure of soft rods, and therefore less effect on their physi- cal properties. In higher carbon steels a fine grain is important, for it is this structure that makes for such steels their field of usefulness, where high strength, high elastic limit and toughness are re quired. Theoretically, the ideal structure would be ob tained if the entire rod could be finished at about the critical temperature. But this is, of impracticable, for the reason that it is impossible to regulate the finishing temperatures so closely, and for the additional reason that there is, neces- sarily, particularly in rolling very long lengths of very small sections, a marked difference between the finishing temperatures of the first and last end of arod. The higher the finishing temperatures above the critical range the coarser the grain, and the coarser the grain the more does the steel lack the qualities that give it value. In order to destroy the coarse or uneven structure that may be created as just described, it is necessary to anneal the steel course, i pte? a 9 ate 1322 THE IRON AGE May 1914 by heating it just above its critical temperature and slowly cooling it down. Above this range the coarse crystalline structure which previously existed is entirely obliterated, due to the iron and iron car- bide going into solid solution, in exactly the same manner as was described in connection with the dead soft annealing of low carbon wire. The effect of overheating in coarsening the grain structure of a 0.45 per cent. carbon steel and the refining influence of this type of annealing is shown in Figs. 5 and 6. CREATING DEFINITE STRUCTURE BY ANNEALING The third and last class of annealing to be de- scribed—that to obtain definite structure—is one of comparatively recent development in the steel wire industry and one which promises to be of consider- able value. Heat treatment scientifically applied and controlled has opened a field of unusual oppor- tunity. It cannot be said that the use of the micro- scope and pyrometer has led to the discovery of anything new in the way of heat treatment proc- esses; nor have they created new fields for the em- ployment of wire. They do accomplish, however, two important things: 1. The making of a product of higher quality than had hitherto been the case, by supplying a material of superior structure for the purpose, and of greater uniformity than could possibly have been the case under less intelligent direction in manufacture. 2. The placing of the manufacture of such materials in the wire mills on 8—Specially bon) steel for a scientifically improved basis, with fewer rejections and consequently with less cost to the user. To-day a wire problem essentially involving structure is first studied under the microscope until the struc- ture giving the best results is found. After that, by means of the pyrometer and other improved fa- cilities of the present up-to-date wire mill, it is a simple matter to see that the heat treatment neces- sary to supply the desired structure is employed in the practical manufacture of the wire. Annealing of the type under discussion is applied principally to the higher carbon wires. Since the structure of such wires can be varied considerably within a small range of annealing temperatures, it covers specific products and not general classes, as would be the case in regard to the two previously described types of annealing. Figs. 7 and 8 illus- trate excellently this special type of annealing. These photomicrographs show the structures of two annealed pieces of the same coil of high carbon wire, in which the annealing temperature of the one speci- men was 1300 deg. F., and of the other 1250 deg. F. It is impossible to identify the structure by a simple observation of the fracture, which is the ordinary rough and ready method; nor is it possible to regu- late annealing temperatures so closely w use of pyrometers. THE PRACTICAL SCOPE OF PATENTID In passing to the next great class of | ment applied to steel wire, patenting, it is ing to note that we likewise pass to ano! of wire as regards grading by carbon co It naturally eovers the medium carbon ste ely employed chiefly on carbons between 0.35 0.85 per cent. In the medium carbon steel wires s! rengt) and toughness are required for both pr finished wire. Patenting makes possible t ( bination of strength and toughness, and to t pr ess is due in large measure a broad field of tion for steel wire. Wire Rope.—From a tonnage standpoint, wir; rope is the most important product of this class heat treatment. In some respects it is the most important from a quality viewpoint, for the reason that in the manifold uses of wire rope the of human life is of vital consequence. There are also economical considerations relative to the han- dling of enormous tonnages at low cost, of which there is no better illustration than that furnished by the steel industry itself in the mining, loading and handling of tremendous quantities of ore and coal, There is probably no feature of the wire business that has been given more scientific study than the heat treatment of rope wire. Rates and degrees of heating and cooling have been standardized to such annealed (0.85 car- Fig. 9—Patented (0.85 carb globular structure an extent through the use of the microscope, pyrom- eters and testing instruments, that a degree of uni- form quality is reached that previously was impos- sible. Music Wire.—Another important class of wire dependent for its superior quality upon the patent ing process is music wire for pianos and other stringed instruments. In order to have tone ane hold pitch music wire must possess extremely high tensile strength and must also have suitable physica! properties to enable it to be applied in the instru- ment. By a proper combination of drafting and patenting it is possible to obtain music wire trom a 0.70 per cent. carbon steel which will have a ten sile strength of 400,000 Ib. per sq. in., and be suff ciently tough to be wrapped about itself without breaking, and be swaged flat to one-half its org inal thickness without splitting. Through this t markable combination of properties, which in ste¢! are usually antagonistic, music wire may justly be said to represent the highest development 1 manufacture of wire. Without the patenting prow ess as we know it to-day it would be impossi0!¢ produce wire of such characteristics. The Structure of Patented Wire—The "2" the TION GREEN ROD PROCESS | FIRST AL | ~~ | DRAFT CTION _ Oo | 47 35 WING | So aceite T —— 7 TRENGTH | ¢eoo0 | 113000 | 150000 93.000 5Q IN ONGATION 125 | a | 3 NCHES wing effect of cold-drawing and annealing o d soft annealing gave a tensile strength of 50, the first and and toughness of patented wire are due to on condition and to its peculiar structure. rhe t step in the patenting process is to heat the wire to a temperature above its critical range. This, e, causes the carbide of iron to become homo- 9 distributed. In patenting, the degree of eating is regulated according to the carbon content the steel, the size of rod or wire, and the time the ‘terial is subjected to the heat. After sufficient ting, the next step is to cool the material rapidly w its critical range, the structure obtained de- pending upon the rate of cooling. In practice, pat- ting is usually conducted as a continuous opera- the wire being led through the heated tubes furnace and cooled by being brought into the nto a bath of molten lead comparatively cool seldom under 700 deg. F. A better understanding of the structure of a pat- ted wire may be had by a comparison of the struc- ture obtained by slow and by rapid cooling. If the steel after being heated is allowed to cool slowly thi the critical temperature range, the homo- pre-existing solid solution of iron and iron le separates into a heterogeneous mixture of onstituents, resulting in the plate-like struc- alled “pearlite.” In a patented wire, part of rbide of iron is in solid solution and the re- er, while not in solid solution, has not had form into plates. The difference in structure een slow and rapid cooling is seen in Figs. 7 '. The photomicrograph of the patented wire as a result of the rapid cooling, a structure ght be termed nondescript. Metallographists will recognize the structure as “sorbite,” which, in the ing of the higher carbon steels from above al temperature, is that stage of transition eding the pearlitic, the final condition of ealed steel as shown in Fig. 7. The patented therefore, represents an unsegregated condi- s against the segregated or coarsely laminated ture of annealed wire. The high tensile trength of patented wire is due to the amount of n solution, and its toughness to the fine- the grain structure. ‘ions of Patenting.—Patenting serves two CONDITION aa GREEN ROD | FIRST | SECOND FIRST | THIRD ae GA | TERIAL | gor” DRAFT DRAFT PER CENT REDUCTION BY DRAWING 0 288 S| + - oo nest —_ TENS LE STR ENGTH | THE IRON DRAFT DRAFT DRAFT DRAFT ORAFT ORAFT 30 | SO? 65 AGE 1323 nuienietpncsabitalia ———————————————————————— THIRD FIFTH PROCESS FIRST THIRD {| FIFTH | SEVENTH DRAFT ORAFY ANNEALED ORAFT DRAFT ORAFT ORAFT t , ie | 70 85 2! 62 80 | 88% 130000 145000 82000 124000 143000 151 500 2 1k 3t 2 a oe I sical } perties of low t_) 000 Ib. per sq. in. and an elongatior 1 anne ng important functions in the wire business: 1. In the process of manufacture, the removal of the effects of cold work, such as drawing. 2. In the finished wire, to give in conjunction with cold drawing, the required combination of strength and toughness. The effect of wire drawing on medium and high carbon wires is similar to that previously described in connection with low carbon wires. Strictly speaking, patenting is not necessary simply to re- lieve strain, for annealing would serve that pur- pose, but the structure obtained by patenting per- mits much further cold drawing than does the struc- ture obtained by annealing. This is due primarily to the increased ductility and toughness of the patented wire. The effect of patenting as just de- scribed is shown in Table 2 and Figs. 10 and 11. The table represents typical practice in manu- facturing a certain wire of 0.50 per cent. carbon steel from a No. 5 gauge (.207 in.) rod to a fin- ished size of 0.02 in. The rod in question as it came from the rolling mill had a tensile strength of 95,000 lb. per sq. in. and an elongation of 10 per cent. After the first draft of 28% per cent. there is an increase in tensile strength of 27,000 lb. per sq. in., and the elongation is reduced to 2.9 per cent. After the first patenting of the wire it has a ten- sile strength of 115,000 lb. per sq. in. and an elonga tion of 8.2 per cent. It is then subjected to 4 drafts, being thereby reduced 65 per cent. from the first patenting point before the second patent- ing is necessary. After the second patenting the wire has a ten- sile strength of 128,000 lb. It is then drafted 76 per cent. further before the final patenting, which leaves the wire with a tensile strength of 156,000 lb. The properties of the finished wire depend largely upon this last patenting and the subsequent drawing to the finished size. In the case in ques- tion the wire was drawn 3 drafts and reduced 66 per cent. from the last patenting size, ending at finished size with a tensile strength of 218,000 Ib. It will be noted that the tensile strength of the wire immediately after patenting is higher as the size of wire decreases. This is due to the fact that in FOURTH FIRST THIRD FOURTH FIRST THIRD DRAFT DRAFT 30 66 %6 30 66 $5000 | 122000 | 146000 143000! 163000 | 176000 156000 | 190000 208000 | 156000 | 184000 | 2/8000 POUNDS pra $0 IN } donate hese — PER conr | i mr | a | os | 28 | 27 | 26 20 | 19 | 18 20 | 19 TEN INCHES ng the effect of cold drawing and patenting on the physical properties of higher carbon (0.50 per cent.) steel e first patenting stage, process annealing gave a tensile streneth of 70,000 } per sq ir and 18 per cent elong tior | | | | -_- — — a ee eee Ge 2 ee pemmatng” er ae eee as “a 5, Pap 1324 practice the smaller the wire the more quickly it cools, and consequently the greater the amount of carbon in solution. This, as explained previously, is the condition of a patented wire that makes for its strength. In Table 2 and the note thereto are given the corresponding tensile strength and elongation of the same wire when patented and when annealed. It will be seen that the tensile strength of the an- nealed wire is 70,000 lb. per sq. in. as against 115,000 Ib. per sq. in. of the patented wire. This is due to the fact that, on account of the compara- tively slow cooling in annealing, none of the carbon of the steel is in solution. It might be supposed that, owing to its being softer and of higher elonga- tion, the annealed steel would withstand a further degree of drafting than the patented steel. On the contrary, however, on account of the rapid loss of ductility characteristic of the annealed wire struc- the ture, annealed structure will not withstand uu se Fig 10—Showing the increase of tensile strengtl di ie to ct of patenting, medium-carbon (0.50 per cent.) steel drawing to anywhere near the same degree as will the patented structure. Generally speaking, the patented wire structure has more than twice the ductility of the annealed. Fig. 10 shows graphically the increase of ten- sile strength in cold drawing from a rod of 0.50 per cent. carbon steel, wire 0.02 in. in diameter and the effect of patenting in removing the results of the cold work. It indicates also the importance of the patenting process in creating a structure that permits an increase, by heavy drafting, of 50,000 lb. per sq. in. in tensile strength, and leaves in the finished wire a remarkable degree of tough- ness rather than brittleness. Incidentally, it may be noted from this chart that the same regular in- crease in tensile strength, due to drawing, is char- acteristic of the higher carbon steels as of the lower carbon steels. Obtaining High Tensile Strength.—Fig. 11 shows a typical practice in obtaining a tensile strength of 375,000 lb. per sq. in. in a music wire 0.03 in. in diameter from a patented rod 0.192 in. in diameter, of 0.70 per cent. carbon. It indicates the marked increase in tensile strength from the last patenting point, and emphasizes the remark- able character of a wire of such strength possessing the workable properties necessary for music wire. It will be seen that from the last patenting point the wire is reduced about 94 per cent., elongated 18 times its length, and to do this on the wire in question, 19 drafts were taken. The increase in tensile strength per sq. in., due to this heavy draft- ing, amounts to about 200,000 lb. from the last patenting point. In the final drafts there is an enormous increase of tensile strength. In fact, as THE IRON AGE May 1914 the curve shows, a certain reduction end increases the tensile strength muc! an equal reduction near the patenting ; might think a wire made according to practice would be as brittle as a clay but, on the contrary, it is singular], stands wrapping, bending and flattening, remarkable degree. PRACTICAL SCOPE OF HARDENING AND Hardening and tempering is probabl: commercial importance and applicatio: other type of heat treatment given to | steels. In the past fifteen years it has tremendous impetus by the growth of t! bile business and the increased use of a Outside of the manufacture of wire, and tempering are usually separate a: operations, but in wire the two terms together, there being practically no fi fulness for wire simply hardened. It follows, therefore, that in wire making, and tempering should be conducted usua continuous process. In the making of wire the material is first run through th tubes of a furnace, then quenched quick bath of oil or water, then run into the ten bath of, say, molten lead, each wire being tinuous motion from the time it enters th ing furnace until it is wound on a reel. Suc! products as springs made of untempered wire, ha: ened and tempered after forming, do not of cours: have the several steps conducted as a continu process, but there is no difference in essential pri! ciples. Hardening and tempering apply to the higher carbon steel wires—those in which the bon range is from 0.65 per cent. to 1.00 per ce The Process of Hardening and Tempering.— In hardening wire the first step is identical with that previously described for patenting, and is complished in practically the same manner. 1 is, the wire is heated above the critical ter ature to enable the iron and iron carbide « uents to go into solid solution before que: After quenching, the steel, on account of its den cooling through the critical temperat hard and brittle. Cooling in this manner |s t rapid to permit the segregation of the co! ents, iron and iron carbide; and, as a result siderable of the carbon content is in solid s the amount depending upon the total carbon patenting it was pointed out that carbon tion causes hardness in the wire. It will be ent that in hardening, as above defined, the an of carbon held in solution will be much greater in the patenting process, due to the much mor id rate of cooling through the critical temperat secured by the use of a quenching bath of low ' perature. The structure thus obtained in the hare ened wire depends on the rate of cooling. rhe hardness is finally lowered to the desired degree “temper” by carefully adjusting the temperature the “tempering” bath. This process, simple as it appears, is in pre tice the most complicated in principle of any "' the heat treatments described, and demands greé accuracy of temperature control fo secure the "! shades of temper demanded by the multiplicit; uses to which the finished product is app!le¢ the consumer. os In passing it may be stated that the field commercial tempered wire requirements is SUC" cs to necessitate a wide range of temperature 0” | various quenching baths in the tempering roe a wire mill. In general, the reheating ince” ® +har ’ Ma 1914 s usually considerably below the crit- ature. ‘f Tempering on Tensile Strength.—With npering temperatures between 500 and ’ the tensile strength runs from about per sq. in. to 150,000 lb. per sq. in. At temperature the decrease in tensile _as we should expect, much greater per range than at the higher temperatures. to 600 deg. F. there is a drop of 60,000 while between 1000 deg. F. and 1100 e drop in tensile strength 10,000 Ib. per sq. in. amounts to CONCLUSIONS he foregoing discussion of the several ents of importance in the wire business apparent that at the basis of the industry ertain fundamental laws which govern all n the manufacture of steel wire, whether 56 Q e4 AR CENT REDUCTION IN AREA BY DORAWING g the process for producing 0.0 ) having tensile strengt! ib. per sq. In treatment incident to drawing or heat incident to the various operations de- Like all natural laws, those gov- e behavior of steel in the manufacture of inexorable, and the results obtained de marily upon the determination of those ipon their proper recognition and con- n actual practice. Herein lies the rea- e vast difference between wire mill prac- e past and that of the present. The heat ts which are applied to-day with such bene- its were known then, but the underlying erning them were not. The scrap and re- the wire mill, the lack of uniformity and table quality of the product, and the com- istomers were all too frequently ascribed vil in the steel.” With the establishment st few years in our colleges of broader r the study of the nature and behavior nd the resultant advent into the steel busi- technically trained young men, and with erein THE IRON 9Or AGE 325 the establishment of laboratories for the study of practical steel problems, with their invaluable aids in the shape of the microscope and the pyrometer, there has been given an impetus to a development in the steel wire business that has been unprece- dented. The present day wire mill, with its hun- dreds of pyrometers and temperature regulating and recording silent but forceful testimony to the ype of automatic apparatus, passing of the old gives rt. Professor Sauveur Philistine clumsily “practical” man whon has described as “‘the industrial standing in the way of scient applications to dustrial operations.” In the works with which I am associated, : physical laboratory for the study of heat treat- problems connected ments and other metallurgical with the manufacture of high grade wire was es years ago. A convincing prootl of its practical value lies in the fact that the facili tablished several carrying on this work have been steadily nereased. To-day tech nically trained men and extensive equipment, voted entirely to the work. Our physical laboratory is in practical and efficient adjunct to our producing de- partment. Of fundamental importance in the prac- tical application of the work of a laboratory of this kind, is the training of the men carrying on the work. To make their work of the greatest value, hese men should be more than merely technically trained. We believe that the excellent results we have obtained in the heat treatment of wire are due in large measure to the fact that our laboratory men, in investigating a problem, study