The Iron Age 1930-03-27: Vol 125 Iss 13

IRON AGE New York, March 27, 1930 ESTABLISHED 1855 Teaching Heat Treating OST steels, whether carbon alloy, require some specific heat treatment produce the best results. Few, any, steels will perform satisfactorily natural state; just the addition different chemical elements may intensify one set prod- ucts, heat treatment may varied produce different re- sults the same steel. The engineer, the applica- tion heat treatment, should have thorough knowledge the composition the steel and the effects different alloys those steels, combining the proper chemical elements with intelligent heat treatment, there results steel with the highest chemical and physical qualities. Again, the treating steel consists heating and quench- ing, normalizing, annealing and tempering, any one which will produce certain changes, either desirable undesirable, the steel. For this reason, for other, quite obvious that knowledge the influence the chemical composi- tion combined with the proper heat treatment necessary the designing construction engineer. Some the larger in- dustries maintain train- ing course their own particular field, which the graduate engineer spends year, more, acquiring practical training and knowledge that should have re- ceived during his four years technical train- ing. With this end view, the University Illinois *Superintendent heat- treating laboratories, Uni- VOL. 125, No. How the University Illinois Covers the Subject and What Equipment Uses has added the curriculum for engineers practical course the heat treatment steels, given both semesters for students senior standing mechanical engineering. would impossible impart knowledge the subject the time allotted without exercising great care choosing the proper equipment and installing pre- sent model laboratory. The furnace equipment comprises gas and electric fur- naces. Each line consists complete heat-treating unit—one high temperature furnace, 2500 deg. Fahr., two furnaces for temperatures 1800 deg., and one draw- ing tempering bath, controlled from 400 1000 deg. Furnaces and pyrometers are arranged that every fur- nace the room, them, may operation the same time and correct temperatures read from the indi- cators. addition the heating and cooling equipment, there complete laboratory for microscopic investigation consisting grinding wheels, carborundum belts and disks for finishing specimens for microscopic inspection; etching table, microscopes, hardness testing machines, and tensile testing machine complete one part the labor- 915 atory. separate room, away from heat and dust, will found the recording and controlling pyrometers. outline the course given accompanying tab- The aim the course familiarize the student with the methods treating and examining steels that will have least the foundation from which work. Industries are concerned primarily with results. gear should fail the question not who made it, but rather why did fail? There are several ways deter- mining the answer. First, does the steel from which the part was made conform the spec- ifications, the carbon content? Our students are sample, prepared them- selves and examined un- der the microscope, ap- proximately the per cent carbon the steel. Second, was the part properly heat treated be- fore machining? The mi- croscope, again applied ent steels. the sample, examining the piece for different structures, may disclose 6.—Annealing improper normalizing annealing, and the diffi- culty may removed proper heat treatment. the study alloy steels, test pieces smaller diameter are of- ten used demonstrate the fact that these steels are nuch stronger than plain carbon steels, and may have higher tensile strength, though smaller section, than plain carbon steels. Another point taken into con- sideration the fact that different elements have different effects the critical temperatures and the resistance abrasion, shock and corrosion. All ‘ Alloy tool steels, particularly the high-tungsten steels, 916—The Iron Age, March 27, 1930 Outline Course Heat Treating 1.—A study manufacturing processes and the composition and con- stitution iron and steel. 2.—A study pyrometry and the calibration thermocouples against standard couple. 3.—Tensile and hardness testing plain carbon steels heated dif- ferent temperatures and quenched various quenching baths. 4.—A study critical temperatures and how obtain them differ- 5.—Grain structures, macroscopically and microscopically. normalizing and hardening steel. 7.—Tempering steel. 8.—Carburizing and case hardening. 9.—Effects elements the properties steel. 10.—A study structural alloy steels. 11.—Alloy tool steels. 12.—Microscopic study all steels before and after treatment. are subjected various heat treatments—annealing, hard- ening and tempering—in order bring out the best quali- ties and produce efficient cutting tool. the machining steel castings forgings, very often the mechanic confronted with difficulties over which has control. The machine tool refuses remove stock the required speed becomes dull, requiring too much grinding. drilling, finds the drill will not per- form should. examination the structure will reveal network cementite, the hardest structure steel, and also suggests the student the necessity HYDRAULIC ing Machine Part mens shown held grips proper normalizing and annealing and learns that will heat the steel 1800 deg. Fahr. and quench, this so-called cementite broken and all that remains perature, 1400 1450 deg., and allow cool the furnace, which pre- pares the steel for machining with- out difficulty. all the prob- lems the student taught identify the microstructures and determine the condition the steel those structures. One the most important operations the heat treat- ment lower carbon steels enable them resist wear and absorb shock the process carburizing and case- hardening. Why should motion parts engines car- burized? Why use alloy steel with low-carbon content? after carburizing, desirable give the parts double heat treatment, and when the double treatment unnecessary? this connection, studies are There Are Furnaces, Gas and Electric, This Room. High-pressure gas furnace and quenching tank foreground and electric furnace background made different carburizing materials, temperatures, length time held temperature, methods quenching prevent warpage and the process carburiz- ing for colors. order aid the student his laboratory experi- ments and conserve his time, the instructor charge has prepared laboratory manual which has been use for three years, during which has been revised and enlarged. Metal for Brass Pickling Containers DDRESSING the American Society En- gineers Buffalo, Feb. 25, Schenck, president Duriron Co., Dayton, Ohio, made plea for more thorough testing corrosion resisting metals under actual service conditions. expensive installations are made routine laboratory tests and with scanty background experience, expensive failures are almost certain occur. cited several concrete examples illustrate his main thesis, among them the following: “For several years have been furnishing various pieces equipment large parchment paper company. Parchmenting done running special grade paper through strong sulphuric baths and thoroughly wash- ing it. The composition the bath was given ‘sul- acid with sodium sulphite and some other impuri- furnished samples various bronzes and steels which absolutely know would practically unaffected this particular corrosive solution. The samples were tested the paper company and invariably reported not standing up. “To make long story short, someone happened mention, during visit one our men the plant, the difficulty they were having with the rapid solution cop- per conveyor chains the solution. This remark cleared the whole problem, while the samples were send- ing down were suitable for sulphuric acid, they were not suitable for copper sulphate, which was, course, present, due the very rapid dissolving the copper chains. High- silicon iron, which have developed under the trade name Duriron, the only material which will stand the combination the free sulphuric acid and weak copper sulphate. The installation Duriron squeeze rolls, which are alternately exposed the effect the acid and air, solved the problem. “If the copper sulphate content were appreciably higher the solution, the 18-8 chromium-nickel alloys would the work, but they will not stand the high percentage free sulphuric acid. “An example these conditions case tanks for pickling brass and bronze. The high nickel-chromium alloys successfully withstand the sulphuric acid pickling bath, but they are very rapidly soluble the presence copper sulphate. the other hand, the high chromium- nickel alloys will stand copper sulphate, but not sulphuric acid. This problem has been solved successfully far instructing the operators not replace the free sulphuric acid, but leave appreciable percentage copper sul- phate which acts inhibitor the corrosive action.” Paint Coatings and Strength Riveted Joints 1927 the German railroads prescribed that all iron parts used the construction railroad cars should coated with white lead oil paint the joints before assembly. 1928, the railroads gave instructions that immediately after the removal the rust all iron parts were carefully painted with red lead, and shortly before assembly all joints were receive second coat red lead. Egan, article Krupp’s Monatshefte, Vol. 10, 1929, describes tests has made riveted joints treated above and also the unpainted condition, and records the results his measurements the amount slip the joint when under tension. shown that the presence the paint between the parts has adverse effect, but the four coats red lead paint the joint according the later prescription does not produce worse results than the two coats white lead oil paint the earlier pre- scription. The breaking stress was not affected the coats paint. The Age, March 27, 1930—917 | Light Metals Automotive Field New Alloy with Very Low Expansion—Car Designing Now Performance Basis—Facts About All-Aluminum Car DR. ZAY JEFFRIES* approaches the subject automotive materials with considerable uncertainty because what automotive material today may not tomorrow. Aluminum and magnesium, principally because their low gravities, are being adopted standard for air- craft construction wherever their other properties will per- mit. While cost one consideration, small saving weight compensates for large cost differential. The aircraft industry passing through the stage which the cost raw materials small compared with the total cost construction. This condition will change the future such direction that the cost materials will more important factor, but seems probable that the trend will toward greater percentage light metals. Aluminum being generously employed outboard principally because the desire combine port- ability and relatively high power. Also Diesel engines some aluminum used reduce the total weight and some used pistons because the combination lightness and high heat conductivity, permitting the em- ployment higher speeds and greater power output than possible with iron pistons equivalent engine size. The same true the large spark ignition internal com- bustion engines—for example, those used gas-electric rail cars and for marine purposes. Aluminum Trucks and Buses might expected that the choice materials for truck and bus construction would more influenced economics than for pleasure cars. Trucks and buses are usually run the original purchaser substantial destruction and many users have opportunity and incen- tive ascertain accurately the operation cost. Further- nore, there not the possibility for competition style and general the purchaser truck bus less apt influenced esthetic and psychological factors. factor which must considered for the largest units weight restriction highways and bridges. Aluminum might used for weight reduction such cases, regard- less the transportation economics. fact that truck and bus manufacturers, espe- cially those making heavy and high-speed vehicles, are en- deavoring use aluminum both the chassis and body. interesting note that the service conditions trucks and buses are severe that the only aluminum that can used for some parts the heat-treated material comparatively recent development. The experimental work now process the field promises some interesting re- sults the near future. number the points discussed below apply trucks and buses well pleasure cars. considering the use aluminum automobiles, may interest recall some the earlier practices. the days real mass production automobiles, the cost fabricating was high that the cost raw and metallurgist, Cleveland. The article part paper, “Light Metais the Automotive Industry,” presented first regional meeting the American Society for Testing Materials, Detroit, March 918—The Iron March 27, 1930 semi-finished materials was small part the total. made little difference final cost whether crankcase was aluminum cast iron. The plant was usually behind production and aluminum cases could machined faster than iron and more finished cars could produced with given plant investment. The engines were usually slow speed and excess weight had fought order obtain performance, the aluminum case was welcome the engineer. Thus came aluminum crankcases and for the same reason aluminum oil pans, aluminum gear cases, and number other parts. With increased production came the urge for decreased cost and the stamped steel oil pan replaced large ex- tent the aluminum oil pan. The old-time conventional en- gine had four main parts from bottom top, namely, oil pan, crankcase, cylinder block and cylinder other major economy resulted when the and inder block were cast one piece. was necessary for the cylinder bores cast iron and consequently the aluminum crankcase largely gave way cast iron. Aluminum Body Construction body construction aluminum was used both sheet and cast forms. The light weight was helpful keeping the center gravity low. Dies for forming body sections from sheet are very expensive and many the old- time models were not made sufficient numbers war- rant the die cost. For hand forming, aluminum was supe- rior steel and equal stiffness could attained with half the weight steel. Consequently aluminum was used considerable extent automobile bodies. Mass produc- tion led the almost universal use large presses and dies for forming body sections. Also the manufac- turers made improvements quality for deep drawing and steel was largely adopted for bodies. course while all these changes were process, many experiments were made with the object utiliz- ing aluminum every possible way the automobile. The aluminum piston thus came into use, but this subject vill discussed more detail later. Two automobile manufacturers America put aluminum engines their cars. There developed differences opinion among auto- motive engineers the fitness aluminum, regardless cost, for many automobile parts. 1919 the Aluminum Co. America undertook answer some these questions and engaged Lawrence Pomeroy design car which aluminum would used for every part where would function well better than other materials. The work continued for seven years, during which time four-cylinder and six-cylinder test cars were made and later number the six-cylinder were made, one which was tested running more than 100,000 miles. All-Aluminum Car high spots this investigation may inter- est. the first place, possible use effectively only about $250 worth aluminum 133-in. wheelbase car. The use this amount aluminum will reduce the weight the iron and steel chassis from about 2800 1800 lb. Non-metallic parts like tires and battery solu- tion cannot replaced any metal. There are certain parts like crank and camshafts, springs, gears, bolts and forth, for which steel clearly superior aluminum. Standard starters and generators were used and these con- sisted mostly steel and copper. The principal aluminum parts were pistons, connecting rods, cylinder heads, cylinder block, crankcase, oil pan, wheels, brakeshoes, frame, front axle, rear axle housing, torque, tube, gearcase, steering column, gasoline tank, radiator shell, and brake addi- tion, large number small parts were made aluminum. The body was made cast aluminum and weighed about the standard pressed steel body, but was materially more rigid. From the automotive engineer’s standpoint, the performance results pated from the power- weight ratio. The advan- tage gained power- weight ratio can used the designer’s discre- tion obtain the desired combination perform- ance and ‘fuel economy. The weight saving not only that resulting di- rectly from the substitu- tion aluminum for heavier metals, but there indirect saving weight the result the use lighter tires, springs and other parts. Furthermore, the generous use aluminum may make possible the substi- tution for parts otherwise dangerously close the upper stress limits. For example, aluminum differential car- rier might overstressed steel and iron car weighing 4000 but might usable aluminum car the same size weighing 2700 Ib. course, the use much aluminum involves number problems. not possible with all parts merely substitute piece aluminum about equal stiffness and weighing about one-half that the iron steel part. Engineering thought must exercised the selection alloy, decision where forgings, stamped parts, permanent mold, sand and die castings can best utilized, and the changes design and methods fabri- cation accommodate aluminum. The best application aluminum will come only after its extensive use. Problem Coefficient Expansion One the problems major importance arising from the use ferrous metals and aluminum combination caused differences coefficient expansion. While this particularly true the engine where relatively high temperatures are encountered, the problem obtains other parts well. The high expansion aluminum com- pared with ferrous metal may advantageous for alumi- num brakeshoes. usually, however, the opposite and requires careful consideration. aluminum cylinder head attached cast iron cylinder block, for example, the differences expansion may result strains which Important Points Dr. Jeffries’ Paper possible use effectively only about $250 worth aluminum 133-in. wheelbase car. This means reduction weight the iron and steel chassis from 2800 1800 aluminum alloy has coefficient expansion 0.0000105 per degree Fahr. between and 212 deg. Fahr. pistons used almost entirely Europe—only about per cent cars made America. UTOMOBILES are designed today pretty much around performance. always important factor but money being spent gain operating satisfaction. tend permanently warp the aluminum, making frequent gasket adjustments necessary avoid leakage. The Aluminum Piston Again the connecting rod large end bearing, the clearance too small there danger seizure when the engine stands very cold weather and the clearance too large the bearing may noisy when the motor hot. These difficulties can overcome sufficient attention detail, but they are mentioned indicate the need for careful engineering the application aluminum. Perhaps the part which has given the greatest difficulty and which most engineering effort has been expended the piston. The advan- tages high heat con- and lightness have been great that the difficulties arising from the difference coefficient expansion between the aluminum piston and the cast iron cylinder have some cases been endured and others various expe- dients minimize the troubles have been used. Some the difficul- ties experienced the past have been caused poor lubrication, im- proper machining, lack care fitting and adoption aluminum pistons for motors ill- adapted for their use, but Low cost problem has been expan- aluminum piston fitted with too little clearance cast iron bore there danger seizure when the motor hot and the clearance too generous there may piston slap when the motor cold. The principal methods minimizing this difficulty have far been special design the piston itself. The so-called “split skirt” and the “invar strut” designs have been most The “split skirt” all alum- inum and close fitting made possible slotting the skirt strut” design, inserts iron-nickel alloy low expansion are cast the piston two sides adjacent either boss. Suitable slotting permits the low expansion insert com- pensate for the higher expansion aluminum the skirt. Although aluminum pistons are used practically the exclusion all others Europe, rough estimate indi- cates that only about per cent the cars being cur- rently produced the United States are equipped with them. Aluminum pistons cost more than cast iron pistons, but when the fact taken into consideration that, using aluminum, higher compression ratio can em- ployed and about per cent additional power secured, the higher price more than justified this basis alone. seems apparent that there still some trouble with even the present close-fitting aluminum pistons. New Alloy Developed RECENT aluminum alloy development this field may have far-reaching effects. There has been developed August, 1927, page 146. The lron Age, March 27, 1930—919 the Aluminum Co. America alloy, No. 132, having coefficient expansion 0.0000105 per degree Fahr. between and 212 deg. Fahr., per cent less than that pure aluminum and per cent less than the pres- ent piston alloys containing about per cent copper. The clearance used fitting pistons not merely matter the coefficient expansion the piston alloy but depends also the coefficient expansion the cylinder and the heat conductivity the piston. No. 132 alloy can fitted with per cent less clearance than the ordinary aluminum alloy cast iron cylinder. Engineers seem agreed that the trunk type piston, with its large bearing surface, freedom from distortion and collapse, has real advantages. Aluminum company engineers have recently worked out design motor which preserves the advantages the trunk type piston and permits the use aluminum with its advantages. No. 132 alloy has about the same expan- sion the so-called austenitic non-magnetic irons and steels. One these irons the “Niresist” cast iron which the International Nickel Co. has been work- ing. contains about per cent Monel metal, with some chromium and manganese, can cast like cast iron and has coefficient expansion about 0.0000095 per degree Fahr. between and 212 deg. Fahr. Also the austenitic stainless steels the Nirosta type and Hadfield’s manga- nese steel have the proper thermal expansion for use with No. alloy. applying this combination, the high expansion inder must allowed expand freely when heated and accomplish this high expansion cylinder block helpful. Such block works better with aluminum cylinder head than does cast iron. This points practically alumi- num motor with high expansion iron alloy for the cylin- der sleeve. The question might properly asked—why use aluminum motor just permit the use aluminum trunk type pistons? view the present status the use aluminum American automobiles, this would rep- resent revolution. However, matter which now receiving much attention. Automobiles Designed Now Performance Automobiles are designed today pretty much around performance. Low cost always important factor, but money being spent gain performance. The gen- erous use aluminum capable reducing the weight nost water-cooled American cars about per cent. About per cent saving weight can readily effected without reduction power. Such weight saving improves the performance. The use the aluminum engine would not only reduce weight and improve the functioning the piston, but the cylinder block could cast for insertion liners” which would make for economy construc- tion and desirable servicing. The crankcase-cylinder-block casting would much simpler cast with provision for insertion wet cylinder sleeves than present practice casting the cylinder barrels integral with the crankcase and block. Aluminum Used Greater Extent Europe Although aluminum used much greater extent per automobile Europe than America, comparisons should not hastily drawn. The conditions are different. The cost fuel higher Europe. The taxes are gener- ally high, and higher the greater the horsepower. some countries there also road tax which higher the greater the weight the vehicle. All these factors favor the use aluminum, and Germany even mag- nesium used considerable extent combat weight. Again, the mass production forces Europe have not been active America and change toward more iron and steel may witnessed there the future. Opposed this trend are the factors mentioned above and the fact that there ample production capacity Europe and keen competition sales. Suggest New Phase Automobile History May not be, however, that America entering new phase automobile history? have great excess manufacturing capacity. Competition quality and per- formance quite keen price competition. can now definitely stated that any performance which can attained iron and steel car can substantially im- proved using aluminum. aluminumize medium sized car completely feasible would apparently cost, ultimately, taking into consideration the various economies and higher scrap value, about $100 more than the present cars. the time the car reached the con- sumer the added amount would, course, increased. The developments strong heat-treated alloys for both cast and wrought products, the more common use strong aluminum forgings, the development structural shape rolling strong alloys and the advent magnesium engineering material provide outlook for the future more fraught with potentiality for use light metals than any time the history the automotive industry. How Secure Best Conditions for Pouring Steel Ingots the casting large ingots top pouring, the ideal temperature conditions would that, the commence- ment pouring, the stream metal from the ladle should very hot counteract the cooling effect the air and the chilling effect the mold bottom. After the first few inches rise the mold, desirable that the stream, means manipulation and change pouring speed, should made flow cooler until the mold over half full. The top third the ingot should poured the hottest tem- perature possible. All this said Pacher article Stahl und Eisen, May 1929, “The Casting Steel Ingots.” Unfortunately, means not exist for raising the tem- perature the metal the ladle while pouring, and the ideal conditions can only approximated bringing another ladle with hotter metal complete the teeming 920—The Iron Age, March 27, 1930 the ingot. The ideal freezing conditions, which would con- sist the mass metal being uniform temperature throughout and cooling uniform rate, are likewise un- attainable. Mr. Pacher describes also method compressing in- gots while liquid the mold. appears modi- fication the Harmet process. Pressure applied the bottom the ingot before solidification mold tapering upwards. The ram three parts, telescoping one within the other. The whole ram, one unit, first driven short distance, then the two concentric inner rams are forced further equal distance, and, lastly, the move- ment continued the central ram alone. The central liquid portion the ingot thus pressed upward prevent the formation shrinkage cavity the top part the ingot. Baldwin Machine Shops Work Erecting Form Accuracy building any machine having many inter- dependent parts demands close attention fits and alinement, but further difficulties are added when some the members are extremely large and massive, the case the modern locomotive. the Eddystone, Pa., plant the Baldwin Loco- motive Works, responsibility for alinement and accuracy fits concentrated the machining departments. All parts and assemblies however huge intricate must finished the shop such predetermined limits that hand fitting required the erecting floor. And, erect- ing forms designed reject inaccurate parts automatical- are the stern monitors all machining and sub- assembly operations. Side frames and cylinders, frequently gigantic proportions and call- ing for very large machine tools and massive work hold- ing fixtures, are im- pressive examples the working the shop departments erecting form re- Such quire plenty room for handling, and the shops which they are processed not only have ample space between ma- chines, but have aisles that accommo- date standard gage railroad cars and auto trucks. fact, not uncommon for visitors view the various opera- 1—Planers Having Two Rail and Two Side Heads tions these shops Rough and Finish Two Frame Members One Set-Up from their seats the plant automobiles station wagon. Machines Side Frames Ft. Long and Weighing Tons Main side frames ft. long and weighing 44,000 are not uncommon. The shop which these steel cast- ings are machined rectangular, and operations are progressive, with back tracking. Frames arriving from the foundry railroad cars are either put into production immediately piled the receiving end the shop await the preliminary laying-out, which the first shop operation. this laying-out the castings are measured assure that they will clean properly, that is, machine size. From the layout table the frames the planer department, conspicuous for the two 96-in. 50-ft. and eight 36- in. 50-ft. planers number smaller machines. Each frame planer has two rail and two side heads, and the sides and tops two frames are rough and finish planed simultaneous- one set-up. The planing two frames shown Fig. second layout operation follows planing. this the pedestal ways, ped- estal cap lugs and the other parts the drilled, are scribed, The Iron Age, March 27, the straight leg the forward pedestal being the finished surface from which the layout man works. Large Frame Slotters Shape Pedestals and Other Parts The frames are then taken one battery triple head locomotive frame slotters which shape the pedestals and contact points six eight frames one setting, shown Fig. These machines, impres- sive size, are said the largest ever built. With the frames clamped against angle plate, each machine slots the ways three pedestals simultaneously and also the pedestal cap bearings, cylinder bearings, frame fits, ete. Angular cuts are made possible the swiveling type heads these machines. Special steel templates used during machining assure accuracy form the pedestal opening and tramming calipers are used for checking the distance from one pedestal another. Frames requiring cross planing cylinder fits, cut- outs, etc., are taken, after slotting, traversing shapers. Holes for filling pieces, pedestal caps, cylinders, brake work, etc—from 130 them, ranging size from in. and then drilled. This work done battery double and triple-head frame drills, ~ 2—After the Planing and Second Lay-Out Operations, the Frames Are Taken the Triple-Head Slot- ters. Fig. designed take pieces ft. long, and having one swiveling head for drilling angle. One group these machines used for flat work, while another group drills the top edge the frame. While being drilled the frames are held against angle plate. The next step, important one, fitting up. Oper- ations include chipping out and filing various corners, fitting the pedestal caps, and reaming the pedestal cap bolt holes, the reaming being done from the top down because the taper the holes. Layout frame fit- tings, such spring hangers, bumper knees, spring seats, etc., also done the fitting gang. Fitting pedestal caps shown Fig. With the frame rigidly clamped the lining-up form, bottom side up, from two four fitters work, according the number pedestals the frame. When the fitting completed and the alinement the pedestal caps approximately correct, the frame removed from the lining-up form and placed its side trestles. The pedestal ways are then checked for accuracy form means template gages and the pedestal caps remounted. Then, using the cylinder fit Iron Age, March 27, 1930 base surface, the fitter means “fish line,” makes final check the alinement the pedestal caps the frame. The cylinder fits are hand scraped micrometer dimensions. With the machining and fitting completed the frames are delivered the erecting department. Cylinder Machining Checked Every Stage workmanship pieces impressive size also seen the cylinder machine shop the Baldwin plant. Cylinder castings weighing six tons and more are received direct from the steel iron foundry standard gage cars and are processed progressively, finally being shipped the erecting shop the point entrance into the cylinder department. this case also, layout the first step. The casting placed large layout plate the position used the locomotive, and checked assure that all parts will true properly. The locating base point from which all dimensions are scribed is, course, cylinder proper. The first machining operations are boring the cylinder Here, the pedestals and contact points six eight frames are shaped one setting barrel and facing the ends, which are done horizontal boring machines, Fig. roughing and then finishing cut being taken. The barrel held limits plus minus 0.003 in. for out-of-round taper. The cylinder casting then goes group planers for rough and finish planing the splice flange and frame fits. Two cylinders, right and left, mating halves, are mounted one bar, and supported the planer table special fixture developed the company. The accuracy this planing operation these huge pieces noteworthy. the next operation, the valve chamber bored, the machines used being similar those for boring the cylin- der barrel. this set-up the valve chamber accurately alined from the splice flange and frame bearings. Next the production line are small boring mills, which steam pipe and feed water connections, by-pass valves and other parts are machined. Short-work planing such parts the boiler flange, frame key, lug bearings, the next step, completing what known the heavy machine Subsequent operations, all progressive, include drill- ing some 160 holes the cylinder casting. For this work IG. (above) —From —Boring Cylinder Barrel and Facing the Ends Are the First Machining Opera- tions the Cylin- der Department IG. (left)— Fitting Ped- estal Caps Important The frame rigidly clamped the lining-up form, bottom side up. After other fitting and inspection op- erations, the frames are delivered the erecting depart- ment The Tron Age, March 27, J IG. there battery more radial drills, each with pit front into which the lowered bring the part little more than floor level. Where tapping required, stud holes, peep holes and pipe holes, the same machine taps well drills. Drilling progressive along this long line machines. one group holes being drilled one machine, another group another machine, and on. Equipped with Expanding Mandrels work Hydrostatic testing the cylinder castings follows the drilling and tapping operations. this test the heads are put on, all openings blanked off and 250-lb. water pressure applied. required that the cylinders watertight before the bushings are pressed in. Connected with the cylinder machining shop the bushing production department. Bushings are made fit individual cylinder barrels and valve chambers, the size which are taken means inside micrometers af- ter the hydrostatic test. From 0.012 0.014 in. over cylinder bore size left all bushings insure pressing fits. These bushings are castings made from special iron. The valve bushings are first roughed vertical boring mills in. finished size and then taken layout plate for laying-out the ports. Holes are drilled within the scribed lines and the port openings then finished slotter. The cylinder bushing mounted expanding mandrel engine lathe shown Fig. and turned finish size suit the cylinder chamber which used. From the lathes the bushings the fitting department where they are pressed into the cylinder means hydraulic equipment arranged shown Fig. Definite pressures are specified for each size bushing. The lined cylinder then rebored and the cylinder head, valve head and steam pipe and other fits are ground assure steam-tight joints. this point the right and left-hand cylinder castings are ready for assembling, Iron Age, March 27, 1930 6—Cylinder Bushings Are Turned Lathes which special form, made sur- facé plate, angle ground bearimg blocks for the cylinder other parts. When the cylin- der castings are lined and clamped, the splice flange holes and the inserted and tightened. The assembled ready for planing the boiler fit, large planer having spe- cial head that permits machining boiler fits dif- ferent radii being used. Final Inspection Recorded The huge castings, completely machined and bolted together for erection, are finally delivered the in- spection department, located close-by, where the en- tire assembly checked gages various types, all significant dimensions being recorded. inspection made this point the inspector the railroad for which the locomotive being built. soon has passed the work, the completed cyl- inder loaded car and shipped the erecting shop per schedule. While not produced mass production basis, these huge locomotive parts proceed through the ma- chine shops with dispatch. Feeds and speeds that shorten machining time have been closely studied, and numerous workholding devices have been developed facilitate operations. But workmanship erecting form standards, not speed, the first law the plant. Thus are the wastes due hand fitting and re- handling large and massive parts eliminated, and thus the economical scheduling production and simpli- fication erecting are obtained. Wynn and published Charles Sever, Ltd., Man- chester, England (price 2s. 6d.). discusses non- technical terms this important subject, much neglected the trade literature obscured chemical and mathematical discussions lost upon the uniniti- ated. Unfortunately, the present book, containing only 16mo pages brief that only the commonly under- stood obvious facts are mentioned. 7—Finished Bushings Are Hydraulically Pressed into the inders. Definite pressures are specified for each size bushing Practice Making Duplex Steel Methods Control Slag and Oxidation—Elimination Twice Much Phosphorus Ordinary Basic Practice CARLIN* the acid Bessemer with the dephosphorizing power and close control the basic open-hearth, interesting both from chemical and economic view- point. carried out usually tilting Talbot furnace 100 300 tons capacity and was designed originally for the rapid manufacture low-carbon steel tonnage quality. steel practice, which combines the rapidity Certain refinements have been developed recently and the process now capable producing steel any car- bon content, quality which approaches and, with good practice, rivals that the regular basic open-hearth process. common with the majority processes, two factors greatest importance are the slag and the charge. Characteristics the Slag its function and composition the slag differs radically from that the regular basic process. The most im- portant slag function either process the elimination phosphorus. The mechanism this elimination has been consist the oxidation phosphorus ferric phosphate and its subsequent neutralization lime, according the following reactions: The algebraic sum reactions (1) and (2) gives re- action which means that the oxidation and permanent removal phosphorus depends upon excess both ferrous oxide and lime, and further favored low temperatures. the pig and scrap method the regular basic process, charge approximately per cent pig iron and per cent scrap generally used. Practically all the scrap basic open-hearth manufacture, with phos- phorus content approximately 0.015 per cent. The pig iron used produced from basic ore and contains around 0.225 per cent phosphorus. charge there would approximately 240 lb. phosphorus re- moved. the duplex process the charge may consist duplex metal blown entirely from basic pig iron. The phosphorus content 200,000-lb. charge would about 450 The slag the duplex process, therefore, must capable oxidizing and removing twice much phosphorus that the regular basic process. The iron oxide content thus necessity comparatively high, and for this rea- son sulphur elimination retarded except when unusually large amounts lime are added. Immediately after the tap the slag for the next heat made up. This done charging alternately roll scale *427 Wayne Street, Beaver, Pa. 34, United States Bureau Mines, Herty, Jr. and burned lime. The furnace not emptied completely, and the heat the residual metal serves fuse the scale and lime into homogeneous mass. The amounts scale and lime charged have been determined experience and vary with the quality desired and certain extent with the charge. Proportioning the Charge NLIKE the regular basic process, the charge usual- completely molten and consists duplex metal followed approximately per cent its weight pig iron. Duplex metal the name given the product Bessemer blow which has not been deoxidized recar- burized manganese. the acid Bessemer process, possible remove permanently practically all the carbon, manganese and silicon initially present the pig iron. Due the absence basic slag, phosphorus and sulphur are not eliminated and found that their percentage composi- tion actually increases, due oxidation the iron. This increase amounts approximately per cent. Owing the extreme rapidity the process, dif- ficult stop the blow predetermined carbon content, and the usual practice blow full, which means that the resulting product contains about 0.05 per cent carbon maximum, 0.10 per cent manganese maximum and phosphorus and sulphur content some per cent higher than that the initial pig iron. Duplex metal may produced from either basic Bessemer pig iron, the only difference being the phosphorus content. Charging Blown Metal Into Furnace Duplex metal charged into the open-hearth furnace from ladles approximately tons capacity, this weight corresponds that Bessemer blow. The ladles may either the lip spout variety, which means that, the lip type used, the duplex metal poured from the top, while the spout type used, the metal teemed from the bottom. slag consisting silica, iron and manganese oxides produced the Bessemer process; tilting the converter the end the blow, considerable amount slag necessity run into the ladle with the metal. the lip type ladle used, vari- ous amounts this objectionable slag are then charged into the open-hearth furnace. The amount duplex metal charged determined the capacity the furnace. soon the charge complete, approximately per cent its weight pig iron added. This causes violent reaction, owing evolution carbon monoxide, according the follow- ing reaction: The violence the boil determined the degree oxidation the duplex metal, its temperature and the tem- perature the pig iron. result the vigorous re- The Iron Age, March 27, 1930—925 action the metal and slag are intimately mixed, and the concentration ferrous oxide, together with low silica, insures rapid and practically complete oxidation and removal phosphorus. Interrelation Iron Oxide and Carbon this point interesting comparison with the regu- lar basic process suggests itself. the regular process, iron oxide the form iron ore used oxidize excess carbon, while the duplex process excess carbon the molten pig iron used reduce the iron oxide which saturates the duplex metal. present not practicable determine the de- gree oxidation the duplex metal. Consequently the amount pig iron necessary effect complete deoxida- tion and provide for slight excess carbon more less guesswork. The rate which the iron oxide the metal reduced the carbon the pig iron depends upon the concentration each and upon the temperature. soon carbon present the metal it, also, acted upon the iron oxide the slag. The diffusion and reaction rate proportional the concentration the iron oxide the slag, the viscosity the slag and the temperature. Oxidation carbon the ferrous oxide already present the metal, and that which diffuses from the slag, proceeds simultaneously. The rate the start, until the ferrous oxide and carbon solution come near equilibrium, exceedingly rapid. The intensity diminishes equilibrium ap- proached and, when medium, uniform boil present over the bath, may assumed that the carbon and ferrous oxide solution are practically equilibrium and that the reaction proceeds due only diffusion ferrous oxide from the slag. The importance regulating and controlling the amount ferrous oxide the duplex metal and the slag cannot overestimated. The composition the slag is, course, easily controlled, but that the duplex metal difficult. duplex metal heat may blown comparatively short time and, unless the flame care- fully watched the end, overblowing great extent possible, Governing Extent Oxidation Ideal procedure would determine the extent oxidation scientifically and then calculate the amount carbon pig iron necessary. This not practicable yet and the next best procedure add amount pig iron which greatly excess. This may done checking the carbon number heats soon the violent reaction has subsided. This will give rough in- dication how much pig iron necessary leave ex- cess carbon, which then can oxidized slowly the slag. happens sometimes that, due excessive overblow- ing insufficient pig iron, both, the fracture test the end the heavy boil shows the carbon extremely low. This means that the ferrous oxide the metal was sufficient oxidize all the carbon without the help the slag. heat tapped this condition, even though sufficient coal coke added bring within the car- bon specification, will extremely wild, and indicative very poor practice. practice necessitates care- ful watch the violence the boil and, toward the end the heat, the carbon dropping rapidly, more pig iron should added. The duplex process offers exceptional opportunity study the rate the reaction. Although carbon eliminated according this reac- tion both the regular and the duplex processes, the regular process carbon elimination, except when ore 926—The Iron Age, March 27, 1930 added, depends upon diffusion, which turn depends upon temperature, composition and viscosity slag. Exact conditions slag viscosity and temperature, from heat heat, are difficult duplicate and maintain. study the reaction practical scale, necessary provide system which allows knowledge the tem- perature and the concentrations both ferrous oxide and carbon the metal the start the reaction. These concentrations should such that the reaction con- siderable distance from equilibrium the start. Such conditions would insure freedom from slag viscosity com- plications. present impossible determine the tempera- ture with instrument, but may assumed constant within fairly close range. the duplex process the oxygen content the metal may determined and the carbon content calculated from analysis the pig iron and the total volume the metal. this manner slag viscosity may disregarded; for may assumed that, until equilibrium between carbon and ferrous oxide the metal approached, diffusion ferrous oxide from slag metal little importance. comparatively short time and, during this period, the tem- perature may assumed remain constant. the car- bon and oxygen contents are determined regular inter- vals and the results plotted time-carbon-oxygen dia- gram, interesting and practical information may ob- tained. Due the silicon and manganese content the pig iron, the results obtained would relative, but inas- much the concentration manganese and silicon the bath whole would small, the results would not affected from practical standpoint. Finishing the Heat Ideal finishing conditions include (1) Equilibrium between slag and metal with respect iron oxide. (2) judicious use silicon and manganese (deter- mined carbon content) effect deoxidation nearly possible and promote fluxing and elimination the solid deoxidation products. (3) tapping technique which will provide ladleful steel before the slag comes. (4) minimum amount slag covering the metal the ladle. (5) Dilution the ferrous oxide concentration the slag the ladle the use burnt lime and spar. (6) temperature high enough warrant holding the heat the ladle. Economy will not permit tapping the heats equili- brium, but the amount scale charged regulated with due respect the charge, the amount pig iron added, and the carbon desired, ideal conditions will ap- proached. considered that the carbon content and tempera- ture determine approximately the amount ferrous oxide the metal, ration manganese silicon may cal- culated which will provide for maximum deoxidation and optimum fluxing the deoxidation products. Care and practice plugging the tap hole will insure that the next heat will tapped through hole large enough keep the steel the right temperature, and yet small enough hold the slag back until the ladle prac- tically full. early slag run occur, wildness the ladle and excessive loss carbon, manganese and silicon will result. When the heat the ladle with its blanket slag, diffusion iron oxide from slag metal takes place just does the furnace. theory, the rate diffusion does not depend upon the amount slag, but practice found that the amount very important, especially when the iron oxide content the slag high. For this reason the amount slag the ladle should kept minimum. possible correct the harmful effects large amount highly oxidizing slag the addition mixture burnt lime and spar. This mixture should added after the slag comes. Its purpose dilute the concentration ferrous oxide, thereby checking diffusion. high finishing temperature serves decrease the amount ferrous oxide solution for given carbon content, and decrease the viscosity the metal. This decreased viscosity provides the best conditions for fluxing and eliminating the deoxidation products. the above practices have been followed, the various reactions should equilibrium and, the temperature high enough warrant holding the heat the ladle, this will promote complete diffusion and equaliz