The Iron Age 1928-11-15: Vol 122 Iss 20

RON New York, November 15, 1928 ESTABLISHED 1855 Aircraft Industry and Near Philadelphia HORACE KNERR* the banquet the American Society for Steel Treating held connection with the National Metals Exposition Philadel- phia, the aircraft industry was prominently featured. This was two-fold significance: first, that the construction air- craft rapidly becoming one the foremost industries, and second, that becoming metal working industry. During the year 1927 the number airplanes made this country was less than 2000, including those for Army, United States Air Mail, Navy, and commercial require- ments. been estimated that during the present year the production will approximately 15,000 planes, increase seven and one-half times. While the tonnage metal now used airplanes and airships small, and perhaps never will compare with that now used automo- biles, nevertheless important. One prominent manufacturer high-grade alloy steels estimates sales about 5000 tons for aircraft consumption during the year. This, the conservative figure cents per pound, represents business $1,000,000 for one company alone. Seamless steel tubing today the prin- cipal material construction for aircraft. One manufac- turer seamless tubing the Philadelphia district the present time producing well over half million feet per month for the aircraft industry, about 7,000,000 ft. *Consulting meta!lurgical engineer, 538 East Washington Lane, Philadelphia. 1211 VOL. 122, No. year, and the plant being enlarged 10,000,000-ft. capacity. Two leading manufacturers are each turning out air- craft engines valued from $3,000 $8,000 apiece the rate 100 150 per month. This figures approxi- mately million dollars monthly. The welding industry has also found surprisingly large outlet aircraft manu- facturers, due principally the development the welded fuselage. Large requirements more ordinary tonnage steel, distinguished price and quality from that used the actual flying machines, are found shops, machinery and hangars, together with other such ground facilities beacons and accessory landing field equipment. Aluminum alloys high strength, both cast and wrought (the latter the duralumin type), had their original application aircraft construction. Their field usefulness has now extended automobiles, railroads and other lines, considerable tonnage. Philadelphia, long known the “workshop the world,” has prominent place the aircraft industry. Its geographical position approximately line with both east-and-west and north-and-south air mail routes. There are landing fields within miles the center the city, about half them being inside close the city limits. Several these are located closer the busi- ness section than other large centers. The all-year- round weather conditions for both land and water are better than many aviation centers further west north. flying field that will rival size and accommodations the famous landing fields Europe—such Croydon 2 ; + 45 | 4 } ¢ London, Bourget Paris Tempelhofer Berlin—is established within twelve minutes automobile from City Hall, the Camden terminal the Delaware river bridge. will cover site 175 acres and will have four runways, each 2500 ft. length. the Philadelphia Navy Yard the famed naval aircraft factory which was the center the Navy’s pro- duction both heavier-than-air and lighter-than-air craft during the war. This great plant now devoted re- search, testing and development. Within half hour’s flying distance the naval air station Lakehurst, the home the Los Angeles and the journey’s end the Graf Zeppelin. Bristol, few miles outside the city limits, are the works the Keystone Aircraft Corporation, manu- facturing large planes the bomber type for the Army well many commercial craft. the city’s border Bryn Athyn also the factory and test field the Pitcairn Aviation Co., part whose plant shown the head piece this article. This con- cern operates the air mail from New York Alabama This new field will known “Central Airport”. preliminary training course aviation. Graduates are line enter the regular naval flying courses and be- come officers the naval aviation reserve. Here also the course heat-treatment and metallography steel conducted under the auspices the Philadelphia chapter the American Society for Steel Treating, many whose students are employees plants which are identified one way another with the aircraft industry. The high quality this work was officially recognized the national society the recent convention when President Hughes awarded the “president’s bell” the Philadelphia chapter for its energy initiating and sponsoring this educational effort. Mushet Steel Made the First Alloy Tools HIGH-CARBON manganese-tungsten steel was oped about 1868 Englishman, Robert Mushet. Whereas steels known before that time required rapid quenching from high heat order become hard, Mushet’s steel was excessively hard after air cooling and ORACE KNERR was graduated electrical engineering Uni- versity Pennsylvania, 1910. After some routine laboratory work and steel inspection joined the Naval Aircraft Factory staff early 1916. From 1918 1925 was chief metallurgist—a period during which the rigid airship Shenandoah was constructed. Since 1925 has been practicing consulting metallurgical and aeronautical engineer. active member the American Society for Steel Treating, and largely responsible for the educational course jointly sponsored the society and Temple University. (Photo Copyright Bachrach) and manufactures the planes for this service well those used five other air mail lines, together with planes for commercial and private use. few miles from Philadelphia, near Wilmington, the new factory the Bellanca Aircraft Co., which now undertaking production program 300 six-passenger planes for commercial purposes. flying field adjoins the Delaware River, covers more than 300 acres, and affords all necessary land and water landing facilities. Various producers materials, parts, accessories and service used aircraft are located and about Phila- delphia. Bridgeport, Pa., miles from the city, the plant the Summerill Tubing Co., entire section whose mills has been devoted the production seamless tubing for aircraft, both mild carbon steel and chrome- molybdenum steel. cope with the increasing demand (which exists all lines aircraft construction) new mill now being erected this organization. Steels and other alloys used aircraft are necessarily the highest type, requiring heat treatment under close technical control. The size and shape many fabricated parts are such call for delicate manipulation. provide such service Metallurgical Laboratories, Inc., has installed complete testing and laboratory facilities, and specially designed furnaces capable heat-treating not only the numerous parts and fittings aircraft, but also engine parts steel aluminum alloys, axles, struts and the long wing beams, spars alloy steel tubing which are now used leading aircraft manufacturers. The Navy Department conducts Temple University 1212—November 15, 1928, The Iron Age retained that hardness even after high tempering. For these reasons was called “natural” “air-hardening” “self-hardening” stecl, and time came used for machine tools for cutting the harder steels and cast irons. Owing the lack uniform ferroalloys needed the manufacture, these early high-alloy steels varied chem- ical composition between the following approximate figures: Carbon 1.85 2.15 Manganese 2.5 1.5 Tungsten 9.0 5.5 Other air-hardening tool steels introduced compete with Mushet steel without infringement the patent rights were lower carbon, contained few per cent chromium, substituted molybdenum for the tungsten. Such steels formed the basis experimentation which led Taylor and Maunsel White discover the distinctive heat treatment which induced the quality red-hardness tungsten-chromium steels. What now known “high- -speed” steel later development. Present day representatives Mushet steel are the “fast-finishing” steels, inexpensive quality tool steels for cutting hard metal. typical analysis contains 1.25 per cent carbon, manganese, 3.5 tungsten and 0.3 chromium. Work benches number plants San are covered with %-in. steel plate. The workmen may ham- mer the top the bench without denting the wood. the plant the Howard Automobile Co. the legs the covered work benches are cast iron. | 7 | q 7 ; "7 f ‘Ne y 7 7 7 7 7 7 4 7 ‘Pa. the foreground tri-motored com- mercial plane for passengers. All fuselage skeletons are steel tubing, welded the intersections Aircraft Corporation, Bristol, Electric Heat Treating Machine (at Right) Necessary for Certain Aircraft Parts. Inside dimensions are ft. square and ETAIL Wing Section (Below) and At- tachments Keystone Bomber. Made steel tubing and duralumin sections if The Iron Age, November 15, 1928—1213 7 7 7 Non-Destructive Detection Flaws Hidden Fissures Rails Located and Measured Electrical Methods—Process May Used Track Service ELMER SPERRY* cause bar rail non-destructive methods “cough all the skeletons its closet,” its internal physical condition, must necessity subjected intense energization. Both alternating current and magnetism are forced completely out, owing their energization being confined skin effect. not pos- sible reach the interior any structure either these methods. Direct magnetism direct current are the only methods The rail user has compelled the rolling mills produce rails progressively harder and harder until the present-day rail, very high-carbon steel, hard that practically tool ordinary high-speed steel will effectively machine it. Permeability steel always bears inverse ratio the hardness factor. Hard steel thus very low permeability and some heat-treated and quenched manganese steels even fall practically zero magnetic permeability. Since for most purposes heavy energization throughout the whole area required, this once puts these feeble magnetic densities out the picture. are therefore left with only one our four possible energizations—direct current. This has the great advantage not being limited any law saturation, simply obey- ing Ohm’s law. there practical limit the amount current that can put through the conductor, especially the short time necessary make the inspec- tion. This has another advantage, allowing secure any character result required. Through varying the energization possible make wide range determi- hes) More * a Z ~ aations, including the different molecular characteristics the specimen well the soundness the steel cracks, flaws, inclusions and other physical imperfections. This course extends all non-magnetic conductors Uniform distribution the primary energization throughout the mass completely secured using direct current, that, matter where the flaw irregularity exists the interior the structure, reached pletely and its detection made possible. Avoiding Extraneous Disturbing Elements One difficulty immediately foreseen was that neutral- inevitable variations, large small, the primary energizing current, and thereby preventing false indica- *President Sperry Gyroscope Co., Brooklyn, and President- elect the American Society Mechanical Engineers. This abstract paper delivered Mr. Sperry Oct. 26, New York, before the American Iron and Steel Institute. 1214—November 15, 1928, The Iron Age tions. the plan developed incorporated means this end, completely neutralizing all such variations, regardless their magnitude, and preventing them from reaching the interpretive portion the equipment. Thereby the explora- tion method itself was confined exact conformity with the interior characteristics. This was found comparatively easy accomplish, and may illustrated one method. The main primary energizing current made traverse the rail, section thereof, main brushes con- tact with the track. Intermediate between these brushes are three searching brushes 11, and shown dia- gram. These are connected two opposite primary coils and 23, constituting the primary transformer 24. These coils are oppositely wound and produce opposite magnetic excitation the transformer. All variations the primary current will picked the two outer Method Re- laying Indica- tions from Rail Instru- ments, Through Transformer Eleven Fissures Were Lo- Indication cated This 105-Lb. Rail, Indicated. The num- bers tell, the extent their divergence, the ap- proximate size flaw brushes and thus completely neutralized their in- fluence the secondary 25. But, passing along the track, when fissure occurs between one end brush and the middle brush, the first coil will become excited greater extent than the other. The transformer will become active and the secondary will induced half, say the positive side, sine wave curve. the next instant the fissure passes between the middle and the rear brushes, giving opposite excitation the secondary, completing the alternating wave add- ing the negative side. now have true alternating wave. This wave then passes the amplifiers and may examined both its magnitude and characteristics. call was sent out for pieces rail that had broken service. Three rails came, two from one road and one from another, where the transverse fissures had grown until the rails had broken service. When 2000 amperes was put through these rails found that one piece j lei 7 S S S 7 7 was entirely free from even minute hidden flaws. The second had one large flaw—transverse fissure—which had not come the surface and was completely hidden. The First Transverse Fissure (Above) Ever Apprehended the Electrical Method Five the Eleven Fissures Spotted the Instrument Rail trical Method (Low- Right) third piece rail, some ft. long, contained less than transverse fissures. ascertaining the importance these fissures, had blue print made showing both their size and location the rail. Then the Rail Committee came the laboratory, whereupon broke these rails and with 100 per cent results. One illustration shows the first transverse fissure ever apprehended the electrical method, which may some day historic importance. sketch shows the exact locations determined for these fissures. Another view shows the appearance the fissures found the rail. The smallest one, was only per cent the area the head the rail Since that time the method has been used about rails furnished the laboratory from various roads the United States. Many these were perfectly sound and gave not the slightest indication anything but the finest continuous and homogeneous structure throughout. But the others about fissures were located. Upon breaking these rails the flaws were found exactly where the apparatus indicated, and none these gave the slightest superficial indication either their size location, with the exception two only, which had come the surface. one shipment rails, all which had broken service, the railroad was sure that number other fissures existed. Upon examination they were found per- fectly homogeneous and without even the smallest fissure flaw being indicated. The process was intensified apprehend easily flaw equal per cent, but the rails showed absolute soundness and freedom from any internal imperfections. the railroad officials, not satisfied with this finding, felt that they were correct their assumption fissures this group, certain rails were selected, the webs burned off and the heads completely broken into small pieces with steam hammer. The breaking was not shearing any sense and was such character that, had there been any fissures, they would have located the break. Each fracture was examined carefully both faces and the showed the finest possible structure with complete homogeneity. have had trouble locating some fissures such, for instance, one illustrated. Can Tell Size Well Place Positive indication afforded not only the exact location the fissure but also its size. The uniformity potential drop which exists all other points the rail interrupted fissure. Although the disturbance minute, through the amplification brought usable magnitudes operate indicators recorders, paint spray, etc. sound rail the direction current flow axial unless disturbed. The slightest disturbance changes this alinement flow and means have been found utilize this deviation, both angle and magnitude the mean axial departure, for giving accurate interpretation the cause, especially when all elements are magnified recognizable. Thus the size, characteristic and exact loca- The Iron Age, November 15, 4 ‘ 7 J J | § § q tion the fissure other flaw are accurately determined. This latter method has advantage over the first, the indications and determinations are all realized without physical contact with the surface the rail other metallic conductor being investigated. Testing 1000 Rails Mill the laboratory was found possible increase the sensitivity and responsiveness this last-named method get accurate record the soundness Brush Arrangement Under Car. The paint gun shows center. Just left set copper brushes; another set right center the rail down flaw defect representing less than 0.1 per cent the area the head the rail. important that this found equally true with non-ferrous metals. complete set apparatus was devised and taken one the largest rail mills and there set and employed investigating 1000 39-ft. rails varying from 130 lb. section. These rails had passed most rigid inspection before being submitted the process. Rail after was passed through the process, showing perfectly straight line and complete soundness struc- ture. The entire batch rails was remarkably free from defects, but such defects existed were invariably picked and recorded the process, both magnitude and position the rail. Many these proved surface abrasions and defects which were not looked upon the inspectors objectionable, but the interesting feature that all were located and recorded. Many “roll-ins” and head seams surface cracks were found, which had escaped the inspectors’ observation but were invariably located and recorded; thus and thus only were they brought under the observation inspector. Although the rails had been handled repeatedly magnetic lifter, and although this had been greatly accentu- ated some rails, ascertain the result, the accuracy the inspection process was not affected thereby. was found that heat-treated rails could searched well normal rails. high-manganese rail that had been heat treated and was non-magnetic was put through the process, with high degree accuracy. Rails developing fissures after being only short time service are the majority instances found associated with shatter zones. Now that these zones can com- pletely located and recorded the non-destructive method, might wise eliminate rails containing such defects from main track, especially where the traffic dense, and utilize them less important positions. Finding Fissures Busy Tracks Referring now the inspection rails track, the car now operated the roads members the American Railway Engineering Association consists standard track maintenance trailer car upon which built 1216—November 15, 1928, The Iron Age inclosure containing the power plant, radio apparatus and recording mechanism. motor car required for towing purposes; the operating speed miles hour more. The power plant placed the forward end the platform includes 25-hp. gas engine with necessary starter and auxiliaries, directly connected 4000-ampere, 2-volt generator operating 900 r.p.m. One illustration shows the contact brushes which the top surface the rail, and between which flows the energizing current. Each contact assembly consists eight individual copper brushes, pressed against the rail head springs. These brushes are mounted rigid frame which raised and lowered lever the car. There are two sets eight brushes contact with each line rails. Small brushes, equivalent searching equip- ment, are mounted between the brushes and form the mechanism for picking the difference potential from the resistance effect the air gap the internal break the rail head. This micro-voltage carried set four radio tubes which step 200,000 300,000 times. Near the center the cut the paint spraying device can seen. relay controls the release spray paint against the side the rail whenever defect found any point its length. How the Permanent Records Are Made Above the table containing the necessary batteries for the tubes shown the suspended aluminum case containing the amplifiers. the table are the relays, ten being re- quired for various purposes. top the recording table travels friction-driven moving strip paper. con- tact with the paper are seven pens which are actuated the relays circuit with the tubes. Fissures located one line rails are indicated the paper three pens, and similar set pens for the opposite line rails. The center pen records location joints. The relays are adjusted that short transverse line drawn one pen the internal break small area; two pens operate the break intermediate size Recording Table, Showing Seven Pen-Drawn Lines Left and Rail Numbers Right. Nicks the lines tell conditions the rails and all three pens large area. The fissure pens are automatically thrown out circuit when the pen for loca- tion joints operates. The three lines the left record defects the left- hand rail; the middle line locates the joints; the three hand lines indicate defects the line rails. The short transverse lines thus permanently record the location internal breaks and their size area. num- bering machine also conveniently identifies each rail the record, while the paint spray notifies the trackmen the existence and location defective rails. | 7 | ; 7 4 1 | 7 7 7 7 | | 7 7 7 q 4 7 wae Rotary scratch brushes, not illustrated, are set ahead the front contact brushes and remove rust foreign material from the running surface the rail insure good contact for the contact brushes. buzzer horn placed the car operates relay notify the operator, and further check the proper functioning the apparatus. Instruments Sensitive But Under Control found possible bring the apparatus easily into such adjustment that, unless discontinuities exist the rail head, there not the slightest indication either the indicator recording pens, showing that the rails are structurally sound and normal. The apparatus also found susceptible such adjustments will bring other characteristics outside discontinuities, cases where such indications are found desirable. would fulfill specified test requirements. have noticed that, under our standard current densities, the temperature the rails has always risen. This temperature rise comes from within, contrast with the usual method heating from without. Also the electrical saturation invariably accompanied phenomenon which nothing short positive and most striking molecular realinement and read- justment, constituting vigorous magnetic radiations from the innermost portions outwardly. therefore cannot but have beneficial aging and positive strain-releasing influence. Thus effect equivalent the aging weeks and even months may concentrated into minutes seconds, bringing the rails higher standard test qualifica- tion and general usefulness this artificial internal molecular release and adjustment. have already hand sufficient data state positively that important Ten Relay Sets Table, with the Suspended Aluminum Cases. The batteries for energizing -the tubes are placed beneath the table Comparing this method with the old destructive method diseovering hidden fissures discontinuities, experience has shown that defects, especially this class, are re- vealed more accurately and more reliably the electrical method. The following incident illustrates this very clearly: Record was made hidden fault consti- tuting fissure crack some considerable magnitude. repeated searchings the same region this rail the records were absolutely consistent, both magnitude and location. This piece rail was cyt out and the regular standard destructive method was proceeded with well established laboratory, but grinding and etching failed reveal any- thing photographically the microscope. The sample was finally virtually abandoned the laboratory con- taining flaw. However, knowing our electric process that definite and quite serious fault actually existed this point, urged that the sample re-etched using the strongest possible re-agents procurable. This was done, whereupon the microscope revealed transverse crack crevice about in. long exactly the point electrically indicated. Seasoning Rails Electricity by-product the electrical method has interesting bearing improving the quality the rail. There have been instances mills where “aging” “seasoning” was necessary bring the rails the point where they gain this character definitely secured by-product this electrical inspection process. With the detector car becomes possible sweep tracks free from the aggravating menace transverse fissures. About 5000 rails were broken last year, through fissures having grown the extent causing the failure the rails service. The present practice remove the entire heat, heavy cost, from the road where these fissures are repeated, this being mandatory some States. Our experience the present searching large num- ber rails, and ascertaining about the percentage fissures existing, indicates that the lifting these heats altogether too radical demand. Probably between and per cent the rails lifted are perfectly sound and should untouched and remain the roadbed, thus making possible definite saving the railroads the use the car. The value the recovery eight non-ferrous metals from secondary sources 1927 was $256,352,000 against $274,540,900 1926, reflecting decrease $18,188,900, according reports made the Bureau Mines. Dunlop, who compiled the figures, said the decrease total value was due lower yearly average price all the metals covered the report, other than nickel, for the total recoveries were about 11,000 tons more than 1926. The metals included the report are copper, brass, lead, zinc, tin, antimony, aluminum and nickel. The Iron Age, November 15, 1928—1217 r i 7 3 7 7 q ; 4 4 34 4 5 A a 7 1 Several Methods Gating Molds Multiple Pencil Gates for Thin Castings—Explanation Use Equalizing Gates PAUL RAMP* gates molds, covered THE IRON AGE Oct. and Nov. description other special types gates here added. particular, the use pencil gates, considerable numbers the mold, taken up, and their utility and limitations are shown. Equalizing gates, for in- tricate castings, are found overcome previous troubles and very much worth while. the discussion many the simpler forms Pencil Gates Cylindrical Castings making cylindrical castings that must particularly clean, such rolls, pump plungers and many other articles, advisable pour these castings end. One illustration cross-section cylinder mold. the right are shown the drag mold, cheek mold, cope mold and the pouring and runner basin, all vertical section. The plan the pouring and runner basin shows the small pencil gates, imdicated LLL. partial cross-section this mold partly filled with metal, the metal falling into the mold being indicated the arrows marked Referring again the vertical section, the metal poured from the ladle into the pouring basin and imme- diately fills the runner basin, which must kept full until pouring completed. The metal flows from the bottom the runner basin through the small pencil gates and enters the mold C-C, dropping the bottom the mold This pouring continued until the mold full. provide for riser feeding head casting this character, the mold extended several inches the end the casting proper, which this case shown the flange indicated The depth this riser must vary according the volume metal required fill the mold and the length the casting. The excess metal re- quired form the riser feeding head can cut off the machine shop. Another illustration how the metal enters the pour- ing basin and flows into the runner and into the pencil gates afforded the plan. The view the lower left *Superintendent foundry and pattern shop, Newport News Shipbuilding Dry Dock Co., Newport News, Va. Runner shows why pencil gate more effective than bottom gate for casting this kind. When mold being filled with metal, any impurities that may find their way into the mold, may already there, float the top with rising metal. They continue rise with the metal unless they come contact with the walls the mold. such case they cease flow up- ward with the metal and cling the mold surface, regard- less how much metal flows by, unless some agitation produced dislodge them. This plan pouring dislodges any impurities that may cling the side the mold, and continues dislodge them, how many times move- ment they may come contact with the mold ‘surface. This accomplished action the metal dropping through the pencil gates, where each stream strikes the body metal that has preceded it, and un- usual agitation created. The illustration attempt show visually the effect these numerous streams metal the body metal the lower part the mold. The continual agitation the surface the metal persists until the mold filled, thus automatically dislodging any impurities inclined cling the mold surface. This makes possible for them carried the top the mold, into the feeding head section, where they will harm. Pencil Gates Pipe Castings ENCIL gates cylindrical castings are such important devices that method using them pipe castings will described. These castings are pipes in. di- ameter and in. thick. prevent the casting from cracking, green sand core used; dry sand core were used the casting would crack cooling. This pipe cannot poured end, shown the other case, be- cause then the pressure the lower end would too great green sand core. result, instead being in. thick, might three times that, owing the fact that the green sand core could not withstand this pressure. the green sand core were rammed hard enough retain its original shape, the metal would not lay it, Use Pencil Gates Thin Pipe Cast Horizontally, Two Rows Gates Being Used, Fed from Common Runner 1218—November 15, 1928, The Iron Age > but would cut the core badly and produce sand holes well blow holes. For this reason the pipe molded hori- zontal position and gated with two rows pencil gates, along the upper surface the mold. The pencil gates used case this kind are small possible, but, course, must large enough prevent the metal from chilling its journey from the runner the mold. Pencil gates are shown both views. The metal poured into the two basins indicated quickly possible, fill the basin before any impurities can find their way into the pencil gates the points indicated CCC. usual practice use two ladles that will carry enough metal fill the runner, and make the runner large enough hold sufficient metal fill the mold. When this done the pouring operation simply question dumping both ladles into the basin quickly possible, and letting the metal flow through the pencil gates into the “J Cross Section Mold Partly Poured mold DDD. Two rows pencil gates should used mold this kind. This plan gating very thin casting superior trying gate the joint the mold, gravity assists the flow the metal from the time enters the until the cavity full, and the hottest metal always top. using gates this kind green sand core the upper portion the core can rightly termed part the gate arrangement, the this point must carefully vented with cinder bed otherwise, and the sand mixture used, and very often surface-nailed the point where the metal strikes it, there will danger Equalizing Gates FTER the proper gate provided for leading the metal the mold, sometimes necessary, owing the shape the mold, consider further how the metal fill the cavity. many cases what termed equalizing gate necessary, prevent cold shuts large, intricate castings. Cross-Section Cylinder Mold Pencil Gates Around Periphery Cylindrical Castings Cast Vertically. Metal from basin fills runner and goes down the multiple gates example the use equalizing gate shown the cross-section locomotive cylinder mold. This sketch not taken from any definite blueprint, but drawn from memory illustrate the use the equalizing gate. this case the metal, poured into the runner basin flows through the down gate and into the mold From this point flows around the exhaust core and fills the saddle portion the mold JJ. When the saddle filled the metal rises level and, equalizing gate used, when the metal reaches the point the mold indicated does not travel upward any more, but remains sta- tionary until enough metal has flown over this high point the mold fill the piston valve section DDD. After this, all the metal the mold begins rise the mold filled. Although the metal may very hot, and comes the risers very satisfactory condition, there grave danger cold shut being produced around Equalizing Gate Used Compli- cated Locomotive Cylinder Casting Avoid the exhaust pipes, live steam pipes and other sections DD, because the time this metal remains inactive while the piston valve section being filled long enough allow crust cold metal form over its surface DD. When all the metal has reached the height indicated and once more starts upward, does not carry this crust with it, and very few cases does fuse it, but flows around it. consequence cold shut division meta) produced the casting this point, and the result leaky steam passage. The remedy for this the equalizing gate shown When the metal enters the mold and soon the saddle portion the mold has been filled, flows through the equalizing gate into the piston valve section the mold, and upward indicated the arrows. And while the metal will rise slower when the entire mold being filled, the use the equalizing gate will continually motion, traveling upward. Thus the danger crust forming over the portion the metal that remains standstill for short time eliminated. There are many molds this character where the metal stopped its upward journey while some lower portion The Iron Age, November 15, 1928—1219 4 4 4 4q being filled. This action invariably creates cold shut, and equalizing gate such described here should used wherever possible. Many large castings have been found defective because the proper equalizing gates were not provided. gating mold this character, good practice add additional inlet gate nearer the upper portion the mold. This suggested inlet gate, shown for the purpose providing hot metal direct the upper portion the mold. General Considerations There are many more kinds gates, but the object this article merely give general idea the impor- tance gating molds and few suggestions how make the gates. production work there are many special skim gates, and gates cores, that will more effective than the hand-made gates described here. But the foundry job- bing business impossible provide special set gates core gates for the great variation work made from Aluminum the Mold Makes Abnormal Steel EVERAL automobile manufacturers, led Upham the Chrysler Corporation, united request- ing the Bureau Standards investigate the problem “abnormal” steel, indicated the McQuaid-Ehn car- burizing test. reason the facilities extended Cen- tral Alloy Steel Corporation and Trumbull Steel Co., Epstein and Rawdon the bureau have been able reach the conclusion that abnormality largely due the method finishing heat steel. Their studies are described the 44-page Research Paper No. 14, Bureau Standards, Washington. The paper starts with statement the authenticated properties normal and abnormal steel. Thus, normal steel cannot changed into abnormal one cold work any commercial heat treatment. Hardening water from salt baths does not prevent soft spots abnormal steels but quenching brine does. Normal low manganese car- burizing steels not develop soft spots even after oil Results the McQuaid-Ehn Test Normal Abnormal Microstructure case Grain size Usually large Small Excess cementite Well defined Coalesced network Pearlite Lamellar Tends toward spheroidal Thickness case Deeper Shallow Izod impact strength Normalized Coarsened That the McQuaid-Ehn test does indicate relative hard- various manners, only one pair did the abnormal sample show lower index number soft spots, deter- mined hardness explorations carburized and quenched samples. Killed steel can either normal abnormal; can steel, Chemical analysis fails show any connection between the ordinarily reported elements and abnormality. Ehn’s opinion was that abnormal steel contains undue amount. submicroscopic oxides. Not all oxides are potent, indicated tests made from open-hearth metal various stages during refining. Some heats are abnormal all times and the ingot; others are normal all times and the ingot; still others are abnormal only until deoxidized. Spectroscopic analysis shows, however, that the alum- inum content exceeds 0.010 per cent the will almost surely abnormal. Oxygen analyses are not conclusive, because the methods use not break aluminum oxides; determined the residue from abnormal steels high. was therefore concluded that aluminum 1220—November 15, 1928, The Iron Age day day small lots. Consequently molder must competent make his own gates for each mold called upon produce. Finally, the important things observe all times gating mold are: should always clean and free from loose sand. 2—Gates must soft enough keep the metal from cutting into the surface and producing dirt. 3—Gates must not soft allow the metal strain into them cut wash. making these gates soft they must pressed down the right hard- ness with the finger hand all green sand work, and not slicked with tool. slicked surface gate for green sand mold will scale off when the iron flows through it. 4—Gates must brushed clean with camel hair brush, and the surface directly over the gate the cope must slicked prevent the loose parting sand adhering the cope surface the mold from being washed into the mold the gate under it. may the culprit and some tests were made during the refining and pouring stages steel plant. was found that aluminum ferrovanadium added the ingot pro- duced abnormality both killed and However, enough aluminum added the ladle kill normal effervescent steel did not produce Ferrosilicon either ladle mold does not produce abnor- mality. the basis these studies, Messrs. Epstein and Raw- don draw the following practical conclusions: Soft spots case-hardened articles can overcome increasing the quenching rate using another type steel. any particular plant the trouble can handled according the practice, equipment, quality, cost and the personal preference the metallurgist. One solution which appears general trend the use the alloy carburizing steels which harden uni- formly water quenching, for example, the nickel molyb- denum steel used for roller bearings. The special man- ganese carburizing steels also belong this class. The former has been called “fine-grained normal” and pre- ferred coarse-grained normal steel for the obvious reason that coarse grain conducive brittleness. With the “fine-grained normal” steels the “regenerative quench” heat” often omitted. When plain carbon steel still wanted, the metallurgist may specify normal steel avoid soft spots. Besides being more likely harden uniformly has the advantage that carburizes somewhat faster. more uniform material may thus obtained. The use normal steel not the only recourse, however. Another metallurgist may decide depend more drastic quenching pressure spray brine get uniform hardness. may even prefer abnormal steel with its fine grain, for the same reasons that the “fine-grained normal” alloy steels are preferred. tap water used for quenching, there danger getting soft spots normal steel well abnormal steel, but with brine other drastic quenching, both types steel will harden uniformly. “Normal” and “abnormal” should not taken syn- onymous with “good” and “bad.” Even each type alloy steel therefore has its particular field and advantages, also normal and abnormal steel may preferred, each according the special conditions plant. The tests indicate that the steel maker ought able produce normal and steel will, subject, course, the limitations chemical composition. (It would hard produce coarse-grained vanadium steel, for instance.) Fine grain would preferable. | | 7 7 7 7 7 | 7 { Making Electric Heating Appliances How, for Different Uses, Filled Tubular Elements Are Annealed Calorized Made Part Casting against oxidation tubular forms electric heating elements the method developed the Edison Electric Appliance Co. the manufacture electrically heated waffle irons, irons, flat irons, toasters, percolators, soldering irons, The wire coils the resistors are in- serted steel copper tubes into which packed mag- nesium oxide. the case flat irons hot plates for cooking ranges this element placed the mold the foundry and becomes integral part the casting. Some the details the processes are shown the accompany- ing illustrations taken one the two Chicago plants the company, which also has plant Ontario, Cal., and which the outgrowth merger the Hotpoint com- pany, the Hughes company and the appliance division the General Electric Co. some ten years ago. The tubes, which range from in. diameter, are cut length cold cut saws and are counterbored both ends centering machines permit the crimping washers hold the coil inside suspension. The coils are nichrome wire, which formed winding the wire motor driven spindles high speed. They are cut the proper lengths, which range from in., according the type appliance which they are used. When coil inserted tube, washer put one end and yoke shaped washer slipped into the other hold the coil tension and then the assembly taken the filler room. Here the assemblies are put into racks hold- ing time with hoppers above and tubes running from the hoppers the upper ends the assemblies. These racks are made vibrate high rate motors and cams which cause the magnesium powder pack tightly runs from the hoppers. Full washers are then put both ends and crimped into place hand. The magnesium oxide packed still more tightly swaging the tubes swaging machines which reduces the diameter 1/64 in. These units are then annealed gas-fired furnace, which ft. long, ft. wide and ft. high. Built brick suitably insulated and steel encased this furnace has run- ning through three nichrome steel tubes about in. diameter. They extend about ft. beyond one end for cooling zone. The tubes are plugged both ends while the work inside and city gas forced in, passing through water seal point close the discharge end in- sure neutral atmosphere. Formerly nitrogen was used. The work pushed through bundles, one bundle pushing the preceding one. Heat supplied through two gas burners, equipped with inspirators, underfiring the work through one end the furnace. The gas supplied lb. pressure and inspirates the air the proportion maintain complete combustion. Only the steel tubes are annealed here and the temperature range 1400 1500 deg. Fahr. The furnace was manufac- tured the Surface Combustion Co., Toledo, Ohio. The waste heat from this furnace utilized dry- ing oven, ft. long and ft. square cross section. Electric Flat- Are Made Steps from Station Station the Assembly Bench The Iron Age, November 15, 1928—1221 J 2 2 7 in | 4 7 0- r 7 v- 7 le 7 7 ; 7 Prior assembling the tubes and coils, the former are pickled and then dried this oven. After annealing the tubes are again cold swaged and reduced another 1/64 in. diameter. in-and-out type furnace used anneal miscellaneous stampings, punch press products, etc. This unit ft. wide, ft. high and ft. deep. fired with burner and inspirator each side. The electric heating units are now formed into various shapes for different applications. Some them are rolled give square shape the tube. For the heavy duty broiler oven plate tube about ft. length coiled spirally. This type unit calorized. Those coming con- tact with hot water are tinned and the others are incor- porated into various appliances without any treatment. Calorizing this case consists dipping into molten tin and then into molten aluminum. For this process two cast The Swaged Tubes Contain- ing the Resist- ance Wires Are Annealed Passage Through This Fur- nace 1222—November 15, 1928, The Iron Age One the Sub-assembly Departments Elec- tric Flatiron Manufacture iron pots are supplied, held place brick structure, which has furnace underneath. This structure ft. long, ft. wide and ft. deep. The pots are in. long and in. deep, while they taper width from in. the top in. the bottom. Heat supplied four gas burners for each pot, two firing each end and the flames impinging. Inspirators are supplied control the atmosphere for the prolongation the life the pots and supply air the gas-air mixture the right proportion insure per- fect combustion and minimize consumption. The ele- ments calorized are first dipped the tin and then into the aluminum. The first carried 600 deg. Fahr. and the latter 1600 deg. This furnace was also designed and built the Surface Combustion Co. The calorized elements are now sent the terminal as- q 7 sembly department, where the ends the tubes are cut off for about quarter inch, leaving the ends ter- minals protruding. Leads are then brazed on, using mica washers insulate from the tubing. After testing elec- trically for short circuits, the elements are sent the stockroom drawn for assembly the various ap- pliances needed. previously stated, these elements are inserted the foundry molds when, flat irons and hot plates, they become part the casting. The foundry this plant equipped with continuous molding machines which consist circular frames, about ft. diameter, mounted hori- zontally with the floor and rotated motor. Brackets The Calorizing Furnace Uses City ing Gas for Heating Permanent Molds, Mounted Rotating Fixture, Are Used Casting the Flatirons q hold the molds are placed these frames short intervals. The molds dies are two parts, one stationary and the other movable, close open the mold. This opening closing the mold accomplished cams which op- erate the frame rotates. the molds pass one station they are opened and operator inserts the elements; they are then closed and the molten iron poured the next station and then they are opened again for the casting drop out. The iron consists two castings, the pressure plate and the sole plate, which are later bolted together. The hot plates are cast the pouring floor flasks con- sisting cast iron drag and sand cope. All elements are preheated before inserting the molds. The Iron Age, November 15, 1928—1223 3 Business Building Has Welded Frame Designed for Arc-Welded Steel Construction, Upper Carnegie Building Cleveland Presents Some Unusual Features ITHOUT rivet bolt its steel framework, Upper Carnegie Building, Cleveland, the first commercial store and office building erected the arc-welding process. “shop” fabrication and field erection the members the structure were fused to- gether joints the use the electric arc. The steel framework is, therefore, actually one-piece structure. The building was designed and built its owners, the Austin Co., Cleveland. The Welding Engineering Con- struction Co., Cleveland, acted consultant and welding inspector. The welding was done the Lincoln Electric Co., Cleveland. four-story structure modern architecture, the building ft. wide and 119 ft. long. The ground floor divided into stores, the three upper stories containing offices. Designed for welding, the structure contains unique features construction which resulted saving, structural steel tonnage, stated, about per cent. The framework exclusive the welded bar joists contains 115 tons steel. The most economical riveted design, was figured, would have required over 130 tons. All fabrication was done outdoors the yard the Bliss Road fabricating plant the Austin Co. Five weld- ing operators were employed. Five Lincoln “stable-arc” welders the motor-generator type supplied the welding current. Machines 300-ampere capacity were used gen- erally, with the 200-ampere size for some work. joining the H-columns their base plates con- necting angles were required. The ends the columns 1224—November 15, 1928, The Iron Age being milled, the columns were set upright their plates and attached welding continuous bead along the outside edges the column flanges. Plates were used instead angles beam stiffeners. These were welded between the flanges the continuous beams, where the columns joined the beams. The stiffeners carried the lines the column flanges through the beams. Where the col- umn flanges were the webs the beams, Tee stiffeners were used. Lattice girders the front bay the building Upper Carnegie Building, land, the First Commercial Store and Office Building Steel Construction Stiffeners Were Welded Between the Flanges the Continuous Beams the Column Connec- tions. They carried the lines the column flanges through the beams. Angles and blocks welded the bottom the beams lo- cated the flanges and webs the supporting columns the first floor partitions and the store-front bulkhead beams. Such girders permitted installation concealed piping. With span ft. in. and depth in., they are composed almost entirely angles, only the verticals the ends being plates. The members were laid out, held place C-clamps and then welded. field bolts were used hold the members the structure place until welded, novel method shoring was required. square frame was bolted around the col- umns, provide means for connecting the braces. The column shoring connection, frame, consisted two q | J 7 a. = 7 7 q 4 Some the Methods Used Erecting the First Welded Steel- Frame Building for Commercial Use Are Shown Here. Several Unusual Were Em- ployed for Specific Purposes ETAIL First Floor Continuous Beam Column Connection (Above) Continuous Beams (Upper Right) Allowed Reduction the Size Both Beams and Columns from Those Required Riveted Design, Without Decreasing the Strength Rigidity. The 36-in. girder beam across the front spans six 17-ft.