The Iron Age 1927-04-21: Vol 119 Iss 16

THE IRON AGE New York, April 21, 1927 ESTABLISHED 1855 “Neutral Study Cost Analyses Determine When Take Business and When Let Some One Else Lose Money article foundry costs recently lished,* has suggested, further study FOUNDRY operator, who has expressed interest ub- ant peration along lines which may be. best defined juoting paragraph from his letter: The suggestion have make one that vital interest many manufacturers nowadays. Stated broadly, the metal forming business, either foundries, forges press shops, suffering from excess capacity. Such shops quote price that might keep them out red ink are running only partly full. Shops that quote price run them capacity are losing money. would interesting make study determine what might call the “neutral point” for shop oper- ation: meaning that the point below which, work were offered, the shop would lose less money shutting down skeleton force than taking the work and running full, and above which the shop would lose less money taking the work and running full than shutting down skeleton staff. Without venturing solution this problem the IRON Dec. and 30, 1926. The author, both that article and this, consulting foundry engineer, Francis Street, Brookline, Mass. DANGER CRITICAL 47.2% Fig. 1—Relation Tonnage and Prices Profits Rated VOL. 119, No. Plant Operation ARROCK readers’ case, any specific business industry, because lack knowledge conditons, for other reason, may discuss the question rather broad way the hope suggesting something value. Using the data the gray iron foundry recently two charts have been pre- pared. These show operating conditions all daily out- puts 100 per cent rated capacity, and present graphically the results expected from the accept- ance low-priced tonnage business. the figures used previously were presented detail, only the necessary summaries are repeated here. The procedure consists estimating costs various outputs from per cent rated capacity 100 per cent and plotting the results accurate drawing. Sales lines corres- ponding various units, per pound prices, show the total incomes. Fixed Charges Analyzed Table shows the interest charges, the investment “O” tonnage being obtained extending the inter- est line. That is, “O” tonnage have the starting Labor' $32 0/40 All Labor Expense Supplies +7 Output per Day 1133 AW new far ha New viet tad the ] le - the for re- en- An- fice eri- sed tion nts an on- wn ion The tee! rith ays ted = = = charges, assuming that the minimum charges, which approach when are about open the plant; curtailing operations. All figures are reduced per- day basis, the year being taken 300 days. should remembered that this hopeful discus- sion method, rather than precise accounting. Table the daily payroll. extending the labor lines “O” tonnage, only the lines for molders and coremakers converge, being assumed that produc- tion per molder-day remains constant, 500 and that one coremaker required for every four molders. That is, this departmental subsidiary shop, one which the class work fairly uniform, that only the elements varying tonnages and sale prices need considered. Obvious disturbing factors interfere with this easy hypothesis: local conditions enter the problem. Theoretically there should charge “O” ton- nage for some the labor: but, aside from “lag” cidental the attempt eliminate all labor idle days, there the other condition being ready start the shop. Also, only the points for outputs be- ginning per cent rating are plotted. very low tonnages some labor items become irreducible long the shop operating, “ready start,” and the labor line records this fact “O” tonnage. Table III the estimated factory burden over- head. These charges, extended the “O” tonnage position, record higher than actual expense for shop which shut down. Table records all supplies including those for melting. Due “lag” appreciable amount appears tonnage. Iron priced 1.25c. net the castings. Selling expenses (not including labor) and defectives returned are included one item the summary, Table The melting expense based per cent yield good castings. Interest Charged Into Costs The practice here charging interest invested money into the costs has been criticized being burden that most plants cannot assume; and also the ground that stockholders’ money not strictly borrowed money, bank loan. Accepting the invest- ments Table being correct under the conditions, would necessary borrow money, believe, be- fore the capacity rating had been reached; have had unusually heavy capitalization the start operations. probable that interest charge seme amount would assumed some point the expansion the tonnage. Our flat rate per cent merely covers such too gener. ous terms. the other hand there cha cept this for depreciation buildings and for rent—management’s use stockho! prop. erty. interest charges incorporated the costs. This partly because, having earned it, woul expect participate bonus earnings returnable above per cent rated capacity our chart; partly ause the incentive, the “bogey”; partly like anchor windward. These may not basically the accountant. But hazardous business founding, least know it, interest charge the costs seems advisable. part record which forms the basis for pricing, estimating new work, ap- praising new tonnage, becomes most important feature. reasons Diagram Shows Limiting Conditions The cost items Table have been plotted Fig. such manner that the effects tonnage and prices may seen glance. The total cost the product 100 per cent rated output (50,000 day) $2,996.40, 6.00c. Ib. The total cost 10,000 Three sales lines, total income lines, are drawn this chart: (a) The upper line shows sales prices which return per cent invested capital all ton- nages, but based upon cost figure 6.40c. all tonnages. (b) The middle line drawn for sales 6.40c. returning per cent invested capital 100 per cent rated output only. (c) The lower line records sales made 6c. the cost 100 per cent rated output. determining points and the middle line 6.40c. price used. The upper line shows the ad- vantage sticking for fair price all work, but particularly the light, difficult work that formed the basis the previous discussion this general subject. The Loss Point (as term it) occurs where the sale line crosses the total cost line; the Critical Point where crosses the interest line; the Danger Point where crosses the factory burden line. This chart evidently records operation which expense immediately corrected meet tonnage de- mands; that is, the cost line straight line, not series steps such must prevail actual practice. the other hand, the chart records ideal condition, assuming accuracy the data, and one which means perfect control. Reducing the staff, this chart, Table I—Interest and Return Investment Output, Ib. 00 138.00 152. 165.00 178.00 192.00 205. Table Expense Affected Output 60.00 125.00 160.00 200.0 Helpers and common labor........... 101.60 162.00 213.60 264.20 Administrative 199.50 208.75 228.50 240.00 Lb. per employee per day............ 130 148 166 $6.64 $6.32 $6.13 $6.13 $6.07 Administrative labor “B” includes: inspector, shipper, storekeeper, production clerks, timekeeper, penters, pattern makers, clerks. Administrative labor “A” includes: clerks, 21, 1927, The lron Age superintendent, watchmen, teamsters, salesman and executives foremen, master mechanic and helpers. — corresponding decrease tonnage and income. represents, perhaps, the unattainable but rable objective executive effort. think, how- means The cha 1 desire ever, that because its “perfection” will best serve basis for diseussing the “neutral point.” Sales Lines Varying Prices Fig. which the data Fig. have been transferred, four sales lines are shown, representing total incomes prices 6.40c., 6.25c., and 6.00c. The sales line cent return invest- before. One new feature shown this chart. 100 per cent rated output (50,000 Ib. day) the ratio experience careful study the elements cost from the “O” tonnage basis. The total cost this point the lowest; the organization the strongest. How much tonnage can handled this organiza- tion? What Tonnage Can Handled? have drawn line, from expense “O” ton- nage parallel the normal cost line, indicate our opinion. The point where the line meets the new “effectiveness” line under marks the probable limit- ing tonnage. The gain made out expenses, this way, measured the A-D line, transferred the upper part the chart under the cost line, (F-G) Sales Income lines General Expense SAut Revised ” 20000 30,000 5Q000 per Pounds Fig. 2—Effect Profits Varying “General Expense” about 32/100. the sum four items: $123.00 Factory burden 143.00 Selling expense and defectives.. 50.00 Administrative labor and B... 376.00 $692.00 “General Expense” total cost less iron and sup- plies, $2,155.40. the point Danger Point, same ratio (sealed) about 42/100. That is, point production has been reached when action imperative, the general effectiveness the cent rated output. Including interest, burden, sell- expenses and defective charges these figures not materially alter the ratios, but equivalent may found, omitting these items, thought this chart, and many plants, not possible correct the organization that becomes effec- 47.2 per cent rated output 100 per cent rating, but assume that some improvement pos- and have halved the desired gain under the point the upper part the chart, designating this point The dash-dot line just above shows the gain that result could hold the 100 per cent rating What the maximum tonnage which organization can handle? “O” tonnage, “General Expense” reaches the standby ready-to-run grouping the the plant has developed. Expenses have reduced the lowest point, whether actually from Unit Prices Received for Product where records reduction costs. This gain, amounting about $50 per day, cannot maintained under increasing tonnage conditions, but tapers off zero 100 per cent rating. That is, the organization reverts its original 32/100 ratio 100 per cent rating. Below the tonnage, the gain, perhaps modified after the period stress, becomes permanent—a new condition affairs established. The reduction costs $50 about cent expenses. Most must come from administrative labor and some probably from economies factory burden. Labor this group must reduced, preferably elimination and re-grouping duties; possibly change pay. With this “skeleton” and effective organization charge, the problem heavy tonnage low prices may faced with confidence. How Low-Priced Tonnage Works Out The immediate effect drop the average sale price, due the acceptance low-priced tonnage “to fill the plant,” shown the increase the loss between points and average sale price below 6c. would accentuate this feature, with the loss fully recoverable only tonnage above capacity rating. true that high tonnages the shop begins show profit, but frequently the expected tonnage never realized. The conditions large tonnages and excess plant capacity are conflicting and contradictory. ironclad selling agreement unusual. transac- tion may made all good faith but, where there The Iron Age, April 21, ~ high production capacity, little falling off general business conditions reacts shortening specifica- tions and curtailment tonnage. The “gain” area the right point resulting from reducing the organization, purposely left un- shaded, accentuate decision which might made this tonnage—to proceed toward high tonnages lower prices with the usual organization, “stand by” with the tonnage hand, 47.2 per cent rating, Table Factory Burden With Increasing Output Output, Ib. 10,000 20,000 30,000 40,000 50,000 $20.00 $20.00 $20.00 $20.00 $20.00 5.00 5.00 5.00 5.00 5.00 Liability ..... 15.00 20.00 25.00 30.00 35.00 Power, light... 32.00 39.00 46.00 53.00 60.00 2.00 13.00 14.00 15.00 16.00 Water and sewers ..... 3.00 4.00 5.00 6.00 7.00 Factory burden.$70.00 $87.00 $101.00 $115.00 $129.00 $143.00 with the operating force reduced suggested. The immediate effect low-priced tonnage, when “go- ahead” decision made, may severe and should not overlooked. industry having “excess capacity” faces elimination plants; have known two fail dismally when the owners rushed headlong into large tonnage low prices the hope breaking even. Operating Above Normal Capacity Also, that foundry unusual character which can “hold” its cost figure when the tonnage begins exceed its rated capacity, unless improves its directly productive facilities—not condition this discussion. Frequently find instances sharply increasing costs, when molders are crowded too closely together the hope raising the tonnage figures. Reduction costs comes from improvement direct labor out- put first, and believe that appraisal new low- priced business demands careful examination pro- duction possibilities. increase molding speed—above 500 Ib. mol- der-day this case—would obviously affect the chart and the problem. The high proportion direct and semi-direct labor the capacity tonnage indicates what generally happens when plant forced much above its rating—namely, that supervision becomes in- adequate, direct labor production falls off, defectives increase, the anticipated gain disappears, and the chance even break, least, 100 per cent rating lost. The shop condition then that boom times rather than depression; high rather than low sale prices. The operation forced, abnormal and sensitive. Good Will Tonnage Must Guarded Every shop reasonably good history has stand- ing the trade measurable the tonnage that con- tinues come it, even times severe depression. This tonnage represents practical good will, and asset that must guarded. New customers whose business may prove desirable the long run are added the list from time time the natural course events—not spasmodic increments. Founding—not the manufacture finished articles which castings may the basic portation has greatly facilitated the past few years, but its value seems permitting construction and operation shops outlying rent areas, rather than widening Iron castings, particularly, are sold close the Mal- leables reach wider market, but new plants are rap- idly limiting activities closer Brass high 10M) e, but price not compatible with “tonnage” sions. Founding the ordinary sense industry immediate deliveries, continually changing convenience and accessibility the buyer. has “standard” product that can made times, seasons. Even schedule deliveries from its strongest customer may not undertaken advance without considerable risk, because “change de- sign” other probably good reason. Keenly competi- tive, local character, special service, founding re- quires care the treatment established trade known value, particularly times depression. offer these suggestions because believe that this element factor that cannot disregarded the appraisal proposed new business the uncertain Table Required for Varying Outputs Output, Ib. ... 10,000 20,000 30,000 40,000 50,000 Melting ...... $33.80 $58.00 $76.20 $88.40 23.00 30.00 43.00 57.00 70.00 Oils, com- 2.00 3.00 4.00 5.00 6.00 Maintenance 1.00 2.00 3.00 4.00 5.00 Miscellaneous. 5.00 7.00 9.00 12.00 15.00 Supplies ..... 25.00 $74.80 $112.00 $150.20 $186.40 $216.60 duration and problematical earning power implied the original question. Discussion the “Neutral seems possible confine the “neutral point” with- narrow limits the following tentative defini- tions: the point where correction operation becomes imperative, probably both sales and the shop. the chart this point not lower tonnage than 2—It designates the greatest tonnage which the proposed “skeleton” “O” tonnage organization can handle effectively; Fig. but, with little concession, 3.—It the normal settled point demand the established trade, fair price represented the 6.40c. sales line. This local condition. he What value accrues from the gain arising from organization “squeeze” should carefully Table V—Profit Loss Recorded, According Output Output, Ib. $25.00 Selling expenses and defectives....... 10.00 $560.00 Gain 1136—April 21, 1927, The Iron Age 10,000 20,000 30,000 40,000 $125.00 $250.00 $375.00 $500.00 74.80 112.00 150.20 186.40 216.60 16.00 24.00 33.00 40.00 654.80 950.50 1,242.90 1,535.55 101.00 115.00 129.00 91.00 99.00 107.00 115.00 123.00 proportionately indicated the chart, tapering off 100 per cent plant rating? Does not the the industry implied the original ques- sustained reduction general adminis- trative well other items the ex- are assuming that this latter procedure the one, but the immediate effect other de- must recognized. the point which low-priced tonnage may taken sufficient quantity reach the break-even Assuming that the 23,600 Ib. tonnage will cross the new “reorganized” cost line The tonnages are then Old business 23,600 Ib. 6.40c., $1,510.40 New business 15,900 6.00c., 958.35 Sales 39,500 Ib. 6.25c., $2,468.75 The sales line will break even C-2. The nages are then Old business Ib. 6.40c., $1,510.40 New business 19,600 Ib. 1,146.40 Sales 43,200 6.15c., $2,656.80 The sales line will break even 100 per cent rating, when the figures become Old business 23,600 Ib. 6.40c., $1,510.40 New business 26,400 Ib. 5.65c., 1,489.60 Sales 50,000 Ib. 6.00c., $3,000.00 These figures confirm opinion that, times ression, when break-even condition probably the best obtainable, good policy tighten up, economize, and take only that extra tonnage which, reasonable cut price, will eliminate loss. Making cuts the theory that the shop must run capacity break even questionable meas- the whole, this particular appraisal indicates that below the neutral point; action the new tonnage has been deferred little too long, except the economies expenses have justified it. like ure. Conference Simplification Steel Sash WASHINGTON, April general conference solid-section steel sash the De- partment Commerce April has been called Director Wetherhill the National Committee Metals Utilization. The items discussed in- the division products the industry; standard The mmendations made are the result survey con- committee representing manufacturers. the re re a Make Buses Kent, Ohio Twin Coach Co., Kent, Ohio, has purchased the American Car Foundry Co. the plant Ohio, formerly oceupied the Fageol Bus Co., was taken over few years ago the Car company and moved Detroit. The new com- shortly begin the manufacture buses. Fageol, formerly the head the Fageol and Akron and Kent men are interested the company, which has been capitalized with $4,000,- per cent preferred stock and 400,000 shares par common stock. New Steel Mill Motors line steel mill motors, known the These motors have been designed collaboration the standards committee the Association Steel Engineers. They are the roller type. manner, estimate new business required economies are disregarded confirms this opinion. comparison the tonnages required for both the orig- inal and the new “reorganized” cost line, reach the break-even point the different sales prices, follows: Cost Line (d) Old business 23,600 Ib. 6.40c. New business 17,400 New Cost Line 23,600 Ib. 15,900 Ib. 39,500 Ib. 6.25c. 79.0 23,600 19,600 Output 41,000 Ib. Per cent rating 82.0 (e) Old business 23,600 Ib. 6.40c. New business 20,800 5.87c. 43,200 Ib. Output 44,400 Ib. Per cent ratng 88.8 86.4 (f) Old business 23,600 Ib. 6.40c. 23,600 6.40c. New business 26,400 Ib. 5.65c. 26,400 Ib. 5.65c. Output 50,000 Ib. 6.00c. 50,000 Ib. 6.00c. Per cent rating 100.0 100.0 That is, are not going able maintain the reduction expenses approach rated ca- pacity—which the condition shown Fig. 2—then does not pay slash prices fill the plant. Our location the “neutral point,” the basis this analysis, between points and B—that is, occurs after the operations fail earn interest charges, but before they fail earn “factory burden.” Its final location depends upon the amount sta- bilized fairly priced business the books; upon the strength the “skeleton” “O” tonnage organiza- tion; and upon the value the proposed new tonnage, not only with respect its price, but particularly the certainty and speed with which will carry the operation the break-even point. appraisal the neutral point will disregard plant capacity 100 per cent rating, and will seek locate the economical tonnage, the break-even point under conditions minimum rather than maximum Hoover Address National Foreign Trade Meeting Secretary Commerce Hoover will principal speaker the fourteenth annual convention the National Foreign Trade Detroit May 25, and 27. Mr. Hoover will heard May special luncheon session under the auspices the American Manufacturers’ Export Association. Other addresses the convention will Roy Chapin, chairman the board Hudson. Motor Car Co., “The Motor Influence Our Foreign Trade;” Silas Strawn, chairman the board Montgomery, Ward Co., Chicago, “Foreign Uses for American Cap- Governor Green Michigan will also speak. There will about other addresses various sub- jects. Mexican Invoice Regulations WASHINGTON, April 19.—The tariff item and rate duty goods shipped into Mexico must indicated their consular invoices, under recent decree, ac- cording cablegram received the Department Commerce from Acting Commercial Attaché George Wythe, Mexico City. addition this, Treasury order provides that the invoice classification goods must divided into two groups, consisting (a) duti- able goods and (b) non-dutiable. Government offi- cials, the report said, have advised that tolerance will shown during April for failure comply with these The Iron Age, April 1927—1137 regulations. Charging and Igniting Ore for Sinter Importance Screens—Porous Bed for Active Charge Method Igniting Carrying Gases Away EDWARD TOURNIER ATERIALS properly proportioned, mixed and screened when necessary, are deposited substantial bin the top the building. This bin large enough for hr. supply. From this point fed gravity the charge car, pans and finally into railroad cars stock pile. the bottom this overhead bin roller feeder about in. diameter and ft. long, direct con- nected through gear reducer motor. The ma- terial fed set Hummer screens with wire cloth having in. openings. The large pieces sinter and other material from the moistened charge are screened out and deposited into the bedding hopper the charge car, while the finer material constituting the charge fed into the charge hopper the car. Screens Perform Several Functions These screens are used for several purposes. previous years, get bedding porous hearth for the grates, was necessary purchase foreign material screen out the coarse sinter from the return fines. each case this material had conveyed the charge car separate conveying apparatus from that used the regular charge. Now all handled together one product, and separated being deposited the charge car. Another purpose the screen loosen the charge further rains lightly from the screen into the car. have seen how the proper amount moisture the mixer increases the voids the charge the maximum. This looseness and these voids can enhanced again the action the screen. the screen not employed, the material must drop ft. from the overhead bin and pack into the car. This then carried into the sintering pan and the sintering action curtailed. dense hard sinter produced and loss tonnage results. raining the material through the screen and charging the loose, fluffy material into the pan, the burning time cut down about per cent and the sintering zone proceeds practically plane from the top the charge the grates, making pop-corn structure the sinter and thoroughly sintering the charge. Before using the Hummer screens this more less segregation the larger particles oc- curred the bin above. This segregation was carried down through the charge car and into the pan, caus- ing uneven burning. With the screens now used, this segregation counteracted and layer de- posited the pan practically uniform from one edge the pan the other. These screens have been use only since May, 1926, but have already demonstrated, beyond any doubt, their value preparing the charge for sintering. The charge car has two hoppers, one for the bedding the second three installments article bringing intermittent sintering date. The first ap- peared page 775 Iron for March 17. The third will discuss improvements equipment, performance and costs, sintering magnetic concentrates and the prob- able future trend the process.] 1138—April 21, 1927, The Iron Age porous hearth and the other for the charge. The car operated motor mounted driving the back axle through gear reducer. There roller feeder the whole width the pan each hopper. The roller feeders are driven through gears mesh with others mounted the wheels the car. the car reaches the end the pan idler gear mesh with the roller feeder the bedding hopper dropped into mesh with its wheel gear. the charge hopper reaches the edge the pan, its gear, also, thrown mesh. The car travels over the pan track straddling the pan’s width, depositing the bedding the grates and the charge top the bedding. approaches the farther end each gear lifted out mesh turn and the car passes on. The whole operation done without stopping the car, about sec. this operation the charge slides over wide chute into the pan, with the mini- mum amount packing possible. Ignition The ignition hood may drawn along the charge car may under its own power. plants where there are several pans line desirable have the ignition hood self-propelled. After the pan charged and the hood moves over the pan into place frame around the edge the hood quickly dropped the edge the pan and the gas oil and air pipes coupled the supply lines opposite the pan. the case oil ignition, the oil generally tank the hood and piped series horizontal spray burners placed about every ft. apart under the hood. Air and atomized oil are forced through the burn- ers the fan suction applied and torch ignites the oil. The flame spreads instantly and the whole hood full flame. Unconsumed oil deposited the charge will cause that spot remain unsintered. Hence necessary atomize the oil carefully and supply enough air consume completely before touches the ore. There must also surplus air, supply oxygen the ignited particles car- bon the surface the charge. Products combustion fill the hood, which about in. deep, and these products flames are all sucked into the charge the forced draft. The hood the combustion chamber and the interstices the porous charge the pan the smoke stack, while the surface that charge, with its thousands fine carbon particles, being exposed the intense heat and becomes ignited like glowing coals. Quick, Intense Ignition Required the surface dry will not ignite or, doing so, will immediately out after the hood Therefore the ignition must quick and intense, must take place while the suction applied from neath. There outlet for the products bustion except through the charge. All unnecessary the and injurious outside air excluded, sealing frame forcing the hood full that they lick out around the edges, and thus 7 7 7 7 7 PERATING side Greenawalt Charg- ing Car Appears Right. The swinging gears for driving are prominent Below ing Igniting Hood Fitted with Two Tanks for Supplying the Oil HAUST Fan Green- awalt One top section the casing has been re- moved show the forms the im- peller and the dif- fuser. The portion base plate motor for ae aa - - The Iron Age, April 21, 4 7 J 1% — _ é | hood from injurious cooling effects air currents. takes from sec. ignite the surface. Gas ignition being more commonly used re- cent years, where available. For this fuel the hood functions exactly with oil. The gas pumped into manifold, mounted the hood, along with the proper amount air for its combustion. From here piped series cross pipes lying U-shaped cast- ings, which constitute the top the hood. The cross pipes are bored and supplied with small nipples about in. apart. These nipples extend through holes the U-shaped castings, angle the surface the charge. small amount air siphoned into the hood around these nipples, and the gas and air mixture into the hood, insuring its being completely filled with flame. Special Fans for Suction Suction for sintering obtained means fan, especially designed for this purpose, extremely rugged and heavy construction. The casing inch- thick cast iron, and the impeller inch-thick cast steel mounted 7-in. high-carbon steel shaft and given dynamic balance before shipment the user. The gases enter from the bottom and are sucked into the impeller around the hubs. The curved blades throw the gases with high velocity through the dif- fusion ring around its periphery into the outside chamber the Here the gases are slowed down considerably and find their way through the outlet and the stack. The fan shaft, mounted large water-cooled babbitted bearings, directly connécted through flexible coupling the motor, which mounted cast iron base bolted rigidly the fan casing. The motor generally 200 hp., although the actual oper- ating power about 135 hp., and has speed from 1500 1800 r.p.m., depending upon the suction de- sired. The suction generally used for sintering flue dust about in. water. sintering iron ores, where the carbon content the charge more easily regu- too much carbon the charge, high suction may cause such intense heat form molten material which clogs the interstices the charge and conse- quently uneven burning and unsintered parts. This can counteracted high-carbon charges the admixture foreign material, ore, roll scale, bor- ings, etc., the use greater percentage re- turn fines. Where the carbon the charge right, high suction desirable. The burning faster and the tonnage the plant increased without, any way, destroying the quality the sinter produced. Trunnions Carry Away Gases Hollow trunnions each end the pan are con- nected pipes which carry the gases large con- crete brick-lined chamber beneath the fan. The gases are sometimes watercooled their way this cham- ber. With proper grates and the use porous bedding the pan, and with agitation the charge pan nor air leaks undermining the charge, the amount dust sucked through the pipes into the dust chamber small. The chamber generally cleaned out about once month. The fan runs continuously, although the draft shut off from the pan during each dumping and charg- ing period. This accomplished bell valve built the bottom intake part the fan casing. This valve operated water, air steam cylinder controlled the operators the pan floor. Details the Rotating Pan The sintering pan ft. ft., built thick air-cooled cast steel sides and ends with 20-in. hollow trunnions each end. The bottom 21, 1927, The Iron Age the pan steel plate riveted the pan six cast steel girders are bolted the side These girders support seven rows cast steel frames which, turn, hold the semi-steel grate bar iron slides guides the bottom the pan between each girder and the next. These bars are notched take the protruding fingers the rocking grate frames. gear segment mounted around the trunnion one end the pan. Meshed with this gear seg- ment, and 180 deg. apart, are two sturdy pinions driven through worm gears from the same motor. The hollow trunnions, supported rollers, are con- nected cast iron pipes from each leading the dust collecting chamber beneath the fan. When the sintering charge burned the the suction from the fan cut off, and the pan dumped means the two pinions and gear around its trunnion. the gear segment leaves the one pinion, still mesh with the other, and, the revolution proceeds, again comes mesh with the first pinion and leaves the other. this manner complete revolution the pan easily accomplished about sec., the material dumped from and the pan position take the next charge. Rocking Grates Operate Automatically the pan dumped, the heavy notched bars be- tween the pan girders slide their guides about foot, pulling the fingers the rocking grates with them. These rocking grates are mounted means pins each end bearing blocks the stee! girders. the pan upside down all the particles dust and sinter beneath the grates are dumped out, automatically cleaning the wind box. The grate openings aggregate about per cent, made slots not over 5/16 in. wide. This amount grate opening can regulated the width bars used. The grate opening area important sintering. The total suction the fan should exerted the bottom the charge. There should resistance either due the grates being clogged with sinter through not enough grate openings the original grates. The holes slots should smal! them- selves, that holes will not sucked the charge. But there should plenty them and they should kept clear foreign matter, that all the power exerted the fan may applied the bottom layer the charge itself. Depth Bed Varies with Charge The depth bed used from in. some cases less more, but this depth regulated, depending upon the nature the charge being Liners beneath the grate bar support are provided, change this depth that desired. high-carbon charges, the bed too deep the accumulated heat the sintering proceeds causes fusion action, which clogs the gas passages and dries out the bottom the charge that will not sinter. the charge fairly coarse and the carbon low, deeper bed can sintered without this fusing action taking and with the result that larger tonnage can at- tained each charge. Generally speaking, sinters best 7-in. depths, and ore, where The sinter drops from the pan into bin beneath. This bin housed all sides, and the pan itself forms the cover when the horizontal position. series suspended gates retards the sinter from ing too fast over the screens. Grizzly bars placed about in. apart take off the coarse cakes sinter, while the rest drops through wire-mesh sturdy construction about in. below the This wire-mesh screen made crimped wire 7 7 7 7 7 and has -in. clear openings. deg. There are about 260 sq. ft. The screen surface. This large screen surface, coupled the above and the retarding action the the sinter bin, assures perfect screening obtained without the use mechanical screens. Cali Need Make Dusty Plant properly constructing sintering plant, there for the excessive dust conditions com- objectionable all older sintering plants. mon Turning Trunnions Used and the Geared Turning Rig Hot, dry flue dust should not dumped sinter- ing plant. should thoroughly moistened the furnace, before sent through the regular con- veying system the sintering plant, and, possible, should allowed cool after moistening. This Sharp Gain River Coal Traffic Pittsburgh Traffic over the Allegheny, Monongahela and Ohio rivers within the district the United States En- Pittsburgh jumped sharply March com- pared with the month before, with total 3,403,893 not ‘ons, 576,033 tons more than February. increase was the movement coal, which Much was almost 444,000 tons larger than Feb- There was increase approximately 7000 the shipment iron and steel products. figures net tons follow: Alle- Monon- gheny gahela Ohio dity River River River Sand 33,900 75,375 eel products 600 36,112 29,016 2,250 18,546 8,859 January... 89,242 2,646,617 Cramp’s Quit Shipbuilding William Cramp Sons Ship Engine Build- Philadelphia, which has conducted shipyard years, will quit shipbuilding within the near has been announced Harry Mull, presi- Curtailment naval construction the United Government and the depressed condition ant shipbuilding are given the reasons for policy. Secretary the Navy Wilbur the transfer contract for the build- the scout Salt Lake City the American done the interest better sintering re- sults and tonnage, not for general cleanliness. There certain amount steam and dust about the return fines feeders and mixer. installing proper ventilating drafts through the elevator shaft and stacks, this steam and dust can controlled. When the pan dumped there certain amount dust arising, especially plants where too deep bed being sintered for the material used, when mixing, charging grate conditions permit uneven sintering, with resultant dead spots the charge. The pan pans should inclosed from the working ; | Showing the Arrangement Grate Bars, the Heavy platform sheet steel partition and with large ventilating opening over each pan. The dust conditions are only momentary, and with the controls and working platform outside the partition, the men are protected from the dust. Brown Boveri Electric Corporation, Camden, J., which has the shipyard formerly operated the New York Shipbuilding Three other vessels the merchant type now under construction the Cramp shipyard will completed. With the abandonment shipbuilding, the com- pany will confine its activities its other lines, which were segregated last year holding company known Cramp-Morris Industrials, Inc. These subsidiary companies include the Vergne Machine Co., Morris Corporation, Pelton Water Wheel Co., Federal Steel Foundry Co., Cramp’s Brass Iron Foundry and Cramp Engine Mfg. Co. Their opera- tions cover the manufacture Diesel engines, castings and hydraulic and other Otis Steel Co. Transport Steel and Scrap Water The Otis Steel Co., Cleveland, planning pro- vide water transportation line for shipping finished steel from Cleveland Detroit and bringing back scrap. The company negotiating for the purchase lease four small boats fitted for this pur- pose and plane equip the dock its plant for the direct handling steel and scrap. American trade marks registered the Philippine Islands are now regarded valid for the full term years granted Philippine marks, regardless the duration registration the mark the United States, according report received the Depart- ment Commerce from Trade Commissioner Butler, Manila. The Iron Age, April 21, ¥ ty | a secre fror 7 ; is — 7 - Theory Explain Abnormal Presence Unusual Amount Dissolved Oxygen Promotes Non-Hardenability—Results Investigation Many Steels JOHN GAT possibility the selection suitable mate- rial for carburization from shipment steel be- fore subjecting manufacturing processes large industrial importance. Shortening the McQuaid-Ehn Test Consumers steel, having only one means for ac- complishing this, the McQuaid and Ehn test, and having also but little information regarding its interpretation, concentrated their attention the study images revealed the microscope specimens carburized the specifications the test. many cases was possible observe certain relation be- tween given peculiarities the structure and the final behavior the metal. They were associated, dis- regarding all other variables. majority cases, the establishing such relation terminated any fur- ther study the subject. The situation created introduced considerable amount misunderstanding and trouble when.the re- sults these observations were incorporated the specifications submitted the steel mills. The manu- facturers were obliged make metal which had meet certain requirements, revealed test contain- ing several variables, none which has received yet any amount scientific study and the relative im- portance which was not established. The purpose the original McQuaid-Ehn test was the discrimination between satisfactory and non-hard- enable metal, test designed for shop practice and dealing with magnitudes not requiring any special re- finement. With sufficient precautions, difference can found everywhere and features decidedly secon- dary importance can brought the state where their influence becomes pronounced factor often leading erroneous conclusions. Investigating the True Cause Abnormality the investigation directed toward the establish- ment the true cause non-hardenability, the results which are recorded the following discussion, re- finement experimental procedure was purposely omit- ted and the methods used were, far was possible, reproductions ordinary commercial practice where quenching conducted tap water and uniformity hardening understood within three points, Rock- well Designating “abnormal” steel which will not harden uniformly tap water introduced basis from which all conclusions could drawn without the ne- cessity for any arbitrary definitions and permitted one find which the many features the carburized zone, mentioned the original paper McQuaid-Ehn related this property, are the result condi- tion causing non-hardenability and which are functions ordinary crystallization common all steels. was thought more reliable depend figures furnished close cooperation between steel makers and men charge case-hardening shops the con- suming end the cycle than use data furnished laboratory means only. Only cases where data obtained were lacking sufficient precision involved features liable obscure the meaning observations were the results verified under laboratory conditions with necessary degree accuracy. The author was formerly metallurgist Alloy Steel Corporation, Canton, Ohio with the Central 1142—April 21, 1927, The Iron Age Several hundred heats, mostly alloy steels, repre- sented many thousand samples, were checked for their microscopical appearance after carburizing before releasing them from the plant. The results fina! heat treatment were compared with microscopical ords corresponding heats. All information, derived from this source course several years, indicated that there difference hardenability between steels having widely varying shape and size grains. Steels with rounded grains greatly different dimen- sions hardened with the same ease with large uniform rectangular grains. The question the influence the grain size the utmost importance, because association small grained with non-hardenable and large grained steels with satisfactory ones accepted almost universally. Experiments conducted order demonstrate the influence quenching, normalizing and annealing the final grain size showed that, previous carburizing, Fig. Alloy Iron-Oxygen and Carbon Surrounding Cementitic Mesh Hypereutectoid Zone. Etched deeply with nital. 1500 heat treatment does not affect the character the car- burized zone any way. The necessity for passing through the critical point carburization, involving recrystallization the entire mass steel, totally obliterates pre-existing structure. Not only the normal crystalline structure destroyed but, even ordinary cases, severe cold working excessive grain size duced critical strain not have any effect size and but slight one crystalline outlines. Each heat steel possesses presumably certain factors, parted the process making, which regulate the size austenitic grains. They are brought action soon the upper critical passed and are dormant until all iron transformed into the state. Crystalline dimensions, developed test, are constant for given steel long burizing conditions remain the same. With increased molecular mobility, caused rise temperature, influence factors controlling the size austenitic grains gradually diminishes and increased temperature enlargement crystalline units. sufficiently high n ° at temperature the difference grain size, easily _ <= temperature, disappears though shape grains remains unchanged. time and temperature, the character zone depends temperature only. Time inereased depth eutectoid zone the temperature not changed, any length time will produce identical hypereutec- and gradation zones. Size and Uniform Hardening very large number comparisons grain size uniform hardening, conducted both with Wile Fig. Carburized Specimen. Carbon, 0.02 per cent; oxygen, 0.10 per cent. Etched with sodium picrate. 500 + the laboratory and plants scattered all over the and representing quite fully present commer- ial practice, failed support the point view that mall grain steel inducive hardening troubles. every case, when pearlitic grains hypereutectoid were surrounded cementite alone, the steel hardened uniformly. The work, connected with the study properties steel possessing different grain sizes, covered simul- ‘aneously the influence cementite distribution the boundaries. Smaller grain size goes usually hand hand with the inerease the ratio-free cementite- pearlite the hypereutectoid zone. not clear whether areas these constituents, often the same and observed the outer layers carburized small-grained steels, can identified with “clubbed ementite” generally associated with non-hardenable Careful study the subject showed that distri- ution cementite not constant for given steel funetion the temperature, and that has comparison cases formed large and small- ] steels, especially when made comparing ‘ures with the unaided eye, leaves impres- the former case the depth greater. The statement, that large-grained steel better carbon penetration, was checked care- carburizing representative number samples grain sizes. The amount carbon absorbed weighing, and the depth case es- the separating line between the case and per cent carbon appears the fully an- Several carburizing temperatures were but, their results are gaod accord, only figures, corresponding commercial prac- accompanying table, summarizing the data ob- tained this carburizing series, heats having larger grain size determined preliminary test are re- corded the first place given type. The numbers the second column give average number milli- grams absorbed specimens. The third column rep- resents somewhat arbitrary value carbon absorp- tion, obtained division the total amount carbon alloyed with specimens their surface and depth case. The amount carbon absorbed small and large- grained specimens the same composition was the same. Depth case formed, allowing for the experi- 4 A & Fig. Carburized Specimen. Carbon, 0.10 per cent; oxygen, 0.10 per cent. Etched with sodium picrate. 500 mental errors, was the same for practical purposes, varying inside per cent from average. One Cause Hardening Troubles Hardening troubles were encountered when the ce- mentitic mesh steel was imbedded layer substance softer than cementite. more pronounced cases the layer surroundifig the cementite broadens, and one encounters so-called divorced pearlite when wide areas white substance, after etching with acids, are found between cementitic network and the bounda- ries crystals and even between lamellae pearlite. Deg. (940 Deg. C.) Carbon Absorbed Absorption Depth S.A.E. No. in Mg. Value of Case 1020 134 1.245 1.10 1020 136 1.248 1.09 2315 126 1.250 1.00 2315 127 1.233 1.03 2515 123 1.242 0.99° 2515 123 1.042 1.18 3115 132 1.100 1.20 3115 133 1.060 1.26 6120 155 1.260 1.25 6120 153 1.225 1.23 Cr-Ni-V 144 1.189 1.21 Cr-Ni-V 142 1.136 1.25 132 1.434 0.96 banding “Divorced pearlite” implies that the white substance ferrite, but observations not support this point view. Rejection cementite hypereutectoid zone does not need any comments, but the fact that fol- lowed precipitation considerable amount fer- rite cannot accounted for, based properties iron- carbon equilibria shown the constitutional diagram. The explanation the phenomena lies closer The Iron Age, April 21, ca q + 7 heats the same analysis but having dif- study the properties the white substance. Deep etching indicated that, from the metallographical standpoint, there pronounced difference between ordinary ferrite and this substance. Scratch hardness, equal the hardness pearlite, introduces another point difference. Corrodibility acids well sodium picrate places class itself. The lat- ter reagent attacks hypereutectoid zone weakly but quite easily other regions the sample. Some light thrown the subject the oxygen content the samples having lined cementite. dif- ference can seen chemical composition steels containing and free from unless gas content de- termined. The percentage hydrogen and nitrogen the same both cases. Oxygen content the former case about ten times high. Hardness and microscopical appearance the sub- stance surrounding cementite can serve only indices its being different nature than ferrite. Theo- retical considerations deduced from the properties a. J a 4 ~ # { 3 at ‘ Fig. 4.—Gradation Zone Carburized Specimen. Carbon about 0.20 per cent; oxygen, 0.10 per cent. Note eutectoid envelopes around pearlitic grains. Relief polished and slightly etched with nital. 100 the iron-carbon system bring better understanding the phenomena taking place, but they must necessar- ily tentative character. High-Oxygen Steel Must Considered Examining the core carburized steels, not difficult see that substance, dis- similar the mass ferrite, rejected the grain boundaries. Its appearance does not suggest any the already known constituents steel. seems harder than the ferritic matrix and can brought out comparatively easily relief polishing. one never encounters completely deoxidized steels, natural expect here iron-oxygen compound, though the color does not even resemble any the known oxides iron. were oxide iron, insoluble ferrite room temperature, one could ex- pect that given oxygen content would specify def- inite amount rejected the grain boundaries. three steels selected illustrate this point, the oxygen content was the same, 0.10 per cent, but the percentage carbon varied. Looking very low, 0.02 per cent carbon steel, one can see only few in- clusions this type. With 0.10 per cent their number increases and when carbon was raised carburization about 0.20 per cent every grain pearlite was sur- rounded film this substance. Its percentage rises with increased carbon content until, the hyper- eutectoid zone highly oxygenated steels, strongly predominates over pearlite and cementite. Explains White Substance Around Cementite One led believe that the white substance, sur- rounding cementite, identical with inclusions lower-carbon regions highly oxygenated steels and quite probably ternary alloy iron and carbon, 21, 1927, The Iron Age containing considerable amount sumption makes possible account for lographic peculiarities high-oxygen Austenite amount oxygen. cooling, two sets mations take place: Normal allotropic and changes induced the presence cipitation proeutectoid cementite, taking the gamma range, not affected the presence oxygen all. Cementitic mesh, formed, filled still homogeneous