The Iron Age 1939-08-17: Vol 144 Iss 7

‘itain, is, Power adway. Works uffale, ruction }, Conn. antown, , Pe FRITZ FRANK President J. H. VAN DEVENTER Editor ROWAN News Editor FINDLEY Editor Emeritus WRIGHT Managing Editor Machinery Bditor Art Bditor Metallurgical Bditor Associate Editors Washington Editor Resident District Editors Pittsburgh Chicago Cleveland Detroit Editorial Correspondents London, England Cincinnati FRAZAR Boston Hamburg, Germany Milwaukee Sen Francisco SANDERSON ASA JR. Toronto, Ontario Birmingham Newark, N. J. St. Lowis JR. Owned and Published CHILTON COMPANY (Incorporated) Editorial and Executive West 39th St. New York, Publication Office Chestnut and 56th Philadelphia, Pa. OFFICERS AND DIRECTORS MUSSELMAN, President FRITZ FRANK, Executive Vice-President STEVENS, Vice-President JOSEPH HILDRETH, Vice-President GEORGE GRIFFITHS, Vice-President WILLIAM A. BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JOHN VAN DEVENTER, JULIAN CHASE, THOMAS KANE, CHARLES BAUR, CARROLL BUZBY, FAHRENDORF BAUR, General Advertising Manager DIX, Manager Reader Service Member, Audit Bureau Circulations Member Associated Business Papers Indexed the Industrial Arts Index. Published every Thursday. Subscrip- tion Price: United States and Pos- sessions, Mexico, Cuba, $6.00; Can- ada, $8.50; Foreign, $12.00 year. Single copy, cents. Cable Address, ADVERTISING STAFF Emerson Findley, 621 Union Cleveland B. L. Herman, Chilton Bidg., Phila. H. K. Hottenstein. 1012 Otis Bidg., Chicago H. E. Leonard, 239 W. 39th St., New York Peirce Lewis, 7310 Woodward Ave.. Detroit Ober, 239 39th St., New York Warren, Box 81, Hartford, Conn. Don Harner, 1595 Avenue, Long Beach, Cal. THE Contents AUGUST 1939 Survival the Unfit Open-Hearth Slag Control 900 Ft. Ovens for Auto Bodies Special Tips for Grooves Weekly Ingot Operating Plant Expansion and Equipment 100 Copyright 1939 Chilton Company (Ine.) I The, Ray- id and Ky. Ky. re. Md. 7 Ky. Yhio Ind. le Birm- Work? Consider Labor Costs When most jobs, shop labor costs are the biggest single factor—and they depend large degree the steel used. bars are too hard for bend- ing forming—or have hard spots break dull tools—if some shapes are not straight—or the case alloy steel the required proper- ties are not developed the first heat treat- Purchasing steel that uniform and has the properties most desirable for your particular use Principal products stock for mediate Shipment include— Structurals, Plates, Iron and Steel Sheets, Tubing, Shafting, Strip Steel, Alloy Steels, Tool Steels, Stainless, Babbitt, Welding Rod, etc. 28—THE IRON AGE, August 17, 1939 uying Steel often pays big dividends the form decreased shop costs. You not have pay any more for this kind steel—so why not get it? For several years Ryerson has been building stocks these better, more uniform selection, checking, testing and ing assure the uniform high quality necessary for Ryerson Certification. Try Ryerson Certified Steels your hardest job—and check the labor costs. Many have told that pays. Joseph Ryerson Son, Inc. Plants at: Milwaukee, St. Louis, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey 4, WSs - | | | | THE IRON AGE ... AUGUST 1939 ESTABLISHED Vol. 144, No. Nature's fundamental laws known survival the That not accurate designation for the process natural selection, since would imply but one survivor. better one would the put into reverse English, the Some people profess believe that this very cruel law and that should repealed. matter fact, perhaps the cruelest thing imaginable would ar- range for the perpetuation the unfit. And that just what being attempted our topsy-turvy New Deal economists connection with business and industrial entities. When business sick that cannot possibly get well, even through the minis- trations the ablest business doctors, the sooner permitted die, the better. There may good reason for forbidding euthanasia the case people suffering from incurable diseases; none all the case incurable business. -The fact that the New Deal has attempted, through man-made legislation, re- peal Nature's fundamental law survival the fit applied business concerns may well account for the fact that recovery and reemployment have been long delayed. past depressions, the curative effects began when the unfit business—the high sed cost members industry—folded and went out business. That made better ore business for the survivors and better business for them meant lower costs and prices and stimulus demand. Then, when the business revival really got under way, new ing units entered the field, further building the strength and stature the industry. The process was exactly analogous Nature's way discarding the dead cells 3. living organism and replacing them with new ones. That normal, healthy growth. Nowadays seem think that must coddle the unfit. business has such poor profit outlook that cannot raise money let dip its hand into the United States Treasury. small concern can't keep pace with larger one, let's hobble the bigger fellow. chain store can sell cheaper than independent one, let's tax the chain store out existence. Silliest all such crackpot notions, perhaps, Attorney General Professor Thur- man Arnold's idea that concern with the money and the will advertise its products taking unfair advantage the concern that lacks either both. Strong men are not reared swaddling them cotton batting. Nor are pros- perous coddling lame ducks. ager ‘ | 3 Livre | J | the modern, high-speed excavators built this prominent manufacturer, design not penalized excess weight. Inland Hi-Steel, fabricated the arc welding process, provides greater strength for vital parts that take the stresses and strains dig- ging. the same time, lighter sections reduce weight many these parts much 20% and-25% gain larger payloads and lower operating expense. Inland Hi-Steel, the new low alloy, high strength steel, even more corrosion-resisting than copper alloy. easy weld and fabricate—used many leading makers construction equip- ment, trucks, tractors, freight cars, etc. Wherever anything must moved, Hi-Steel cuts dead weight, increases strength and makes for lower costs. Write for Bulletin No. 10. DETROIT SHEETS STRIP TIN PLATE BARS PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING Bans modern excavators, Inland Hi-Steel used for car bodies, crawler frames, revolving frames, where lightness with strength cuts operating costs. ! LAG fluidity undoubtedly has considerable influence the rate carbon drop and thus the production basic open hearth steel. control this fluidity, the viscosimeter has been found the best tool. Detailed data viscosimeter technique and results obtained are included herein. slag fluidity, has been use the Edgewater Steel Co. plant for the past six years. Mention has been made pre- vious papers, but believed that fully detailed description its use should prove considerable value. The following data were all obtained from basic open hearth steel produc- tion, all fully killed steel, ranging carbon from 0.50 0.90 per cent. the use the viscosimeter, much more accurate control slag fluidity may obtained. The main- for certain types steel and for certain methods deoxidation results more uniform furnace practice. more consistent slag quality, which analyses, and accordingly pos- sible tap more heats grade and heats more uniform nearly all characteristics. Fig. shows sketch the cosimeter, which steel forging with funnel one end, connected 0.25 diameter tube in. long. made two pieces allow teady removal the previous slag sample. filling the funnel with molten slag, and measuring inches the distance the molten slag out into the 0.25-in. tube before Bulletin No. 68, solidifying, there thus obtained indication the fluidity the slag. With increasing fluidity the slag runs out the hole greater distance, and some cases runs out the end the viscosimeter. This latter indicates very fluid slag. Temperature the viscosimeter itself and temperature the molten slag are doubt factors, but practice once the viscosimeter placed use warmed the effect temperature may neglected. Today, much heard about slag composition and about the presence the slag dicalcium-silicate and tricalcium-silicate, etc. The furnace operator not particularly concerned with the slag composition from the mineralogical standpoint, but more interested having solution available for work the various mate- rials which make his slag. has materials the slag, such lime, that are not solution, his vis- cosimeter readings will give him indication this fact, and its use better knowledge the condition the slag will obtained than the usual hit miss methods saying viscosimeter the funnel part being con- LONTROL ° REAGAN Edgewater Steel Co., Oakmont, Pa. ° ° Any attempt control basic open hearth slags must course start with the charge, and this consists balanc- ing the charge that the heat will melt desired carbon. This neces- sitates charging suitable amount lime, either limestone burnt lime, combination both, and this amount depends upon the silicon the charge. such method control, series heats may balanced have them melt quite close the desired carbon. The fol- lowing data represent figures for four groups heats, the charge the various groups being balanced accord- ing the carbon equivalent the charge’ and indicating that the car- bon equivalent the charge in- creased, the carbon which the heats will melt will also increase: Carbon equivalent 2.59, carbon melting 1.16; same manner, 2.68 and 1.22; 2.70 and 1.30; and 2.75 carbon equivalent, 1.34 carbon melting. The carbon equivalent does not re- main fixed factor, but depends first upon the analyses the charge (car- bon, manganese, silicon phorus), second upon the furnace and 42 THE IRON AGE, August it: 4 4 \ ¥ uch poms, 4 BARS oxygen content slag. cosimeter first used the low point the FeO its operation fast nace requiring lower carbon equiva- lent than slow furnace). Another factor that must considered fur- nace delays due bottom repairs etc. long delays charging necessitate the carbon equivalent the next heat charged. obtain best results all heats should have nearly possible definite and consistent percentages each type scrap and pig iron. Such control the charge may seem like ideal condition but attempt such ideal conditions has been made several production shops with very gratifying results. After the charge has been selected well possible, and melted down, Bulletin No. 68, 41. Transactions, 1932, 147. the next step the use the viscosi- meter. Even though the charge may vary over wide ranges, fluidity control device will certainly help the furnace operator make consistently certain type slag which knows from past experience best suited for the type steel that being made. the type steel made the plant, the viscosimeter first used the low point the FeO curve. This shown Fig. The low point the FeO (or oxy- gen) curve depends upon the amount oxidation during melting, the metal- loids the charge and the amount lime charged. Due the small amount CaO the slag this time (about the middle the lime boil) assumed that all oxygen the slag available. The explanation this curve follows. Early the before the lime boil, the formed during the oxidation the scrap are very high FeO, and the charge melted down and the percentage the metalloids increases, FeO being continually reduced from the slag and consequence the percentage iron oxide the slag reduced. When the heat “under cover” the pounds iron oxide the slag are found minimum, and this minimum indicates the low point the FeO curve, and this low point determines what the FeO the finishing slag. The factors controlling the low point are the total oxidation the slag this point, the percentage silicon the charge and the amount lime which has gone into solution the slag. has been shown previous paper (see Fig. that the higher the SiO, content the slag, the lower will the FeO content the slag’ Thus can seen that when the the slag the highest, and also the slag most fluid, then will the lowest FeO content the so-called low point the FeO curve found. This low point the FeO curve can more clearly seen the graphic picture (see Fig. Heat “A” which the progress heat for several hours previous its being melted until was tapped clearly Table analyses the heat for all metalloids, complete slag analyses, slag all detail are 9:35 2.25 0.31 0.081 0.047 10:00 2.08 0.34 0.075 0.019 10:30 1.82 0.36 0.064 0.005 11:00 1.57 0.40 0.059 11:30 1.47 0.42 0.046 11:31 12:00 0.43 0.085 12:03 12:13 0.27 0.021 12:23 0.28 0.022 12:33 0.26 0.019 12:53 1.05 0.31 0.017 1:04 1:13 0.98 0.36 0.016 1:34 0.90 0.40 0.016 1:38 1:53 0.84 0.44 0.013 2:03 2:13 0.77 0.45 0.015 2:22 2:24 0.73 0.44 0.015 2:25 2:36 0.014 2:42 024 TABLE Log Heat “A” Viscosi- meter, Inches FeO 7.30 1.51 5.9 5.36 1.64 5.0 5.13 1.39 6.9 4.33 1.26 3.6 4.79 1.77 1000 Ib. lime 2.6 2500 Ib. 250 spar 1.9 8.55 3.15 0.5 7.75 4.16 spar 2.9 7.30 4.41 185 fine ore 2.5 7.07 4.03 tb. spar 6.8 7.07 Spiegel added 6.2 32—THE IRON August 24.90 18.97 1.91 32.94 7.39 15.60 25.76 2.30 2268 2.79 37.14 3.26 37.11 5.40 3.19 5.36 264 1132 1940 288 46.73 5.36 10.71 47.52 5.56 10.25 18.08 47.70 630 500 Time ,hours ul | th In 4.3 10.60 3.15 0.2 935 > ar | This graph shows that about 11:00 the low point the FeO curve was reached when the FeO con- tent was 4.33 per cent. the same time the SiO: the slag was 29.48 per cent and the fluidity was in. This low point usually found about the middle the lime boil and series slag samples starting some time pre- yious the lime boil will usually in- dicate the low point giving the most fuid slag reading the viscosimeter. this time slag sample sent the laboratory for determination FeO and when this fact known start made shaping the slag. will noted that soon the low point reached the curve grad- turns upward. This may ex- plained the fact that the low point the curve the SiO, content the slag very high and the CaO content very low (on Heat about 32.94 per cent CaO and 29.48 per cent During the lime boil CaO continually dissolving the slag, and after certain percentage has gone into solution the slag thickens very rapidly and many lumps undissolved lime are found the slag. Due the presence these lumps the effective slag metal area increased very much and has been found that the lower layers the slag this time are usually less fluid than the upper layers. Both these items make the transfer oxygen from slag metal slower than the transfer from gas slag, and result after certain fluidity has been reached the increase the FeO the slag very rapid. This can clearly noted the FeO curve Heat “A” where the FeO increases from 4.33 per cent 11:00 the low point 5.81 per cent one hour later. Experimental work has shown that with fluidities in. less the oxygen pick-up very rapid. This indicates very heavy slag. Slags with greater fluidity give constant oxygen (neither increase de- crease) while very fluid slags usually show loss oxygen during the re- period. From this can seen that maintaining definite slag fluidity allows the operator increase de- the oxygen content the slag, and the use the viscosimeter this may controlled. Needless say, the skill and judgment the melter plays very important part the use this device. First, must know what fluidity wishes main- and, second, must very familiar with the action the various materials has available maintain this The melter somewhat RIGHT IS. Relation iron oxide BELOW Progress Heat for sev- eral hours previous being melted and until was tapped. Figures taken before deoxidizer Total slag 1] v 1.70 0090 £1.30 £0.10 Clock time THE IRON AGE, August 17, a | ler 204 Each vertical point represents one her the vest low limited the materials has avail- able for controlling slag fluidity. name them briefly, there lime, usual- burnt lime; iron oxide, the form fine ore mill scale; sand, fluorspar and temperature. Fluorspar thins the slag, causing more lime dissolve and increases the percentage CaO the slag. Herty has shown that with increase CaO increasing basicity, Fe,O, also fining period. Pounds oxygen are shown rather than percentage FeO the percentage would change but total pounds oxygen would not change. this heat there found very basic slag with the pounds oxygen in- creasing very rapidly the end the the increasing basicity the slag was the cause for this increase, and was Fig. (Heat 24455) shows slag with decreasing oxygen with three tinct decreases indicated, first the main ore addition, second smaller ore addition and third afte additions burnt lime and scale, SiO, content was high all through this heat (from per cent) fluidity was from in, these data may seen that lim and silica were the most Fluidity, ao ow Oxygen iron oxides slag, pounds time which gained oxygen during the refining period. increases. Examples this will presented later. The addition iron oxide the slag gives results similar the addition fluorspar thinning the slag and also dissolves more lime increase the CaO content the slag, the thinning action FeO being particularly noticeable lower car- bons with their higher FeO’s. course the direct addition FeO also increases the percentage FeO the slag. Lime increases the CaO con- tent the slag, provided goes into solution, and increasing the basicity and decreasing the fluidity, also in- creases the content. Sand increasing the SiO, content decreases the FeO content dilution and also increases the fluidity the slag. The effect various additions, slag analyses, etc., slag fluidity may noted the next three graphs taken from Herty’s work this Fig. (Heat 24463) shows heat which gained oxygen during the re- Cooperative Bulletin No. 68, pp. 54-55. 34—THE IRON AGE, August 1939 ag, inches ides Oxygen iron 10:00 9:00 Fluidity, RIGHT 7—Action oxy- gen slag heat which lost oxygen during the refining period. Oxygen iron oxides slag,pounds o Clock time which gave constant oxygen during the fining period. most noticeable when the percentage SiO, was about per cent and the CaO content about per cent—or about o’clock. can also noted that this increase took place spite very fluid slag. Fig. (Heat 24447) .shows con- stant oxygen during the refining period and the oxygen just started in- crease when the SiO, content the slag dropped about per cent. Fluidity this heat was medium about in. factors the change oxygen the slag, with evidence also show that two slags similar content CaO and SiO, the most viscous slag increases more rapidly loses less rapidly. Now, order control slag ities the effects various the various types slags considered. First, with basic slag found that the content the metal usually for given FeO content the the chi the less sho low rate the not wit has slag OCK TIME aI tota was in] unle are slag xygen should veakly slag, than strongly basic slag. This possibly due tie-up lime and FeO the slag, making some the FeO unavailable. There tendency for weakly basic slags decrease due having relatively small changes fluidity with temperature. additions ore are made while the slag weakly basic, the amount carbon eliminated the ore will greater than the slag very because the transfer oxygen from slag metal will more rapid and the amount carbon eliminated will greater than with basic slag. There will also less possibility the formation lime-iron compounds which make un- available some the With this increase the CaO content the slag the addition lime. Fluor- spar additions and the use fine ore assist putting into solution undis- solved lime the slag. With strongly basic slags found that the FeO content the metal usually lower, for given FeO the slag, than for weakly basic slag. Before ore additions, this type slag, basic and heavy, will contain more FeO than weakly basic slag, and very basic slags rapid change fluidity with temperature found un- less they are kept fluid with fluorspar. the FeO content the slag kept low possible, the slag should not allowed become basic early the heat. Herty that with very fluid slags the most rapid increase total oxygen found with high lime and low silica contents, and the silica the lime decreased the rate increase was less and, finally, fairly low limes and high silicas the total oxygen decreased. FeO does not build shown previously, but with very fluid slags, decreases. Herty has also that with very fluid slags per cent CaO and ‘otal pounds oxygen was from per min., but with heavy slags similar analyses the oxygen change over 1.0 lb. per The relative fluidity slags has shown and the data sufficient interest reproduce Fig. 8). explains the change content the slag with change slag composition the following theory. all times during the heat the slag being deliberately the upper layers the slag higher temperature than the Bulletin No. 68, 56. Bulletin No. 68, pp. 60-61. TABLE Slag Analyses for Heat Sample No. CaO 1 .19 P.O; SiO, TABLE III Log Heat Sample No. 4:00 5:30 7:40 1.40 1.14 1.12 0.91 4.5 3.5 6.02 9.80 2.89 3.56 1.76 25.7 40.15 5.70 1.61 1.66 1.14 0.91 Additions Ib. fluorspar. 200 fluorspar. Deoxidizer added. Tapped CN oo = lower layers. Therefore given slag has relatively small change fluidity with temperature would expected that the rates transfer oxygen would depend upon factors other than changes fluidity. How- ever, the slag had high rate. change fluidity with temperature, TABLE Log Heat Iron Ore Lime Viscosity, 5:45 7.8 10:40 8.3 0.79 Inches 2300 Ib. 1.03 0.028 0.34 0.018 0.39 1100 Ib. Deoxidizer added Tapped 500 Ib. Spar THE IRON AGE, August dis. after after 4 this and lime rtant 3000 lb. 600 Ib. seale. 0.76 100 Ib. fluorspar. TABLE Log Heat Viscosity, Time 4:50 6:20 6:25 6:50 7:00 7:40 8:00 8:50 8:55 9:00 9:05 9:10 9:15 9:20 3.8 9:35 9:40 10:15 would expected that the rate transfer oxygen from slag metal would slower than the rate trans- fer oxygen slag. tests made samples slag and held the test spoon for various lengths time poured into the viscosi- meter some interesting results were obtained. The slag samples were with- drawn from the furnace eight dif- ferent periods during heat high carbon steel. For any given set samples the first sample was poured into the viscosimeter soon possi- ble, averaging sec. from the time the spoon was taken out the furnace. Samples were held the spoon for various lengths time poured into the viscosimeter and this system was followed for each set samples. can noted that slags No. and No. which were far the most wedkly basic, showed the least drop temperature and stayed fluid and the slags became more basic the fluidity decreased more rapid- ly, and finally sample No. the slag could not poured from the spoon sec. after the spoon was withdrawn from the furnace. These results indi- cated that the slags became more basic, the viscosity the slag metal surface would much higher for given viscosity the slag gas inter- face than would the case the more acid slags. These results indi- cate that the change FeO content the slag affected slag com- position may attributed changes 36—THE IRON AGE, August 17, 1939 Inches 9:50 lron Ore Lime Seale Spar 1180 500 Ib. 500 450 450 200 200 Ib. 200 200 Ib. 200 Ib. 200 Ib. 200 Ib. Deoxidizer added Tapped slag fluidity with changes tem- perature between gas and metal sur- faces. together with the appearance slag cakes taken the same time also slag analyses shown and Table Table III gives log this typical heat. Slag from this heat typical siliceous slag taken early the with high slag fluidity. The for this slag (or the lime-silica ratip corrected for 0.82 and analyses 33.12 per cent 27.76 per cent CaO. Extreme fluidity found nearly all slags this type. Slag “B” another quite fluid slag taken about the middle lime boil and also the low point the FeO curve. FeO this slag per cent, compared with 8.77 cent the previous slag, while 28.40 and CaO 35.81 per cent Some lime has gone into solution and the heat this time about all melted and under cover, and 7:45 crease the CaO content and 2000 Ib. iron ore added 7:40, slag taken, shortly before the addition burnt lime and iron ore. Lime has again gone inte solution and has increased the from 35.81 41.53 per cent. | 0 1.31 1.15 ce 5 . ty] kil ab HEAT HEAT if pad EAT has and the slag has in- creased viscosity from 7.4 Slag taken shortly after the ore addition, and the effect the ore upon the increase FeO can noted, FeO increasing from 6.02 980 per cent; all other constituents are about the same, and slag viscosity has increased from 4.5 in. 3.5 in. Slag taken tapping, with slag fluidity 4.0 in. and 19.20 per cent with CaO about 46.90 per cent. This slag was kept rather heavy all through the heat and the viscosity Time held spoon, seconds ranged between 3.5 and 4.5 in. during the refining period. About the only Slag analyses for fluidity tests. change the appearance the slag cakes that can correlated with slag analyses the lime-silica ratio and this only all details the heat are available. The slag gradually changes from high silica glassy type slag high lime dark black slag. Relative fluidity Per cent MnO SiO: 20.47 28.80 19.55 28.08 17.66 26.72 16.42 25.24 15.29 23.20 11.95 19.00 17.24 10.62 16.34 Data two other heats will found Figs. and 11, showing typical control practice with the vis- killed heat made finish 0.75 0.80 carbon with FeO content about per cent, final phosphorous 8—Change relative fluidity open hearth about 0.025 per cent and slag fluidity slags with decreasing temperature. Can — THE IRON AGE, August 17, the the per 33.44 7.01 1.72 and 34.67 6.77 1.76 36.43 6.52 1.76 lock 38.19 6.24 1.67 1.72 and into slags and log this heat are shown Tables and respectively. ® we = 0.45 FeO Low Point 2.52 Before Deoxidizer 7.70 3.87 Final 0.022 Time Charge Tap— Carbon, per cent Clock time Min. Additions Spiegel Lb. FeMn 600 This spiegel-killed heat was made finish 0.75 0.80 carbon, with FeO content about per cent, final phosphorous about 0.025, and slag fluidity tapping about in. tapping about in. This heat melted about 1.31 carbon and the FeO the low point was 2.52 per cent. This low FeO would indicate, along with the high slag fluidity, that either lime FeO the form scale would have added this slag enable the operator finish (200 addition) the heat with the required phosphor- under 0.04 per cent and with FeO about per cent. Dué the addition spiegel deoxidizer with its silicon content about per cent, two things must kept mind: First, the slag must sufficiently basic (ratio CaO 0.35 FeO Low Point 4.59 Before Deoxidizer Final 1.20 Clock time Time Charge Tap— Hr. Min. IG. Typical silico-manganese killed heat. Slag fluidity heats killed with this type deoxidizer important, especially with low FeO slags, the large amount silicon added can easily cause phosphorous 38—THE IRON AGE, August 17, 1939 SiO:) that after the silicon the increased the slag will not cause reversion phosphorous, addition, sufficient fluidity must maintained prevent phosphorous reversion has been found that with fluid slags reversion liable occur. this heat 1200 burnt lime was added the lime the charge was the low Scale was added 8:05 o’clock and again 8:25 showing that the melter anticipated trouble with his phosphorous unless either lime in- crease CaO scale increase the FeO was added. His slag viscosity indicated that had sufficient lime his slag the only other thing could was add scale. Final FeO this heat was 7.70 per cent per cent aimed at) and final phosphorous was 0.030, with slag fluidity in, See Table for log. Fig. and Table give details typical silico-manganese killed heat. With this type deoxidizer, carrying higher silicon content, necessary carry more fluid slag than using spiegel. this heat the addition was indicated the very fluid early slag. Slag fluidity was high during all the early stages this heat and FeO the low point was 4.59 per cent, some- what higher than usual. However, phosphorus preliminary 9:20 o’clock 0.028 per cent indicated that more FeO would needed this slag, especially with this type deoxidizer; 500 Ib. scale was added which increased the fluidity from in. in. Final fluidity aimed was in. and actual measurements were 8.6 in. Slag fluidity heats killed with this type deoxidizer important, especially with low slags, the large amount silicon added can easily cause phosphorous reversion. Final phosphorous this heat was 0.021 per cent and final was 8.06 per cent. Slag fluidity very important factor the production basic hearth steel. undoubtedly has com siderable influence upon the rate carbon drop and just what its effect upon several other factors still unknown. Operators also are loss understand the effects slight changes slag composition fluidity, and always there the tion temperature one the most important unknowns. Possibly temperature and metal hold the answer many the dustry’s problems. Nevertheless, the viscosimeter very useful tool maintaining definite slag viscosities. : 7 7 B+ 0.030 ab fir in tic = 070 (4 900 OVENS FOR AUTO BODIES finishing plant General Mo- tors Corp. near Los Angeles, where the Buicks, Oldsmobiles and Pontiacs the Far West are now being put together from the innumer- able separate parts made Mid-West factories, automobile bodies per day move through interesting series natural-gas-fired ovens over 900 long receive their final finish. The first 150 ft. this magic tunnel—the bonderizing unit—is particularly inter- esting virtue its efficient and au- tomatic operation and the latest de- high-capacity liquid heating which incorporates. This bonderizing unit, ft. wide ft. in. high, divided into six contiguous compartments with open- ings from one the other just large enough clear the car body dimensions. Its function spray upon every exposed square inch the body sequence solutions which conditions the steel surface with phosphate coating before the applica- tion the priming coat, the ground coat, and the final duco layers. Compartment No. serves clean away oil, grease and other smudge with powerful alkali spray. Com- partments No. and are successive rinsing chambers, and compartment No. actually applies the bonderizing solution. The fifth cham- ber again rinses the surface, and No. gives chromic acid spray-bath for neutralizing excess bonderizing solution. all, over 130 spray pipes are located the top and sides the compartments. Centrifugal pumps the water and various mix- tures Ib. pressure. Water-over- the South Gate assembly and inspirating burner assemblies, recently the bonderizing six Surface Combustion orp. immersion- pressure stalled, serving oven. flows carry away the accumulated grease and other impurities from all tanks except No. the bonderizing unit. None the bonderizing solu- tion permitted escape. every case, the liquid heated immersion-type, high-pressure air- inspirating gas burners with cast iron tips. Pilot lights ignited. Natural gas used pres- sure Ib. and fired angle down into steel which run longitudinally through the liquid the storage tank. Such system permits maximum degree heat removal from the hot products combustion these products travel along their hairpin routes the ex- haust blower intakes. Operation completely automatic, and correct tem- peratures are maintained throughout the tank liquid thermostatic control. Compartments Hot water rinse Hot water rinse Bonderizing water Neutralizing bath Water Hourly Capacity, Gal. ture, Consump- Burners Gal. Per Hr. Deg. tion, Cu. Ft. 2637 750 180 3169 2637 750 180 1102 1852 750 180 1102 2523 280 170 864 1142 280 180 495 1673 280 170 1102 The accompanying table gives data indicative the economy achieved, and the photograph illustrates the com- pactness and convenience repre- sentative solution heating unit (this one being the 2-burner unit for com- partment No. 2). This equipment has given eminently satisfactory service since its installa- tion 1938, and considered model for modern efficient use gas fuel liquid heating. The remaining 750 linear feet gas-fired equipment the body-finish- ing line broken follows: ft. recirculated hot-air oven for drying the freshly-applied bonderizing coat; 220 ft. low-pressure gas-fired oven for drying the priming coat; another 220 ft. gas oven for drying the glaze; ft. gas oven suc- ceed “wet standing”; ft. gas oven dry the ground coat; and 148 ft. gas oven follow duco spray operations. All these ovens are fired with natural gas through low- pressure burner systems. final spot- drying oven dries the body polish. The seven ovens carry total gas burners whose cumulative input rating 17,500,000 B.t.u. per hr. all, the South Gate plant consumes about 10,000,000 cu. ft. natural gas per month. THE IRON AGE, August ict ° j — rly ne- ock ore rer med ents eats FeO i this FeO upon ques- sag ature the ies. ANUFACTURE BOILE manufacture boiler plate the United States the gamut the series processes developed for the making iron steel. The demands industry and the cooperating efforts the technical and practical research have brought about the present developed state the art steel making. The use specifications and the inspection materials for boilers and pressure have kept pace with the devel- opment production methods with the result that higher quality and greater operating safety now assured. Among the early requirements, 1817, found that the specifi- cations called for boilers made wrought iron instead cast iron copper, the materials previously Thus, have example definite change boiler plate material. Until 1838, boilers worked above Ib. per sq. in., and the usual pressure was something less than Ib. per sq. in. Then the pres- sures were increased and per sq. in. and inspection recom- mended; but not required, course. From 1864 1869, there were 288 boiler explosions; per cent the failures were due defects con- struction, either materials work- manship, and per cent resulting from neglect during the operation the boilers. This not only indicated the need improvement materials, but also the necessity for regular competent inspection. short period, there- after, the convincing proof the value inspection was fact. 1881, reported that the 15,000 boilers regularly inspected, there were only two boiler explosions. From the standpoint the boiler plate material itself, the use wrought iron for boiler plate was decided improvement over the previ- ously used cast iron and some the so-called charcoal 40—THE IRON AGE, August 1939 THEISINGER Welding and Metallurgical Engineer, Lukens Steel Co. though wrought iron was soft and re- sisted shock, and therein lay its pref- erence over the hard and brittle cast iron, still left much desired because its low strength, the limited size the plates that could ob- tained, and the quality the material The significant period the boiler plate industry must have been around 1860 when bessemer steel was being introduced and the Siemens-Martin, open hearth process, was being de- veloped. Also, this period, the Lake Superior ore beds were discovered and the coal fields were being opened for the production coke which soon replaced charcoal the ferrous metals industry. claimed that early 1855 the boilers the Mississippi steam- boats were made steel produced Kelly’s pneumatic process, the con- temporary the bessemer 1875, Holley had produced boiler plate made from bessemer steel that could flanged backward ward and doubled upon itself. Since the interest herein quality, the development paramount importance was the Thomas-Gilchrist process, the basic production steel wherein the removal phosphorus and some extent the sulphur was effected. Also during this period, consider- able attention was being brought bear methods testing boiler plate material. 1875, when the United States Government that plates used construction steamboat boilers stamped with their tensile strength, the Lukens Steel Co., having been the first mill roll boiler plate America, purchased testing machine and began ing the physical properties iron steel. The new testing machine the Watertown Arsenal was supplying much needed information the mild steel 1882. The Americar Society Testing Materials held its first meetings those Manufacturers, fabricators users boiler plate wanted cations that would applicable suppliers that the material could ordered and made definite ments. uniform test program devised, and spite the fact that many different groups were resented the preparation, similarity the specifications was apparent. The manufacture boiler steel carried out the basic hearth practically the exclusion all other steel making processes. There are many factors contributing the popularity the basic open with respect the quality product. Likewise the was commercial success the large percentage discard and other accumulating around steel mill the fabricating shops could the raw material charge and melted. From the standpoint ity, the open hearth lends itself read ily, because the charge once can kept that condition fluxes and other materials are until the analysis the melt has tained the right chemistry give desired physical and engineering erties. The open hearth control extends! the pouring pits where the design the ingot molds considerable portance, also the and cleanliness the molds pouring. Hot tops are used the top the ingot liquid for sufficient length time the steel expel its impurities gases into this hot top section later discarded the rolling mills. The pouring operation must | as lat fill on the an ori to per tor res rol cor gra Gre per the plo: low stee Ves sho gon core quit pan plat Wer and le at lying new its all quire- fact was plat There the hearth hearth large be re qual- read has ive the ble erature rior carried out prevent splashing the hot metal along the sides the molds, order avoid scabs the surface the finished plate, well unusual amount conditioning the slabs. our opinion, bottom pouring pro- duces better plate surface regu- lating the rise metal the molds group from center runner the bottom the ingot molds. strong skin then formed the ingot, preventing cracking and the formation scabs the ingot. After the ingots boiler plate steel have solidified, they are removed from the molds, reheated the soaking pits and rolled into slabs that are approxi- mately one half the thickness the original ingot. These slabs are allowed cool and inspected for surface im- perfections. Such defects are removed chipping with the acetylene torch and even machining the slabs resorted times. boiler plate inspected after rolling and tensile and bend test speci- mens taken from every plate ac- cordance with the requirements. 33,000 65,000 Ib. per sq. in. tensile grade, there now available group steels higher tensile properties. peratures are possible the use the high strength steels, thereby em- ploying less thickness than lower tensile grade were used. The Ib. per sq. in. minimum tensile have been adopted for many vessels and the forming and welding such material has assumed regular routine. Most this steel has gone into vessels constructed cordance with paragraph U-68, re- X-raying and stress relieving. experience the com- with specifications for steel dates back the beginning use. The original requirements similar the common mild steel grade the present, calling for ap- OLLING ingot, in, thick—the larq- est and heaviest ever made Lukens. The final product will plate 200 in. long, in. wide and thick, weighing 87.090 proximately 65,000 per sq. in., with proportional yield point and ductility values. However, the steels later acceptance, doubt. are more interest that higher physical properties obtained these plain carbon and low alloy steels have affected some extent the fabricating procedure through the introduction welding. combination chemical ele- ments, the desired physical properties are obtained not only the plate ma- terial, but also the deposited weld metal. There are number welding rods available for the higher tensile steels with possibly many varieties chemistry their make-up. conclusion, the industry has come accept the 70,000 Ib. per sq. in. minimum tensile steels for pressure vessels within the past few years, and while they have brought some welding and other fabricating problems, these problems have been overcome and shop procedures have been established. There are now other alloy steels avail- able and may that least some these will incorporated into.the existing codes. Some beyond the present range 90,000 and 100,000 per sq. in. tensile strength, and though expected that their fabrication require careful con- trol, experience and research can develop the methods operation. There are limitations the size boiler plates that can made, but the needs far have been satisfied. For example: One fabricator has re- ceived carbon-molybdenum plates that are in., weighing 50,000 plate. The ingot weight for each ingot was 90,000 per cent plate material. * * The writer indebted Charles Lukens Steel Co., for his help the preparation this paper. Mr. Huston, who joined Lukens 1875, was charge operations for many years. boiler plate, and remains active service today after vears with the company. THE IRON August Ba and your job worth has been one management’s problems for many decades, but that question “why” certain job worth certain amount money has become im- portant during the last years that has reached almost the propor- tions plague. most cases when industrial engineers have some definite problem solve, the first approach inves- tigation previous and present facts concerning the problem, and the selec- tion some means measuring stick for the analysis these facts. The present situation this problem seems the quest for that measuring stick, evidenced from the fact that since about 1922, some differ- ent plans job rating have been pub- lished some form other; and there are probably twice that many more that have been written and used some extent but which have not been brought public attention. the days the so-called “efficiency ” experts,” such men Taylor, Emer- son, Barth, Gantt, Halsey and Merrick were all trying develop new meth- ods wage payment, either mat- ter personal publicity honest attempts, their parts, meet the peculiar conditions some individual problems. has turned out, all these plans are fundamentally sim- ilar, differing only minor details the method administration. And now there again flood job rat- ing plans, each one developed because the author felt that his plan was the only one which could adequately fill his particular need. But what are the details this problem for which solution de- sired? What the purpose all this frenzied activity developing job rating plans? 42—THE IRON AGE, August 1939 BARRETT ROGERS Assistant Professor Industrial Engineering, Purdue University ° ° There is, every industry and al- most every company, variety jobs which must properly filled that the company can function smoothly. Perhaps two these jobs are ex- actly alike. Some them are widely different nature type work, yet the degree training skill may relatively equal. The same general type operator could fill any these jobs (although perhaps not easily interchangeable). general level supply for that level operation found, and about the same level wages paid for all these different jobs. the other hand, there are also many different levels work the same general type operation, requiring different degrees skill and training. Thus, there are two major wage problems—first, pay the same gen- eral level wages for all operations requiring about the same degree skill and training; and second, pay different levels wages for opera- tions requiring different degrees skill and training. But, most im- portant that these different levels wages paid about the same pro- portion the different degrees skill and training are required the jobs. Once known how much more skill training one job requires than an- other, not difficult allocate rela- tive amounts money for these dif- ferences. The trouble has always been the measuring these different job requirements. From this general statement, should most interesting list some the results which should ex- pected from the proper solution this problem (1) Show the relative value requirements) all present jobs jobs one department, between partments, and between hourly and salary paid jobs. (2) Determine the relative any new job. (3) Convert these relative value into correct actual real money values, for the amount money employee takes home which finally interested. (4) The application the pla should give consistent results variety times, places, and tions. pected from the installation (1) Prevent inequalities for similar work, eliminate duce individual employee tion. (2) Standardize present jobs der (a) clarify the each, and prevent inefficient ping duties; (b) provide cut and adequate basis for (3) Improve lations providing adequate intelligent arbitration wage tions. the actual real values high, the unnecessary excess mean higher costs, inability competition, reduced profits losses, and perhaps eventual tion the enterprise. the real ues are too low, the ard living will lower than necessary for his particular tion, the desirable employees will | 7 { \ and Per vers pan true cei 7 mitt any two thou ing mall ing form erate Tates and lead, one yee fe ques: meet should and the general quality and production level the enterprise will During the latter part 1938, the Personnel Department Purdue Uni- versity contacted different com- true cross-section what has been accomplished actual practice job rating. Sixty-three replies were re- which companies ad- mitted they had made attempt any job evaluation procedure. Thirty- two (or about per cent) had some form job evaluation procedure, al- though five were very informal, leav- ing that were some extent for- mally organized. this group 27, (or per cent) were based some form Point Rating Systems, the balance being based the Rank- ing type classification. Operating Without Plan The procedure followed the “in- formal” plans seemed be, “to coop- with other manufacturers, get- ting the breakdown jobs and the for each classification work, and letting this govern the wage rates the individual company.” in- some the difficulties to- Ward which plan this sort might statement may quoted from the large steel companies re- HAT the purpose the recent frenzied ac- tivity developing job rat- ing plans? What results should expected ofa proper plan? How Rank- ing and Point Rating plans function? All these questions are answered this first tion two-part article. garding wage surveys competitor companies the local communities where this steel company had branch plants. “From these comparisons, learned that the comparative rate situ- ation was aggravated our own; that even the same community, the differences wages for comparable jobs varied frequently much 100 per cent; that could justify, the basis such comparisons, ANY rate that were paying could select; and, that the ‘going’ prevailing rate for any particular class labor could determined only within such wide limits render the comparison valueless far be- ing aid the selection correct rates.” The same situation existed both the plants this steel com- pany and those their competitors, namely that their job nomenclature was not standardized, which resulted corresponding inconsistencies rates, and that their base rates and bonuses were not uniform. The author believes this clearly indicates the con- ditions most companies where some formal plan job rating has not been established. Types Plans The more formal plans logically fall into general classes: First, the ranking, classification, grading pro- cedures; and second, some form point rating. The poorest these methods properly administered might satisfactory, and the best them poorly applied would equally un- satisfactory. Ranking Grading The simplest method, course, con- sists sorting the names the jobs, just deck cards may sorted, until general good judgment they have been arranged the order in- creasing importance. slightly more complicated program would set classes, with general description for THE IRON AGE, August q this jobs paid plan wage each class, and sort the jobs into these various classes. either case, this sorting ranking may done the rankings from several individuals working independently, giving what some call “Pooled Judgment.” The grades classes may set before the sorting done and the jobs sorted those classes. most cases, how- ever, the sorting ranking seems have been done first, and the grades classes determined from the results the ranking. Usually few KEY jobs are used anchor points guides order divide the total range into smaller units. 44—THE IRON AGE, August this arrangement jobs must tied with some scale wages, and this usually done one two ways. The first method plot the average rate for the highest and the lowest jobs along some uni- form scale and draw straight line be- tween these two points, assuming that all jobs between these two will dis- tributed equally along this line. The second method assume that the selected classes grades are equal range and divide the difference be- tween the lowest and highest rates equally over the number grades se- lected. There are some advantages this type procedure. can done most important that ent levels wages paid about the same proportion the different degrees skill and training are required the jobs. The important thing, however, the determination how much more skill training one job quires than another. Photo cour- tesy rather quickly, provided too good job not required, and there responding low cost installation, simpler, whole, and easy for the foremen and workers stand; less theoretical and les mechanistic than point plan; and some persons maintain that based the same judgment used any point system. The disadvantages, however, seem outweigh the advantages such extent make this type cedure undesirable for anything except logical step the development adequate point system. For ple, these ranking procedures the engineer doing the ranking assume that knows what job consists, and there corresponding tendency disp