The Iron Age 1934-04-12: Vol 133 Iss 15

PROCESSES Ohio MANAGEMENT STEEL CO. Warren, THE THOMAS YEAR SERVICE THE METAL WORKING INDUSTRY CTION 7 THE IRON APRIL 12, 1934 Page WE DO OUR PART Here again are current examples three the many and varied industries represented our order books every month. Each month the list growing, more and more manufacturers every field industry learn that our line tool steels they can find exactly the right steel just fitted for their specific problems. The complete line includes Krokoloy, the leading chrome cobalt tool steel, for maximum runs and toughest jobs; Martin Steel for the most intricate Blanking and forming dies for shovels—blank- ing, forming and trim- ming dies for washing machine parts blank- ing and forming dies for carpet sweeper parts— just three the many products whose manu- facture one more our tool steels, cast shape, play leading part. shapes with minimum material; Castaloy for use instead cast iron forgings; all three alloy tool steels, cast shape and hardened still air; and Carbomang, oil hardening tool steel, cast shape for purposes where alloy steel castings are not required. Our trained sales engineers can help you with your die casting and machine tool problems. They are your service without obligation. Write for set our specialized literature, Series DETROIT ALLOY STEEL COMPANY Foot Iron Street Eastern District Sales Manager: Andersen 135 Post Ave., Lyndhurst, New Jersey THE Pa. Executive March Ofhces: $6.00 year S., Canada $8.50, Foreign $12.00, Detroit, Michigan Central District Sales Manager: William Eakin 707 Berkshire Ave., Pittsburgh, Pennsylvania published every Thursday the JRON AGE PUBLISHING Office: Cor. Chestnut 56th Sts., Entered second class matter the Post Office Philadelphia under 133, No. Vol. ¢ : may with mere ‘ ARSOMANG take: direc Sam ques: ploy: until sume the Sam for THE IRON AGE ... APRIL 12, 1934 ESTABLISHED 1855 Vol. 133, No. not take much stock Dr. Wirt’s charge that there deliberate and or- ganized attempt the part group brain trusters force into state socialism. There may “pinks” even “reds” the advisory group, but they would never agree upon plan. Any one with sufficient ego and individualism believe that mere scholastic experience qualified him redesign America would make poor communist. From the standpoint public interest, however, intent quite secondary effect. The suicide just dead though had been murdered. far results are concerned, the steps now being taken will ultimately lead socialization fascism makes difference whether these steps are directed organized brains take place because difficult prove intent, easy demonstrate effect. Dr. Wirt, for example, tells plan the “revolutionists” thwart recovery and drive Uncle Sam into the investment business. Discarding the question intent, let’s apply the question effect the capital goods industries. know that these industries the great bulk our considerable remainder unem- ployment. agreed that recovery not assured until these industries approach the level con- sumer industries. one had deliberate intent block recovery the capital goods industries, keep its unemployed millions from getting work and thus drive Uncle Sam into the investment banking business and eventually into management industry, could have devised more effective instruments for the purpose than the Securities Act 1933 the pending Fletcher-Rayburn Bill. The former has nearly dried the stream private long term in- vestment. The latter bill, becomes law, will probably stop the remaining trickle. doubly unfortunate that these bills which profess the purpose protecting those with money invest actually penalize millions workers with money keeping them out jobs. Also with unquestionable effect toward socializa- tion, even though without intent, are the Wagner Bill and the Cotton Control Bill, now pending, and the proposed Oil Industry Control Bill which preparation. The Congressional investigation the Wirt charges will not amount much confined the question intent. deals with the ques- tion effect, regardless intent; answers the question “Where are these steps leading may accomplish much. FTER all, the intent which prompts act not important the effect the act. The kindly elephant who sat upon the nest while the mother bird was away had the best intentions the world, but the effect her act was disastrous. ~ 4 .2 She a k or i = for hey elohia Py industrial plants using heat- ing processes, and especially steel mills, during the depres- sion have been making studies the best methods reducing fuel losses. This has become especially important cwing the necessity for production with vast amount idle time be- tween operations. Small orders and immediate delivery have imposed new problem the tween production and fuel. Furnaces had lighted fill possibly small order only shut down when more tonnage was sight held warming fuel anticipating renewal operation. The low amount inventory car- ried and the insistence short time shipments customers seriously af- fect the best economy furnace oper- ations. Rising costs fuel also have direct bearing the final results but operating schedules and frequent lighting cold furnaces are paramount importance. With all this view, study has been made three 84-in. plate mill heating furnaces try analyze the factors influencing the number light-ups based against produc- tion. Although roughly known advance what the answer be, this study has been made effort The purpose analyze the reason for the increasing fuel consumption. also made show how delays the mill due mechanical break- downs, roll changes, waiting steel and scheduling the mill operations affect fuel economy. The furnaces used, which these data have been assembled, serve the 84-in. plate mill the Republic Steel Corpn. the Youngstown plant. These furnaces are ft. long and ft. wide, with effective heating area 532 sq. ft. They are triple fired, having soaking chamber with brick hearth where the slabs obtain uniform temperature before being discharged, while the main heating section has both bottom and top firing. 10—The Iron Age, April 12, 1934 How Irregular Operations Affect Each the three furnaces equipped with Blaw-Knox regenerative air preheater. All the data here presented are from actual operating records. Many times data are taken from test runs which are made after elaborate prep- arations and when conditions are ad- justed proper testing procedure and conducted under the critical eye the test engineers. For that reason was thought well take actual quantities reported the combus- tion department. The gas quantities were obtained from integrating orifice actual operating rec- ords plate-mill heating furnace, the author gives quantita- tively the increased fuel require- ments intermittent delayed illustration the enhanced costs flow meters and temperatures from recording potentiometer recorders. The record assembled shown Table Charged Heating Furnace and Gas Consumption Gross Charged Tons Furnace per Run Charged Hours Hour 3.7 2 72 12.00 240 7.26 652 13.60 982 13.63 727 10.10 812 14.80 17.32 " 655 48 13.65 14.73 670 13.96 766 10.65 13 851 64 13.30 14 634 47 13.50 5 414 48 8.63 12.26 877 12.20 586 34.5 17.00 9 293 35 8.37 760 15.83 645 13.45 749 12.28 555 11.57 353 7.36 25 433 48 9.03 278 4.79 622 12.98 690 56.5 10.45 401 12.16 574 11.95 645 20.15 749 42.3 17.70 555 353 11.02 433 13.54 36 278 32 8.69 Cu. Ft. Million Million Coke B.t.u. B.t.u. per Gas Fuel Charged 4380 2260 2.290 4395 2278 2.620 1860 963 4.010 3465 1795 2.75 4635 2400 2.445 3945 2043 2.810 3181 1868 2.300 1740 901 2.175 2820 1461 2.230 1478 765 2.360 2840 1470 2.195 $151 2150 2.805 3934 2039 2.400 2838 1470 2.320 2646 1370 3.310 4001 2072 2.350 3975 2060 2.350 2405 1247 2.130 1800 932 3.180 3015 1562 2.055 3178 1647 2.545 3295 1758 2.345 2981 1544 2.780 2447 1268 3.590 2469 1280 2.955 2283 1182 4.250 2856 1479 3.030 3594 1860 3.150 2590 1343 2.990 3179 1648 3.220 2678 1385 2.150 2795 1449 1.931 2481 1286 2.315 1947 948 2.685 1969 1020 2.355 1783 924 3.220 > at — cpe rur — — Rur 1 6 ‘ ‘ 10 12 14 15 16 17 18 19 20 21 99 24 26 9° 98 > an 31 32 33 34 or 36 brought about the depression with its smallness orders and demands for immediate delivery. The data were contributed symposium, so-called, trans- fers conducted the American Society Mechanical Engineers. Tables and cperating periods designated the run number, together with the num- Furnace Economy ber gross tons charged and furnace hours operated. The furnace hours here tabulated referred total time the furnaces were under fire, includ- ing holding time and pushing time. During this time the fuel was mea- sured and reduced standard condi- tions. From these data the total heat required and heat per gross ton was determined, based the higher heat- ing value the coke gas assumed average plant analysis, which gave heating value 518 B.t.u. per cu. ft. This analysis shown detail Fig. Temp. of Preheated Air, Rur Deg. F. 900 2 910 800 15 900 16 910 17 S90 18 865 9 900 20 850 21 940 22 910 920 24 960 25 880 26 890 780 28 930 9 900 30 850 31 940 $2 910 920 960 880 890 Temp. Flue Gas Before Preheater 1475 1465 1360 1480 1500 1440 1470 1470 1450 1475 1460 1430 1220 1220 1370 1460 1480 1465 1440 1330 1440 1410 1430 1400 1430 1415 350 1435 1460 1435 1490 1470 1480 1440 1480 1470 Heat Steel, Million B.t.u. 774 676 188 511 770 570 636 99° vad 514 Table the Furnace Gases Per Cubic Feet of Coke Oven Gas————— Heat Heatin Total Heat Heat Products Per Cent Flue Comb. Air Gases Latent Heat 146.0 11.3 157.3 216.3 145.0 11.3 156.3 215.3 133.5 11.0 144.5 203.5 147.5 11.5 159.0 218.0 148.5 11.6 160.1 219.1 142.5 11.1 53.6 212.6 147.5 11.5 159.0 218.0 147.5 11.5 159.0 218.0 143.0 11.1 154.1 213.1 146.0 11.3 157.3 216.3 145.0 11.3 156.3 215.3 142.0 11.0 153.0 212.0 118.5 9.3 27.8 118.5 9.3 27.8 186.8 35.0 10.6 145.6 204.6 145.0 11.3 156.3 215.3 147.5 11.5 158.5 217.5 145.0 11.3 156.3 216.3 142.5 11.1 53.6 212.6 131.0 10.2 141.2 200.2 142.5 11.1 53.6 212.6 139.5 10.9 150.4 209.4 142.0 11.0 53.0 212.0 138.0 10.8 148.8 207.8 142.0 11.0 53.0 212.0 139.5 109 150.4 £09.4 32.5 10.4 152.9 201.9 142.0 11.0 153.0 212.0 145.0 11.3 156.3 2358.3 142.0 11.0 53.0 212.0 148.0 11.6 59.6 218.6 147.5 11.5 59.0 218.0 147.5 11.5 159.0 218.0 142.5 11.1 153.6 212.6 147.5 11.5 159.0 18.0 147.5 11.5 159.0 218.0 GRIFFITHS Republic Steel Corpn., Youngstown From this table Fig. was plotted showing the relationship the num- ber gross tons steel heated per furnace hour against millions B.t.u. per gross ton steel, bearing mind this curve based total furnace hours. This curve, while not the true economy-capacity curve the fur- nevertheless approaches closely. pointed out that the irregularity points is, doubt, mainly due variations size and thickness the slabs heated. Another factor that helps explain the irregular points the fact that the furnaces may driven lightly for only por- tion the time due some delay and then driven very hard for the remainder the time. refer- ence the latter statement, consider the furnace heating the rate gross tons per hour one-half the time and gross tons per hour the last half. The average the fuel con- sumption the two rates (4.17 2.13) 3.15 million B.t.u. per gross ton, while the curve shows 2.48 million B.t.u. per gross ton for the average hourly tonnage 20) 12.5 gross tons per hour, which falls the region the curve but reason. Fig. does not include light-up fuel, average which for three furnaces 1125 million B.t.u., total for all three furnaces. This figure used later determine data for curves that are follow. Table contains the preheated air temperature and flue gas temperature before the preheater determined the recording potentiometer. The heat the steel was determined using 350 B.t.u. per pound steel heated multiplied the number pounds charged. The heat the products com- bustion was determined from Fig. This figure was for the average coke oven gas analysis dur- ing the period operations observed. determine the heat the products combustion, the B.t.u. per cu. ft. The April 12, a ; & : ay Abe . = 860 910 9 840 525 870 601 oad ae va 160 230 586 435 wee 340 218 i 541 | 814 ary - 450 277 340 ty. Gross Tons Steel Heated per Furnace Hour re Fig. coke-oven gas furnaces serving plate mill, the gas based heating value for the gas 518 B.t.u. per cu. ft. coke oven gas was read from the sibly, reducing atmospheres would curve for perfect combustion. The expected but the hands average value for one determination, 1475 small amount excess deg. 146 B.t.u. per cu. ft. gas. nearly always present. The heat the air required for per- Table III shows the per cent heat fect combustion from Fig. will coke oven gas (higher heating 113 B.t.u. per cu. ft. gas. Since value) for various elements the per cent excess air used, this furnace system. The item per cent B.t.u. per cu. ft. coke oven leaving the furnace the total heat gas. The summation 157.3 B.t.u. plus latent heat Table divided the dry flue gases per foot 518, 41.8 per cent. The per coke oven gas. which was added cent heat the air found (518 459) B.t.u. per cubic taking the air temperature, Table II, foot of coke oven gas, giving the total of 900 deg. F, and from Fig. 4 on the heat the dry flue gas plus latent curve for heat air required for heat due water vapor 216.3 B.t.u. perfect combustion the value per cubic foot coke oven gas. The B.t.u. per cubic foot coke oven gas per cent excess air was used found. this per cent added, was considered average condition making 72.6 B.t.u. which divided operation these furnaces. Pos- 518 14.05 per cent. Since all the 5.0 | 8 + | c ” | | c Gross Tons Steel Heated per Furnace Hour Fig. 2—The effect the number light-ups month well that the tonnage heated the fuel consumption indicated these curves: Curve duplicate that Fig. Curve represents 15,000 gross tons heated the month with one light-up; curve for the same tonnage but with two light-ups. Curve for 10,000 tons and one light-up, and curve for the same tonnage but with two light-ups. Curve superposi- tion with curve but for 5000 tons and one light-up, while curve also for 5000 tons but with two light-ups, and curve also for 5000 tons but with three light-ups. 12—The Age, April 12, 1934 gases from the furnace not per the preheater, the percentage loss bas 14.05 27.75 per cent. The per cent heat the steel ob- tained dividing the millions the steel, Table II, the ton millions B.t.u. the coke oven gas thr 34.25 per cent. The total loss therefore 100— 34.25 per cent, 65.75 per cent. Therefore the per cent radiation, con- vection and conduction loss will cent. From the above data curves Fig. Curve No. duplicate the pro curve shown Fig. This curve the trend heating but does not in- und clude light-up fuel. pea Curve based 15,000 gross has tons per month with various furnace ton hour ratings with one cluded. The light-up these fur- slig naces equal 1125 million B.t.u. gro 375 million per furnace per reg light-up. for Curve shows the same rating but two light-ups are included. Curve shows 10,000 gross tons plot Leaving Furnace, To Air, Stack Loss Ete., Run Per Cent Per Cent Per Cent Per Cent 41.8 14.05 27.75 38.00 41.5 14.19 27.31 42.99 39.3 12.47 26.83 53.61 42.1 13.81 28.29 43.25 42.3 13.38 28.92 38.98 42.0 14.19 44.30 42.1 14.11 27.99 37.76 42.1 13.17 30.93 33.01 41.2 2.7 28.50 36.31 41.8 12.50 29.30 37.50 41.5 13.10 28.40 35.90 10.9 13.50 27.40 44.65 36.0 14.13 21.87 5.38 36.0 14.36 21.64 44.53 41.5 14.18 27.32 39.33 42.5 13.18 28.82 37.78 41.8 13.46 28.34 34.76 42.1 14.00 28.10 47.26 38.6 13.15 25.45 38.05 14.70 26.45 42.90 10.4 14.05 26.35 40.25 10.9 14.66 26.24 45.56 40.2 15.51 54.06 13.72 27.18 46.22 40.4 14.32 26.08 55.47 39.0 12.33 26.67 41.5 14.19 27.3 10.9 13.30 27.60 45.10 55.6 14.80 27.40 36.10 37.5 14.75 27.35 40.2 16.59 25.41 38.5 28.38 98.32 42.0 14.49 27.61 47.99 ‘ c 4} - + + o + + + + + + \ q } Q 5 9 + + + + a, + <} | > } 4. | | | | | } | | . per month heated with one light-up based various furnace hour rates. Curve the same curve except for two light-ups. Curves and are for 5000 gross tons per month with one, two and three light-ups respectively. interesting note from this analysis that curves and coincide, which shows that with the same vary- ing furnace hourly rating 5000 gross tons per month with one light-up re- quired the same total heat per gross ton 10,000 gross tons per month with two light-ups. comparison B.t.u. per gross ton, the curves show that the fuel consumption could higher with increase monthly production depending the number light-ups and loading. Therefore, under certain conditions, the oft-re- peated statement “that since tonnage has the B.t.u. per gross ton should down” may error. The family curves seem turn slightly upward the right gross tons per furnace hour. regretted that data were not available for investigating further this portion the curves this time. Fig. shows the furnace hours plotted against: Oven Gas Higher Heating Value) Total Loss, Steel, Per Cent Per Cent Per Cent 38.00 65.75 34.25 42.99 70.3 29.70 53.61 80.44 19.56 3.25 71.54 28.46 67.90 32.10 4.30 72.11 27.89 65.75 34.25 33.01 63.94 36.06 36.3 64.81 35.19 66.80 33.20 35.90 64.30 35.70 72.05 27.95 5.38 67.25 32.75 66.17 33.83 50.85 76.25 23.75 9.33 66.65 33.35 7.78 66.60 33.40 4.76 63.10 36.90 7.26 75.36 24.64 8.05 63.50 36.50 2.90 69.30 30.70 0.25 66.60 33.40 71.80 28.20 78.75 21.25 73.40 26.60 81.55 18.45 67.00 33.00 70.90 29.10 9.28 86.59 13.41 72.70 27.30 63.50 36.50 59.50 40.50 8.85 66.20 33.80 70.75 29.25 66.70 47.99 75.60 24.40 100 Heat Losses Per Cent > 6 Gross Tons Charged per Furnace Hour Fig. 3—Curve represents the heat loss flue gas the stack; curve the heat loss due radiation, convection and conduction; curve the total curves and Per cent heat loss flue gases stack, Per cent heat loss due radia- tion, Per cent total heat loss. From Curve would indicate that the percentage stack losses are re- latively constant for all amounts the number gross tons per furnace hour operated. The absolute value may change but the percentage re- mains constant. Curve shows the decrease per cent radiation, convection, and con- duction losses with increased tonnage per furnace hour. Curve the sum curves and and shows again that the probable maximum efficiency these furnaces located about gross tons steel heat per furnace hour. Losses Frequent Startings has been known fact that there are large losses due frequent start- ing and stopping furnaces and from the curves would seem that de- creasing the tonnage per furnace hour per cent increases the fuel re- quired approximately per cent. This shows the disadvantage small orders and quick deliveries imposed steel manufacturers from the heat- ing viewpoint and the necessity trying accumulate orders sufficient make light-ups minimum. Delays mills also have the same influence; the tonnage steel per furnace hour reduced and the fuel consumption mounts very rapidly. Temperature, Deg. & | | 2 | | 0 if 200 600 1000 1400 Per Cent Excess Air Fig. the gas and air for different temperature conditions. The coke-oven gas given higher heating value 518 B.t.u. per cu. ft. and lower heating value 459 B.t.u. The amount air required for perfect combustion 4.34 cu. ft. and the products com- bustion amount 5.05 cu. ft. per cu. ft. The Iron Age, April 12, 1934—13 oS 1 vt ‘Cent 6, 8 0.93 8.50 9.30 8.40 7 26.08 Q 27.40 27.35 25.41 rucible Reaction Ratio, (Area per Ton) Capacity Furnace, Tons Reaction ratios for Bessemer, electric arc, small open-hearth and crucible furnaces. human activities the sequence fundamental advancements fer- rous metallurgy generally consid- ered fair criterion the existing tendencies, especially steel making. With this mind, some significance may accorded the peculiar fact that period about years prior 1900, perhaps 1903, gave all the major steel making principles the metallurgical world, while since then, distinctly new process discovered. Oddly enough, the ad- vent the almost search and systematic experimenta- tion metallurgy coincides just with these latter years. comparison with other phases Judging from our present wealth knowledge the broad subject metallurgy, one must nevertheless impressed the strides made dur- ing the last few decades, especially minimizing the time-honored as- pect upon steel making “individual- accurate process and material control have since dominated the field manage- ment such extent that the long years experience required the past, even for the production ordi- nary grades steel, are outdis- tanced the judicious application comparatively simple scientific prin- ciples. 14—The Iron Age, April 12, 1934 a The design furnace hearths and quality the ultimate product were two factors the relationship which was perhaps the most puzzling all problems confronting man, ever since the advent our contemporary methods steel mak- ing. what extent comparative studies may help clarifying the same shall indicated the follow- ing paragraphs. Reaction Surface and Ratios problem metallurgical re- actions connection with furnace characteristics may best compre- hended when compared with experi- ences gained from the simplest chem- ical experimentation. order illustrate subsequent statements let recall, for example, the addition aqueous solution some hydroxide containing some phenolphtalein indicator aque- ous solution nitric acid, the first the solutions being excess. the test made very narrow test tube in. for instance), will readily noted that the pink color the added tion will not reach the bottom the tube, thereby indicating that the re- action occurred only near the surface contact between both solutions. repetition the same experiment using the identical concentrations and Mass Effect OES the effect mass steel making warrant special study? Mr. Hruska thinks does and sug- gests that quality product needs design furnace hearths. What styles the reaction ratio—the quotient the bath area and the weight metal—is here made starting point. amount the reagents, but pour- ing the solutions into flat glass con- tainer (beaker, casserole, etc.), will show that the pink color covers the entire contents ously. both cases the chemist will write the identical equation for the occur- ring reaction; but why was the reac- tion incomplete the tube and why did proceed quickly the flat vessel? Disregarding nical even hypothetical explana- tions for this phenomenon, ap- parent, that the surface possible contact the two phases was small the first experiment, whereas the second case large area con- tact made speedy reaction possible. Not even stirring with fine platinum wire accomplished the desired result the narrow container. When applying this principle reaction velocities the production modern steels one must bear mind that the molecules fluid steel are much less mobile than those aqueous solutions. Hence, reactions require more time larger reac- tion surface their completion, e., equilibrium. From the same view- point, stirring motion the liquid metal will less effective than case aqueous solutions. Two prin- cipal factors—besides temperature, concentration, mass and pressure— squ nac cou quo Qui thes for that cont ing in./ the stee tion valu tonr ures proc tion: latic tion: rout thes melt reas seve ing the ques ble mad seme nage Satis come 1.0 0.8 | an | the 0.6 the B be | =. are therefore importance quality practical steel making; viz., time and reaction surface. order introduce the mass the fluid steel into the account when dealing with metallurgical reactions, the writer has advocated “reaction ratio,” e., the quotient Bath area square inches Weight metal pounds (Wt) The resulting value may, therefore, defined the reaction area square inches per one pound liquid steel the respective melting fur- nace. The reaction ratio could, course, similarly expressed the quotient Reaction surface square feet Weight the metal tons Quite naturally, any deductions from these expressions must for either the two methods. appears from extensive study available data various heats that maxima deviations for our contemporary processes steel mak- ing range from about 0.14 1.46 sq. Realizing the similarity many thermo-chemical reactions the commercial production iron and steel (decarburization, desulphuriza- tion, the lower these limiting values seem indices so-called tonnage steels, while the higher fig- ures are characteristics quality products. The extent these varia- tions for the principal processes shown the accompanying table. Since all values given the tabu- lation are based actual determina- tions made under routine, any conclusions derived from these data are indicative modern melting technique and may, for these reasons, generalized. Consequently, several new aspects upon steel mak- ing may gained scrutinizing the values. metallurgist ever questioned the superiority cruci- ble and electric steels over grades made large open hearth Bes- semer furnaces, e., heavy ton- nage basis, and yet very little Satisfactory explanation reality was ever offered either re- the practical metal- lurgical professions. This especially significant when steels are produced small melting JOHN HRUSKA Metallurgical Engineer, Berwyn, units and simultaneously large fur- naces, but practically identical chemical composition. The grades (viz., under high reaction ratio) are invariably better quality. Many formerly perplexing prob- lem seems capable being clarified the introduction what has been designated “reaction ratio.” One may only refer the many contra- dictory reports the physical and metallographical properties acid versus basic steels, which dispute has not been settled mutual agreement —although exceptionally large sums were spent since the war dispose this very important metallurgical little study the accom- panying diagram will amply prove this contention. Considerable argument may ex- pected the general applicability reaction ratios metallurgy. Thus, for example, the chemist they may meaningless, because none his formulae, equations and calculations incorporate any effects reaction surfaces nor actual masses entering chemical reactions. This especially true thermo-chemical reactions oc- curring such high temperatures the fabrication ferrous metals. the steel maker, however, they are undefined facts everyday experi- ence; knows that fine steels can under existing conditions duced only furnaces very lim- ited capacity. far did not have any explanation for it. The metal- lurgist suspected from deliberations thermodynamics, thermochemistry and simple shop practices that some fundamental basis must exist between the characteristics melting equip- ment and the resulting physical prop- erties the product. Many mechan- ical, chemical and magnetic phenom- ena ferrous matter point distinctly toward some basic law governing ap- (Concluded page 76) Characteristics Heats Made Various Steel Making Furnaces Melting Furnace Type Lining Crucible Clay Graphite High frequency electric. acid acid basic basic basic basic acid acid basic acid basic acid basic basic basic basic acid acid basic *All figures given above are based capacities. Reaction Surface for Reaction Ratio Nominal Specific for the Capacity Heat, Sq.In.* Same 126 1.371 131 1.192 (Actual data not available) 0.5 ton 1,045 0.862 ton 4,210 0.600 ton 7,208 0.522 ton 7,420 0.470 8,750 0.382 15,100 0.253 ton 2,740 1.250 ton 14,610 0.830 10 ton 20,400 0.849 15 ton 22,800 0.712 20 ton 31,700 0.741 ton 34,700 0.654 20,400 0.464 42,000 0.653 ton 58,350 0.488 ton 69,200 0.487 103,600 0.337 200 ton 105,100 0.221 ton 905 0.220 15 ton 6,050 0.184 8,150 0.147 ton 6,450 0.198 ac tual determinations and not nominal The Age, April 12, 1934—15 ad) r- ill all basic ult ion eel ac- uid ire, dollar day more for your glue and save $100 day your finishing department. That the rather startling advice received re- cently large steel company. The answer the polishing problem, course, not simple just quality glue, but this advice serves give some indication the importance glue the metal working industry. The humble glue pot—long associated with the cabinet maker—is fact the résistance the metal polisher. previous articles the importance closely regulating the variables connection with setting polishing wheels was emphasized. Some these variables were listed tempera- ture the wheel, temperature the abrasive, humidity, and nature the abrasive, but nothing was said about the variation the quality the glue itself. Actually the problem the manufacture suitable glue for use preparing the head polish- ing wheels has perplexed experts for many years. delicate adjustment required between the different prop- erties glue. must set hard and yet not brittle, and must hold the abrasive grains after the glued surface has been worn away. Changing Temperature Doubles Life The temperature the glue time application another important feature. One manufacturer now recommends holding the glue ready for use 165 deg., whereas the com- mon maximum some years ago was 140 deg. The temperature the wheel which the glue spread has lot with the property the resultant head. the experience one company difference deg. 16—The Iron Age, April 12, 1934 heater WHEEL DRYING ROOM Temperature 70°- Relative humidity swinging 24" Storage capacity, /60 wheels door Courtesy Divine Brothers Co. Finish Helps HERBERT SIMONDS temperature the wheel the time the glue was applied increased the life the head 100 per cent. This temperature difference was increase from deg. 110 deg. Obviously anything important doubling the life polishing wheels worthy serious considera- tion. Under severe service, good practice indicates polishing wheel life not much more than hr. The cost re- conditioning worn wheel, together with the lost time the polisher and the expense handling, may run close From this may seen that doubling the life polishing wheels good-sized plant may easily result impressive saving the end the year. The Manufacturers’ Viewpoint The significance the problem compounding glue itself may ap- parent from statement one the altering seemingly minor con- ditions, has been possible double the life polishing wheels, and good-sized plant this may easily result saving $100 large Higgin “Sts a Care this has s} mereia day. describ feature 7, fi ‘ ‘ @) ing whee/s Standard whee/ \ closing doors titted with slat 30” shelves and partitions door abrasives Heat whee/ ” swinging door plan indicates con- venient arrangement the glue and wheel room large steel fin- ishing department. Products Sales 15—Polishing and Buffing large manufacturers, the Milligan and Higgins Glue Co., New York. “Starting matter course with carefully made glue good test,” this company says, “our experience has shown that does not necessarily ap- produce polishing wheel long life Something else besides regular com- the € eg mercial glue needed give desirable day. The accompanying article describes some the important eels, features building head may polishing wheels, and many points modern buffing practice. results this specialized application. Unlike joints between two solid ma- terials, there is nothing in the case the polishing wheel support the glue, and must stand means strength. the glue brittle, the matrix will crack, and not hard, the grain will rub off. Toughness and resistance are important qualities. An- other property must the ability endure the heat friction. Toughness calls for glue derived from the skin animals accustomed rigorous life and hard food. Typical this class are the ox, the horse, the reindeer, and the antelope. For years efforts have been made reduce the equation, but definite formulae have not been established due the variety the source material. Condi- tions with the same kind animal and from the same district vary from year, and properties which cannot measured make the working character the glue. Under present conditions only long ex- perience this particular field, com- bined with practical judgment the glue maker, which creates the most suitable product.” Glue alone course cannot blamed for all the difficulty, the surface characteristics the abrasive play important part the final result. Many authorities that closer sizing abrasives, with irregular dull surface each grain, equally important the character the glue. Certainly both the nature the abrasives used and the glue must considered. Handling Glue the Shop Temperature control the glue pot important. Most glues lose strength after being held for several hours the temperature required for applica- tion. For this reason shops where there intermittent use glue, two heats the glue pots are required, one holding heat during the periods when the glue not used, and the other the heat switched for the time when the glue used. Another item overlooked the fact that glue itself subject bacteria invasion and resultant deterioration. This emphasizes the importance cleanliness all equipment and the frequent changing glue and clean- ing glue pots and containers. Some the methods applying glue the wheel have already been described. Different conditions call for varying technique here well other parts the conditioning process. One polishing shop uses concave pulley rotating hot water The Iron Age, April 12, 1934—17 4 4 | ~ > “ | 4 uw | we: Bids < jacketed trough, which trough con- tains the glue solution. The pulley revolves contact its upper sur- face with the wheel set up, and this way carries the hot glue di- rectly from the pan the surface the wheel. Adjustment the speed and the pressure the pulley against the wheel determine the force with which the glue applied the wheel face. Often this operation com- bined with hand brushing the wheel and occasionally auxiliary mechanical equipment such oscillating brush used make the process more nearly automatic and uniform. Mechanical Application Specifications for glue must take into account the nature cause, for one thing, glues differ foaming, and oscillating brush rotating pulley might develop foam with some glues and not with others. low foaming property now frequently specified good polish- ing wheel glue. Foam means air bubbles enclosed the glue, and this means potential weakness the sur- face. Another method mechanically applying glue and abrasive mount the wheel horizontal spindle with the face resting trough heated abrasive. this position the wheel means small motor the same time that glue brushed the upper surface. Some manufacturers have found difficulty using this method, although one the simplest the mechanical processes and can extended include many wheels revolving the same shaft. Usually the shaft adjustable give varying pressures against the abrasive the trough. better way have the shaft fixed, and have the individual troughs adjustable against the wheels. wheels this method permits adjust- ment due lower level abrasive under one wheel than under another. Special Compounds Many special glues and glue com- pounds are the market. Some these are mixed with solvent which evaporates soon the mixture applied the wheel and thus obviates the necessity heating the glue. compound consisting glue mixed with abrasive now available al- ready mentioned. This applied polishing wheels much buffing compound applied, although claimed that the resulting surface for light work similar that created 18—The Iron Age, April 12, 1934 the usual separate application glue and abrasive. The difficulty getting exact dupli- cate batches glue pointed out Sherwood Prescott, Norton Re- search Laboratories. Only manufac- turers who mix products from many sources are able overcome varia- tions the source material and thus produce glue consistent qualities. Mr. Prescott says that glue should stored air-tight containers pre- vent change moisture content. says further that different sizes abrasive grain should set with different concentrations glue solu- tion. Coarse grain requires more concentrated solution. gives the following table guide for use different sizes abrasive grain: Size Per Cent Dry Glue Abrasive Solution 45 16 40 150 25 20 The viscosity glue decreases the concentration decreases man- ner which graph would repre- sented curve with sharp bend occurring between the points and per cent glue solutions. This calls for accurate weighing the glue mixtures between these points. Mr. Prescott says that glue should never melted with direct heat and recommends con- trolled water jacketed heater. overcome deterioration due high heat some manufacturers mix new glue with glue which has been heated for some length time, but this not good practice. Brothers Co., Utica, Y., gives the history the development glue for modern industrial purposes. This states that until recently technical scientific attention seems have been paid the use glue for polish- ing. developing glue for this specialized purpose, manufacturers have discovered that there con- flict between the strength the glue and the strength the metal being polished, and from this apparent that the utmost possible strength the glue desirable. Glue Standards Many cases complaints polish- ing wheels were thoroughly investi- gated and most these the glue its treatment was found fault. Among other factors the effectiveness the glue varies with the method soaking, the proportion water glue, and the kind glue. 1844 standard for industrial glues was set up, known the Peter Cooper standard, and this still remains the only method which glues from various makers can compared. This standard, however, does not con- sider flexibility. The National Association Glue Manufacturers has published let called “The Story Animal Glue” which describes the sources glue, the method manufacture, and prop- erties service. This booklet, among other things, points out that ground glue more suitable form for the polishing industry. One the chief advantages quickness soaking. addition saving time and equipment, this means less danger mistreatment and less likelihood taking more glue out storage than required for any one job. addition this, ground glue lends itself more easily blending. Examples Wheel Life Robert Kent, Divine Brothers Co., Utica, states that the short life polishing wheel head means excessive amount lost changing wheels and also means re- duced production. finds that short life usually the result poor hold- ing power glue, which indicates that the abrasive grain torn from the wheel before has been used cutting the metal. This waste- ful and increases the expense abrasives. Mr. Kent says: “The interested will naturally use data wheel head life, production, and wage rates that apply his particular case. One method investigation follows: “Find out how long wheel lasts given job, how long takes change wheels, and the annual bill for abrasive grain and glue divided the number wheels. Then find out the average time for setting wheel. “Assume that the polisher receives hr., and that his normal pro- duction rate pieces hr. sume that his wheel lasts half hour and that takes min. change wheel. The loss wages for changing wheels in this case would be 40c. per day. Assume that wheel with two heads requires min. and that the set man will prod shop chan ing be s ten betw Fro arises head prope glue toughe neglig ing The which eo wD Cc 6 } ‘ a 4 rig & . vill ife, ply | of ong the and els. for ives pro- As- hour ge a ging per tting uires re- ceives 60c. per hr. Then the wage cost setting the two wheels be. “The cost abrasive and glue for in. in. wheel, set with No. 120 grain, should average about .025c., making material cost 5c. hr. for the two wheels, total wage and material cost $1.28 per day. the life the wheel head doubled the direct cost will cut two and the saving will 64c. day per polisher. addition there Prepare quantity which will used less than hr. Thoroughly clean all pots and utensils. not mix old glue with fresh glue. Heat the polishing wheel 110 deg. before applying the glue. Heat the abrasive grain 120 deg. before rolling the glued wheel it. Dry the wheels for hr. close deg. . Courtesy Barnadall Tripolé Co. photomicrograph shows the peculiar porous character and absence sharp edges the nat- ural tripoli grain. This material, combined with grease other binders and made bricks bars, forms one the most widely used buffing compounds. will the profit the increased production and the absorption some shop overhead during changing period. this basis sav- ing $1.25 more per polisher can shown. room employing only ten polishers this would amount between $3,000 and $4,000 year.” Directions for Glue Handling From this the question naturally arises, how can the life the wheel head doubled? Mr. Kent feels that the answer simply one proper selection and handling glue. says poor economy buy glue for polishing, price basis. First-run glue the strongest and toughest and its higher negligible comparison with the sav- setting polishing wheels. The friction the wheel the work large quantities heat which tend soften the glue. Hav- ing selected the proper glue, Mr. Kent then gives the following directions for its handling and use: Use distilled water. Soak the glue for hr. just the right amount cold water (not above deg. Melt the glue 140 deg. Maintain the relative humidity be- tween 50 and 55 per cent. Use Hydrometer soaking the glue water some manufacturers find advisable first mix the glue small amount water and then dilute the proper consistency with warm water after the glue has melted. When this determine the percentage glue and water. Water added until the hydrometer indicates the percentage for the particular size grain being used. The effect varying humidity the life the head polishing wheel sufficient warrant most manufacturers installing some type air conditioning equipment. One manufacturer says: “It took break- down our air conditioning system prove its real worth. During the time our breakdown used, roughly, twice many wheels for the same work required when the system carefully con- trolled air conditioning was ser- After metal surfaces have been polished, the polishing lines may removed and the character the sur- face altered further process known buffing. This process, already described, makes use cloth buffs wheels composed disks cloth similar pliant material. The disks may sewed together various ways may held together the center only, leaving the outer portions free. Varying compounds are applied these buffs, depending upon the results desired. Usually buffing comes under two classifica- tions, the first known cutting down and the second known coloring. For the cutting down process one the most popular compounds tripoli, which form silica rock found natural deposits. The value this product for buffing results from the fact that each particle porous and has fibrous structure with sharp edges corners. Tripoli Compounds The Barnsdall Tripoli Co., Seneca, Mo., one the largest producers, gives the production tripoli 1929 16,000 tons. This company obtains the product open quarries, after which the crude stone sorted for color and grade and then placed cates that weather drying produces better grade than artificial drying, and therefore extremely large sheds are needed, the process weather drying requires from three six months. Two colors and three grades fineness are produced. The finest grade, known air float, passes through 200-mesh screen. This used make paste for the most delicate buffing processes. The best selection tripoli com- pound made the metal finisher after trial with many grades. When compound leaves haze metal surface usually sign that there too much grease. Monel metal and nickel especially important have compound made with minimum grease develop the deep color usually desired. Tripoli sometimes omitted even where high luster produced, but when successfully dispensed with means that the previous polishing and emery buffing have been adjusted accord- ingly. Fine emery and tallow form another compound freely used the early stages buffing. Cakes emery and paste are made with various sizes grits. This com- pound used spirally sewed buffing sense midway between polishing (Concluded Page 74) The Iron Age, April 12, rh ers re- old- ates rom cylindrical test specimen, which first marked with crosses, then measured and then ma- chined several stages various points. After each stage machining the distances Fig. 2.—Diagrammatic representation the caliper gage for measuring the diameter after each step machining. between crosses are measured. the same way” and from the same material may differ such degree point the magnitude and nature their stresses that when two identical machine parts are produced from them one may fulfil its task properly while the other may not. forgings that are “made Tests have revealed the complicated nature the stresses often encount- ered. For example, there are periph- eral stresses, spiral-shaped stresses running along the outer layers solid cylinder, also radial and axial stresses, stresses angle the axis the specimen and forth. These various stresses may arise sing- nature and magnitude different points. Accordingly great as- sition ascertain the magnitude and 20—The Iron Age, April 12, 1934 Consulting Engineer, Berlin, Germany direction the stresses occurring given these tests cylindrical speci- men that has been subjected defor- mation given certain number cuts varying depth and width that the layers the material con- taining stresses are removed. The stresses remaining the untouched layers produce slight alterations the shape the test specimen; these alterations can determined special precision measuring equip- ment. The difference between the values measured prior the cutting process and afterward permits some conclu- pparatus Determine Stresses sion drawn the nature, direction and intensity the stresses remaining the unmachined parts the test specimen and also the dissipated stresses the removed layers. the cuts are continued after each series measurements, the subsequent measurements the untouched parts the specimen will again produce correspondingly new values, provided stresses existed the layers removed the second, third further steps machining. These processes are diagrammati- Prior the test, the cylindrical test specimen “a” polished lathe and its surfaces marked scrib- ing tool with microscopically crosses the number and position which depend upon the ac- curacy the results required. The distance these marks from the first the Scope have at, mean the Wher readi for sibly Series precis that can | --—; _-—! A ; ca = ire, ved ued nts, the will new ond, nati- test lathe fine and The first Fig. Diagrammatic representation face test specimen with pins and crosses. Fig. 4.—The distance from the face the pins the first crosses and intervening crosses well the radial distances the crosses apart are measured. Fig. 5.—Layers with longitudinal shearing stresses are removed machining the vicinity the faces. Differences di- mensions compared with the conditions obtaining prior machining are ascertained. Al- terations radial stresses are revealed alterations the distances between crosses the face. Large Castings and Forgings mark established comparator the conventional manner. Fig. the carriage the comparator, the scale, the measuring slide, the adjustable telescope, the micro- each the latter has thread micrometer the field After the distances all crosses have been ascertained, the diameter at, and between, them measured means the caliper gage Fig. the arms which carry micro- calipering device and screw When calipering the test specimen, readings are obtained the device which can taken staring values for the differences which may pos- sibly obtain during the subsequent series measurements; their virtual value can ascertained parallel gages. Figs. and reveal that the front side the cylinder can provided with pins having ERE German machine precision built measure the swelling contraction, the case may be, mass metal machining removes stressed por- tions. Telescopes and micro- scopes form part the equip- ment, and automatic means are provided maintain everything the testing room constant temperature. crosses marked their faces, the position and distance these marks being determined special comparator and the large com- turn the test specimen through plane, the large comparator can also used for measuring the faces. All the lengths and diameters thus obtained provide the basis for the subsequent verifying measurements that have effected after each step machining. Fig. dotted lines, are now made. the exposed annular-shaped layer contains longitudinal shear- ing stresses, the section be- comes longer, and the section becomes shorter than before the an. nular-shaped layer was removed; radial stresses were present, the diameters and would have al- tered accordingly. The penetrating effects radial stresses are obtained from the ratio the diameters after The Age, April 12, NG | d = = g f f : bey ; - ? | ie . Fig. 6.—Calibrating the caliper gage means slip gage. exposing further annular-shaped lay- ers etc. Peripheral stresses are revealed the alteration the diameter ring which cut out from the solid material the face the specimen and slit transversally one point. ring can, course, also cut out any other part the test speci- men; but while the separating slit being made and measurement being undertaken, the ring cannot removed from the test specimen its inner diameter smaller than the diameter the neighboring parts the specimen. Fig. shows the deformation the face the still unmachined test cylinders (Fig. after making deep insertion the vicinity the face. spiral-like stresses exist, their torsional effect would interrupted successive cuts that the cross- marks which were originally scribed longitudinal plane parallel the middle axis the cylinder, are now somewhat displaced relative each other. This signifies that the initial position the cross-marks forms the starting point; its new posi- tion (due interruption the stress the exposed layer) forms the end point small are the periphery the testing cylinde