pa1778data.pdf

More documents

Recommendations

Info

$lit- \NBS)NE/$

U.S. STEEL DUQUESNE WORKS HAER No. PA-115 (Page 187) for a specified period of time and air cooling. This method of annealing makes the steel more adaptable to machining and cold shearing, because less scaling or warping results due to the lower temperature reached in heating. Normalizing consists of heating the steel to 100° above its critical range, holding at this temperature, and cooling in still air at ordinary temperatures. Commercially, normalizing produces a uniform physical structure by removing the irregularities produced by the excessively high or low rolling or forging temperatures. Quenching and tempering consists of heating steel to a point above its critical temperature and cooling it rapidly by quenching it in a cooling medium such as water, oil, or brine. Because this operation produces an extreme hardness or brittleness in the steel it must be followed by tempering. Tempering consists of re-heating the steel to a point below its critical temperature for the purpose of regulating its hardness or brittleness, toughening it, or releasing stresses. These two operations (i.e. quenching and tempering) are designed to increase the hardness and the toughness of steel beyond that which can be achieved by other heat treatment methods. Constructed by the American Bridge Company with funds from the Defense Plant Corporation, the original heat treatment plant at the Duquesne Works was housed within a T-shaped building consisting of a transfer bay which was laid out on an east-west axis, forming the cross-member of the T, and a production bay, running in a north-south direction. The major pieces of equipment making up the original heat treatment plant consisted of Car Bottom Furnaces Nos. 1-5, and the Continuous Electric Heat Treating Line. The car bottom furnaces were used in all three major heat treating processes. In the quench and temper process, two car bottom furnaces had to be used in tandem. After the bars had been heated to the proper point above the critical temperature and held for the requisite time, they were quenched in a quench tank located in the transfer bay and immediately put into a tempering furnace which had already been brought up to the proper temperature. The bars would remain in the furnace for the requisite amount of time. Continuous electric heat treating was done in specific periods of time. Steel bars remained in the different furnaces for the same length of time. The charge was moved into the first or pre-heat furnace and held at 1200°F for a period of from twenty to ninety minutes, depending upon the size of the bar. At
U.S. STEEL DUQUESNE WORKS HAER No. PA-115 (Page 188) the conclusion of the period the charge was moved to the intermediate furnace, set at 1350°?, and another charge was loaded into the first furnace. After intermediate heating, the first charge was transferred into the high temperature furnace where it was heated to a point above its critical temperature and held for a specified period of time before being automatically delivered to the quench tank. After quenching, the bars were transferred to the strain relief furnace where stresses, associated with the quenching, were removed. From the strain relief furnace, the bars were either bypassed out of the furnace system to other locations in the building or transferred to the three furnace stages which made up the tempering process. In this manner, steel continually passes through the furnace line. Upon completion of tempering and ambient air cooling, the steel bars were transferred from the final discharge table to other locations in the heat treating building for testing, straightening, centerless grinding, sawing, or other processing. 2 The expansion of the heat treating facilities in 1962 involved the addition of car bottom furnace No. 6, the gas-fired continuous heat treating line, and the Ajax mangnethermic induction line. The gas-fired heat treating line operated on the same principle as the electric heat treating line but with fewer furnaces. Bars were charged into the heating furnace and pre- heated before being transferred to the holding furnace where they were held at temperatures up to 1800°F for two hours and then quenched. After quenching they were transferred to the draw furnace where tempering took place at temperatures between 1000°F and 1350°F for up to two hours. The last furnace in line—the draw-holding furnace—was used as a spare in the system. Like the continuous electric heat treating line, the bars were cooled after tempering in ambient air and then transferred to one of several finishing processes. The Ajax magnethermic induction line utilizes electro-magnetic fields to harden and temper steel bars. 3 ENDNQTES: 1.Defense Plant Corporation, Plancor 186D, "Alloy Steel Plant: Duguesne, Penna." (Washington, D.C., 1943}; United States Steel Corporation, "General Arrangement Heat Treating Equipment, West Heat Treating Department: Drawing #47 298-A,B,& C." 2.W. A. Jayme, "Heat Treating Plant Design," in Carnegie- Illinois Steel Corporation, Steel Plant Design: Rolling Mills, Vol. Ill (Pittsburgh: 1950): 1-53. 3. Salem Brosius, Inc., Operations Manual for Gas Fired Continuous Heat Treating Line, (Carnegie: 1962), 1-16; United
Page 1 and 2:
U.S. STEEL DUGUESNE WORKS HAER Wo.
Page 3 and 4:
U.S. STEEL DUQUESNE WORKS HAER No.
Page 5 and 6:
U.S. STEEL DUQUESNE WORKS HAER NO.
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
# U.S. STEEL DUQUESNE WORKS HAER NO
Page 15 and 16:
Page 17 and 18:
• U.S. STEEL DUQUESNE WORKS HAER
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
FART THREE: 1946-1988 U.S. STEEL DU
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
seeks to develop it into an industr
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
• northern wall and 27'-0" from t
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Installation Date: 1955. U.S. STEEL
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
cooling tower has a capacity of 190
Page 91 and 92:
* * tunnel beneath the clarifier. I
Page 93 and 94:
* U.S. STEEL DUQUESNE WORKS HAER No
Page 95 and 96:
Page 97 and 98:
# U.S. STEEL DUQUESNE WORKS HAER No
Page 99 and 100:
Page 101 and 102:
# » U.S. STEEL DUQUESNE WORKS HAER
Page 103 and 104:
• # # U.S. STEEL DUQUESNE WORKS H
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Historic Name Present Name: Locatio
Page 115 and 116:
dumped. Construction Date: 1957. U.
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
B. Hoist House,: U.S. STEEL DUQUESN
Page 135 and 136:
Page 137 and 138: U.S. STEEL DUQUESNE WORKS HAER No.
Page 165 and 166: Historic Name: Present Name: Locati
Page 171 and 172: • U.S. STEEL DUQUESNE WORKS HAER
Page 183 and 184: STEELMAKING PLANT - HEAT TREATMENT
Page 187: and is set into the floor of the bu
Page 191 and 192: STEELMAKING PLANT - BASIC OXYGEN U.
Page 199 and 200: • U.S. STEEL DUQUESNE WORKS HAER
Page 205 and 206: construction carbon and alloy steel
Page 209 and 210: U.S. STEEL DUQUESNE WORKS HAER NO.
Page 239 and 240:
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
Page 247 and 248:
A U.S. STEEL DUQUESNE WORKS W HAER
Page 249 and 250:
Page 251 and 252:
A U.S. STEEL DUQUESNE WORKS W HAER
Page 253 and 254:
Page 255 and 256:
• • U.S. STEEL DUQUESNE WORKS H
show all

pa1778data.pdf

Create successful ePaper yourself

Delete template?

Save as template?