| 摘要 |
<p>The forging (4) is formed from steel rod (3). It is heated to 830-900[deg] C. First tempering follows, at 100-300[deg] C. A second tempering then takes place, at 300-400[deg] C. During first tempering, the forging is quenched in a salt bath, at a temperature in the range 100-300[deg] C; it is tempered for 60-130 minutes. During the second tempering, the forgings are quenched in a salt bath at a temperature in the range 300-400[deg] C; this which continues for 30-150 minutes. The forgings are heated to 830-900[deg] C for 30-120 minutes. The forging is preheated to 550-650[deg] C for 30-90 minutes, before heating to 830-900[deg] C. The steel rod is hardened wire, selected from nickel-chromium-molybdenum steel and chromium-molybdenum steel. The forging is deformed during a first stage (a) as follows. It is subjected to a first annealing. The rod is then removed and coated. An intermediate stage of drawing follows. Then it is subjected to a second annealing. Removal and coating is repeated. It is further drawn by after-rolling. It is forged using a stamp and roller cut, to complete the forging.</p> |
