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本文研究了加热速度、子先回火程度和加热温度对20CrMnMo,38CrSi钢组织遗传性的影响。试验结果表明:原始组织为非平衡组织时,快速(高频)和慢速(1—2℃/min)加热到临界点Ac_1以上均出现组织遗传现象,其冲击韧性ak值较低。中速(盐浴炉)加热金相显微组织虽细化,但断(?)仍是粗大的,发生了断口遗传,冲击韧性也较低。予先回火可使组织遗传减弱甚至完全消除。慢速和中速加热到临界点以上,若继续加热到某一高温区后,发生了奥氏体自发再结晶,可使金相组织和断口均细化,冲击韧性明显提高。
In this paper, the effects of heating rate, sub-first tempering temperature and heating temperature on the hereditary properties of 20CrMnMo and 38CrSi steels were studied. The results showed that when the original tissue was non-equilibrium, the hereditary phenomena appeared at Ac_1 above the critical point Ac (fast and high frequency) and slow (1-2 ℃ / min), and the ak value of impact toughness was low. Medium speed (salt bath furnace) metallurgical microstructure heated thinning, but the broken (?) Is still coarse, the occurrence of fracture genetic, impact toughness is also low. Pre-tempering can make the genetic inheritance weakened or even completely eliminated. Slow and medium-speed heating to above the critical point, if continue heating to a high temperature zone, the occurrence of austenite spontaneous recrystallization, the microstructure and fracture can be refined, impact toughness improved significantly.