大直径45C_1钢圆棒淬火往往淬不硬,例如φ60毫米的钢料,860℃油淬后表面硬度一般在HRC28～35之间,其组织以为托氏体为主,铁素体较多,马氏体很少,机械性能差。若采用以水代油亚温淬火的工艺可解决上述问题。我们采用从上进入两相区的亚温淬火法,具体工艺为:加热到800℃,保温90～120分钟,空冷到 Large diameter 45C_1 steel round rod quenching often hardened not hard, such as φ60 mm steel, 860 ℃ after oil quenching the surface hardness is generally between HRC28 ~ 35, the organization that the main body of the titaniferous, ferrite more horses Few body, poor mechanical properties. If the water on behalf of the oil sub-temperature quenching process can solve the above problems. We use from the top into the two-phase zone of sub-temperature quenching method, the specific process: heating to 800 ℃, holding 90 to 120 minutes, air-cooled to