Abstract: The effect of rolling with 15% ~ 40% and cooling rate 0. 8 °C/s and 1.2 °C/s in dual phase rigon on deformation-induced ferrite transformation in SCM435 cold-headed steel is studied by thermal simulation test. The results show that rolling of SCM435 steel in the austenite and ferrite two-phase zone (750 ~ 850 °C)，at a cooling rate of 0.8 °C/s, with amount of deformation increasing, the deformation-induced ferrite volume fraction increases, and there is a granular pearlite structure, and the hardness first decreases and then increases at a cooling rate of 1.2 °C/s, with amount of deformation increasing ,the deformation-induced ferrite volume fraction decreases, and a granular bainite structure appears, and the hardness increases.

摘要： 通过热模拟试验研究了两相区轧制,研究了形变量（15%~40%）和冷却速度0.8 ℃/s和1.2 ℃/s对SCM435冷镦钢的形变诱导铁素体相变的影响。结果表明:SCM435钢在奥氏体和铁素体两相区（750~850 ℃）轧制,在0.8 ℃/s的冷速下,随形变量增加,形变诱导铁素体体积分数呈升高趋势,并存在粒状珠光体组织,硬度呈先降低再升高的趋势;在1.2 ℃/s的冷速下,随形变量增加,形变诱导铁素体体积分数呈降低趋势,并出现了粒状贝氏体组织,硬度呈升高趋势。

关键词: 形变量, SCM435钢, 形变诱导铁素体相变, 硬度, 冷却速度;