形变量和冷却速度对SCM435冷镦钢形变诱导铁素体相变的影响

Effect of Deformation and Cooling Rate on Deformation-Induced Ferrite Transformation in SCM435 Cold Heading Steel

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。

The effect of rolling with 15%~40%and cooling rate 0.8℃/s and 1.2℃/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℃),at a cooling rate of 0.8℃/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℃/s,with amount of deformation increasing,the deformation-induced ferrite volume fraction decreases,and a granular bainite structure appears,and the hardness increases.