低碳钢先共析铁素体和形变诱导铁素体的相变机制、组织和性能

Phase Transformation Mechanism,Structure and Property of Pro-eutectoid Ferrite and Deformation Induced Ferrite of Low Carbon Steel

通过Gleeble 1500热模拟机对Q235钢加热至950℃5 min;1℃/s冷至855℃30 s,以应变速率15 s^(-1),进行80%压缩,淬火,获得形变诱导铁素体组织,并用950℃5 min,炉冷获得先共析铁素体组织。试验结果表明,形变诱导铁素体晶粒尺寸≤5μm,平均HV229.55,抗拉强度809 MPa;先共析铁素体晶粒尺寸10～20μm,晶粒不均匀,平均HV210.28,抗拉强度736 MPa。文中分析了形变诱导铁素体和先共析铁素体相变热力学和动力学机制。

Abstract The deformation induced ferrite structure of Q235 steel was got with heating at 950 ~C for 5 min, 1 ~C/s cooling to 855 ~C for 30 s and reduced 80% at strain rate 15 s-1 , then queching by Gleeble 1500 thermal simulation ma- chine, and the pro-eutectoid ferrite structure of the steel was got by heating at 950 ~C for 5 min, furnace cooling. Test re- sults showed that the grain size of deformation induced ferrite was 45μm, average HV value 229.55, tensile strength 809 MPa, while the grain size of pro-eutectoid ferrite was 10 ～ 20 μm grain un-uniform, average HV value 210, 28, tensile strength 736 MPa. The mechanism of thermodynamics and kinetics of the deformation induced ferrite and pro-eutectoid fer- rite are analyzed in this paper.