【摘要】 热轧TRIP钢具有优异的力学性能,热轧生产后经过酸洗处理可以直接用于汽车制造。采用Gleeble3500型热模拟试验机研究了C-Si-Mn-Nb系热轧TRIP钢形变奥氏体在不同连续冷却条件下的组织变化情况,绘制了动态CCT曲线。通过研究不同冷速下试样组织发现,冷却速率越大,组织中未转变奥氏体含量越低。最后,依据对动态CCT曲线的分析在Gleeble3500型热模拟试验机上模拟热轧了TRIP钢。结果表明:实验钢轧后以15℃/s的低冷却速率冷却至贝氏体区等温后,残留奥氏体的含量和稳定性更高,TRIP钢力学性能优异,抗拉强度和伸长率分别达到952 MPa和30%,强塑积高达28560 MPa·%。更多还原

【Abstract】 Hot rolled TRIP steel has excellent mechanical properties,so it can be directly used for automobile manufacturing after hot rolling and pickling. The microstructure evolution behavior of the C-Si-Mn-Nb TRIP steel during continuous cooling after ausforming was investigated by a thermo-simulator system Gleeble3500,meanwhile,the dynamic CCT diagram was measured. Effect of cooling rate on microstructure of the sample was analyzed,it shows that the higher the cooling rate,the less untransformed austenite in the microstructure. Based on the analysis of the dynamic CCT diagram,the simulation of hot rolling TRIP steel was also conducted on the Gleeble3500 simulater. The results show that slow cooling with the rate of 15 ℃ / s to the bainitic isothermal temperature after thermal deformation may lead to higher amount and more stable retained austenite,and the TRIP steel has excellent mechanical properties,tensile strength,total elongation and the strength-ductility product are up to 952 MPa,30% and 28560 MPa·%,respectively.更多还原