退火及配分温度对Si-Mn系Q&P钢组织和性能的影响

Effect of two-phase region annealing temperature and partitioning temperature on microstructure and properties of a low carbon Si-Mn Q&P steel

研究了两相区不同退火温度及不同配分温度的淬火和碳再分配热处理工艺对低碳硅-锰系Q&P钢的显微组织、精细结构、力学性能及残留奥氏体含量的影响。结果表明,采用两相区退火的Q&P工艺室温组织为板条马氏体、铁素体、薄膜状和块状残留奥氏体;随退火温度的升高,实验钢抗拉强度和屈服强度呈上升趋势,伸长率呈下降趋势,残留奥氏体含量先上升后下降;随配分温度的升高,实验钢抗拉强度呈下降趋势,屈服强度、伸长率和残留奥氏体含量呈上升趋势;经Q&P工艺处理后的实验钢强塑积可达28215 MPa·%。

Effect of annealing temperature in two-phase region and partitioning temperature on microstructure and mechanical properties of a low carbon Si-Mn Q＆P steel were investigated on a thermo-mechanical simulator CCT-AY-Ⅱ. The results show that lath martensite, ferrite and retained austenite are obtained in the tested steel. With the increasing annealing temperature, the tensile strength and the yield strength of the tested steel increases, while the elongation of the tested steel decreases, and the volume fraction of retained austenite first increases and then decreases. As the partitioning temperature increases, the tensile strength of the tested steel decreases, while the yield strength, the elongation and the amount of retained austenite of the tested steel increases. The product of strength and ductility of the tested steel could reach up to 28215 MPa%.