轧制方式及热处理工艺对中锰钢组织和性能的影响

Effects of rolling method and heat treatment process on microstructure and properties of medium-Mn steel

中锰钢Fe-0.11C-5.23Mn-1.11Al-0.10Si经不同方式(热轧(HR)、温轧(WR)和冷轧(CR))轧制后,分别进行不同工艺热处理(奥氏体逆相变(ART)和淬回火(Q&T)),研究不同轧制方式+热处理工艺对其组织和性能的影响。结果表明,HR+WR+ART处理试验钢的显微组织主要由板条状奥氏体和铁素体组成,同时存在少量等轴块状奥氏体组织。HR+WR+ART处理试验钢的晶粒尺寸显著减小,具有高体积分数的残留奥氏体,可产生更为广泛的TRIP效应;经HR+WR+ART和HR+WR+Q&T处理后,试验钢均表现出较好的综合性能,但前者更优,即抗拉强度为1001 MPa,屈服强度为745.7 MPa,断后伸长率为49.2%,强塑积为49.25 GPa·%。

Medium-Mn steel Fe-0.11C-5.23Mn-1.11Al-0.10Si was heat treated with different processes(austenite reverse transformation(ART)and quenching and tempering(Q&T))after different rolling methods(hot rolling(HR),warm rolling(WR)and cold rolling(CR)).The effects of different rolling and heat treatment processes on microstructure and properties of the steel were investigated.The results show that the microstructure of the steel treated by HR+WR+ART is mainly composed of lath austenite and ferrite,with a small amount of equiaxed massive austenite.The grain size of the steel treated by HR+WR+ART is significantly reduced,with a high volume fraction of retained austenite,which can generate a wider TRIP effect.After treated by HR+WR+ART and HR+WR+Q&T,the steel shows good comprehensive properties,but the former is superior,with the tensile strength of 1001 MPa,yield strength of 745.7 MPa,elongation after fracture of 49.2%and the product of strength and elongation of 49.25 GPa·%.