淬火加热速率对980MPa冷轧双相钢显微组织和力学性能的影响

Effect of Quenching Heating Rate on Microstructure and Mechanical Properties of the Cold Rolled 980 MPa Dual Phase Steel

用扫描电镜、透射电镜、拉伸试验机等研究了淬火加热速率对980 MPa双相钢显微组织和力学性能的影响。结果表明：在5-150℃.s-1加热速率范围内加热后淬火时,随加热速率的增大,铁素体晶粒有细化的趋势,马氏体尺寸更加均匀,抗拉强度增加到1 300 MPa后基本保持不变,其屈服强度和伸长率先增加后减小,当加热速率为100℃.s-1时,综合性能最好,抗拉强度为1328 MPa,伸长率约为13%,屈强比为0.32。

The effect of heating rate before quenching on microstructure and mechanical properties of the 980 MPa dual phase steel was investigated by means of scanning electron microscopy,transmission electron microscopy,tensile testing machine.The results show the ferrite grains refined and the martensite size got more uniformly with increasing the heating rate from 5 ℃·s-1 to 150 ℃·s-1.Tensile strength of the steel increased to 1 300 MPa,and then almost kept no changes.The yield strength and elongation increased firstly and decreased afterward.When heating rate was 100 ℃·s-1,the combination properties was best and the tensile strength was 1 328 MPa,the elongation was about 13% and the yield ratio was 0.32.