硅含量与淬火温度对Q&P钢组织及性能的影响

采用盐浴对两种硅含量不同的试验钢进行了淬火配分处理,并用金相显微镜、扫描电镜与拉伸试验机对不同淬火温度下试验钢组织及性能的转变规律展开了研究。结果表明,试验钢的显微组织由铁素体、马氏体、残留奥氏体与贝氏体组成;硅含量增加,有利于试验钢中残留奥氏体体积分数提高,抗拉强度和屈服强度显著提高,伸长率降低,强度随淬火温度变化的幅度减小;经260 ℃淬火、360 ℃配分后,2.13%(质量分数)Si钢在拥有高强度的同时保持了较好的伸长率,其抗拉强度为958.66 MPa,屈服强度为458.99 MPa,伸长率为15.35%,强塑积为14.66 GPa·%,综合力学性能最佳。

Effects of Si content and quenching temperature on microstructure and properties of Q&P steel

Two kinds of tested steels with different silicon contents were quenched and partitioned by using salt bath, and microstructure and properties of the tested steels quenched at different temperatures were investigated by means of metallographic microscope, scanning electron microscope and tensile testing machine. The results indicate that microstructure of the tested steels is composed of ferrite, martensite, retained austenite and bainite. With the increase of silicon content, the volume fraction of retained austenite increases marginally, the tensile strength and yield strength increase significantly, and the elongation decreases. In addition, the strength fluctuates slightly with quenching temperature. After quenching at 260 ℃ and partitioning at 360 ℃, the tested steel with 2.13%(mass fraction) Si obtains high strength and good elongation simultaneously, the tensile strength is 958.66 MPa, the yield strength is 458.99 MPa, the elongation and product of strength and elongation reach 15.35 % and 14.66 GPa·%, respectively, therefore, the comprehensive mechanical properties are optimum.