配分时间对Q&P钢组织及性能的影响

在传统C-Mn-Si钢的基础上,采用在线热处理,并通过光学显微镜、扫描电镜、拉伸试验等对一步淬火配分处理后试验钢的微观组织及力学性能进行了研究,且讨论了配分时间对材料组织性能的影响。结果表明:试验钢组织由板条马氏体和残留奥氏体组成,随着配分时间的增加,也有少量贝氏体生成,残留奥氏体含量先上升后下降,马氏体的板条组织逐渐模糊并软化;抗拉强度和屈服强度都逐渐降低,伸长率先升高后降低。配分30 s时综合性能最佳,抗拉强度为989 MPa,伸长率为23.5%,强塑积达到23.24 GPa·%。

Effect of partitioning time on microstructure and properties of Q&P steel

On the basis of the traditional C-Mn-Si steel,the microstructure and mechanical properties of the experimental Q&P steel after on-line one-step quenching and partitioning treatment were studied by metallographic microscope,scanning electron microscope and tensile test.The effect of partitioning time on the microstructure and properties of the steel was also discussed.The results show that the experimental steel structure consists of lath martensite and retained austenite.With the increase of partitioning time,a small amount of bainite is formed,and the retained austenite content first rises and then falls,and the lath structure of martensite is gradually blurred and softened;the tensile strength and yield strength are gradually reduced,and the elongation first increases and then decreases.The best comprehensive performance is achieved under the partitioning time of 30 s,the tensile strength is 989 MPa,the elongation is 23.5%,and the product of strength and elongation is 23.24 GPa·%.