【摘要】 利用扫描电镜、透射电镜和X射线衍射仪对Q&P钢的微观组织进行观察和分析,并通过拉伸试验测量钢的抗拉强度、屈服强度和伸长率。结果表明,随着淬火温度的升高,抗拉强度和屈服强度均表现出下降趋势,而残留奥氏体量和伸长率则呈现出先增加后减小的规律;强度的变化是马氏体和下贝氏体共同作用的结果,而伸长率与残留奥氏体量的变化密切相关;下贝氏体的存在,对残留奥氏体量和碳含量,以及钢的强度均有影响。更多还原

【Abstract】 The microstructure was observed and analyzed by using scanning electron microscopy,transmission electron microscopy and X-ray diffractometer,and the tensile strength,yield strength as well as elongation of the steel were measured by using tensile test. The results show that with increasing quenching temperature,the tensile strength and yield strength decrease gradually,while elongation and the retained austenite increase first and then decrease. The strength of the steel is influenced by the martensite and lower bainite,and the elongation is affected significantly by the amount of retained austenite. The existence of lower bainite not only can affect the volume fraction and carbon content of retained austenite,but also can affect the strength of the steel.更多还原