高强钢的直接淬火回火工艺研究

Study on Direct Quenching and Tempering Process of High Strength Steel

利用光学显微镜、透射电镜等研究了再热淬火回火工艺(RQ-T)和直接淬火回火工艺(DQ-T)对一种780MPa级建筑用钢的组织和力学性能的影响。结果表明,直接淬火回火工艺可以增强材料的淬硬性;随着终轧温度的降低,材料变形量加大,奥氏体晶粒的平均尺寸减小,而粗大板条状组织转变为细小的马氏体和贝氏体。

Effects of the reheat quenching and tempering process （RQ-T） and direct quenching and tempering （DQ-T） on the microstructures and mechanical properties of a 780 MPa grade construction steel were studied by using optical microscope, transmission electron microscope and so on. The results show that the direct quenching and tempering process can enhance the hardness of the material; with the decrease of the final rolling temperature, the amount of deformation of the material increases the average size of the austenite grains decreases, and the thick lath microstructure transforms fine martensite and bainite.