层冷工艺和卷取温度对700 MPa大梁钢组织性能的影响

Effects of Layer Cooling Process and Coiling Temperature on Microstructure and Properties of 700 MPa Girder Steel

对700 MPa级汽车大梁钢进行了热轧试验,采用光学显微镜、扫描电镜和能谱仪等设备研究了不同的层冷工艺和不同的卷取温度对试验钢组织和力学性能的影响。结果表明,在轧后不同的冷却工艺中,前段集中冷却模式所得到产品强度高于后段集中冷却模式所得到的产品强度,两段冷却模式所得到产品强度最优;在相同的冷却模式条件下,降低卷取温度,可有效提高钢材的抗拉强度,屈强比也随着提高,为700 MPa大梁钢的后续优化生产提供了依据。

The hot rolling test of 700 MPa automobile girder steel was carried out. The effects of different layer cooling processes and coiling temperatures on the microstructure and mechanical properties of the test steel were studied by using optical microscope, scanning electron microscope and energy dispersive spectrometer. The results show that in different cooling processes after rolling, the product strength obtained by the former centralized cooling mode is higher than that obtained by the latter centralized cooling mode, and the product strength obtained by the two-stage cooling mode is the best. Under the same cooling mode, reducing the coiling temperature can effectively improve the tensile strength of steel, and the yield ratio also increases, which provides a basis for the subsequent optimization production of 700 MPa girder steel.