采用TMCP工艺制备了厚度为85 mm的Q345高强度钢板,通过拉伸和冲击试验、组织及断口形貌观察等对其组织和性能进行了分析。结果表明:制备的Q345钢厚板的表面组织为多边形铁素体+大量贝氏体的混合组织,其余部位均为铁素体+珠光体组织,屈服强度达到320 MPa以上,伸长率在29%以上,冲击韧性良好;该钢不添加微合金元素,轧后不进行热处理,降低了生产成本,实现了强韧性的良好匹配。 The Q345 high strength steel plate with a thickness of 85 mm was prepared by TMCP process. The microstructure and properties of Q345 were analyzed by tensile and impact tests, microstructure and fracture morphology observation. The results show that the surface structure of the prepared Q345 steel plate is a mixed microstructure of polygonal ferrite + a large amount of bainite, and the rest are ferrite + pearlite. The yield strength reaches 320 MPa and the elongation is 29 %, Impact toughness is good; the steel does not add microalloying elements, after rolling without heat treatment, reducing production costs, to achieve a good match toughness.