高强焊接结构钢HG70C热轧板带在力学性能检验中出现了严重的中心分层缺陷,为此设计了不同应力级别的试样。通过金相检测、电镜扫描分析了拉伸断口的组织,描述了拉伸断裂的机理。研究结果表明,过量的钛元素形成夹杂物,通过拉应力产生了微裂纹;随着应力增加,裂纹逐步扩展。 High-strength welded structural steel HG70C hot-rolled strip in the mechanical properties of the test there was a serious center delamination defects, for which design different stress levels of the sample. The structure of tensile fracture was analyzed by metallographic examination and scanning electron microscope, and the mechanism of tensile fracture was described. The results show that an excessive amount of titanium forms inclusions and microcracks are generated by tensile stress. As the stress increases, the cracks gradually expand.