冷轧Q355钢窄带焊缝断裂的原因

Cause for Weld Fracture of Cold-rolled Q355 Steel Narrow Strip

Q355钢窄带冷轧时焊缝处断裂。对断裂的窄带进行了化学成分分析、金相检验和杯突试验。结果表明:焊缝组织为粗大的马氏体,与母材交界处有孔洞,而且焊缝两侧有明显的咬边缺陷,从而导致其在冷轧过程中断裂。

Q355 steel narrow strip fractured at welding seam during cold-rolling.The fractured narrow strip was subjected to chemical composition analysis,metallographic examination and cupping test.The results showed that the welding seam exhibited coarse martensitie,and voids at the junction between it and base metal,and the evident undercut defect exited in both sides of the weld,thus resulting in its fracturing during cold-rolling.