某船体尾部外板装配焊接后出现一条贯穿于焊缝和母材的裂纹, 通过对船板原材料进行理化性能检验和裂纹断面进行宏、微观检查, 对船体外板裂纹产生的原因进行了分析。结果表明: 船体外板开裂主要是由于焊接顺序及焊接措施不当, 导致船板强制装配拘束应力大, 焊缝中存在较多焊接缺陷, 从而使得裂纹在两条焊缝交接处的高应力区萌生并延伸扩展至母材区。

A welding crack running through the weld bead and the base metal occurred after assembling and welding of the rear outer ship hull plate. The physical testing and chemical analysis for the parent metal and the macro and micro examination for the cracking section plane were carried out to analyze the cracking cause. The results show that the welding defects and the assembling residual stress caused by the unreasonable welding sequence and welding technique resulted in the generating of crack which expanded from the connection zone of two welds where the stress was rather higher to the parent metal.