焊缝噘嘴对螺旋焊管应力分布的影响

用电阻应变测量法对某输气管线管（SSAW焊管）螺旋焊缝周围表面应力进行了在线监测，得到了不同内压下焊缝周围应力分布规律，研究了焊缝噘嘴（国际上称为焊缝角偏差）对管道应力分布的影响。研究测试结果表明，噘嘴造成焊缝附近产生附加弯曲应力，并导致管道焊缝附近外表面拉应力显著减小，而内表面拉应力显著增大，从而会降低管线实际承压能力并增加焊缝附近应力腐蚀开裂的敏感性。指出对在役管道进行安全评价和管线管质量控制时应重视焊缝噘嘴的影响。

Influence of angular distortion of spiral weld on stress distribution in vicinity of welded joint of line pipe

The stress distribution in the vicinity of spiral welded joints of line pipe under altemating pressure is monitored online by electric logging method, and relevant stress distribution pattern is obtained. The influence of angular distortion atspiral welded joints on stress distribution is investigated. The result of the investigation shows that, angular distortioncauses additional bending stress in the vicinity of welded joints, and results in obvious decline of outer surface tensilestress and increase of inner surface tensile stress, thereby reduces the ability of line pipe undertaking pressure load andincreases the sensitivity of stress corrosion cracking. It is indicated that auention should be paid to the influence of angu-lar distortion in the safety evaluation and quality control of line pipe in service-