采用恒电位阳极极化加速腐蚀电化学试验，研究了J55钢级套管电阻焊（ERW）焊缝的沟槽腐蚀行为，利用激光共聚焦显微镜观察试样腐蚀后的表面形貌和三维微观特征，计算了焊缝沟槽腐蚀敏感系数，分析了沟槽腐蚀的影响因素并对比了无缝套管和ERW套管的经济性。结果表明：J55钢级ERW套管发生了选择性局部腐蚀，焊缝区域存在点蚀坑；其沟槽腐蚀敏感系数均小于1.3，对沟槽腐蚀不敏感；相比J55钢级无缝套管，其经济性较好。

The corrosion behavior of the electric resistance weld (ERW) seam of J55 steel-grade casing was studied by constant potential anodic polarization accelerated corrosion electrochemical test. The surface morphology and three-dimensional microscopic characteristics of samples were observed by laser confocal microscopy and the corrosion sensitivity coefficient of groove corrosion was analyzed. The influence factors of the groove corrosion were analyzed and the economics of the seamless casing and ERW casing were compared. The results show that selective corrosion of J55 steel-grade ERW casing occurred, and there were pits in the weld area; the sensitivity coefficient of groove corrosion was less than 1.3, which was not sensitive to groove corrosion. Compared with J55 steel-grade seamless casing, the economy of J55 steel-grade casing with ERW seam was better.