目的 研究电厂用T91/TP347H钢钨极氩弧焊接头在含氯溶液中的腐蚀行为及其影响因素。方法 将服役前后的焊接接头制作成工作电极，用电化学工作站测试极化曲线和交流阻抗，拟合计算试验数据。将焊接接头在含氯溶液中浸泡，结束后对试样表面进行表征。结果 T91铁素体钢的腐蚀电位最小、腐蚀电流密度最大，电荷转移电阻最小，从而表现出的腐蚀敏感性更强，而ERNiCr-3和TP347H奥氏体钢的对应数值相对较低，其表面形成致密的钝化膜，增强了耐腐蚀性。随着焊接接头服役时间的增加，腐蚀电流密度逐渐增大，耐腐蚀性逐渐降低。氯离子促进了焊接接头表面在溶液中的阳极过程，在点蚀坑的成核和生长过程中都起着重要的促进作用。焊接接头试样边缘位置形成的原电池较为强烈，腐蚀破坏更加严重。结论 T91/TP347H焊接接头容易在T91侧发生腐蚀破坏失效，在580 ℃/25 MPa以上蒸汽参数下长时间服役后，会导致焊接接头整体耐腐蚀性下降，并且T91铁素体钢的下降幅度最大。铬元素、不锈钢组织的溶碳能力和稳定性等因素是决定焊接接头耐腐蚀性强弱的关键因素。

It is a convenient corrosion test method, which can measure the corrosion rate of various metals in real time with high sensitivity, and the current or voltage applied to the metal surface will not cause irreversible effects. Combined with the characterization method, the failure factors of welded joints are comprehensively analyzed. Due to the complex material properties of dissimilar steel welded joints, the strength of welded joints is low, which becomes the source of stress corrosion cracking defects in joints. The corrosion behavior and influencing factors of T91/TP347H steel GTAW joint in solution containing chloride ions were studied.