中文摘要：

316L不锈钢以其优良的耐腐蚀性能、加工性能和高抗氧化性能而被广泛应用于核电、石油、化工等领域。316L不锈钢的应用大多需要焊接成型，但焊接过程中化学成分。组织形态和相关性能的改变，使316L不锈钢的耐蚀性能降低，在焊缝接头处以及焊缝部位优先发生腐蚀。严重影响了不锈钢的使用寿命和安全性。本文采用交流阻抗法和阳极极化常规电化学方法，结合课题组自主研发的扫描微电极技术研究316L不锈钢焊缝区的腐蚀行为，探讨钨极氩弧焊和CO2保护焊两种不同焊接方法对316L不锈钢抗腐蚀能力的影响以及氯离子浓度对焊接样品抗腐蚀能力的影响。结果表明。经过腐蚀电化学方法检测后，焊接样品的耐腐蚀性能较基材样品均发生明显降低。具体表现为氩弧焊焊接样品和CO2保护焊焊接样品在阳极极化曲线的开裂电位Eb，腐蚀电位E0均较基材样品负，钝化区△E较基材样品变窄。交流阻抗谱测试得出氩弧焊焊接样品与CO2保护焊焊接样品的电荷转移电阻只；均较基材样品小。同时，通过不同实验分析均表明，在NaCl溶液和FeCl3溶液中，氩弧焊焊接样品的耐蚀性能较CO2保护焊焊接样品好。实验结果还表明，随着氯离子浓度的升高，两种焊接样品的耐蚀性能均降低。

英文摘要：

The effect of two different techniques, including Argon tungsten arc welding （TIG） and CO2 shielded arc welding, on the welding seam corrosion behavior of the 316L stainless steel, and whether or not the concentration of chloride ions affect the welding seam corrosion of the welding samples are explored. The samples are studied by the traditional electrochemical techniques, such as potentiodynamic polarization curve, electrochemical impedance spectroscopy, and scanning microelectrode technique which is self- assembly made by authors. In conclusion, it is indicates that the corrosion resistance of welding seam zone is lower than that of base materials in any situation. In the NaC1 and FeC13 solutions with different concentration, the anti-corrosion performance of the Argon tungsten arc welding samples are better than that of CO2 shielded arc welding samples. The conclusion is all verified by the three different techniques. Besides, it is also concluded that the corrosion resistant of the both welding samples and base materials are decreased with the increase of the concentration of chloride ions.