某临近海边小区的316不锈钢护栏安装完约两个月后即出现腐蚀失效。采用化学成分分析、金相检验、扫描电镜及能谱分析等方法对护栏腐蚀失效原因进行了分析。结果表明：护栏焊缝区与母材化学成分存在明显差异，使得两者之间存在较大的电极电位差，焊缝处存在一定的焊接残余应力。且安装位置临近海边，空气湿度大，该护栏在焊缝熔敷金属区域发生电化学腐蚀和应力腐蚀，在该两种腐蚀的综合作用下最终造成护栏腐蚀失效。

Corrosion failure occurred about two months after installation of 316 stainless steel guardrail in a neighborhood near the seaside. The causes of corrosion failure of guardrail were analyzed by means of chemical composition analysis, metallographic examination, scanning electron microscope and energy spectrum analysis. The results show that there were obvious the chemical composition differences between guardrail weld seam area and base metal, which led to a large electrode potential difference between them, and there was a certain welding residual stress at the weld seam. Moreover, the installation location was near the seaside, and the air humidity was high, the electrochemical corrosion and stress corrosion occurred in the weld seam deposited metal area of the guardrail. Under the combined action of the two kinds of corrosion, the guardrail corrosion failure was caused.