恒载荷条件下904L不锈钢的腐蚀电化学行为

Electrochemical Corrosion Behavior of 904L Stainless Steel under Constant Load

采用电化学方法研究了不同弹性恒载荷条件下904L不锈钢的阳极极化行为及Cl^-敏感性。结果表明:外加恒载荷可显著改变904L不锈钢的阳极极化行为,随着外加恒载荷的增加,阳极活性电流密度递增,表面点蚀数量增加,钝化膜的阻抗值逐渐降低,点蚀敏感性提高。外加恒载荷和Cl^-含量均会对904L不锈钢Cl^-敏感性产生影响,Cl^-质量分数≤5%时,外加恒载荷可明显改变904L不锈钢的Cl^-敏感性,击破电位显著负移;Cl^-质量分数>5%时,Cl^-含量的增加削弱了外加恒载荷对904L不锈钢Cl^-敏感性的影响,击破电位负移幅度减小。

The anodic polarization behavior and the sensitivity to Cl-of 904 L super austenitic stainless steel under different loading conditions were studied by electrochemical methods. The results show that the anodic polarization of904 L stainless steel can be significantly changed by applying constant load. With the increase of tensile stress, the anodic current density increased rapidly, the number of surface pitting increased, the resistance of passivation film gradually decreased and the pitting sensitivity increased. In addition,both constant load and Cl-concentration affected the Cl-sensitivity of 904 L stainless steel. When the mass fraction of Cl-was less than 5%, the addition of constant load could greatly change the sensitivity of Cl-of 904 L, and the breakdown potential significantly shifted negatively. When the mass fraction of Cl-was less than 5%, the influence of applied constant load on the sensitivity of 904 L Cl-decreased, and the amplitude of negative displacement of the breakdown potential decreased.