Cl^-和H_2S对不锈钢电化学行为的协同影响

Combined Effects of Cl^- and H_2S on Electrochemical Behavior of Stainless Steel

目前,对Cl^-和H_2S共存条件下不锈钢的腐蚀尤其是点蚀行为鲜有研究。采用动电位扫描和交流阻抗测试研究了304,316L和2205 3种不锈钢在含有不同浓度Cl^-和H_2S的溶液中的电化学行为。结果表明:在含有1 200 mg/L Cl^-的溶液中,随H_2S浓度增大,304和316L的点蚀敏感性均增大,但此条件下的H_2S浓度并未对2205双相不锈钢产生影响。当Cl^-浓度增大到1 500 mg/L时,2205产生了点蚀现象,说明虽然H_2S促进了不锈钢点蚀的发生,但Cl^-是诱导不锈钢产生点蚀的关键因素。

Electrochemical behavior of 304,316L and 2205 stainless steel was studied by potentiodynamic polarization and alternating current impedance （EIS） in the solutions with different concentrations of C1-and H2 S.Results showed that with the increase of H2S concentration,the pitting sensitivity of 304 and 316L stainless steel was increased in the solution containing 1 200 mg/L Cl^-.However,under this condition,H2S concentrations did not affect 2205 stainless steel.When the Cl^-concentration was increased to 1 500 mg/L,pitting corrosion phenomenon occurred on the 2205 stainless steel,which illustrated that H2S promoted the occurrence of pitting corrosion of stainless steel,while Cl^-was the key factor of inducing the pitting corrosion of stainless steel.