Cl~-和H_2S对不锈钢电化学行为的协同影响

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。

Combined Effects of Cl-and H2S on Electrochemical Behavior of Stainless Steel

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.