2205双相不锈钢在CO_2-H_2S-Cl^--H_2O环境中的电化学腐蚀行为

Electrochemical Corrosion Behavior of 2205 Duplex Stainless Steel in CO_2-H_2S-Cl^--H_2O Environment

为充分了解2205双相不锈钢在CO2-H2S-Cl--H2O环境下的耐蚀性能,尤其是其抗点蚀特性,借助计时电流和动电位循环极化测试等手段研究了其钝化动力学特征以及腐蚀特征参数如Ecorr、Epit、Epp、ΔE和Jpass的变化,分析了2205双相不锈钢在含CO2和CO2/H2S的Na Cl溶液中的点蚀差异,并对其点蚀和钝化机理进行了讨论。结果表明,2205双相不锈钢具有优越的抗CO2腐蚀性能,随Cl-浓度增大,发生点腐蚀敏感性提高;随H2S浓度增大,点蚀电位Epit和保护电位Epp均降低,钝化区域稳定性下降,点蚀敏感性进一步提高。

By utilizing the chronoamperometry and potentiodynamic cyclic polarization,the kinetic characteristics of the passivity and the changes of corrosion parameters,such as E_(corr),E_(pit),E_(pp),△E and J_(pass) were investigated,and then the pitting corrosion difference of 2205 duplex stainless steel in NaCl solutions containing CO_2 or CO_2/H_2 S was analyzed.Furthermore,the pitting corrosion and passivation mechanism were discussed.Results showed that 2205 duplex stainless steel had excellent anti-CO_2 corrosion performance,and as the Cl^- concentration increased,the occurrence of pitting sensitivity was improved.Besides,with the H_2S concentration increasing,the pitting potential and protection potential were reduced,and the stability of passivation region became lower while the pitting sensitivity was further enhanced.