中文摘要：

在含有不同浓度NaHSO_3的模拟海水溶液中系统考察了2205双相不锈钢的腐蚀行为。利用动电位极化曲线和电化学阻抗谱测试,研究模拟海水中不同浓度HSO3^-对2205双相不锈钢腐蚀行为的影响。通过Mott-Schottky和XPS测试,分析了2205不锈钢在不同浓度HSO3^-模拟海水溶液中钝化膜的缺陷浓度和成分。结果表明,模拟海水溶液中HSO3^-的存在会提高2205不锈钢钝化膜中金属氧化物的含量。在含有0.01 mol/L HSO3^-的模拟海水溶液中,2205双相不锈钢表现出较差的耐蚀性,其表面钝化膜中的缺陷浓度计算结果也与电化学测试结果相吻合。主要是由于HSO3^-在溶液中极易被氧化为HSO_4^-,电离出H^＋,会对2205不锈钢钝化膜产生破坏作用;而当模拟海水中HSO3^-浓度低于0.01 mol/L时,材料阻抗呈上升趋势,HSO3^-会在2205不锈钢表面和Cl^-产生竞争吸附,阻碍Cl^-在不锈钢表面的吸附,从而减少点蚀发生的可能。

英文摘要：

Corrosion behavior of 2205 duplex stainless steel in simulated seawater containing dif- ferent concentration of NaHSO3 has been systemically investigated by means of potentiodynamic polarization and electrochemical impedance spectrum （EIS） measurements. While the defects and the compositions of the formed passive films on the steel were characterized by Mott-Schottky and XPS respectively. The results demonstrate that the existence of HSOf in the simulated seawater contributes to the increase of metal oxide content in the passive film formed on 2205 stainless steel. In the simulated seawater containing 0.01 mol/L HSO3^-, 2205 duplex stainless steel presents the worst corrosion resistant performance, correspondingly the calculated defect concentration for the formed passive film is consistent to the electrochemical test results. The oxidation of HSO3^- induc- es the formation of HSO4^- in aqueous solution, which will give rise to the releasing of hydrogen ions, leading to the increase of acidity of the solution and thus induces the damage of the passive film on 2205 stainless steel. However, when the concentration of HSO3^- in simulated seawater is less than 0.01 tool/L, the corrosion resistance of the steel will rise again. This is because the com- petitive adsorption between HSO3^- and Cl^- on the 2205 stainless steel surface can inhibit the adsorp- tion of Cl^-, which then results in the decline of the pitting corrosion probability.