电化学充氢对GPa钢腐蚀性能的影响

Effects of electrochemical hydrogen charging on corrosion properties of GPa steel

为了揭示氢对钢铁材料在海洋环境下腐蚀行为的影响,以GPa钢为研究对象,在0.1 mol/L NaOH溶液中对其进行12 h恒电流充氢;利用单电池电化学氧化方法测量并计算不同充氢电流密度下GPa钢中氢浓度;利用电化学工作站,通过极化曲线和交流阻抗谱测试GPa钢在质量浓度为3.5%的NaCl溶液中的腐蚀行为,探讨充氢对GPa钢腐蚀行为的影响规律及影响机制。实验结果表明,充氢电流密度提高会增加GPa钢中氢浓度;电化学充氢后,GPa钢的自腐蚀电位降低、腐蚀电流密度增大、阻抗减小,说明充氢提高了GPa钢的应力腐蚀敏感性和腐蚀速率;但充氢电流密度由200 mA/cm^(2)增至400 mA/cm^(2)时,仅腐蚀速率增加,腐蚀敏感性并没有随充氢电流的增加而发生明显变化。

In order to reveal the influence of hydrogen on the corrosion behavior of steel in the marine environment,a GPa steel was investigated.The steel was charged with hydrogen in a 0.1 mol/L NaOH solution at constant current for 12 h.The hydrogen contents in the GPa steel at different hydrogen charging current densities were measured and calculated by single cell electrochemical oxidation method.The corrosion behaviors of the GPa steel in a 3.5%NaCl solution were tested by electrochemical workstation through polarization curve and AC impedance spectrum,and the influencing mechanisms of the hydrogen charging on the corrosion behavior of the GPa steel were discussed.The experimental results show that the increase in hydrogen charging current density increased the hydrogen content in the GPa steel.After the electrochemical hydrogen charging,the self corrosion potential of the GPa steel decreased,the corrosion current density increased,and the impedance decreased,indicating that the hydrogen charging improved the stress corrosion sensitivity and the corrosion rate of the GPa steel.However,when the hydrogen charging current density increased from 200 mA/cm^(2) to 400 mA/cm^(2),only the corrosion rate increased,and the corrosion sensitivity did not change significantly with the increase in hydrogen charging current.