溶液pH值对不锈钢亚稳态孔蚀行为的影响

Effect of pH value on metastable pitting behaviour of stainless steel

用测试动电位的电流 时间曲线法研究了不锈钢在不同pH值的NaCl溶液中的亚稳态孔蚀行为。结果表明 ,随溶液 pH值升高 ,316L不锈钢在NaCl溶液中的亚稳孔形核电位Em 和孔蚀电位Eb 均正移 ;不同NaCl浓度下 ,Em 和Eb 随溶液pH值的变化趋势基本一致。溶液 pH值对亚稳孔形核数有明显影响 ,随 pH值升高形核数降低。但 pH值对亚稳态孔蚀过程的动力学参数 ,包括亚稳孔生长速度、峰值电流和平均寿命 。

Metastable pitting behaviour of stainless steel in NaCl solutions with different pH values was studied by using a potentiodynamic polarization method. With the increase in pH value, the metastable pitting potential ( E m) and pitting potential ( E b) increase. The number of metastable pits decreases as the pH value of the solution increases. However, the pH value has little influences on the dynamic parameters such as the growth rate, peak current and average lifetime of metastable pits. These parameters are mainly affected by the potential.