【作者】 刘英杰； 高志明；

【Author】 Yingjie Liu;Zhiming Gao;Tianjin Key Laboratory of composite & Functional Materials, School of Materials Science and Engineering,Tianjin Univ.;

【机构】 天津大学材料科学与工程学院天津市材料复合与功能化重点实验室；

【摘要】 阴极保护电位过负,会有析氢现象。本实验研究了氢对304不锈钢在3.5%NaCl溶液中腐蚀行为及钝化性能的影响,以304不锈钢为研究对象,使用3.5%NaCl溶液来模拟海水溶液,结合循环极化曲线、电化学交流阻抗谱、M-S曲线测量等试验方法进行研究。结果表明,随着充氢电位的降低,304SS试样钝化膜的法拉第电阻逐渐减小,304SS在3.5%NaCl溶液中的维钝电流IP逐渐增加,击穿电位Epit负移,自腐蚀电位Ecorr负移,自腐蚀电流Icorr呈现增加的趋势,钝化区域变窄,以上均体现出304不锈钢随着充氢电位的负移,耐蚀性降低,点蚀敏感性增强^[1];对循环极化曲线测量后的样品进行SEM观察,可以看出表面点蚀坑尺寸和数量随充氢电位的降低而增加;经过电化学噪声测量,发现随着充氢电位负移,304SS的电流噪声和电压噪声都出现明显的波动,电流值明显增加,对PSD图进行分析发现斜率K值呈现减小的趋势,钝化膜表面局部腐蚀速率随着氢渗透量的增加而出现大幅增长^[2];随着充氢电位负移,M-S曲线斜率减小,304SS钝化膜的施主浓度增加,促进了钝化膜的溶解与破裂,钝化膜溶解加快^[3-5]。更多还原

【Abstract】 There will be a phenomenon of hydrogen evolution when the cathodic protection potential is too negative. In this work, the influence of hydrogen on corrosion performance and passivation performance of 304 SS was studied in 3.5% NaCl solution by means of cycle polarization curve, EIS, M-S testing technology and electrochemical noise. 3.5 NaCl solution was used as simulated seawater solution. The results showed that, as the hydrogen potential decreased, Faradic resistance of 304 SS decreased gradually, Ip increased, Ecorr declined and Icorr increased. The passive zone in cycle polarization curve became narrow., which indicated that the corrosion resistance of 304 SS was destroyed as the decreasing of hydrogen charging; From the photograph of SEM, we can find that amount and size of corrosion pits increased as the decreasing of hydrogen charging potential; It is shown that current and potential noise fluctuated obviously after hydrogen charging. The value of current increased greatly. In the PSD plots we can find that slope decreased after hydrogen charging. The local corrosion rate also grew greatly; As the decreasing of hydrogen charging potential, the slope of M-S curve got lower, donor concentration of passivation film increased, which promoted the dissolution and rupture of passivation film of 304 SS, the corrosion rate of passivation film increased.更多还原