316L不锈钢在FeCl_3溶液中点蚀行为的电化学噪声检测  

Detection of Pitting Corrosion of 316L Stainless Steel in FeCl_3 Solution by Electrochemical Noise

作　　者：贾志军[1] 杜翠薇[1] 李晓刚[1] 

机构地区：[1]北京科技大学新材料技术研究院,北京100083

出　　处：《腐蚀与防护》2011年第7期497-500,520,共5页Corrosion & Protection

基　　金：国家高技术研究发展计划项目(2009AA063405-04)

摘　　要：利用电化学噪声技术检测了316L不锈钢在6%FeCl_3溶液中点蚀的电化学噪声谱,观测腐蚀形貌,分析电化学噪声谱特征参数。结果表明,在浸泡初期,电流噪声波动较小,有暂态峰出现,电流功率谱密度(PSD_1)的斜率变化不大,表明电极表面出现亚稳态蚀点,钝化膜溶解与修复交替进行。在腐蚀后期,PSD_1出现高频白噪声水平,电流噪声波动增大,PSD_1的斜率和低频白噪声水平发生突变,这时电极表面亚稳态蚀点转化为稳定的蚀点。Electrochemical noise was used to detect the pitting corrosion of 3161. stainless steel in FeCl3 solution. The corrosion morphology was observed and the electrochemical noise characteristic parameters were analyzed. The results showed that in the initial stage of the immersion test, the fluctuation amplitude of the electrochemical noise was small and transient peaks appeared. The slope change of the current power spectrum density （PSDI） was insignificant. It was indicated that the recta-stable pitting occurred at the electrode surface and the dissolution and restoration of passive films took place alternately. In the later period of corrosion process, a high frequency plateau of white noise appeared in the power spectrum, the amplitude of the current oscillation increased and the slope of PSD1 had a great change, indicating the transformation from recta-stable pitting to stable pitting corrosion.

关 键 词：不锈钢 点蚀 电化学噪声 噪声电阻 电流功率谱密度 

分 类 号：TG174.3[金属学及工艺—金属表面处理]