Pitting Behaviors of Passivated and Trans-Passivated 304 Stainless Steel

为了进一步了解不锈钢钝化膜与过钝化膜的性质,本文对比研究了在不同电位下极化处理后304不锈钢样品的点蚀及表面膜性质,发现空白对照组样品的点蚀电位和1.1 V过钝化处理后样品的点蚀电位相近,而0.5 V钝化处理后样品的点蚀电位较高. 扫描Kelvin探针（SKP）实验结果也验证了这一现象. 扫描电子显微镜（SEM）结果显示,空白对照组样品表面只呈现一般样品抛光后形貌;0.5 V钝化处理后的样品表面被颗粒状钝化膜所覆盖,该膜层决定了样品具有较好的耐蚀性;而1.1 V过钝化处理后的样品表面出现裂缝,导致不锈钢基体继续发生严重的局部腐蚀,可能成为过钝化膜保护性变差的主要原因.In order to further understand the passivation and trans-passivation behaviors of 304 stainless steels, the samples were pretreated under different polarization potentials and their corrosion behaviors were investigated. It was found that the pitting potential of the untreated sample was the same as that of the sample treated with 1.1 V trans-passivation potential, while the pitting potential of the sample treated with 0.5 V passivation treatment was the highest. This observation was further verified by the SKP results. According to SEM observations, the surface of the untreated sample preserved a polishing morphology, while the surface of the 0.5 V passivation treated sample was covered by a passivation film decorated with small corrosion particles, performing good corrosion resistance. However, cracks appeared on the surface of the 1.1 V trans-passivation treated sample, leading to severe localized corrosion of the matrix and resulting in the deterioration of the trans-passivation film.国家自然科学基金项目资助No(51671163);国家自然科学基金项目资助No(51731008)通讯作者:宋光铃E-mail:[email protected]:SONGGuang-lingE-mail:[email protected]. 厦门大学材料学院,海洋材料腐蚀与防护中心,福建 厦门3610052. 厦门大学固体表面物理化学国家重点实验室,福建 厦门3610051. Center for Marine Materials Corrosion and Protection, College of Materials, Xiamen University, Xiamen 361005, Fujian, China2. State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, Fujian, Chin