摘要
综合运用动电位扫描极化曲线和动电位电化学阻抗谱研究了不同时效温度下AM355半奥氏体沉淀硬化不锈钢在3.5%(质量分数)Na Cl溶液中的点蚀行为。极化曲线的结果表明,时效时间均为4 h时,时效温度为350℃的点蚀电位Eb100最高,在动电位扫描极化曲线反向扫描过程中,均未出现保护电位Ep,钢表面产生蚀孔后再钝化能力较差。实验结果显示,时效温度会影响合金元素分布,析出相变化与点蚀电位成反比,到一定温度后,点蚀电位与残余奥氏体变化同步。
The effect of aging treatment at different temperature on the pitting corrosion behavior of stainless steel AM355 in 3.5%(mass fraction)Na Cl solution was studied by means of potentiodynamic polarization technique and dynamic electrochemical impedance spectrum. The result showed that among others the pitting potential was the highest for the steel aged at 350 ℃ for 4 h. The repassivation potential didn't appear during reversed scanning for all the steels aged at different temperatures indicated they are hard to be repassivated. The aging temperature also showed effect on the distribution of alloying elements, while, the variation of Ebwas related to the among of precipitated phase and residual austenite of the steel.
引文
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