晶粒尺寸对含铜锡中铬铁素体不锈钢耐蚀性的影响

以含低熔点元素Cu和Sn的超纯165%(质量分数)Cr铁素体不锈钢为实验材料，通过在35℃恒温6%(质量分数)FeCl3溶液中对实验钢进行浸泡腐蚀实验，并采用三电极体系测定实验钢的极化曲线，初步研究了晶粒尺寸对这种铁素体不锈钢耐蚀性能的影响.实验中，采用经典的失重法计算腐蚀速率，利用动电位扫描法测绘极化曲线，以进一步探究实验钢的腐蚀过程.研究表明，这种铁素体不锈钢的点蚀电位值随晶粒尺寸增大而大幅提高.浸泡腐蚀实验结果证实，存在一个相对合理的晶粒尺寸范围，晶粒尺寸过小或过大都不利于提高耐蚀性能.

Influence of Grain Size on the Corrosion Resistance of Medium Chromium Ferritic Stainless Steel Containing Cu and Sn〓

The corrosion test of ultra purified 165 wt%Cr ferritic stainless steel containing Cu and Sn was carried out by immerging the specimens into the 6 wt% FeCl3 solution at 35 ℃， and the polarization curves of the steel were measured using potentiodynamic polarization method. The influence of grain size on the corrosion resistance of ferritic stainless steel was investigated. The corrosion rates were calculated through gravimetric tests. The results show that the pitting potential of the stainless steel greatly rises with the coarsening of grain size. There is a relative reasonable range of grain size and over fined or over coarsened grain size are unbeneficial for the corrosion resistance of the tested steel.