运用临界点蚀温度(CPT)、环状阳极极化曲线和电化学阻抗谱等方法研究了不同温度下316L不锈钢的海水腐蚀行为. 结果表明, 晶粒尺寸不同的两种316L不锈钢的CPT基本相同; 随着海水温度升高, 点蚀电位和再钝化电位均呈线性降低, 但是细晶钢的点蚀性能下降更大, 85℃时粗晶钢比细晶钢的点蚀电位约高60 mV. 与粗晶钢相比, 细晶钢在65℃下形成的钝化膜微缺陷更多, 且点蚀诱导时间较短.
The corrosion behavior of 316L stainless steel in seawater was investigated by measurements of critical pitting temperature, cyclic anodic polarization and electrochemical impedance spectroscopy under different temperature. The results indicated that two 316L specimens with different grain size showed similar critical pitting temperature. The increase of seawater temperature led to the linear decrease of pitting potential and repassivation potential. The pitting resistance of the fine grain steel decreased larger than that of coarse grain steel with temperature increasing, the latter had a higher pitting potential about 60 mV at 85℃. Compared with the coarse grain steel, the surface of passive film formed on the fine grain steel showed more defects and thereby which showed a shorter incubation time of pitting corrosion at 65℃.