不同铬含量耐候钢在高湿热模拟环境中的耐腐蚀性能

摘要

Cyclic wet-dry corrosion testing was conducted on weathering steels containing Cr with two mass fractions (1.990％, 3.194％) in simulated high temperature and humidity environment of the South China Sea with aperiodic wheel immersion accelerated corrosion chamber.Then electrochemical tests were conducted on the weathering steels after cyclic wet-dry corrosion for different times.The corrosion resistance of the weathering steels was studied and compared with that of Q235 steel (Cr mass fraction of 0.164％).The results show that the higher the Cr content, the lower the corrosion rate of the tested steel.In the initial stage of corrosion, the steel containing3.194％ Cr had the smallest free-corrosion current density, relatively large capacitance arc radius and the largest charge transfer resistance and total resistance (rust layer resistance+charge transfer resistance), showing the best corrosion resistance.In the final stage of corrosion, due to accelerated corrosion, the rust layer resistance, charge transfer resistance and total resistance of the steel containing 3.194％ Cr were lower than those of the steel containing 1.990％ Cr.%采用周期轮浸加速腐蚀试验箱模拟南海高湿热环境, 在该环境中对2种铬质量分数 (1.990％, 3.194％) 耐候钢进行周浸腐蚀试验, 对周浸腐蚀不同时间的耐候钢进行了电化学试验, 研究了不同耐候钢的耐腐蚀性能并与Q235钢 (铬质量分数0.164％) 的进行了对比.结果表明:铬含量越高, 试验钢的腐蚀速率越小;在腐蚀初期, 铬质量分数3.194％钢的自腐蚀电流密度最小, 容抗弧半径较大, 电荷转移电阻和总电阻 (锈层电阻+电荷转移电阻) 最大, 耐腐蚀性能最好;在腐蚀后期, 由于出现腐蚀加速现象, 铬质量分数3.194％钢的锈层电阻、电荷转移电阻和总电阻均小于铬质量分数1.990％钢的.