高湿热海岸大气环境中Q235B钢的腐蚀演化规律

Corrosion Evolution of Q235B Steel in a Simulated Hightemperature and High-humidity Coastal Atmosphere

采用干/湿交替的实验方法模拟大气腐蚀过程,利用X射线衍射和极化曲线的方法,研究了低碳钢Q235B在高湿热海岸大气环境中的腐蚀演化规律。结果表明,在高湿热海岸大气环境中,低碳钢在腐蚀演化的初期阶段腐蚀速率最大,中期阶段腐蚀速率较为平稳,而后期阶段的腐蚀速率则迅速减小。此外,低碳钢的腐蚀速率随着模拟环境中的Cl-含量的增加而增大。相比于低湿热大气环境,高湿热大气环境更有利于Fe_3O_4的生成,而Fe_3O_4的含量又会随Cl-浓度的增大而减小。

Evolution of the Q235 B steel corrosion in a simulated high-temperature and high-humidity coastal atmosphere was investigated by dry/wet cyclic corrosion test, X-ray diffraction（XRD） and polarization curves measurements. The results indicate that, in the simulated coastal atmosphere, the corrosion rate of low carbon steel is greatest in the early stage. Then the corrosion keeps stable in the middle stage, while decreases rapidly in the later stage. Otherwise, the corrosion rate of the steel increases with growing Cl-content. Besides, the simulated coastal atmosphere promotes the formation of Fe_3O_4, while the formation of Fe_3O_4 in the rust layer decreases with the increasing Cl-content.