湿度对船板钢在海洋大气环境中腐蚀行为的影响研究

Study on Effect of Humidity on Corrosion Behavior of Steel Plates for Ship-building in Marine Atmospheric Environment

通过在不同湿度条件下,进行模拟海洋大气环境的周浸实验,研究了海洋大气环境中湿度对船板钢AH36腐蚀行为的影响,基于腐蚀失重计算了不同湿度各个腐蚀周期的腐蚀速率,采用SEM观察了锈层表面的微观形貌,同时对腐蚀后的试样进行了极化曲线测试。结果表明:当生成相对稳定的锈层后,随着湿度的逐渐增大,腐蚀速率先增大后减小,在湿度60%时腐蚀速率达到最大。在相对低的湿度条件下,AH36形成致密锈层所需的时间相对较长;而在相对高的湿度条件下,AH36形成致密锈层所需的时间相对较短。湿度对船板钢AH36初期(24 h)的腐蚀电流影响较弱,随着时间延长,不同湿度条件的腐蚀电流差距逐渐增大。

The effect of humidity on the corrosion behavior of the AH36 steel plates for ship-building in marine atmospheric environment was studied based on dry-wet circles testing by simulating the marine atmospheric environment under different conditions of humidity.The corrosion rates of each corrosion cycle under different humidity was calculated through corrosion weight loss,and then the micro-morphology of the rusty layer surface was observed by SEM,meanwhile the polarization curve testing for the corroded samples was carried out.The tested results showed that when a relatively stable rusty layer was formed,the corrosion rate increased first and decreased subsequently with the gradual increasing of humidity and reached the maximum when the humidity was 60%.Under the condition of relatively low humidity,it took a relatively long time for the AH36 steel to form a dense rusty layer.However,under the condition of relatively high humidity,it took a relatively short time for the AH36 steel to form a dense rusty layer.It was concluded that humidity had relatively weak effect on the corrosion current of the AH36 steel plates for ship-building at the initial stage(24 h),while the differences of corrosion current density under different conditions of humidity gradually increased with time expanding.