环境温度对船用耐蚀钢腐蚀行为的影响

Effect of Environment Temperature on Corrosion Behavior of Corrosion Resistant Ship Hull

采用国际海事组织(IMO)模拟油轮货油舱内底板环境试验方法,对比分析了传统船板和耐腐蚀船板的腐蚀失重与腐蚀形貌,深入研究了环境温度对船用耐蚀钢腐蚀行为影响规律。结果表明,环境温度对船板腐蚀行为存在显著影响,随着环境温度(30～50℃)的升高,点蚀坑的数量逐渐增多,点蚀坑深度先增大后减小,在45℃时达到峰值。2种钢点蚀行为差别较大,传统船板钢点蚀坑的深度直径比(h/D)随环境温度的增大而增大,而耐蚀船板则呈现逐步下降的趋势。耐蚀合金元素的加入有效降低了船板钢在不同温度下的腐蚀速率,减小了钢的点蚀坑数量,改善了点蚀坑的扩展方式。即点蚀坑由纵向深度方向扩展,转为横向表面方向扩展,有效提高了船板的安全性。

Tests which accord to IMO on simulated inner bottom conditions in cargo oil tanks （COT） was adopted to compare and analysis the corrosion mass loss and corrosion morphology of conventional and corrosion resistant ship hull steel, and deeply studied the corrosion behavior at different temperature. The results showed that, temperature had significant effect on the corrosion behavior, with the rise of the temperature, the number of pits increased, the depth of pits increased and then decreased, reaching the peak at 45 ℃. Spot corrosion behavior conventional and cor- rosion resistant ship hull steel was greatly different. The value of hiD （depth/diameter） increased with temperature rising, while the value of corrosion resistant steel decreased The addition of corrosion resistant alloy elements appar- ently decreased the corrosion rate and the number of pits. The expanded mode of pits was also improved with the ad- dition of corrosion resistant alloy elements. The expanded mode of pits was changed from along the depth direction vertically to along the surface direction laterally.