不同影响因素下海管铺管船张紧器用钢的腐蚀规律

Corrosion Laws of Tensioners in Pipe-laying Vessels at Different Influencing Factors

张紧器是海管铺管船的核心装置之一,主要作用是夹持管道,其腐蚀会造成巨大的安全隐患和经济成本。利用室内模拟失重实验和电镜扫描等方法,对张紧器履带钢(A)和底座钢(B)在不同腐蚀方式(干湿交替、全浸没),时间、温度、盐度下的腐蚀规律进行探究。结果表明:A钢的耐腐性优于B钢的;不同温度下干湿交替阶段的腐蚀速率是全浸没阶段的4~9倍;随着腐蚀时间的增加,腐蚀速率减小,并与时间呈幂函数关系;随着温度和盐度的增加,不同腐蚀方式下呈现出不同的腐蚀规律;干湿交替阶段以局部腐蚀和点蚀为主,腐蚀产物主要是FeOOH和Fe3O4;全浸没阶段以均匀腐蚀为主,腐蚀产物主要是FeOOH。

Tensioner is one of the core devices of submarine pipe-laying vessel.Its main function is to clamp the pipeline.Its corrosion causes huge potential safety hazards and economic costs.The corrosion laws of tensioner’s track steel(A)and base steel(B)under different corrosion modes(dry-wet alternation,full immersion),time,temperature and salinity were investigated by indoor simulated weightlessness experiments and electron microscope scanning.The results show that the corrosion resistance of A steel is better than that of B steel.The corrosion rate at different temperature in dry-wet alternation stage is 4-9 times higher than that in full immersion stage.With the increase of corrosion time,the corrosion rate decreases and has a power function relationship with time.With the increase of temperature and salinity,the steel show different corrosion laws in different corrosion modes.Local corrosion and pitting corrosion are the main corrosion phenomena in the dry-wet alternation stage,and the main corrosion products are FeOOH and Fe3 O4.Uniform corrosion is the main corrosion phenomena in full immersion stage,and the corrosion product is mainly FeOOH.