X65管线钢及牺牲阳极材料在海水环境中的交流腐蚀行为研究

Research on AC Corrosion Behavior of X65 Pipeline Steel and Sacrificial Anode Materials in Seawater Environment

目前针对海洋环境下的管线钢及牺牲阳极交流腐蚀行为研究鲜有开展,为给海管交流腐蚀风险评判以及牺牲阳极在交流干扰下的消耗性能提供参考,通过交流腐蚀模拟试验研究了模拟海水环境中X65管线钢、铝合金和锌合金牺牲阳极在不同交流电流密度下的交流腐蚀行为。结果表明:施加交流干扰后,X65管线钢、铝合金牺牲阳极和锌合金牺牲阳极试样电位均发生负向偏移,且交流电流密度越大,偏移量越大;3种材料的腐蚀速率随交流电流密度的增大而增大,但铝合金的腐蚀速率远大于锌合金和X65管线钢;X65管线钢在0~30 A/m^(2)交流干扰下,呈现均匀腐蚀,当交流电流密度增大至100 A/m^(2)时,表面出现点蚀坑;铝合金在不同交流电流密度下的表面均会产生点蚀,而锌合金材料则以均匀腐蚀为主,海洋环境中锌合金的服役性能优于铝合金。

Currently,few studies have been conducted on the AC corrosion behavior of pipeline steel and sacrificial anodes in the marine environment.In order to provide a reference for evaluating the AC corrosion risk of submarine pipeline and the consumption performance of sac-rificial anodes under AC interference,the AC corrosion simulation test was employed to study the AC corrosion behavior of X65 pipeline steel,aluminum alloy and zinc alloy sacrificial anodes under different AC current densities in simulated seawater environment.Results showed that the potential of X65 pipeline steel,aluminum alloy sacrificial anode and zinc alloy sacrificial anode samples were negatively shifted after AC inter-ference was applied,and the greater the AC current density,the greater the offset.The corrosion rates of three materials increased with the in-crease of AC current density,but the corrosion rate of aluminum alloy was much higher than that of zinc alloy and X65 pipeline steel.Moreo-ver,X65 pipeline steel exhibited uniform corrosion under 0~30 A/m^(2) AC interference,and when the AC current density increased to 100 A/m^(2),pitting pits appeared on the surface.Aluminum alloy exhibited pitting corrosion on the surface under different AC current densities,while zinc alloy was mainly uniform corrosion.In the marine environment,the service performance of zinc alloy was superior to that of aluminum alloy.