船用Q235碳钢的海洋微藻附着诱导微生物腐蚀特性

Microbiologically Influenced Corrosion Characteristics of Marine Q235Carbon Steel Induced by Attachment of Marine Microalgae

研究了在含三角褐指藻的人工海水(含藻海水)中,循环光照12h/黑暗12h、光照、黑暗条件下船用Q235碳钢的腐蚀行为,以及腐蚀7d后的电化学性能,并与无藻海水中的进行了对比,分析了三角褐指藻的生命活动对碳钢腐蚀行为的影响。结果表明:在含藻海水中,光照条件下,氧气的去极化反应占主导,碳钢表面发生点蚀,腐蚀产物主要为γ-FeOOH;黑暗条件下,CO2腐蚀导致碳钢表面发生均匀腐蚀,腐蚀产物主要为FeCO3;循环光照12h/黑暗12h条件下两种腐蚀方式共同作用,腐蚀产物由γ-FeOOH、Fe3O4和FeCO3组成;与在无藻海水中浸泡7d后的相比,在含藻海水中,不同光照条件下浸泡7d后,碳钢的电荷转移电阻减小,自腐蚀电流密度增大。

The corrosion behavior of marine Q235carbon steel in artificial seawater with Phaeodactylum tricornutum(seawater with algae)under cyclic light 12h/dark 12h,continuous light,and continuous dark conditions,and the electrochemistry performance after corrosion for 7days were studied,compared with that in the seawater without algae.The effects of the life activity of Phaeodactylum tricornutum on the corrosion behavior of carbon steel were analyzed.The results show that in the seawater with algae,the depolarization reaction of oxygen was dominant under continuous light condition,resulting in pitting on the carbon steel surface,and the corrosion product wasγ-FeOOH.Under the condition of continuous dark,carbon dioxide corrosion caused uniform corrosion of Q235carbon steel surface,and the corrosion product was FeCO3.The two types of corrosion methods were combined under the cyclic light 12h/dark 12hcondition,and the corrosion products consisted ofγ-FeOOH,Fe3O4 and FeCO3.In the seawater with algae,the charge transfer resistance of carbon steel decreased and the selfcorrosion current density increased after immersion under different light conditions for 7days,compared with that in the seawater without algae.