Q235钢在含硫酸盐还原菌海水中的腐蚀行为

为了更好地揭示微生物腐蚀的机理,文中采用腐蚀电位法、极化曲线法、电化学阻抗法、环境扫描电镜法对低碳钢Q235在灭菌海水、接种硫酸盐还原菌(SRB)的海水中的不同腐蚀行为进行了研究.结果表明:在含有SRB的海水中,低碳钢的自腐蚀电位向负相有较大的偏移,最终在-740 mV左右逐渐稳定;与在灭菌海水中的腐蚀相比,低碳钢在含SRB海水中的腐蚀电流密度变大,极化电阻减小,腐蚀速度加快;经微生物腐蚀后,低碳钢表面出现了大量的腐蚀孔,发生了严重的孔蚀行为.

Corrosion Behaviors of Q235 Steel in Seawater Containing Sulfate-Reducing Bacteria

In order to better reveal the mechanism of microbiological corrosion, the corrosion behaviors of mild steel Q235 in marine conditions with/without sulfate-reducing bacteria (SRB) were investigated via such electrochemical methods as the corrosion potential, the polarization curve, the electrochemical impedance spectrometry and the environmental scanning electron microscopy. The results show that (1) due to the existence of SRB, the corrosion potential of Q235 steel in marine conditions rapidly shifts to the passive potential region until it is gradually stabilized at a value of about -740 mV; (2) in the marine condition with SRB, both the corrosion current density and the corrosion rate increase, while the polarization resistance becomes lower; and (3) after the microbiological corrosion, there forms a large amount of holes on the surface of Q235 steel, which shows the occurrence of heavy pitting corrosion.