Q235钢在含硫酸盐还原菌海水中的腐蚀行为

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

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-740mV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.

In order to better reveal the mechanism of microbiological corrosion, the corrosion behaviors of mild steel Q235 in marine conditions with/without sulfate-seducing bacteria （SRB） were investigated via such electrochemical methods as the corrosion potential, the polarization curve, the electrochemical impedance spectrometry and the en- vironmental 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 th.e 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.