硫酸盐还原菌对铜合金腐蚀电化学行为的影响

A COMPARATIVE STUDY ON SULFATE REDUCING BACTERIA INFLUENCED CORROSION OF COPPER ALLOYS

用电化学方法研究了硫酸盐还原菌(SRB)生物膜对HSn70-1AB和BFe30-1-1铜合金腐蚀的电化学行为;用扫描电镜(SEM)和透射电镜(TEM)及X—射线能谱(EDS)分析了铜合金表面生物膜特征及其成分。结果表明,铜合金表面生物腐蚀与SRB的生长特性密切相关,SRB处于指数生长期时,HSn70-1AB和BFe30-1-1铜合金的自腐蚀电位(Ecorr)和极化电阻(Rp)均迅速下降,腐蚀加剧,且后者腐蚀速度大于前者;而当SRB进入稳定生长阶段,两种合金的Ecorr和Rp均缓慢下降,腐蚀速度减缓,且二者腐蚀速度接近。表面生物膜的特征也有较大区别,HSn70-1AB铜合金表面的腐蚀产物膜比较平滑,BFe30-1-1铜合金表面的腐蚀产物膜较粗糙;且后者表面膜中S含量高于前者,腐蚀倾向明显增强。

The growth characterization for sulfate reducing bacteria （SRB） under anaerobic condition was studied.Measurements of corrosion potential and the polarization resistance were used to investigate the electrochemicalbehavior of HSn70-1AB and BFe30-1-1copper alloys in medium containing sulfate reducing bacteria.The resultsshow that the biological corrosion of copper alloys is closely related to growth characterization of SRB. The corro-sion potential and the polarization resistance of electrode for copper alloys drastically moved toward negative di-rection as the SRB was in the logarithm phase,corrosion rate increased rapidly.While both o! them would slowly drop down as SRBwas in the logarithm phase, corrosion rate increased rapidly.While both of them would slowlydrop down as SRB entered into stable growth stage,corrosion rate also descreased.Scanning electron microscopy（SEM）and X-ray energy dispersive spectrometer （EDS） were respectively used to analyze the morphology andchemical composition of the biofilm. The results showed that biofilm characterization formed on the copper alloyssurface were totally different.