目的在铜表面制备聚吡咯涂层,研究其在3.5%(质量分数)Na Cl溶液中的耐腐蚀性能。方法采用恒电位法、恒电流法和循环伏安法在铜表面制备聚吡咯薄膜,用扫描电子显微镜观察聚吡咯膜形貌,用动电位极化曲线、长期浸泡实验研究铜表面聚吡咯膜的防腐蚀情况。结果三种方法都可以在铜表面形成结构致密、结合力较好的呈菜花状结构的聚吡咯膜。聚吡咯膜在3.5%(质量分数)Na Cl溶液中的极化曲线与空白铜不同,形成了钝化区。在60 min,0.659 V和60 min,1 m A条件下制备的聚吡咯膜的腐蚀电位与空白铜片相比,分别提高了约50 m V和150 m V,阳极溶解电流密度比空白铜片均降低了1个数量级。在长期浸泡实验中,带有聚吡咯膜的铜片的腐蚀速度低于空白铜片。结论聚吡咯膜可以延缓铜片的腐蚀,恒电位法制备的聚吡咯膜具有更优良的耐蚀性能。
The effects of sulphate-reducing bacteria(SRB)on the 2205 duplex stainless steel in the sea water and oil industry environments were studied by electrochemical impedance spectroscopy(EIS),potentiodynamic polarization and microorganism analysis.The results showed that the detected SRB was the non-spore bacillus of about 0.8μm×(1.8-2.2)μm in size and the content of S was about 7.59% in the corrosion products.SRB contributed to the corrosion evolution which caused the corrosion failure of 2205 duplex stainless steel pipe in the liquid hydrocarbon cooler.During the corrosion process,the produced H2S could significantly influence the anodic process and finally accelerate the corrosion.SEM observation indicated that the distribution of SRB on the surface of 2205 duplex stainless steel was nonuniform.X-ray photoelectron spectroscopy analysis revealed that the surface film was composed of Cr2O3,MoO3,FeS,FeS2,Fe(OH)2 and FeO after immersing the sample in the SRB medium for 14d.
