In this work, the microbiologically influenced corrosion (MIC) behaviors of welded 304L stainless steel (304L SS) and Cu-bearing 304L SS (304L-Cu SS) in a Pseudomonas aeruginosa culture medium were comparatively studied. Open circuit potential (OCP), linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization were employed to characterize the corrosion behavior of the (welded) steel substrates. The biofilm morphology and the live/dead staining condition of the sessile cells were observed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). And the pitting corrosion was investigated with a 3D mode of CLSM. The experimental results showed that the copper (Cu) addition had no obvious influence on the microstructure of 304L SS in welding zones (WZs) and base metal. The WZs of 304L SS and 304L-Cu SS in sodium chloride solution possessed a lower pitting potential and a higher corrosion current density. However, owing to the continuous release of Cu ions, inhibiting the excretion of corrosive extracellular polymeric substances (EPSs) and the extracellular electron transport (EET) process, both the localized and uniform corrosion attack induced by the P. aeruginosa biofilm was significantly reduced. In comparison with that of 304L SS, the corrosion resistance of 304L-Cu SS in the WZ against P. aeruginosa was obviously higher.

在这项工作中，微生物对304L不锈钢（304L SS）和含铜304L SS（304L-Cu SS）的腐蚀（MIC）行为产生了影响。 铜绿假单胞菌培养基进行了比较研究。使用开路电势（OCP），线性极化电阻（LPR），电化学阻抗谱（EIS）和电位动力学极化来表征（焊接）钢基材的腐蚀行为。通过扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）观察了固着细胞的生物膜形态和活/死染色情况。用CLSM的3D模式研究了点蚀。实验结果表明，铜（Cu）的添加对焊接区（WZs）和母材中304L SS的组织没有明显影响。304L SS和304L-Cu SS在氯化钠溶液中的WZ具有较低的点蚀电位和较高的腐蚀电流密度。然而，铜绿假单胞菌生物膜明显减少。与304L SS相比，WZ中304L-Cu SS的耐腐蚀性铜绿假单胞菌 明显更高。