The influence of water pollution and welding defects on MIC (microbiologically influenced corrosion) was studied. The open circuit potential (OCP) was measured during MIC test. It was found that OCP shifted to a highe...The influence of water pollution and welding defects on MIC (microbiologically influenced corrosion) was studied. The open circuit potential (OCP) was measured during MIC test. It was found that OCP shifted to a higher level when the system was inoculated with bacteria while the OCP of those samples in water without bacteria was kept at a low level. The OCP decreased dramatically when MIC started in polluted water. Combination of weld defect heat tint, polluted water and adding bacteria causes MIC happen at high rate. Some elements inside the tubercle were analyzed with EDXA. The pits and biofilm were observed with SEM. Microbiological analysis revealed the difference of bacteria between corroded and uncorroded samples.展开更多
The electrochemical corrosion behaviour of three Zr-Ag alloys (Zr-1Ag, Zr-3Ag and Zr-5Ag) was investigated. Open circuit potential, linear potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) ...The electrochemical corrosion behaviour of three Zr-Ag alloys (Zr-1Ag, Zr-3Ag and Zr-5Ag) was investigated. Open circuit potential, linear potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were employed in aerated artificial saliva (pH = 4.0) at 37°C. Silver alloying additions are found to be effective in enhancing the corrosion resistance of zirconium in artificial saliva environment. In fact, Zr-Ag alloys exhibit higher open circuit potentials, larger breakdown potentials and higher impedance values as compared to cp Zr. This behaviour can be ascribed to the formation of a thicker and more stable passive film with increasing compactness, able to provide better protection against the corrosion attack.展开更多
The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in ...The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in phosphate-buffered saline solution(PBS,pH=7.2)and in PBS simulating in vitro inflammatory conditions(PBS+H2O2,pH=5.0).It has been established that the tendency of the investigated steel materials towards corrosion de-creases in the following order:SAF 2101<SAF 2304<SAF 2205 in both ag-gressive environments.The superior corrosion resistance exhibited by SAF 2205 is ascribed to the formation of a passive film with enhanced protective effectiveness than the one formed on SAF 2101 and SAF 2304,and this im-provement is ascribed to a synergistic effect of Mo+N owing to the high mo-lybdenum content in the alloy.展开更多
文摘The influence of water pollution and welding defects on MIC (microbiologically influenced corrosion) was studied. The open circuit potential (OCP) was measured during MIC test. It was found that OCP shifted to a higher level when the system was inoculated with bacteria while the OCP of those samples in water without bacteria was kept at a low level. The OCP decreased dramatically when MIC started in polluted water. Combination of weld defect heat tint, polluted water and adding bacteria causes MIC happen at high rate. Some elements inside the tubercle were analyzed with EDXA. The pits and biofilm were observed with SEM. Microbiological analysis revealed the difference of bacteria between corroded and uncorroded samples.
文摘The electrochemical corrosion behaviour of three Zr-Ag alloys (Zr-1Ag, Zr-3Ag and Zr-5Ag) was investigated. Open circuit potential, linear potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were employed in aerated artificial saliva (pH = 4.0) at 37°C. Silver alloying additions are found to be effective in enhancing the corrosion resistance of zirconium in artificial saliva environment. In fact, Zr-Ag alloys exhibit higher open circuit potentials, larger breakdown potentials and higher impedance values as compared to cp Zr. This behaviour can be ascribed to the formation of a thicker and more stable passive film with increasing compactness, able to provide better protection against the corrosion attack.
文摘The electrochemical behaviour of three duplex stainless steels,(SAF 2101,SAF 2304,SAF 2205)was investigated.Open circuit potential,EOC,measurements,and electrochemical impedance spectroscopy(EIS)were employed both in phosphate-buffered saline solution(PBS,pH=7.2)and in PBS simulating in vitro inflammatory conditions(PBS+H2O2,pH=5.0).It has been established that the tendency of the investigated steel materials towards corrosion de-creases in the following order:SAF 2101<SAF 2304<SAF 2205 in both ag-gressive environments.The superior corrosion resistance exhibited by SAF 2205 is ascribed to the formation of a passive film with enhanced protective effectiveness than the one formed on SAF 2101 and SAF 2304,and this im-provement is ascribed to a synergistic effect of Mo+N owing to the high mo-lybdenum content in the alloy.
