Electrochemical impedance spectroscopy （EIS）, anodic polarization and scanning electron microscopy techniques were used to investigate the damage mechanism in the transpassive potential region of AISI 316 and AISI 3...Electrochemical impedance spectroscopy （EIS）, anodic polarization and scanning electron microscopy techniques were used to investigate the damage mechanism in the transpassive potential region of AISI 316 and AISI 316L solution-annealed stainless steels （SS） with different degrees of sensitization. Depending on the DC potential applied during EIS tests, the AC responses in the transpassive region included three different regions：the first one associated with anodic dissolution of the passive layer, the second one contributed to the disso-lution at the area near grain boundaries, and the last one attributed to pitting corrosion. In addition, the fitting results to experimental data showed that as the DC bias during the EIS test increases the charge transfer resistance （Rct） decreases. Moreover, the Rct values decreased as the sensitization temperature increases but the AISI 316L SS samples exhibited a higher resistance to intergranular corrosion than 316 SS samples.展开更多
The mechanical behavior of steel employed in the hull of a steel tank damaged by corrosion has been analyzed. The tank was used to filter a deep-water well for an 8-year period. Influence of porosity and dissolution o...The mechanical behavior of steel employed in the hull of a steel tank damaged by corrosion has been analyzed. The tank was used to filter a deep-water well for an 8-year period. Influence of porosity and dissolution of material may be introduced in the main constitutive relation adding a new damage variable C, which describes electrochemical damage. An elastoplastic theoretical model coupled to damage of a member, and other for damage related to thermodynamic energy are developed. This theoretical development has been used to analyze mechanical behavior of steel used in the body of a steel tank damaged by corrosion in water purifier plants, Eastern System, Mexico City, where three of every ten filters show excessive corrosion inside the steel plate filtration tanks. With samples taken from steel of the tank’s hull and reinforcement of false bottom supporting filtering material inside the tank, metallography tests were carried out;localized and generalized types of corrosion were determined, as well as the type of corrosion composites generated due to anticorrosive coating used inside the tank from its manufacturing.展开更多
文摘Electrochemical impedance spectroscopy （EIS）, anodic polarization and scanning electron microscopy techniques were used to investigate the damage mechanism in the transpassive potential region of AISI 316 and AISI 316L solution-annealed stainless steels （SS） with different degrees of sensitization. Depending on the DC potential applied during EIS tests, the AC responses in the transpassive region included three different regions：the first one associated with anodic dissolution of the passive layer, the second one contributed to the disso-lution at the area near grain boundaries, and the last one attributed to pitting corrosion. In addition, the fitting results to experimental data showed that as the DC bias during the EIS test increases the charge transfer resistance （Rct） decreases. Moreover, the Rct values decreased as the sensitization temperature increases but the AISI 316L SS samples exhibited a higher resistance to intergranular corrosion than 316 SS samples.
文摘The mechanical behavior of steel employed in the hull of a steel tank damaged by corrosion has been analyzed. The tank was used to filter a deep-water well for an 8-year period. Influence of porosity and dissolution of material may be introduced in the main constitutive relation adding a new damage variable C, which describes electrochemical damage. An elastoplastic theoretical model coupled to damage of a member, and other for damage related to thermodynamic energy are developed. This theoretical development has been used to analyze mechanical behavior of steel used in the body of a steel tank damaged by corrosion in water purifier plants, Eastern System, Mexico City, where three of every ten filters show excessive corrosion inside the steel plate filtration tanks. With samples taken from steel of the tank’s hull and reinforcement of false bottom supporting filtering material inside the tank, metallography tests were carried out;localized and generalized types of corrosion were determined, as well as the type of corrosion composites generated due to anticorrosive coating used inside the tank from its manufacturing.
