Localized corrosion of LY12CZ under stress in chloride media
(1.北京市北京航空航天大学材料科学与工程学院
2.School of Material Science and Engineering, Beijing University of Aeronautics and Astronautics,Beijing 100083, China)
2.School of Material Science and Engineering, Beijing University of Aeronautics and Astronautics,Beijing 100083, China)
Abstract: Electrochemical methods were applied to investigate the corrosion behaviour of LY12CZ under applied stress in 3% sodium chloride aqueous solution. The experimental results indicate that LY12CZ shows two breakdown potentials on its polarization curve: one is related to the dissolution of the intermetallic particles and the other is related to the cracking of oxidation film and the dissolution of the matrix. When the stress is applied, it varies both breakdown potentials and makes the intermetallic particles and matrix dissolute at lower potentials. The relationship between the variation of the two breakdown potentials and applied stress was summarized. At the same time the influence of stress on the pitting and intergranular corrosion sensitivity of LY12CZ was also investigated. From the results it can be concluded that the stress can significantly affect the localized corrosion behaviour of LY12CZ in 3% NaCl solution.
Key words: LY12CZ; localized corrosion; intermetallic; applied stress; mechanochemical effect