Grain-interior corrosion and tensile performance degradation of 2XXX Al–Li alloy in an actual marine environment

Abstract

The actual marine corrosion behavior and tensile properties of 2195 alloy and 2297 alloy in T8 state were studied by means of marine environment outdoor xeposure testing. The cross-sectional and macro morphologies of the alloys after outdoor exposure for different times were analyzed. The results indicated that the alloys possessed poor marine-corrosion resistance and rapidly corroded in an actual marine environment. The grain-interior corrosion (GIC) was the main corrosion mechanism for 2195 alloy and 2297 alloy, leading a lot of corrosive holes. Moreover, the reasons for GIC was discussed through microstructure analysis. Additionally, the trend of tensile performance of both alloys during outdoor exposure to marine environment was also studied. It is found that the tensile properties of both alloys gradually degraded with the increase of exposure time due to the occurrence of corrosive holes. After exposure for 12 months, the tensile strength and yield strength of 2297 alloy declined more than these of 2195 alloy.

Keywords

• 2195 alloy
• 2297 alloy
• Marine environment
• Tensile properties
• Microstructure
• Corrosion characteristics