Stress corrosion crack of ZnAl15 alloys in hot and humid environment

Corrosion behavior of cold-drawn, stress-relieved and as-annealed ZnAl15 alloys in hot and humid environment was investigated. The results show that stress corrosion crack of ZnAl15 alloys occurred in hot and humid environment and the main corrosion products was ZnO with a small amount of Al(OH)3. The as-annealed and stress-relieved ZnAl15 alloys resulted in better corrosion resistance than the cold-drawn, especially the as-annealed. It implies that the residual stress from cold-drawing and the phase transformation stress from decomposition of supersaturated solid solution accelerated corrosion together during corrosion process.

► Stress corrosion crack of ZnAl15 alloys occurred in hot and humid environment
► The corrosion products were ZnO and Al(OH)3
► Residual stress and phase transformation stress accelerated the corrosion