Mechanistic understanding on the fatigue cracking in fretting corrosion of alloy 690TT under partial slip regime in 100 ℃ and 290 ℃ water

This study comparatively investigated the fretting corrosion fatigue cracking of alloy 690TT under partial slip regime in 100 ℃ and 290 ℃ water. The results revealed that the occurrence of continuous dynamic recrystallization. The process at 290 ℃ was considerably faster resulting in smaller size of ultra-fine grained structure. The increase in the water temperature resulted in the transformation of the crack initiation mechanism from intrusion/extrusion theory to the low-angle dislocations boundary attack mode. Furthermore, an increase in water temperature resulted in corrosion overcoming the influence of mechanics in crack propagation. In addition, the relevant mechanisms were discussed.