Corrosion fatigue damage mechanism and life evaluation of Inconel Alloy 690TT steam generator tube in high temperature pressurized water. (March 2023) - Li, Z.H.
Abstract: Corrosion fatigue behavior of the actual Alloy 690TT steam generator (SG) tubes in high temperature water were systematically studied by using the designed boat-shaped specimen. Results demonstrated that the environmental fatigue correction coefficient of the SG tube in high temperature water was lower than that of round bar specimen in ANL model, which may be related to the internal surface oxide film rupture-persistent slip bands (PSBs) deformation zone preferential dissolution caused by the shape effect of SG tube. Moreover, the corrosion fatigue life of the actual SG tube was evaluated by the method of model correction. Highlights: The corrosion fatigue crack initiation mechanism was internal surface oxide film rupture-PSBs deformation zone dissolution. TiN inclusions caused a small amount of localized microcracks, but no inclusion-induced long crack propagation was found. The fatigue correction coefficient of the SG tube in high temperature water was lower than that of bar specimen in ANL model. The corrosion fatigue life of the SG tube was evaluated by the method of model correction. It was demonstrated for the first time that the boat-shaped specimen could evaluate the fatigue life of the complete SG tube.