Corrosion Fatigue Crack Growth Behavior of Inconel 600 in High Temperature and High Pressure Water Environment
맹완영 , 강영환 , 남태운 , , Wan Young Maeng , Young Hwan Kang , Tae Woon Nam , S . Ohashi , T . Ishihara
Abstract
It is important to predict the corrosion fatigue crack growth rate of Inconel 600 for the structural integrity of nuclear power plants. In order to evaluate the corrosion fatigue crack growth rate of Inconel 600 in various applied load types, 3 different types of cracking loads which simulate corrosion fatigue, SCC and mixed mechanism of corrosion fatigue and SCC were applied to CT type Inconel 600 specimens in high temperature water at 290℃ with 4ppm dissolved oxygen concentration. There was synergistic effect on corrosion fatigue crack growth rate when mixed mode of SCC and corrosion fatigue load is applied to Inconel 600 specimens in the environment. The measured crack growth rate of the specimen to which mixed load were applied wsa faster than the predicted crack growth rate based on the superposition model. The increase in the crack growth rate indicates that there is sysnersistic interaction of fracture process at the growing crack tip which experiences mixed load of SCC and corrosion fatigue. So it is necessary to account for the synergistic acceleration of corrosion fatigue crack growth to predict the life of structural components of Inconel 600 alloys in corrosive environments.