Cooperative tests on crack initiation and crack propagation in stress corrosion environment

In order to ensure the safety of machinery and structures in corrosive environment, the development of corrosion resistant materials and the research on the techniques of evaluating materials in corrosive environment have been carried out. At present, the life due to crack development is discussed by fracture mechanics, and the evaluation of life in corrosive environment can be done with a certain degree of accuracy. In order to collect the unified data which become the base of life evaluation, the standardization of the testing method is desirable. This cooperative tests were carried out for the purpose of collecting the information on the life evaluation techniques in stress corrosion environment. As the object, the large LP turbine rotors for nuclear power generation were taken up, and the tests on the crack initiation and crack propagation were carried out. As the test environment, the accelerated test in 38% NaOH + 0.01% CuO aqueous solution on ASTM A470 3% Ni-Cr-Mo-V steel was carried out. The results are reported. (K.I.)