Study on the performance degradation of PH13-8Mo stainless steel in hot and humid marine atmospheric environment

The natural environment corrosion test of PH13-8Mo stainless steel was carried out in Hainan experimental station. The evolution law of performance degradation of PH13-8Mo stainless steel in hot and humid marine atmospheric environment was studied by macroscopic and microscopic corrosion morphology, corrosion rate, tensile properties and stress corrosion. The results show that pitting corrosion mainly occurs in PH13-8Mo stainless steel in hot and humid marine environment, and its performance decreases slightly. The maximum corrosion depth is 94 μm after three years of test. The change trend of corrosion depth of PH13-8Mo stainless steel with test time follows the power function relationship, and the corrosion rate during exposure is a slowing process. The results of mechanical properties showed that the tensile strength and percentage reduction of area of PH13-8Mo stainless steel decreased by 6.2% and 20.2% respectively after three years of test. The stress corrosion results show that the stress corrosion threshold K_ISCC of PH13-8Mo stainless steel is 85.6 MPa·m^1/2, and the stress corrosion cracking sensitivity coefficient is 0.98, which indicates that the material has strong resistance to stress corrosion in marine atmospheric environment.