EFFECTS OF SC ON CORROSION AND STRESS CORROSION CRACKING BEHAVIOR OF SC MODIFIED 304L AUSTENITIC STEEL IN HIGH TEMPERATURE WATER ENVIRONMENT

抄録

In the current work, several newly developed austenitic stainless steel with minor additives Sc have been developed based on quantum chemical molecular dynamics method and density functional theory. The oxide films formed on the alloys surface in BWR and PWR environment are characterized by SEM, Raman spectroscopy, and XPS. The effect of Sc addition on the SCC behaviour of modified 304L in PWR and BWR environment were investigated by using SSRT technique, and the SCC susceptibility of the Sc added new alloys in high temperature water are evaluated. It is found that the Sc additive can reduce the thickness and defect density of the oxide film compared with the reference alloys. SCC tests show that the additives can also decrease the SCC susceptibility in terms of lower SCC fracture area ratios and higher strength. The SCC resistance decreased with Sc addition increasing. Sc seems to be most effective with the amount of 0.05%-0.1% for 304L. The new alloys seem promising for retarding both oxidation and SCC in high temperature water environment.