Effect of Thermal Treated Temperature on Localized Corrosion of G3 Alloy

The effect of thermal treatment temperature on localized corrosion of G3corrosion resistant alloy(CRA)was studied by SEM,SSRT and weight loss methods.The results show that G3CRA has excellent pitting corrosionresistance.The formation and dissolution of precipitates are the major factors influencing the pitting of G3alloy,thelarge number of precipitates can make considerable damage to the uniformity of the passive film,the susceptibility topitting increases.With the increase of thermal treated temperature,the formation of large amounts of precipitatesdeteriorates the protection of the passive film,and the crevice corrosion resistance becomes low.The crevice corrosionresistance was the lowest after annealing at 700 ℃ for 2h.When the allay was annealed at 900 ℃ for 2h,theprecipitates were enriched at local area as a result of re-crystallization and the crevice corrosion resistance of G3CRAwas improved.The fractures of G3CRA changed from ductile fracture to brittle fracture after annealing at 700℃for2h,and the susceptibility to stress corrosion cracking was significant increased.