IN SITU TEM OBSERVATION OF SCC IN 310 STAINLESS STEEL
310奥氏体不锈钢应力腐蚀的透射电镜原位观察

The in situ TEM observations of dislocation emission, motion and the initiation of nanocrack in 310 stainless steel in water were carried out. Using a special constant deflection device,the dislocation configuration change ahead of a loaded crack tip before and after anodic dissolution in the the deionized water and the initiation, propagation of nanometre scale stress corrosion cracks have been oberved. The results showed that SCC in thin foil specimen of 310 stainless steel can occur in water.The localized anodic dissolution of 310 stainless steel in water at room temperature facilitated dislocation emission, multipication and motion. A nanocrack initated in the DFZ or at the blunted crack tip in corrosion solution after dislocations emission, multiplication and motion reached critical condition. Because of the influence of the corrosion solution, the nanocrack propagates and forms a cleavage microcrack during stress corrosion instead of blunting into a void as it does during a tension test without solution.