摘要
The specimens of 304 austenite stainless steel with the hydrogen attackbubbles or cracks were heat treated at 600 deg C for 6h. The SEM and TEM observations on thespecimens before and after the heat treatment showed that the bubbles or cracks could be healedcompletely by heat treatment. The healing of hydrogen attack bubbles or cracks is closely related toheat diffusion of Fe and C atoms in austenite. The driving force of crack healing results from theplastic deforming energy E_s induced by the growth of hydrogen attack bubbles or cracks. Thecritical condition of healing of bubbles or cracks is E_s >= 2 gamma/r (where gamma is the surfacetension, r is the radius of bubbles or half length of crack). During healing of the hydrogen attackbubbles or cracks, the recovery, polygonization and recrystallization of the sub-grain also occured.
The specimens of 304 austenite stainless steel with the hydrogen attackbubbles or cracks were heat treated at 600 deg C for 6h. The SEM and TEM observations on thespecimens before and after the heat treatment showed that the bubbles or cracks could be healedcompletely by heat treatment. The healing of hydrogen attack bubbles or cracks is closely related toheat diffusion of Fe and C atoms in austenite. The driving force of crack healing results from theplastic deforming energy E_s induced by the growth of hydrogen attack bubbles or cracks. Thecritical condition of healing of bubbles or cracks is E_s >= 2 gamma/r (where gamma is the surfacetension, r is the radius of bubbles or half length of crack). During healing of the hydrogen attackbubbles or cracks, the recovery, polygonization and recrystallization of the sub-grain also occured.
基金
Thanks are due to the National Natural Science Foundation of China(Grant No.59971011)
National Key Basic Research and Development Programme of China(No.G19990650) for financial support.
