Crack Healing of Hydrogen Attack in Carbon Steel by Heat Treatment

The experiment is aimed at obtaining the result of Crack healing of hydrogen attack (HA) in carbon steel. The recovery method used is heat treatment. Through SEM, it is Observed that HA cracks have gotten different healing effects. The results indicate that the HA CraCks with 10um length can be healed completely by five-times circle heat treatment between normal temperature and 1000 for 10h. The studies show that cracks healing are controlled by heat diffusion and the recovery kinetics is source from the plastic deforming energy E_s, which is formed during the growth of HA bubbles or cracks. These findings of the research have led to the conclusion that the critical condition of healing bubbles or cracks is the Plastic deforming energy Es mere than the surface tension force of HA bubbles or cracks if the atoms of H, C, Fe can diffused rapidly.