Yu Fanghua. Investigation of interaction between hydrogen and defects in corrosion fatigue fracture process by positron annihilation[J]. Nuclear techniques, 1993, (6): 325-330.
Yu Fanghua. Investigation of interaction between hydrogen and defects in corrosion fatigue fracture process by positron annihilation[J]. Nuclear techniques, 1993, (6): 325-330.DOI:
Two fractured samples one corroded in artificial seawater and the other in air
have been investigated by positron annihilation spectroscopy. Both samples released hydrogen in the temperature regions from RT to 200℃ and from RT to 400℃
respectively. The results indicated that hydrogen enhanced fatigue defects and shielded from positrons localized in defects. From the deep points of the H- T and I2- T curves
it was discovered that hydrogen was released from grain boundary
dislocations and microvoids
respectively. In the first cracking stage grain boundary released more hydrogen than in the second stage. The interaction between hydrogen and microvoids made the volume and number of voids enlarge faster. The binding energies of hydrogen with grain boundary
dislocations and microvoids were estimated. The effect of hydrogen on corrosion fatigue fracture was discussed using da/dN-△K curve and SEM fracture appearance.