1987 年 36 巻 404 号 p. 495-499
Hydrogen induced cracking and its fracture morphology have been studied for Ti-6Al-4V alloy with various microstructures. The susceptibility to hydrogen induced cracking and the crack propagation rate in air for delayed cracking were high for the mill annealed and β annealed specimens consisting of α+β microstructure. But the susceptibility and the propagation rate were low for the β quenched specimen consisting of α prime phase.
The characteristic fracture morphology of hydrogen induced cracking was terrace and wall type fracture, and it was related to the hydride precipitation behavior for any microstructure. The characteristic fracture morphology of delayed cracking was observed for the β annealed specimen consisting of packets of α phase, and it was fluted fracture showing tubular voids. The mechanism of formation of the morphology was discussed.