The effect of Ti precipitates on hydrogen embrittlement of Fe-18Mn-0.6C-2Al-xTi twinning-induced plasticity steel

The effect of Ti precipitates on hydrogen embrittlement (HE) was investigated using Ti-free and Ti-bearing TWIP steels through slow tensile tests and thermal desorption analysis. Whereas Ti-free steel did not show the reduction in elongation by hydrogen charging, Ti-bearing steel revealed a great reduction in elongation, indicative of the low resistance to HE. During plastic deformation, hydrogen atoms migrated from grain boundaries and dislocations to twin boundaries for Ti-free steel and to the interfaces of Ti particles for Ti-bearing steel. The low resistance to HE of Ti-bearing steel was due to a ductile to brittle transition near hydrogen-trapped TiN particles.