Influence of heat treatment on tritium distribution in V–4Cr–4Ti alloy

Correlation between hydrogen distribution in V–4Cr–4Ti alloy and impact strength

“…Bands of tritium-accumulated regions are clearly observed along the rolling direction. It is known that these bands of tritium-accumulated regions correspond to the areas where precipitates consisting of Ti, C, N and O are densely distributed [8,9]. Namely, hydrogen isotopes are trapped in/around the precipitates.…”

“…The specimens fabricated under different conditions, however, should have different microstructures, and consequently different distributions of hydrogen. Indeed, the present authors have found by tritium radioluminography that distribution of hydrogen in a V-4Cr-4Ti alloy is strongly affected by that of precipitates consisting of Ti, C, N and O [8,9]. Therefore, it is necessary to understand the correlation of microstructure, hydrogen distribution and susceptibility to hydrogen embrittlement.…”

“…Tritium diluted by deuterium (T/D = 5.6 Â 10 À3 ) was introduced into the specimen by gas absorption method using vacuum apparatus at 673 K in the manner described elsewhere [9]. The total concentration of hydrogen isotopes (D and T) was adjusted to be 100 or 1500 appm.…”