Work

Hydrogen uptake of Ti64 and surface–nitrided Ti64 in flowing pressurized water at 300 °C

Year: 2026

Type: article

Abstract: The exposure of Ti64 and surface-nitrided Ti64 in flowing simulated primary water at 300 °C led to hydrogen absorption. Although the corrosion rates of the two materials were similar, the hydrogen uptake was much higher for nitrided Ti64. At a fluid speed of 7 m·s −1 , 1-mm thick nitrided Ti64 samples absorbed 380 wt·ppm within 72 days, which corresponds to more hydrogen than the production due to the reduction of water associated with the oxidation of the nitrides. The transport of hydrogen across the TiO 2 /Ti interface was proposed to be the rate-limiting step in the hydrogen uptake of untreated Ti64. For nitrided Ti64, the presence of Ti 2 N facilitated hydrogen absorption: lower energy barriers or higher hydrogen solubility in the nitrides are possible explanations. At ambient temperature, hydrides were observed for both studied materials but hydride-induced embrittlement was significant for nitrided Ti64 only, as its hydrogen absorption was higher.

Source: Nuclear Materials and Energy

DOI: 10.1016/j.nme.2026.102114