Tritium (hydrogen) accumulation and release processes at MnS precipitates and surrounding α-Fe matrix area at room temperature were studied by means of T autoradiography using a pseudo-binary alloy of Fe–MnS. Hydrogen accumulation at the MnS precipitates at room temperature was clearly observed but only at a limited occasion. The process involves diffusion, solution and trapping in a complex way including a temperature effect. Tritium autoradiography proved to be a very good technique to obtain H area profiles in a near surface region, whereas it was only a snap shot at a particular time and temperature. It could lead to a totally different interpretation of the accumulation process without detailed dependences of H diffusivity and solubility in inclusion species and α-Fe upon temperature.

Hydrogen Diffusion and Trapping Process Around MnS Precipitates in α-Fe Examined by Tritium Autoradiography. T.Otsuka, T.Tanabe: Journal of Alloys and Compounds, 2007, 446-447, 655-9