The effect of TiC on the hydrogen induced ductility loss and trapping behavior of Fe-C-Ti alloys

The hydrogen trapping of TiC and its effect on hydrogen embrittlement is investigated for Fe-C-Ti alloys with variable carbon content. Two conditions are compared; an as-quenched and quenched and tempered state in which carbides are generated. The hydrogen impact is demonstrated by tensile tests on unstressed samples without and after in-situ hydrogen charging. Thermal desorption spectroscopy and hot/melt extraction are performed to understand the carbide trapping ability and interpret the observed tendencies. The results indicate a correlation between hydrogen trapped at dislocations and the embrittlement degree. Slightly modified thermal treatments allowed confirming the beneficial effect of TiC addition.