Evaluation of the Effect of TiC Precipitates on the Hydrogen Trapping Capacity of Fe-C-Ti Alloys

Abstract

The present work evaluates the hydrogen trapping behavior of different laboratory cast generic Fe-C-Ti martensitic alloys. Titanium carbides were precipitated in the materials by well-designed heat treatments. A quenched and tempered martensitic matrix with final strength above 1000 MPa was aimed for and verified by means of hardness measurements. Tempering allowed generating precipitates with different characteristics in terms of coherency, size and distribution due to the secondary hardening effect, as was evaluated by transmission electron microscopy. The hydrogen trapping capacity of the TiC precipitates was investigated by thermal desorption spectroscopy, while melt extraction was performed to determine the amount of hydrogen present after cathodic hydrogen charging. Generally, it could be concluded that the incoherent particles in the quenched material were not able to trap hydrogen, whereas the quenched and tempered material trapped hydrogen at the interface of small probably coherent TiC.

The impact of hydrogen on the ductility loss of bainitic Fe–C alloys

“…The specific interaction between the hydrogen-trapping capacity and carbideforming elements has been evaluated as well before. [35][36][37][38][39][40] In this study, the complex microstructure of industrial steels was avoided by focusing on a specific microstructural component which was induced in lab-cast generic Fe-C alloys by a well-designed thermal cycle. Two bainitic microstructures, induced in alloys with variable carbon content, were evaluated for their interaction with hydrogen.…”

“…The specific interaction between the hydrogen-trapping capacity and carbide-forming elements has been evaluated as well before. 35–40…”