Changing the interfacial composition of carbide and oxide precipitates and its effect on hydrogen trapping

Hydrogen trapping at metal/oxide and metal/carbide interfaces is changed by changing the interfacial composition. This has been exemplified for oxides before and will be extended to carbides in the present study for the case of the iron/vanadium carbide (VC) interface. VC has the sodium chloride structure with an equal number of C- and V-atoms on the (100) planes. It will be assumed that the carbide interface is a (100)-plane having a composition between the limiting cases with either 50% V and 50% C for excess carbon in iron or 50% V and 50% carbon vacancies for excess vanadium in iron. The latter will provide strong traps for hydrogen. For validating the simple model a modified interpretation of atom probe and thermal desorption data became necessary as discussed in the present work.

Prof. Dr. Reiner Kirchheim