A thermodynamic model of the Z-phase Cr(V, Nb)N

Precipitation of large Z-phase particles, Cr(V, Nb)N, replacing fine MX carbonitrides, Nb(C, N) or V(N, C), has recently been identified as a major cause for premature breakdown in long-term creep strength of a number of new 9%–12% Cr martensitic steels, especially the high Cr variants. A thermodynamic model of the Z-phase has been developed based on the regular solution model. The model predicts Z-phase to be stable and to fully replace the MX...