Structural Diagrams and Solid Phase Reactions of the Quaternary 7%Cr-Fe-C-N System

Abstract

The isothermal diagrams of the 7%Cr-Fe-C-N system were examined at various temperatures between 1300° and 700°C in the range of compositions up to 0.34% carbon and 0.25% nitrogen. In consideration of the phase relationship, the phase reaction of the 7%Cr-Fe-C-N system was made clear and the sectional diagrams were constructed at fixed contents of 0.05, 0.1 and 0.2% nitrogen. In the Fe-Cr-C-N system, it was assumed that two quaternary peritecto-eutectoid reactions (γ+Cr₂₃C₆\ ightleftarrowsα+Cr₇C₃+Cr₂N and γ+Cr₂N\ ightleftarrowsα+Cr₇C₃+CrN) exist at about 780° and 770°C, respectively.