Mechanism of Formation of Vanadium Carbide Layers on Carbon Steel by Powder Packed Method

Abstract

The effect of C content on the formation of V carbide layer on carbon steels by a powder packed method was investigated. The continuous duplex carbide layer consisting of an outer V₂C and inner V₆C₅ and V₈C₇ layers was formed on Fe-0.7C and Fe-0.3C (in wt.%), but it was discontinuous on Fe-0.1C. Internal carbide precipitates were observed within the matrix in Fe-0.3C and -0.1C. These precipitates in Fe-0.1C were disappeared after long treatment. The inner carbide layers were confirmed to grow inwardly, which suggests that VCl₂ gas can penetrate through the carbide layers to the steel substrate.