Crystallography, orientation relationships and growth behaviour of TiC in wear-resistant steel

Abstract

Morphology, growth behaviour and formation mechanism of TiC and its heterogeneous nucleation effect on ferrite in TiC-reinforced wear-resistant steel were theoretically and experimentally investigated. The dimensionless entropy of fusion (Δ Sm/ R) of TiC is calculated to be 2.9, suggesting that TiC exhibits faceted morphology. The size of TiC is about 0.9 μm after solidification according to the kinetic calculations of TiC particle growth, which is consistent with the size of the TiC observed in the experimental steel. Combined with the calculated planar disregistry between TiC and ferrite using the Bramfitt mode and their actual Kurdjumov–Sachs orientation relationship examined by using an EBSD (electron backscatter diffraction) technique, it indicates that TiC can serve as a preferred heterogeneous site for ferrite during solidification. GRAPHICAL ABSTRACT