Heterogeneous nucleation of M2B-type borides (M = Cr, Fe) attached to TiB2 and Ti(C,N) particles in as-cast high borated steel

Abstract

Here we for the first time reported the heterogeneous nucleation of orthorhombic M2B-type borides (M = Cr, Fe) attached to TiB2 and Ti(C,N) particles with a specific crystallographic orientation relationship (OR) in as-cast boron-containing steel. The ORs were identified as 0001TiB2∥1¯12¯M2B, 12¯10TiB2∥311¯M2B and 001TiCN∥136¯M2B, 100TiCN~∥31¯0M2B. The transmission electron microscopy characterization and lattice misfit calculation showed that the interfaces of TiB2/M2B and Ti(C,N)/M2B were semi-coherent. The heterogeneous nucleation efficiency was investigated in terms of an interfacial energy calculation based on the misfit dislocation theory.