New orientation relationship with low interfacial energy in MC/ferrite system observed in Nb-Ti bearing steel during isothermal quenching process

摘要

Here we report a new crystallographic orientation relationship (OR) between MC-type carbide (M = metal) and ferrite matrix, observed in the specimen held isothermally at 600 degrees C for 20 min, named NEU-OR. The 110 (c)(arbide)// 110 (ferrite) alignment is the main difference from the well-known Baker-Nutting (BN) OR. NEU-OR is related to BN OR by the relative rotation of 45 degrees about the zone axis of (110)(carbide). The interfacial energy between carbide and ferrite with NEU-OR is lower than that with BN OR based on semi-coherent dislocation theory, which benefits increases in the number density of precipitates. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.