NbC Precipitation Kinetics during and after γ/α Transformation of a Nb Microalloyed Steel

摘要

The precipitation kinetics of NbC carbide during and after γ/α transformation of a Nb microalloyed steel was investigated experimentally. The mole fractions of NbC precipitates formed at different isothermal temperatures were measured as a function of holding time by using the electrical resistivity method. The NbC precipitation happened during γ/α transformation and was closely related to ferrite transformation kinetics in the intercritical region while it occured in the bainite matrix after the bainitic transformation was almost done below bainite start (Bs) temperature.