The microstructure evolution, transformation kinetics and especially the C enrichment during isothermal ferrite transformation at 800, 750, 700 °C for Fe-(1.5, 3.0) mass%Si-0.4mass%C alloys were investigated in the present study. Both transformation kinetics and C enrichment in austenite (γ) at grain boundary ferrite (GBF)/γ interfaces suggest that negligible partitioning local equilibrium (NPLE) mode operates during non-partitioned ferrite growth under the conditions investigated. Deviations of C enrichment in γ at Widmanstatten ferrite (WF)/γ interfaces from NPLE limit at early stages were observed. These deviations are deduced to be resulted from intrinsic interface mobility rather than solute drag effect. In addition, mobility of WF/γ interfaces is found to be lower than that for incoherent GBF/γ interfaces reported in literature.
ASJC Scopus subject areas