A New Systematic Approach Based on Dilatometric Analysis to Track Bainite Transformation Kinetics and the Influence of the Prior Austenite Grain Size

This investigation explores the influence of austenitisation heat treatment and thus, prior austenite grain size (PAGS), on kinetics bainitic transformation, using as A case study two high-carbon, high-silicon, steels isothermally transformed (TIso = 250, 300, 350 °C), after being austenised at different temperatures (γTγ 925–1125 °C). methodology, based three defining dilatometric parameters extracted from derivative relative change in length, was proposed to analyse transformation kinetics. These are related time start lapse for most take place rate end transformation. The results show that increasing PAGS up 70 µm leads an increase bainite nucleation rate, this effect more pronounced lowest TIso. However, overall seems be weakly affected by applied TIso). In one steels, > 1050 which affects progress except TIso 250 °C, enhancement autocatalytic could reason behind acceleration