Unraveling the key factors affecting grain growth kinetics of ferrite in low carbon steel: An analytical modeling approach

This study investigates the effects of cementite particle size and coarsening on ferrite grain growth kinetics in low carbon steel through annealing at 650 °C and analytical modeling. Two thermomechanically processed sample sets exhibited similar initial ferrite grain sizes but different cementite sizes, with smaller particles leading to a grain growth rate increase of up to 58% and a characteristic two-stage growth. Modeling indicates that precipitate pinning and solute drag influence grain growth; however, the dominant factor is the variation in the grain growth proportionality constant, strongly governed by the cementite coarsening rate. This work advances understanding by quantitatively linking cementite microstructural evolution to ferrite grain growth, addressing a gap in analytical modeling of this process.