Quantifying the solute drag effect of Cr on ferrite growth using controlled decarburization experiments

The effect of Cr on the kinetics of ferrite growth from austenite was studied using the technique of controlled decarburization over the temperature range 850 degrees C to 775 degrees C. At 850 degrees C, the observed ferrite growth kinetics is in excellent agreement with the predictions of the local equilibrium negligible partition (LENP) model. At temperatures below 850 degrees C, the growth kinetics becomes increasingly slower than the predictions of the LENP model. This was interpreted in terms of the solute-drag effect of Cr, and the cross-boundary diffusion coefficient of Cr was estimated.