Quantifying the Solute Drag Effect on Ferrite Growth in Fe-C-X Alloys Using Controlled Decarburization Experiments

The kinetics of ferrite growth in the Fe-C-Co and Fe-C-Si systems has been quantified using controlled decarburization experiments. The Fe-C-Co system is a particularly interesting system since a large range of Co contents can be considered providing a suitable data set for examination of the composition dependence of the solute drag effect. Six Fe-C-Co alloys containing Co from 0.5 to 20 pct have been considered. Three Fe-C-Si alloys have also been considered and each has been transformed at three temperatures proving a suitable data set for examining the temperature dependence of the solute drag effect. This data set, along with ferrite growth data from decarburization experiments on an Fe-C-2Cr alloy has been used to test the ferrite growth model proposed in the companion article by Zurob et al. It is shown that this model for ferrite growth, that includes diffusional dissipation due to interaction between the solute and the migrating boundary, quantitatively captures both the temperature and composition dependence of the deviation of experimental ferrite growth kinetics from the PE and/or LENP models.