Mathematical Model of Formation of Segregation Zone Caused by Volume Change in Solidification of Iron Alloys

Abstract

A mathematical model with special respect to peritectic transformation has been given on formation of negative segregation zone during uni-directional solidification of iron alloys. The model has been developed for the case of equilibrium solidification and nonequilibrium one.
The analysis predicts that solute-depleted band is formed in the vicinity of the section of area reduction. The reduction ratio of cross section and carbon concentration are suggested to influence the intensity of the segregation. It is concluded that the negative segregation is caused by mass flow of solute-rich liquid in the interdendritic region to feed solidification contraction.