Macrosegregation Caused by Interdendritic Liquid Flow during Solidification of Iron Alloys

Abstract

An analysis is given of solute segregation in solidified samples caused by interdendritic mass flow of solute-rich liquid to feed solidification contraction. Calculations are presented for solidification of Fe-C-P ingot with an abrupt change of cross-sectional area. Noticeable solute-depleted bands with sharp peaks are predicted to form in the vicinity of the section of area reduction. The severe segregation peak is calculated to be produced with the large area reduction.
To clarify the mechanism of formation of negative segregation a series of experiments of uni-directional solidification has been done. A clear negative segregation has appeared in the solidified sample. Extent of segregation is larger for phosphorus than carbon. Reasonable agreement of prediction of the model with the experiment has been obtained.