Formation of Macrosegregation during Uni-directional Solidification of Iron Alloys

In order to clarify the mechanism of formation of negative segregation zone, an experimental study has been done on uni-directional solidification of iron with carbon contents of 0.09 to 0.25% and the solidification rate of about 6mm/min. Melting and solidification of iron were done in crucibles with an abrupt change of cross-sectional area. Solute-depleted band is formed in the vicinity of the section of area reduction. Extent of negative segregation is larger for phosphorus than carbon. Reasonable agreement of prediction of the model with experiment has been obtained.