EFFECT OF SOLIDIFICATION FRONT ANGLE ON FRECKLE FORMATION IN ALLOY 625

摘要

Freckle formation depends on solidification front angle in ingots. Freckles can be divided into two types; one is a solute-enriched liquid trail growing upward and the other is a solute enriched liquid trail growing downward. The effect of solidification front angle on upward type freckling alloy was reported by Sakurai et al. However there are few studies on the effect on downward type freckling alloys. In this study, the effect of solidification front angle on freckle formation was investigated using downward type freckling Alloy 625. Although freckle becomes difficult with decrease in the solidification front angle as expected, the effect on its solidification front angle was larger than that on upward type alloy A286. It is suggested that the difference is due to the freckle formation mechanism