Effect of Alloying Elements on Macrosegregation of Super Clean CrMoV Steel

In order to clarify the mechanism of extensive segregation observed in modified, super clean CrMoV steel forgings for power industry applications ; the effect of such elements as Mn, Ni, Cr and Mo on segregations were studied ; using 8 ton sand mold ingots and unidirectionally solidified experimental ingots. As the result, it was found that heavy carbon segregations and "A" segregations with opposite inclining angle in Mo rich and Mn, Ni poor steels formed by the sinking of markedly segregated heavy liquid because of small partition coefficient and heavy density due to high δ solidification ratio. Therefore, chemistry and ingot shape design have been developed and applied to actual ingots, resulting in relatively small segregations.