Inclusion Distribution in Ingots of Rare Earth Inoculated Steels.

摘要

In this study,consideration has been given to inclusion segregation in 15and 5 cwt,Rare Earth element doped mild steel ingots. The presence of bottom cone macro-segregates in these systems has been confirmed,and a mechanism has been advanced to account for their formation. It is suggested,furthermore,that is mechanism will operate for the case of all refractory inclusion species in steel,be they the products of deoxidation,sulphide modification or some other treatment. A significant finding is that the form and extent of the bottom cone is a sensitive function of the ingot size. On a microscopic scale,the clustering and aggregation of the Rare Earth element -rich inclusions is thought to result directly from the mode of solidification of large ingots. Methods which might avoid or alleviate inclusion clustering and bottom cone segregation are briefly discussed.