Insert for foundry moulds - esp. feeder head or thermally insulating hot top for metal moulds used for casting steel ingots

摘要

The insert or sleeve consists of a mixt. of sand; cellulose; at least one organic binder; and at least one expanding material (I) which does not sinter. Material (I) pref. constitutes by wt. 1-10% of the mixt. used to make the insert or sleeve. Material (I) is pref. graphite which expands by 9-40 times its initial vol., and esp. by more than 40 times its initial vol. Alternatively, material (I) is pref. expandable mica. The insert or sleeve provides the required thermal insulation at the top of a mould so proper feeding of the solidifying metal is obtd. without piping. But the presence of the graphite or mica ensures that the sleeve does not stick to the cast ingot, ie. the sleeve is easily removed.