CONTINUOUS CASTING METHOD AND INGOT PRODUCED THEREBY

摘要

A method for continuously casting an ingot (43) of a metal alloy of the type having a substantial liquidus-solidus temperature range so that the ingot (43) will have a ''smooth'' surface free of hot-tears. A succession of substantially equal volume quantities of the molten alloy is poured into a continuous casting mold at a pressure of less than about 10<-3> Torr. The quantity of each pour is sufficient to cover the entire cross section of the mold (33) by flow under the influence of gravity and each quantity is allowed to substantially solidify between pours to form successive axial increments which make up the ingot (43). Each increment is allowed to cool for at least about 30 seconds between pours to form a sufficiently solid side-wall (47) to prevent hot-tears. Heat is extracted between each successive pour increment adjacent the mold (33) to permit the ingot (43) being formed to be lowered in the mold (33) without hot-tearing the ingot side-walls while maintaining the entire upper surface of the immediately preceding increment at a temperature at which metallurgical bonding with the last increment can occur. Before each successive pouring, the partially formed ingot (43) is lowered in the mold (33) a distance substantially equal to the increment thickness.