Patent ID: 8365807
Filing Date: 2013-02-05
Classification: B22D

Abstract:
1. A method of reducing butt curl during direct chill casting of a metal ingot, which method comprises: casting a metal ingot in a direct chill casting mold in at least two casting stages including an initial casting stage carried out at a first casting speed and a steady-state casting stage carried out after said initial stage at a second casting speed higher than the first casting speed; advancing said ingot emerging from an exit of the casting mold along a direction of ingot advance; and cooling said ingot by directing a liquid coolant onto an outer surface of the emerging ingot; wherein, during said initial casting stage, said liquid coolant is directed onto at least a part of said outer surface in the form of at least two streams, including a constant first stream directed onto said at least part of said outer surface in the form of a series of first jets, and an intermittent second stream directed onto said at least part of said outer surface in the form of a series of second jets, wherein said first and second jets impact said at least part of said outer surface at locations of impact spaced from each other; and further wherein both said first and second streams of liquid coolant are arranged to have locations of impact and rates of flow effective to permit film boiling to take place within said streams when first in contact with said at least part of said outer surface.