Casting metals
AssigneeThe British Aluminum Company Limited
InventorRennie F. T. Wilkins
Life of this patent
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Abstract
Method and apparatus for the direct chill casting of non-ferrous metals comprising varying the chill depth of the mould independently of the level or quantity of liquid metal in the mould by relatively moving the mould and a "hot-top" which may be a sleeve of refractory material during casting. The invention also provides for semi-automatic and automatic casting.
Claims37
A method of direct chill casting of non-ferrous metals through a water cooled open mould having a mould wall and a rigid sleeve means of thermally insulating material which is movable within and relative to the mould wall in the direction of liquid metal flow to increase an overlap therebetween and in which, during the casting operation, liquid metal is supplied to the interior said rigid sleeve means, said sleeve means is moved and pressure is applied to a peripheral region of a pool of liquid metal in the mould so that the axial length of the mould wall in contact with the liquid metal is varied, independently of variations of the quantity of liquid metal within the sleeve means.
A method for the direct chill casting of non-ferrous metals through an open mould comprising the steps of:
- (a) providing an open bottomed annular mould having a vertical wall which surrounds a rigid sleeve of thermally insulating material movable within and relative to said wall in the direction of liquid metal flow to increase an overlap therebetween;
- (b) continuously supplying liquid metal to said mould and commencing withdrawing a partially solidified casting therefrom;
- (c) maintaining a pool of said liquid metal in said mould above a starter block, lowering the starter block with that part of the pool in contact with the vertical wall having a predetermined axial length at the start of casting, moving said rigid sleeve;
- and
- (d) applying downward pressure to that part of the pool in contact with the vertical wall during the casting operation to reduce said axial length to a value which is independent of the total depth of the pool within said rigid sleeve and is suitable for continuing the casting operation.
A method for the direct chill casting of non-ferrous metals through an open mould comprising:
- (a) providing an open bottomed mould having a vertical wall and a rigid sleeve of thermally insulating material slidable within said wall such that liquid metal cannot penetrate therebetween;
- (b) continuously supplying liquid metal to said mould and commencing withdrawing a partially solidified casting therefrom;
- (c) maintaining a pool of liquid metal in said mould;
- and
- (d) axially moving said sleeve relative to said wall to provide an overlap between the wall and sleeve to a predetermined value in the direction of liquid metal flow whereby the axial length of the mould wall in contact with the liquid metal is varied independently of variation in the level of liquid metal in said mould, said predetermined value being suitable for steady state casting conditions.
A method for the direct chill casting of non-ferrous metals through an open mould comprising the steps of:
- (a) providing an open mould having a vertical wall;
- (b) supplying liquid metal to said mould,
- (c) disposing a rigid sleeve of thermally insulating material within the upstream end of the mould and in spaced relationship to the vertical wall forming an annular gap between the vertical wall and the sleeve which allows the liquid metal to enter said annular gap;
- (d) applying gas under pressure to the upper end of said gap during the casting operation to vary the axial length of that part of the vertical wall in contact with the liquid metal in said annular gap independently of variations of the quantity of liquid metal within said sleeve.
A method for the direct chill casting of non-ferrous metals through an open mould comprising the steps of:
- (a) providing an open bottomed annular mould having a vertical wall surrounding a rigid sleeve of thermally insulating material movable within and relative to said wall in the direction of metal flow to increase the overlap therebetween;
- (b) continuously supplying liquid metal to said mould and commencing withdrawing a partially solidified casting therefrom;
- (c) maintaining a pool of said liquid metal in said mould above a starter block, lowering the starter block with that part of the pool in contact with the vertical wall having a predetermined axial length at the start of casting;
- (d) automatically varying the axial length of that part of the vertical wall in contact with liquid metal independent of the total depth of the pool within said rigid sleeve during the casting operation in the sense to reduce said length as the casting speed increases and to increase said length as the casting speed reduces.
Dependencies are inferred from the claim text.