US3520353A

US3520353A - Casting moulds with corner plate coolant flow passages

Info

Publication number: US3520353A
Application number: US651227A
Authority: US
Inventors: Geoffrey Hoyle; Edward Martin Barrs
Original assignee: British Iron and Steel Research Association BISRA
Current assignee: British Iron and Steel Research Association BISRA
Priority date: 1966-07-06
Filing date: 1967-07-05
Publication date: 1970-07-14
Anticipated expiration: 1987-07-14
Also published as: DE1558183B1; GB1166052A; AT276647B; SE325999B

Description

CASTING MOULDS WITH CORNER PLATE COOLANT FLOW PASSAGES Filed July 5. 1967 July 14,1970 G. HOYLE ET A1.

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CASTING MOULDS WITH CORNER PLATE COOLANT FLOW PASSAGES Filed July 5, 1967 2 Sheets- Sheet 2 /N VEN TOPS Geoff-REY vHome EowARa mer/v @rms ATTORNEYS United States Patent Olce Patented July 14, 1970 3,520,353 CASTING MOULDS WITH CORNER PLATE COOLANT FLOW PASSAGES Geoffrey Hoyle and Edward Martin Barrs, Sheiield, England, assignors to The British Iron and Steel Research Association Filed July 5, 1967, Ser. No. 651,227 Claims priority, application Great Britain, July 6, 1966, 30,274/ 66 Int. Cl. B22d 27/ 04 U.S. Cl. 164-348 8 Claims ABSTRACT OF THE DISCLOSURE The disclosure concerns a mould for casting metal, the corners of the mould being obtuse angled and coolant flow means being provided on the exterior faces of the mould sides and corners.

This invention is concerned with improvements in and relating to moulds for casting and more particularly to casting moulds for use in conjunction with electroslag refining equipment.

According to one aspect of this invention there is provided a mould for casting metal comprising a plurality of side walls interconnected by corner plates to provide obtuse angle corners in the cast product and means for delivering a ow of coolant down the exterior faces of the side walls and a flow of coolant along the outer faces of the corner panels.

In order that the present invention may be well understood there will now be described two embodiments, given by way of example only, reference being had to the accompanying drawings in which:

FIG. 1 is a part sectional plan view on the line B-B of FIG. 2;

FIG. 2 is a part sectional elevation on the line A--A of FIG. l;

FIG. 3 is a transverse cross section of the walls of another embodiment of mould, and

FIG. 4 is a fragmentary elevation of one major wall of the mould of FIG. 3.

The mould, which is of conductive material, is here open ended and the cavity is defined by four walls 1 interconnected by corner plates 2 so that the transverse section of the mould and hence the cast product has obtuse angle corners for example 135. The mould unit at the lower end is surrounded by a trough 3 and at the upper end by a header 4 which has inwardly directed outlet apertures 5 to direct coolant, generally water, on to the exterior of the walls 1. The corner plates each in part define a coolant feed passage to pass coolant to the header from one of a pair of coolant inlet branches 6 coupled to an inlet pipe 7. An outlet 8 is coupled to the trough. In a modication of the mould shown in FIGS'. 1 and 2, the walls diverge in the downward direction of the mould so that the corner plates are trapezoidal.

In operation the mould is positioned on a suitable base and a slag powder is fed into the mould. An electrode of metal to be refined is fed down into the slag, and a conductive path is established through the electrode, slag and .the base or a second electrode. This causes slag to melt and then the electrode to melt. The molten metal passes down through the slag and forms a pool in the mould above the base.

As the metal is removed from the electrode the slag is progessively displaced upwards fby the metal accumulating in the mould, though a slag skin does form against the surface of the mould due to the chilling action of the mould wall. Freezing takes place progressively and at any time there is a comparatively small molten metal pool. On completion, the electrode is withdrawn and freezing continues until complete. The mould is then withdrawn from the casting.

Referring to FIGS. 3 and 4 there is shown a simplified embodiment of mould in which the coolant feed passages are replaced by a pair of spaced tins 9', each projecting outward from the junction of a wall 1' and a corner plate 2. A header 4 is provided surrounding the upper part of the mould with apertures as before for directing a spray on to the walls 1 and additional apertures for directing a spray on to the corner panels. The additional apertures are arranged, as by being of larger diameter, to give an increased flow of coolant at the corner panels and the apertures nearest the ns are angled not only to direct the coolant toward the corner panel face but also toward the adjacent iin to direct coolant into the angle defined by the fin and corner panel. The arrows 10 of FIG. 4 diagrammatically show the directions of the coolant lflow from the header at a corner panel.

The above described moulds provide these advantages:

(l) Because the mould has a taper, and because the four wide-face panels are rectangular, the four corner panels are trapezoidal. These corner panels would be diicult to cool =by direct spraying, especially if a large mould taper was employed, due to the fact that the falling curtain of water would not be wide enough at its base to cover the full width of the corner panels.

(2) It would be difficult to cool square tapering ingots having or radiused corners by spray cooling. Corner cooling is facilitated by making the mould corners at and by ensuring a large flow of water in this region. The method also ensures adequate cooling of the vertical corner welds where increased wall thickness gives slower heat transfer.

(3) By cutting off the ingot mould corners and by virtue of the thicker ingot slag skin produced at the corners due to the increased cooling, an ingot free from a sharp corner is produced. This minimizes any tendency towards segregation of elements in the casting at the columnar crystal junction within the corners.

We claim:

1. relatively thin walled mould for casting metal comprising:

(a) a plurality of relatively wide side walls;

(b) relatively narrow corner plates interconnecting said side walls -to provide obtuse angle corners in the cast product;

(c) means for delivering a ilow of coolant down the exterior faces of said side walls and for delivering a fiow of coolant along the outer faces of said comer plates, said means including a spray header;

(d) means for conveying coolant to said means (c);

and

(e) means defining corner plate coolant flow passages located at each junction of a side wall and a corner plate for restraining the coolant ow over said corner plates from passing onto said side walls.

2. A mould according to claim 1 in which each corner plate is trapezoidal and of increasing Width in the direction of the end which will be lowermost and said side walls are rectangular.

3. A relatively thin walled mould for casting metal comprising (a) a plurality of relatively wide side walls;

(b) relatively narrow corner plates interconnecting said side walls to provide obtuse angle corners in the cast product;

(c) spray header means having coolant discharge appertures for delivering a flow of coolant down the exterior faces of said side walls; and

(d) means cooperating with said corner plates to dene coolant feed passages for feeding coolant up said corner plates to said spray header means.

4. A mould according to claim 1, in which said restraining means comprises an outwardly projecting fin at each junction between a side wall and a corner plate and in which said means for delivering a ow of coolant along the outer faces of said corner plates comprises portions of said spray header associated with the corner plates, each said portion having discharge apertures, at least some of which are directed towards the corner plate and at least some of which are arranged to direct coolant into the angles formed between the corner plate and the associated ns.

5. A mould according to claim 3 in which said spray header means is a spray header extending about the uppermost part of said mould with which header each passage is connected.

6. A mould according to claim 4 in which said spray header extends about the uppermost part of the mould and has further portions associated with the side walls, said further portions having additional coolant discharge apertures for delivering the flow of coolant down the exterior faces of the side walls, at least some of the discharge apertures in the corner plate portions being of a larger diameter than said additional apertures.

7. A mould according to claim 1 in which said means for delivering a ow of coolant delivers a greater flow along the outer faces of the corner plates than down the exterior faces of the side walls.

8. A mould according to claim 2 in which said means for delivering a ow of coolant delivers a greater flow along the outer faces of the corner plates than down the exterior faces of the side walls.

References Cited UNITED STATES PATENTS 1,336,459 4/1920 Woodward 164--128 2,829,410 4/1958 Beaver. 1,936,280 ll/l933 Williams 164-348 X 2,479,191 8/1949 Williams et al. 249-79 3,448,790 6/1969 Maskall 249-79 X 2,851,750 9/1958 Schaaber 249-78 X 1,781,392 11/1930 Hultgren 249-80 FOREIGN PATENTS 276,210 8/ 1927 Great Britain. 764,015 12/1956 Great Britain.

ROBERT D. BALDWIN, Primary Examiner