US3228071A

US3228071A - Continuous-casting mold

Info

Publication number: US3228071A
Application number: US272594A
Authority: US
Inventors: Robert A Schultz
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1963-04-12
Filing date: 1963-04-12
Publication date: 1966-01-11
Anticipated expiration: 1983-01-11
Also published as: NL6403743A; ES297984A1; AT252478B; GB1019746A; BE646302A; DE1293959B

Description

Jan. 11, 1966 R. A. SCHULTZ CONTINUOUS-CASTING MOLD 2 Sheets-Sheet 1 Filed April 12, 1963 INVENTOR.

Q Q 6 .2 O O O O H. o o 1 o o m n 9 d L| Attorney United States Patent 3,223,071 CGNTINUQUS-CASHNG MUM Robert A. Schultz, Penn Hills Township, Allegheny County, Pa., assignor to United States Steel Corporation, a corporation of New Jersey Filed Apr. 12, 1963, Ser. No. 272,594 Claims. (ill. 22-512) This invention relates to a water-cooled mold suitable for the continuous casting of slabs and, in particular, to a prismatic mold having end walls adapted to come and go with the side walls thereof on thermal expansion and contraction.

The problems associated with molds for the continuous casting of steel slabs are well set forth in Goss Patent No. 2,893,080. A further source of difficulty is the possible opening of the joints between side and end walls of a mold made up of separate wall members, with the result that molten metal enters the opening and freezes therein.

I have invented an improved mold for the continuous casting of slabs which overcomes the aforementioned difficulties and has further advantages over molds previously known. In a preferred embodiment, I provide a mold having a pair or" base plates with supporting feet thereon and composed of side and end walls each of which includes an inner plate and an outer backing structure with a water-cooling passage therebetween. The inner plates are secured to the backing structures by attachments similar to flexible staybolts distributed over their area. The end walls are slidably mounted on the backing structures of the side walls and move with the inner plates thereof on expansion or contraction. I provide means for adjusting the end walls to a slight angle relative to the vertical, to provide a downward taper to the ends of the mold cavity.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating the present preferred embodiment. In the drawmgs:

FIGURE 1 is a side elevation partly in section;

FIGURE 2 is an end elevation partly in section;

FIGURE 3 is a horizontal section taken along the plane of line IIIIII of FIGURE 1; line 1-1 of FIGURE 3 indicates the plane on which the section of FIGURE 1 is taken;

FIGURE 4 is an enlarged portion of FIGURE 3;

FIGURE 5 is an enlarged portion through one of the attachments taken along the line V-V of FIGURE 3; and

FIGURE 6 is a fragmentary isometric view of one of the supporting feet.

Referring now in detail to the drawings, my improved mold, indicated generally at 18 is mounted on a pair of spaced supporting beams 11. The mold has spaced base plates 12 one resting on each beam 11. The spacing between the plates is governed by the width of the horizontal section through the mold cavity C. Feet 12a extend outwardly from plates 12. The feet of one of the plates 12 rest on blocks 12b bolted to one beam 11. Links 120 are pivoted to hearings on the bottom of the feet on the other plate 12 and to bearings mounted on the other beam 11.

Spaced opposed side-wall backing structures 13 are upstanding on plates 12. These structures are fabricated from steel plate and each comprises an outer plate 14 with vertical side flanges 15 and intermediate flanges 15a on the upper ends of which top plates 16 rest. Spaced horizontal webs 16a intersect flanges 15a and abut flanges 15. Gusset plates 17 (see FIGURE 6) extend outwardly from the lower ends of flanges 15 and the adjacent flange a to plates 12. The inner edges of plates 12, flanges 15 and plates 16 extend beyond outer plate 14 toward the mold cavity and a mold side-wall plate 18 of copper or the like is thereby spaced inwardly away from plate 14, leaving a cooling-water passage P therebetween. The edges of flanges 15 and top and

bottom plates

16 and 12 engaged by plate 18 have a gasket to seal this passage.

The sides of plate 18 extend beyond backing structure 13 and it is secured thereto by a plurality of attachments 19 like flexible staybolts distributed over the area thereof. The details of the staybolts are shown in FIGURE 5. As there shown, a block 20 brazed to the outer face of plate 18 forms a seat for the spherical head of a bolt 21 which is secured in its seat by a cap 22 screwed on the latter. Bolt 21 extends outwardly through a hole in plate 14 which is counterbored as at 23, to accommodate cap 22. The counterbore has a diameter slightly greater than that of the cap, except in the case of the bolts along the vertical center line of plate 18. A compression sleeve 24 is telescoped on bolt 21 and screwed into the hole. A spherical nut 25 is threaded onto bolt 21 and turned tightly against the outer end of the sleeve which is shaped to fit the nut snugly. A cap 26 is screwed on the outer end of sleeve 2- and both the cap and the inner end of sleeve 24 are provided with sealing gaskets.

It will be evident from the foregoing that staybolts 19 securely hold the mold side-wall plate 18 to backing structure 13 yet, by reason of their flexibility," permit movement of the former relative to the latter as necessitated by expansion and contraction. That is to say, plate 18 may expand and contract in its own plane but is held rigidly against movement from or toward backing structure 13. This eliminates bowing or buckling of plate 18.

Water boxes 27 are formed at the upper and lower corners of structure 13, as viewed in FIGURE 1, for introducing cooling water into space P and draining it there from. Thus top plates 16, which are directly exposed to the teeming stream of molten metal and base plates 12 which are exposed to the hot casting as it leaves the mold, are effectively cooled.

The end walls of the mold are generally similar in construction to the side walls and are clamped between the plates 18 of the latter. Each end wall has a backing structure Z9 and a mold-wall plate 36 of channel section sealed thereto with a cooling-water passage P therebetween. Stay-bolts l9 connect the plate to the backing structure. Cooling-water boxes similar to those shown at 27 are provided on backing structures 29.

The clamping of the side Walls to the end walls is effected by stud bolts 31. These bolts extend through bushings 32 adjustably secured in horizontal slots 33 in the side flanges 15 of backing structures 29 by bolts 34, and through horizontal slots 18a in the projecting side edges of plates 13. Bolts 34 are inserted through horizontal slots in the flanges 15 of structures 29. This permits the mold end walls to be tilted at a small angle to the vertical, to afford a slight downward taper to the ends of cavity C, and also allows variation in the spacing between opposite mold-Wall plates 30.

The bolts 31 also extend slidably through corner posts 35 of square-section tube and are provided with compression springs at their ends. Posts 35 fit in the dihedral angles between plates 18 and flanges 1S and are slidable on pins 36 fixed in backing structures 13 and projecting laterally therebeyond. As shown in FIGURE 1, top and bottom horizontal slots 13a have vertical clearance for bushings 32. Middle bushings 32 fit tightly into middle slots 18a to afford a fixed line from which vertical expansion occurs. Thermal-expansion stresses in plate 18 are further reduced by horizontal stress-relief slots 18b in the portions of plates 18 extending beyond side-wall backing structures 13.

The advantage of the mold of my invention is that, on expansion and contraction of side-wall plates 18, the endwall plates move with them and no relative movement therebetween occurs. Expansion of plates 18, furthermore, reduces the stress on backing structures 13 (which do not expand with plates 18') because staybolts 19, the only means securing the two together (except for friction at the edges of structures 13) permit the required range of movement between their ends, i.e., they have a quality of flexibility.

The end walls float relative to backing structures 13 by virtue of their slidable mounting on pins 36.

The taper of the end walls may be adjusted to the extent desired yet the joints between side and end walls are maintained closed under heavy pressure by stud bolts 31 and their springs.

Adequate provision is made for

cooling plates

18 and 30 thus expediting the formation of a solidified skin on the exterior of the casting.

Although I have disclosed herein the preferred embodiment of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

I claim:

1. A mold for continuous metal casting comprising a pair of opposed spaced side walls and a pair of opposed spaced end walls defining therebetween a cavity for the continuous formation of a metal casting, said side walls and said end walls each comprising an inner plate adapted to contact molten metal and a backing structure for said inner plate, the inner side wall plates extending laterally beyond the edges of the backing structures therefor, the side wall backing structures including outer plates spaced from the adjacent inner side wall plates so as to define passages for cooling water between the adjacent inner and outer plates, means sealing said passages along the edges of said outer plates, means securing said inner side Wall plates to the adjacent backing structures so as to permit expansion of said inner plates while preventing movement of said plates toward and away from the adjacent backing structures, and means for clamping the inner end wall plates between said inner side wall plates so that no relative movement between said end Wall plates and said side wall plates occurs as said side wall plates expand and contract.

2. A mold according to claim 1 in which said means securing said inner side wall plates to the adjacent backing structures comprises a plurality of staybolts distributed over the area of said inner side wall plates.

3. A mold according to claim 1 wherein said means for clamping said inner end wall plates includes guide pins extending from each side of each side wall backing structure parallel to the plane thereof, a corner post at each of the corners of said mold, said corner posts being slidably mounted on said guide pins, bolts extending parallel to the end wall plates between corner posts at the same end of said mold and permitting sliding movement of said posts With respect thereto, the end wall backing structures between said corner posts being adjustably secured to said bolts to permit expansion and contraction,

and means at each end of the mold urging the posts at the same end toward each other, whereby said inner end wall plates are immovably clamped between said inner side wall plates.

4. A mold for continuous metal casting comprising a pair of opposed spaced side walls and a pair of opposed spaced end walls defining therebetween a cavity for the continuous formation of a metal casting, said side walls and said end walls each comprising a plate adapted to contact molten metal and a backing structure for said plate, the side wall plates extending laterally beyond the edges of the backing structures therefor, the side wall backing structures including outer plates spaced from the adjacent side wall plates so as to define passages for cooling water between said outer plates and the adjacent side wall plates, means sealing said passages along the edges of said outer plates, a plurality of staybolts distributed along the areas of said side wall plates securing said plates to the adjacent backing structures so as to permit expansion of said plates While preventing movement of said plates toward and away from the backing structures, guide pins extending from each side of each side wall backing structure parallel to the plane thereof, a corner post at each of the corners of said mold, said corner posts being slidably mounted on said guide pins, bolts extending parallel to the end wall plates between corner posts at the same end of said mold and permitting sliding movement of said posts with respect thereto, the end wall backing structures between said corner posts being adjustably secured to said bolts to permit expansion and contraction, and means at each end of the mold urging the posts at the same end toward each other, whereby said inner end wall plates are clamped between said inner side wall plates so that no relative movement occurs therebetween as said inner side wall plates expand and contract.

5. A mold for continuous metal casting comprising a pair of opposed spaced side walls and a pair of opposed spaced end walls defining therebetween a cavity for the continuous formation of a metal casting, said side walls and said end walls each comprisng a plate adapted to contact molten metal and a backing structure therefor, and means for clamping said end wall plates between said side wall plates so that no relative movement occurs therehetween comprising guide pins extending from each side of, each side wall backing structure parallel to the plane thereof, means slidably mounted on said pins for supporting said end wall plates and backing structures therefor, and means for urging said side wall plates together thereby clamping said end wall plates immovably between said side Walls.

References Cited by the Examiner UNITED STATES PATENTS 2,283,450 5/1942 Mitchell et al. 22l46 2,510,100 6/1950 Goss 2257.2 2,747,244 5/ 1956 Goss 22-572 3,049,769 8/1962 Schultz 2257.2 XR

FOREIGN PATENTS 538,863 4/ 1957 Canada.

I. SPENCER OVERHOLSER, Primary Examiner. MARCUS U. LYONS, Examiner.

Claims

1. A MOLD FOR CONTINUOUS METAL CASTING COMPRISING A PAIR OF OPPOSED SPACED SIDE WALLS AND A PAIR OF OPPOSED SPACED END WALLS DEFINING THEREBETWEEN A CAVITY FOR THE CONTINUOUS FORMATION OF A METAL CASTING, SAID SIDE WALLS AND SAID END WALLS EACH COMPRISING AN INNER PLATE ADAPTED TO CONTACT MOLTEN METAL AND A BACKING STRUCTURE FOR SAID INNER PLATE, THE INNER SIDE WALL PLATE EXTENDING LATERALLY BEYOND THE EDGES OF THE BACKING STRUCTURES THEREFOR, THE SIDE WALL BACKING STRUCTURES INCLUDING OUTER PLATES SPACED FROM THE ADJACENT INNER SIDE WALL PLATES SO AS TO DEFINE PASSAGES FOR COOLING WATER BETWEEN THE ADJACENT INNER AND OUTER PLATES, MEANS SEALING SAID PASSAGES ALONG THE EDGES OF SAID OUTER PLATES, MEANS SECURING SAID INNER SIDE WALL PLATES TO THE ADJACENT BACKING STRUCTURES SO AS TO PERMIT EXPANSION OF SAID INNER PLATES WHILE PREVENTING MOVEMENT OF SAID PLATES TOWARD AND AWAY FROM THE ADJACENT BACKING STRUCTURES, AND MEANS FOR CLAMPING THE INNER END WALL PLATES BETWEEN SAID INNER SIDE WALL PLATES SO THAT NO RELATIVE MOVEMENT BETWEEN SAID END WALL PLATE AND SAID SIDE WALL PLATES OCCURS AS SAID SIDE WALL PLATES EXPAND AND CONTRACT.