Claims
- 1. Apparatus for direct casting of controlled thickness sheet from the melt on a chilled casting surface of the type comprising,
- a molten-metal-containing tundish including a backwall, opposed sidewalls and a floor therebetween and having the sidewalls and floor closely adjacent and contoured with the chilled casting surface such that a layer of molten metal is delivered over a lip on the tundish to the casting surface during casting,
- the lip being a portion of the floor adjacent the casting wheel and said lip including an offset away from the casting surface, thus allowing a longer solidification distance of the melt with the casting surface and a consequent thicker sheet in the vicinity of the offset,
- said lip offset being in the form of a continuously sloping convex surface inclined downwardly from the horizontal,
- whereas the angle formed between a horizontal line and a line tangent to the lip means at the point where the molten metal separates from the lip means is in the range of about 20.degree. to about 70.degree.and
- said lip means being configured to deliver said molten metal by gravity during continuous casting and with a change in flow direction of the molten metal from the point where the molten metal leaves the surface of the means forming the lip to the point said molten metal contacts the casting surface of in excess of about 55.degree..
- 2. The apparatus of claim 1 wherein the lip offset is of non-uniform depth from the tundish floor upper surface downward to a point above a lower surface of the tundish floor.
- 3. The apparatus for claim 2 wherein the lip offset spans substantially the entire width of the tundish between sidewalls.
- 4. The apparatus of claim 2 wherein the lip offset is of increasing depth from near the tundish sidewalls to near the center of the lip.
- 5. A method for providing a desired thickness contour across the width of a metal sheet which is cast on a chilled casting surface directly from the melt comprising,
- providing a tundish containing a pool of molten metal and including a backwall, opposed sidewalls, and a floor therebetween wherein the floor and sidewalls are closely adjacent and contoured with the chilled casting surface such that the casting surface forms a barrier contacting the molten metal pool,
- removing a portion of the floor adjacent the casting surface including a portion of an upper surface of the floor to form a lip having a downwardly sloping surface in the tundish, said sloping surface being adjacent the casting surface, thus allowing greater depth of contact of the melt with the casting surface to control the sheet thickness profile across its width,
- moving the casting surface through the melt pool thereby building a solidified layer of metal with the desired thickness contour of the casting surface,
- adjusting the tundish with respect to the casting surface whereby the angle between a vertical plane through the center of rotation of the casting surface and another plane through the center and the point of separation of molten metal from the lip is in the range of about 30.degree. to about 60.degree.and
- said lip means being configured to deliver said molten metal by gravity during continuous casting and with a change in flow direction of the molten metal from the point where the molten metal leaves the surface of the means forming the lip to the point said molten metal contacts the casting surface of in excess of about 55.degree..
- 6. The method of claim 5 including removing a uniform depth portion of the tundish floor upper surface to form said lip with a uniform convex profile between said sidewalls.
- 7. The method of claim 5 including removing a non-uniform depth portion from the tundish floor upper surface to form said lip with a non-uniform convex profile between said sidewalls.
- 8. The method of claim 5 including removing a portion of increasing depth from the tundish floor to form the lip of increasing depth from the sidewalls to near the center of the lip.
- 9. Apparatus for minimizing transverse ripples in a continuously cast metal strip comprising,
- a tundish for receiving molten metal and a cylindrical casting surface mounted in operative position adjacent the tundish to receive molten metal from said tundish,
- said tundish including a floor and vertically extending walls to hold molten metal and means forming a downwardly sloping convex lip in the floor adjacent the casting surface for delivering molten metal from said tundish to said casting surface over said lip means,
- said lip means being configured to deliver said molten metal by gravity during continuous casting and with a change in flow direction of the molten metal from the point where the molten metal leaves the surface of the means forming the lip to the point said molten metal contacts the casting surface of in excess of about 55.degree..
- 10. The apparatus of claim 9 wherein the lip means, in a cross-section perpendicular to said casting surface, defines a continuous convex curve.
- 11. The apparatus of claim 10 wherein the angle formed between a vertical line through the center of rotation of the casting surface and a line extending from said center of rotation to the point on the lip means where the molten metal separates from the lip means is greater than about 30.degree..
- 12. The apparatus of claim 11 wherein the angle formed between a horizontal line and a line tangent to the lip means at the point where the molten metal separates from the lip means is in the range of about 20.degree. to about 70.degree..
- 13. The apparatus of claim 9 wherein the angle formed between a vertical line through the center of rotation of the casting surface and a line extending from said center of rotation to the point on the lip means where the molten metal separates from the lip means is greater than about 30.degree..
- 14. The apparatus of claim 13 wherein the angle formed between a horizontal line and a line tangent to the lip means at the point where the molten metal separates from the lip means is in the range of about 20.degree. to about 70.degree..
- 15. The apparatus for claim 9 wherein the angle formed between a horizontal line and a line tangent to the lip means at the point where the molten metal separates from the lip means is in the range of about 20.degree. to about about .
- 16. The apparatus of claim 9 wherein said cylindrical casting surface includes circumferentially extending grooves.
- 17. The apparatus of claim 12 wherein said cylindrical casting surface includes circumferentially extending grooves.
- 18. The apparatus of claim 13 wherein said cylindrical casting surface includes circumferentially extending grooves.
- 19. The apparatus of claim 15 wherein said cylindrical casting surface includes circumferentially extending grooves.
Parent Case Info
This is a continuation-in-part of application Ser. No. 101,525, filed Sept. 28, 1987, now U.S. Pat. No. 4,749,024.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4715428 |
Johns et al. |
Dec 1987 |
|
4749024 |
Bartlett et al. |
Jun 1988 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
0147912 |
|
EPX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
101525 |
Sep 1987 |
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