Shroud for billet casting

Patent metadata

Field	Value
Publication number	US-11148192-B2
Application number	US-201916601973-A
Country	US
Kind code	B2
Filing date	Oct 15, 2019
Priority date	Jun 21, 2016
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

Methods of billet casting are provided herein. The methods may include the steps of assembling a billet caster with a shroud extending from a tundish to above a mold such that the shroud does not reach molten metal in the mold, delivering molten metal from a ladle into the tundish, delivering molten metal from the tundish through the shroud to the mold, the shroud inhibiting contact between the molten metal and air, casting the molten metal into billets in the mold and cooling the billets below the mold with a coolant spray, and delivering the cooled billet to a runout table to be cut to length.

First claim

What is claimed is:

1. A system for billet casting, the system comprising:
a shroud and a mold, the shroud comprising an upper portion, a lower portion, and an open bottom, the upper portion and the lower portion define an enclosed passage within the shroud wherein the upper portion forms a nozzle with a nozzle passage extending to the lower portion, the nozzle passage comprising a first nozzle end at a first end of the upper portion and a second nozzle end near the lower portion where the enclosed passage of the lower portion has a larger diameter than the nozzle passage of the enclosed passage at the second nozzle end near the lower portion;
wherein the shroud extends from a tundish to above the mold for pouring a stream of molten metal within the shroud and configured to deliver the molten metal from the shroud to above a meniscus of the molten metal in the mold to inhibit contact between the molten metal and air; and
wherein the shroud is maintained above the mold and does not contact the molten metal in the mold when the molten metal is delivered to the mold.

2. The shroud of claim 1 where the enclosed passage is tapered from a first shroud end at the upper portion to a second shroud end at the lower portion, opposite the first shroud end, and where the passage at the first shroud end is larger than the passage at the second shroud end.

3. The shroud of claim 1 where the enclosed passage is not tapered.

4. The shroud of claim 1 that is formed of a refractory material.

5. The shroud of claim 4 where the refractory material is an alumina-based material.

6. The shroud of claim 4 where the refractory material is encased by a metal casing.

7. The shroud of claim 4 where the refractory material has a variable thickness.

8. The shroud of claim 6 where the metal casing has a thickness of 1.5 mm.

9. The shroud of claim 1 where the upper portion is located above the lower portion and the upper portion is formed of a material different from the lower portion.

10. The shroud of claim 9 where the upper portion comprises a pressed silica outer portion and a zirconia inner portion.

11. The shroud of claim 10 where the upper portion is further encased by a metal casing.

12. The shroud of claim 11 where the metal casing has a thickness of 1.5 mm.

13. The shroud of claim 1 where the nozzle passage at the first nozzle end is larger than the nozzle passage at the second nozzle end.

14. The shroud of claim 13 where the nozzle passage at the first nozzle end has a diameter of 28.7 mm and the nozzle passage at the second nozzle end has a diameter of 17.5 mm.

15. The system of claim 1 , wherein the shroud extends between 1 mm and 55 mm above the meniscus of the molten metal in the mold.

16. The system of claim 1 , wherein the shroud extends between 1 mm and 15 mm above the meniscus of the molten metal in the mold.

Assignees

• Nucor Corp

Inventors

• Sosinsky David J
• Hinker Marcie M

Classifications

• B22D11/053

  Means for oscillating the moulds · CPC title

• B22D11/047

  Means for joining tundish to mould · CPC title

• B22D11/059

  Mould materials or platings · CPC title

• B22D11/055 Primary

  Cooling the moulds {(B22D11/04 takes precedence)} · CPC title

• B22D11/11

  Treating the molten metal · CPC title