Casting powder, casting slag and method for casting steel

Patent metadata

Field	Value
Publication number	US-10486227-B2
Application number	US-201515318294-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Jun 24, 2014
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

Improved casting powders and improved casting slags enable production of steels having high aluminum contents of greater than or equal to 1% by weight and, in some cases, high manganese content of greater than or equal to 15% by weight. In some examples, such steels may also or alternatively include greater than or equal to 0.2% by weight titanium. The casting slag may result from a casting powder that comprises CaO and Al2O3 components essentially in the form of prefused calcium aluminate. Methods for casting steel, including methods for continuously casting steel, are also disclosed based on the use of the disclosed casting powders or casting slags.

First claim

What is claimed is:

1. A casting powder, wherein aside from volatile constituents the casting powder comprises:
40-60% by weight prefused calcium aluminate;
10-30% by weight fluoride-containing component;
3-6.5% by weight SiO 2 ;
5-15% by weight Na 2 O;
2-5.5% by weight Li 2 O;
less than or equal to 10.5% by weight Al 2 O 3 ;
less than or equal to 15% by weight carbon,
wherein a ratio of CaO to Al 2 O 3 in the prefused calcium aluminate is in a range of 0.6 to 1.1.

2. The casting powder of claim 1 further comprising at least one of
less than or equal to 5.0% by weight TiO 2 ;
less than or equal to 5.0% by weight MgO;
less than or equal to 3.0% by weight MnO;
less than or equal to 1.0% by weight Fe 2 O 3 ; or
less than or equal to 1.0% by weight FeO.

3. The casting powder of claim 1 comprising:
40-60% by weight of the prefused calcium aluminate;
15-25% by weight of the fluoride-containing component;
3-6% by weight of the SiO 2 ;
7-12% by weight of the Na 2 O;
2-5.5% by weight of the Li 2 O;
less than or equal to 10% by weight of the Al 2 O 3 ;
less than or equal to 15% by weight of the carbon;
less than or equal to 3.0% by weight TiO 2 ;
less than or equal to 1.0% by weight MgO;
less than or equal to 1.0% by weight MnO;
less than or equal to 1.0% by weight Fe 2 O 3 ; and
less than or equal to 1.0% by weight FeO.

4. The casting powder of claim 1 wherein the fluoride-containing component is CaF 2 .

5. The casting powder of claim 1 comprising less than or equal to 6.0% by weight of the SiO 2 .

6. The casting powder of claim 1 further comprising 1.5-3% by weight TiO 2 .

7. The casting powder of claim 1 comprising 3-5% by weight of the SiO 2 and 1.5-3% by weight TiO 2 .

8. A method of casting steel, the method comprising:
using a casting powder that comprises:
40-60% by weight prefused calcium aluminate,
10-30% by weight fluoride-containing component,
3-6.5% by weight SiO 2 ,
5-15% by weight Na 2 O,
2-5.5% by weight Li 2 O,
less than or equal to 10.5% by weight Al 2 O 3 , and
less than or equal to 15% by weight carbon, wherein a ratio of CaO to Al 2 O 3 in the prefused calcium aluminate is in a range of 0.6 to 1.1.

9. The method of claim 8 wherein the method is a continuous casting method.

10. The method of claim 8 further comprising producing steel with an aluminum content of greater than or equal to 1% by weight.

11. The method of claim 8 further comprising producing steel with a manganese content of greater than or equal to 15% by weight.

12. The method of claim 8 further comprising producing steel with a titanium content of greater than or equal to 0.2 percent by weight.

13. The method of claim 12 wherein the produced steel includes greater than or equal to 1% by weight aluminum and greater than or equal to 0.2% by weight titanium.

Assignees

• Thyssenkrupp Steel Europe Ag
• Thyssenkrupp Ag

Inventors

• Balichev Evgeny
• Dresler Matthias
• Rudnizki Jenny

Classifications

• C21C7/0087

  Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal · CPC title

• C21C7/076

  Use of slags or fluxes as treating agents (C21C7/06, C21C7/064, C21C7/068 take precedence) · CPC title

• B22D11/001

  of specific alloys · CPC title

• B22D11/108 Primary

  Feeding additives, powders, or the like · CPC title

• B22D11/111 Primary

  by using protecting powders · CPC title