Refractory material and casting nozzle

Patent metadata

Field	Value
Publication number	US-9821371-B2
Application number	US-201414777909-A
Country	US
Kind code	B2
Filing date	Mar 19, 2014
Priority date	Mar 21, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A refractory material contains: 40 mass % or more of MgO; 4 to 30 mass % of a free carbon component; and one or more of B 2 O 3 , P 2 O 5 , SiO 2 and TiO 2 , in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component. A void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle. A sum of respective thicknesses of the void layer at two positions on the opposite sides is 0.2 to 3.0% of a ratio with respect to particle size of the maximum-size MgO-containing particle. An inorganic compound of MgO and the one or more of B 2 O 3 , P 2 O 5 , SiO 2 and TiO 2 exists entirety or partially in a surface of each of the MgO-containing particles.

First claim

The invention claimed is:

1. A refractory material containing, in terms of a chemical composition as measured after being subjected to a heat treatment in a non-oxidizing atmosphere at 1000° C.: MgO in an amount of 40 mass % or more; a free carbon component in an amount of 4 to 30 mass %; and one or more selected from the group consisting of B 2 O 3 , P 2 O 5 , SiO 2 and TiO 2 , in a total amount of 0.3 to 3 mass %, with the remainder being at least one other type of additional refractory component,
wherein a void layer exists in an interface between a carbon-containing matrix microstructure residing at least on opposite sides of a maximum-size one of a plurality of MgO-containing particles in the refractory material, and the maximum-size MgO-containing particle, a sum of respective thicknesses of the void layer at two positions on the opposite sides being 0.2 to 3.0% in terms of a ratio with respect to a particle size of the maximum-size MgO-containing particle,
and wherein an inorganic compound comprised of MgO and the one or more selected from the group consisting of B 2 O 3 , P 2 O 5 , SiO 2 and TiO 2 exists in an entirety or a part of a surface of each of the plurality of MgO-containing particles.

2. The refractory material as recited in claim 1 , wherein the additional refractory component consists of Al 2 O 3 , except for inevitable components originating from raw materials or resulting from manufacturing conditions, and wherein a mass ratio of Al 2 O 3 to MgO (Al 2 O 3 /MgO) is 0 to 0.65.

3. The refractory material as recited in claim 1 , wherein, in a state at room temperature after being subjected to the heat treatment in a non-oxidizing atmosphere at 1000° C., an amount of the refractory material except for the free carbon component is 100 mass %, a total amount of particles having a particle size of 0.1 mm or less among raw material particles is 5 to 45 mass %, and a maximum thermal expansion rate at temperatures of up to 1500° C. is 1.1% or less.

4. The refractory material as recited in claim 1 , wherein an entire amount of the refractory material as measured after being subjected to a heat treatment in a non-oxidizing atmosphere at 600° C. before start of the heat treatment in a non-oxidizing atmosphere at 1000° C. is 100 mass %, the refractory material contains one or more metals selected from the group consisting of Al, Si and Mg, in a total amount of 0.5 to 6 mass %, and/or B 4 C in an amount of 0.5 to 1.5 mass %.

5. A casting nozzle which is partially or entirely formed of the refractory material as recited in claim 1 .

6. A casting nozzle comprising the refractory material as recited in claim 1 , wherein the refractory material is disposed to define a part or an entirety of a surface of the casting nozzle to be subjected to a contact with molten steel.

7. A casting nozzle comprising a plurality of layers comprised of: a first layer disposed to define a part or an entirety of a region of the casting nozzle to be subjected to a contact with molten steel, the first layer being composed of the refractory material as recited in claim 1 ; and one or more second layers arranged on a back side of the first layer, each of the one or more second layers having a composition different from that of the first layer, wherein adjacent ones of the plurality of layers are integrated together in direct contact relation to each other.

8. A casting nozzle which is partially or entirely formed of the refractory material as recited in claim 2 .

9. A casting nozzle which is partially or entirely formed of the refractory material as recited in claim 3 .

10. A casting nozzle which is partially or entirely formed of the refractory material as recited in claim 4 .

11. A casting nozzle comprising the refractory material as recited in claim 2 , wherein the refractory, material is disposed to define a part or an entirety of a surface of the casting nozzle to be subjected to a contact with molten steel.

12. A casting nozzle comprising the refractory material as recited in claim 3 , wherein the refractory material is disposed to define a part or an entirety of a surface of the casting nozzle to be subjected to a contact with molten steel.

13. A casting nozzle comprising the refractory material as recited in claim 4 , Wherein the refractory material is disposed to define a part or an entirety of a surface of the casting nozzle to be subjected to a contact with molten steel.

14. A casting nozzle comprising a plurality of layers comprised of: a first layer disposed to define a part or an entirety of a region of the casting nozzle to be subjected to a contact with molten steel, the first layer being composed of the refractory material as recited in claim 2 ; and one or more second layers arranged on a back side of the first layer, each of the one or more second layers having a composition different from that of the first layer, wherein adjacent ones of the plurality of layers are integrated together in direct contact relation to each other.

15. A casting nozzle comprising a plurality of layers comprised of: a first layer disposed to define a part or an entirety of a region of the casting nozzle to be subjected to a contact with molten steel, the first layer being composed of the refractory material as recited in claim 3 ; and one or more second layers arranged on a back side of the first layer, each of the one or more second layers having a composition different from that of the first layer, wherein adjacent ones of the plurality of layers are integrated together in direct contact relation to each other.

16. A casting nozzle comprising a plurality of layers comprised of: a first layer disposed to define a part or an entirety of a region of the casting nozzle to be subjected to a contact with molten steel, the first layer being composed of the refractory, material as recited in claim 4 ; and one or more second layers arranged on a back side of the first layer, each of the one or more second layers having a composition different from that of the first layer, wherein adjacent ones of the plurality, of layers are integrated together in direct contact relation to each other.

Assignees

• Krosakiharima Corp

Inventors

• Morikawa Katsumi
• Sasaki Akinari
• Makino Taro
• Li Ling

Classifications

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title

• B22D41/54 Primary

  characterised by the materials used therefor · CPC title

• C04B2235/402

  Aluminium · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title

• C04B2235/425

  Graphite · CPC title