Refractory material and casting nozzle

Patent metadata

Field	Value
Publication number	US-2016297003-A1
Application number	US-201414777909-A
Country	US
Kind code	A1
Filing date	Mar 19, 2014
Priority date	Mar 21, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

Provided is a refractory material having both excellent erosion/corrosion resistance and thermal shock resistance, which has hardly been obtainable by conventional techniques, and a casting nozzle using the refractory material. The refractory material of the present invention contains: 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, wherein a sum of respective thicknesses of the void layer at two positions on the opposite sides is 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.

First claim

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., on an assumption that 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 , which contains, on an assumption that 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 %, 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.

Assignees

• Krosakiharima Corp

Inventors

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

Classifications

• C04B2235/428

  Silicon · CPC title

• C04B2235/401

  Alkaline earth metals · CPC title

• B22D41/54 Primary

  characterised by the materials used therefor · CPC title

• C04B2235/3217

  Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina · CPC title

• C04B2235/3821

  Boron carbides · CPC title