Hearth roll and continuous annealing facility

Patent metadata

Field	Value
Publication number	US-10337082-B2
Application number	US-201515510936-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Oct 3, 2014
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

Provided is a hearth roll for supporting and conveying a steel sheet in a continuous annealing furnace, wherein all of a shaft portion and a roil main body are made from one or more ceramic materials, preferably constituted with concentric ceramic layers of different ceramic materials centering on the rotation shaft of the roll. The hearth roll has not only an excellent pickup resistance but also a long roll life free from maintenance for long periods. Also provided is a continuous annealing facility using the hearth roll in at least one of a heating zone, a soaking zone and a cooling zone.

First claim

The invention claimed is:

1. A hearth roll for supporting and conveying a steel sheet in a furnace of a continuous annealing facility having a heating zone, a soaking zone and a cooling zone, wherein the hearth roll comprises a shaft portion made of a ceramic material as a rotation center of the roll and a roll main body made of a ceramic material formed on the circumference of the shaft portion and having an outer peripheral surface in contact with the steel sheet,
wherein the hearth roll is constituted with concentric ceramic layers made from different ceramic materials centering on a rotation axis of the roll, and a ratio of thermal expansion coefficient of the ceramic material in an inner layer to the ceramic material in an outer layer within an operating temperature range is in a range of 0.5-1.5.

2. The hearth roll according to claim 1 , wherein the shaft portion and the roll main body are made from different ceramic materials.

3. The hearth roll according to claim 1 , wherein the roll main body is constituted with different ceramic layers.

4. The hearth roll according to claim 2 , wherein the roll main body is constituted with different ceramic layers.

5. The hearth roll according to claim 1 , wherein the ceramic material has a high-temperature strength of not less than 200 MPa and a thermal shock resistance of not lower than 350° C.

6. The hearth roll according to claim 1 , wherein the ceramic material is any one of silicon nitride, silicon carbide, alumina and zirconia.

Assignees

• Jfe Steel Corp

Inventors

• Fukunaga Takayuki

Classifications

• F27D3/026

  transport or conveyor rolls for furnaces; roller rails · CPC title

• C21D9/563 Primary

  Rolls; Drums; Roll arrangements · CPC title

• C21D9/56 Primary

  Continuous furnaces for strip or wire · CPC title

• C04B2237/84

  Joining of a first substrate with a second substrate at least partially inside the first substrate, where the bonding area is at the inside of the first substrate, e.g. one tube inside another tube · CPC title

• C04B2237/704

  of one or more of the ceramic layers or articles · CPC title