Hearth roll for continuous annealing furnace and method for manufacturing hearth roll for continuous annealing furnace

摘要

PROBLEM TO BE SOLVED: To provide a hearth roll for a continuous annealing furnace capable of providing stable transportation of a metallic strip and making service life longer, and a manufacturing method of the hearth roll for the continuous annealing furnace.SOLUTION: A hearth roll for a continuous annealing furnace comprises: a cylindrical outer layer sleeve 2 made of heat resistant steel; and a cylindrical inner layer sleeve 3 which is made of a metal having thermal conductivity higher than that of the outer layer sleeve 2 and containing copper, and of which the outer peripheral surface is joined to an inner peripheral surface of the outer layer sleeve 2. An angle θformed by a free edge of an axial direction end part of the outer layer sleeve 2 and a joint boundary 6 between the outer layer sleeve 2 and the inner layer sleeve 3, and an angle θformed by a free edge of an axial direction end part of the inner layer sleeve 3 and the joint boundary 6, satisfy formula (1) and one of formula (2) and formula (3). θ+θ=180° ±10° ...(1), 55°≤θ≤80° ...(2), 125°≤θ180° ...(3).SELECTED DRAWING: Figure 3