GROOVED DOUBLE LAYERS ROLL

摘要

PROBLEM TO BE SOLVED: To provide a grooved double layers roll which causes almost no accidents such as cracks or defects by respectively dispersing the maximum distortion in the roll axial direction centering to the roll edge surface of the grooved double layers roll composed of HIS(High Speed Tool Steel Roll) system stock, the maximum distortion in the roll radius direction, and the maximum distortion in the roll circumferential direction. SOLUTION: The grooved double layers roll which comprises an outer layer 1 and an inner layer 2 composed of HIS system stock and in which a groove for constituting an aperture die is formed on the outer circumferential surface of the outer layer 1 and the groove is formed in advance on the outer circumferential surface of the portion corresponding to the groove of the inner layer 2 so that the ratio between the minimum outer layer thickness t2 which is the minimum outer layer thickness in the portion forming the groove and the maximum outer layer thickness t2 which is the maximum outer layer thickness except the portion forming the groove becomes less than a constant value predetermined through experimental tests.