ROLL OUTER LAYER MATERIAL FOR HOT ROLLING WITH EXCELLENT FATIGUE RESISTANCE PRODUCED BY CENTRIFUGAL CASTING, AND COMPOSITE ROLL FOR HOT ROLLING PRODUCED THROUGH CENTRIFUGAL CASTING

• Main Authors: ICHINO KENJI, SHIBATA HIROMITSU, MOCHIDA TETSUO
• Format: Patent
• Language: English
• Published: 02.09.2013
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; PERFORMING OPERATIONS; PUNCHING METAL; ROLLING OF METAL; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a roll outer layer material for hot rolling produced by centrifugal casting, in which a roll surface layer has excellent fatigue resistance.SOLUTION: A roll outer layer material produced by centrifugal casting has a composition which contains, in terms of mass%, 2.3-2.9% C, 0.2-0.8% Si, 0.2-1.0% Mn, 5.0-7.5% Cr, 4.4-6.5% Mo, 5.3-7.0% V, 0.6-1.5% Nb, 0.002-0.1% Ti, and 0.01-0.2% Cu, while satisfying a relation: 14.0≤(Mo+1.7V)≤17.0 (wherein Mo and V are the contents of the elements (mass%)) and which further contains 0.001-0.03% Al and/or 0.001-0.03% REM. The material contains carbides in an amount of 13-40% in terms of areal proportion. Due to this configuration, the surface layer has significantly improved fatigue resistance. A shaft material is fusion-bonded to and integrated with this roll outer layer material to produce a composite roll. This composite roll, which is produced through centrifugal casting, is excellent in the fatigue resistance of the surface layer and is suitable for use as a roll for hot finish rolling.