| 摘要 |
<p>There is provided a roll surface layer material made by centrifugal casting for a hot rolling mill, the roll surface layer material including a roll surface layer with excellent fatigue resistance. A roll surface layer material made by centrifugal casting has a composition including, on a mass% basis, C: 2.3% to 2.9%, Si: 0.2% to 0.8%, Mn: 0.2% to 1.0%, Cr: 5.0% to 7.5%, Mo: 4.4% to 6.5%, V: 5.3% to 7.0%, Nb: 0.6% to 1.5%, and Co: 0.1% to 4.0% so as to satisfy 14.0 ‰¤ (Mo + 1.7V) ‰¤ 17.0 (where Mo represents a content (mass%) of Mo and V represents a content (mass%) of V) and further including Al: 0.001% to 0.03% and/or REM: 0.001% to 0.03%, wherein a carbide is contained at an area fraction of 13% to 40%. Thus, the fatigue resistance of a surface layer is considerably improved. A composite roll obtained by integrally welding a shaft member to the roll surface layer member is treated as a centrifugal cast roll that includes a surface layer with excellent fatigue resistance and is suitable for hot finish rolling mill rolls.</p> |
