Improved work roll, particularly for use in closed gap rolling, has a composite structure comprising a cylindrical outer layer ( 14 ) made of steel, and providing the work surface of the roll, separated from a steel core ( 12 ) by an intermediate layer ( 13 ) of material such as aluminium or copper having a lower Young's modules than that of the layer ( 14 ). Provided that the dimensions of the outer layer ( 14 ) and intermediate layer ( 13 ) are chosen appropriately, this combination can release a work roll having an affective Young's modules which is lower than that of steel whilst at the same time retaining the advantages of a steel work surface and enabling higher rolling speeds.
1. A work roll for use in the reduction of the thickness of metal sheet, the work roll having an effective Young's Modulus in the range 40 GPa to 190 GPa, wherein the roll has a composite structure comprising an outermost cylindrical layer and at least one cylindrical inner layer, joined to the outermost layer, and wherein the Young's modulus of the material of the inner layer is lower than that of the outermost layer, and wherein the inner layer comprises a cylindrical core of the roll and an intermediate layer positioned coaxially between the outermost layer and the cylindrical core, and wherein the intermediate layer has a constant radial thickness along the length of the roll.
2. A work roll as claimed in claim 1 wherein the intermediate layer has a radial thickness in the ranges 5 mm to 40 mm.
3. A work roll as claimed in claim 2 wherein the intermediate layer has a radial thickness in the range 20 mm to 40 mm.