Patent ID: 7546756
Filing Date: 2009-06-16
Classification: B21B,C21D,C22F

Abstract:
1. A method for processing a workpiece selected from the group consisting of a metal slab or billet, comprising: rolling comprising passing the slab or billet between a set of rotating rolls of a rolling mill stand to roll the slab or billet, wherein the slab or billet is introduced between the rolls at an angle of between 10 and 25° with respect to a perpendicular to a plane through center axes of the rolls, wherein the slab has a thickness of at least 32.5 mm at commencement of said passing step; and wherein the rolls of the rolling mill stand comprise a faster roll and a slower roll-which respectively have a peripheral velocity, and the peripheral velocity of the faster roll is at least 10% and at most 50% greater than the peripheral velocity of the slower roll, and the thickness of the slab is reduced by the rolling by at most 15% per pass, or a thickness of the billet in the plane of the rolls is reduced by at most 15% per pass, by the rolling, wherein, after passing of the slab or billet between the set of rotating rolls of the rolling mill stand to roll the slab or billet once, the passing of the slab or billet between the set of rotating rolls of the rolling mill stand to roll the slab or billet is repeated at most one time.