Wear- and seizing-resistant roll for hot rolling and method of making the roll
AssigneeHitachi Metals, Ltd.
InventorsAkira Noda, Toshiyuki Hattori, Ryosaku Nawata
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Abstract
A wear- and seizing-resistant roll for hot rolling has a composition consisting essentially, by weight, of 2.0-4.0% of C, 0.5-4.0% of Si, 0.1-1.5% of Mn, 1.0-7.0% of Cr, 2.0-10.0% of Mo, 2.0-8.0% of V and balance of Fe and inevitable impurities; and has a metal structure comprising a matrix substantially comprising martensite, bainite or pearlite, 0.5-5% in area ratio of graphite, 0.2-10% in area ratio of MC carbides and 40% or less in area ratio of cementite. The roll of the present invention is suitable for work roll in the latter stand of a finishing train of a hot strip mill.
Claims14
A wear- and seizing-resistant roll for hot rolling, which has a composition consisting essentially, by weight, of 2.0-4.0% of C, 0.5-4.0% of Si, 0.1-1.5% of Mn, 1.0-7.0% of Cr, 2.0-10.0% of Mo, 2.0-8.0% of V and balance of Fe and inevitable impurities, and has a metal structure comprising a matrix, 0.5-5% in area ratio of graphite, 0.2-10% in area ratio of MC carbides and 40% or less in area ratio of cementite.
A wear- and seizing-resistant compound roll for hot rolling, which comprises an outer layer of a wear- and seizing-resistant iron-based alloy and a steel shaft metallurgically bonded to the outer layer, the iron-based alloy having a composition consisting essentially, by weight, of 2.0-4.0% of C, 0.5-4.0% of Si, 0.1-1.5% of Mn, 1.0-7.0% of Cr, 2.0-10.0% of Mo, 2.0-8.0% of V and balance of Fe and inevitable impurities, and having a metal structure comprising a matrix, 0.5-5% in area ratio of graphite, 0.2-10% in area ratio of MC carbides and 40% or less in area ratio of cementite.
A method of producing a wear- and seizing-resistant compound roll for hot rolling, which comprises an outer layer of a wear- and seizing-resistant iron-based alloy and a steel shaft metallurgically bonded to the outer layer, the iron-based alloy having a composition consisting essentially, by weight, of 2.0-4.0% of C, 0.5-4.0% of Si, 0.1-1.5% of Mn, 1.0-7.0% of Cr, 2.0-10.0% of Mo, 2.0-8.0% of V and balance of Fe and inevitable impurities, and having a metal structure comprisingly a matrix, 0.5-5% in area ratio of graphite, 0.2-10% in area ratio of MC carbides and 40% or less in area ratio of cementite, wherein in Si-containing inoculant is supplied into a melt of material for said outer layer at least in a vicinity of a bonding portion of said melt and said steel shaft.
Dependencies are inferred from the claim text.