A composite cemented carbide roll comprising an inner layer made of an iron-based alloy, and an outer layer made of cemented carbide which is metallurgically bonded to an outer peripheral surface of the inner layer; the cemented carbide of the outer layer comprising 55-90 parts by mass of WC particles and 10-45 parts by mass of an Fe-based binder phase having a particular composition; a shaft member and a shaft end member being metallurgically bonded to at least one axial end of the inner layer; the inner layer being made of an iron-based alloy containing 2.0% or more in total by mass of at least one selected from the group consisting of Cr, Ni and Mo; and the shaft member and the shaft end member being made of an iron-based alloy containing 1.5% or less in total by mass of at least one selected from the group consisting of Cr, Ni and Mo.

A centrifugally cast composite roll for hot rolling comprising an outer layer made of an Fe-based alloy having a chemical composition comprising by mass 2.6-3.6% of C, 0.1-3% of Si, 0.3-2% of Mn, 2.3-5.5% of Ni, 0.5-3.2% of Cr, 0.3-1.6% of Mo, 1.8-3.4% of V, and 0.7-2.4% of Nb, 1.4 ≤V/Nb ≤2.7, a V equivalent (Veq=V+0.55 Nb) being 2.60-4% by mass, and the balance being Fe and impurities, and an inner layer made of an iron-based alloy and integrally fused to the outer layer.

There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. Its outer layer includes chemical components by mass ratio: C: 1.5 to 3.5%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 1.0 to 6.0%; Cr: 1.5 to 6.0%; Mo: 0.1 to 2.5%; V: 2.0 to 6.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.2%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: a chemical composition of the outer layer satisfies Formula (1) and has 5 to 30% of M.sub.3C carbide by area ratio; an outer layer Shore hardness (A) of a roll surface satisfies Formula (2); and a residual stress (B) of the roll surface satisfies Formula (3),
2×Ni+0.5×Cr+Mo>10.0  (1)
Hs 75≤A≤Hs 85  (2)
100 MPa≤B≤350 MPa  (3).

The present invention relates to the technical field of material processing and provides a method for making a metal material composite, including: contacting a first surface of a first plate with a second surface of a second plate; placing the first plate and the second plate in a recess in a circumferential direction of a first roller such that a third surface of the second plate contacts a bottom wall of the recess in a circumferential, the third surface being opposite the second surface, the first plate having a greater hardness than the second plate; and controlling a first roller and a second roller to rotate, thereby rolling to combine the first plate and the second plate into a composite plate, where a fourth surface of the first plate contacts a surface of the second roller and the fourth surface is opposite the first surface during the rolling. According to the method for making a metal material composite in the present invention, flashings and burr on the side edges of a composite plate are avoided by placing the first plate and the second plate in a recess for machining.

A centrifugally cast composite roll comprising an outer layer formed by a centrifugal casting method, and an inner layer made of ductile cast iron and integrally fused to the outer layer, the outer layer being made of an Fe-based alloy comprising by mass 1.3-3.7% of C, 0.3-3% of Si, 0.1-3% of Mn, 1-7% of Cr, 1-8% of Mo, at least one of 2.5-7% of V, 0.1-3% of Nb and 0.1-5% of W (V is indispensable), and 0.01-0.2% of B and/or 0.05-0.3% of S, the balance being substantially Fe and inevitable impurities, the outer layer having a structure containing no graphite; the inner layer comprising a core portion fused to the outer layer, and a drive-side shaft portion and a free-side shaft portion integrally extending from both ends of the core portion; the total amount of Cr, Mo, V, Nb and W being 0.35-2% by mass in an end portion of the drive-side shaft portion and 0.15-1.8% by mass in an end portion of the free-side shaft portion, the former being larger than the latter by 0.2% or more by mass.

A centrifugally cast, hot-rolling composite roll comprising an outer layer formed by a centrifugal casting method, and an inner layer made of ductile cast iron and integrally fused to the outer layer; the outer layer having a chemical composition comprising by mass 1-3% of C, 0.4-3% of Si, 0.3-3% of Mn, 1-5% of Ni, 2-7% of Cr, 3-8% of Mo, 3-7% of V, and 0.01-0.12% of B, the balance being Fe and inevitable impurities, and meeting the relation expressed by Cr/(Mo+0.5W)<−2/3[C−0.2(V+1.19Nb)]+11/6, wherein W=0, and Nb=0, when W and Nb are not contained; and containing by area 1-15% of MC carbide, 0.5-20% of carboboride, and 0.5-20% of Mo-based carbide.

A centrifugally cast, hot-rolling composite roll comprising an outer layer formed by a centrifugal casting method, and an inner layer made of ductile cast iron and integrally fused to the outer layer; the outer layer having a chemical composition comprising by mass 1.6-3% of C, 0.3-2.5% of Si, 0.3-2.5% of Mn, 0.1-5% of Ni, 2.8-7% of Cr, 1.8-6% of Mo, 3.3-6.5% of V, and 0.02-0.12% of B (or 0.01-0.12% of B, and 0.05-02% of S), the balance being Fe and inevitable impurities, and meeting the relation expressed by Cr/(Mo+0.5W)≥−2/3[C−0.2(V+1.19Nb)]+11/6, wherein W=0, and Nb=0, when W and Nb are not contained, and containing by area 1-15% of MC carbide, 0.5-20% of carboboride, and 1-25% of Cr-based carbide.

A centrifugally cast composite roll for hot rolling comprising an outer layer having a composition comprising by mass 0.8-3.5% of C, 0.1-2.5% of Si, 0.1-2.5% of Mn, 1.2-15% of Cr, 1-5% of Ni, and 1-10% of Mo+0.5×W, the balance being substantially Fe and inevitable impurities, and an inner layer made of an iron-based alloy and integrally fused to the outer layer; the outer layer having Shore hardness of 67-82 at the initial diameter of the composite roll; and the maximum Shore hardness of the outer layer in a range 30 mm or more deep from the initial diameter being higher by 1 or more than the Shore hardness of the outer layer at the initial diameter.

A composite cemented carbide roll comprising an inner layer made of an iron-based alloy, and an outer layer made of cemented carbide which is metallurgically bonded to an outer peripheral surface of the inner layer; the cemented carbide of the outer layer comprising 55-90 parts by mass of WC particles and 10-45 parts by mass of an Fe-based binder phase having a particular composition; a shaft member and a shaft end member being metallurgically bonded to at least one axial end of the inner layer; the inner layer being made of an iron-based alloy containing 2.0% or more in total by mass of at least one selected from the group consisting of Cr, Ni and Mo; and the shaft member and the shaft end member being made of an iron-based alloy containing 1.5% or less in total by mass of at least one selected from the group consisting of Cr, Ni and Mo.

There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. A centrifugally cast composite roll for rolling having an outer layer and an inner layer, the outer layer including chemical components by mass ratio: C: 1.0 to 3.0%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 0.1 to 6.0%; Cr: 0.5 to 6.0%; Mo: 0.5 to 6.0%; V: 3.0 to 7.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.1%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: the chemical composition of the outer layer satisfies following Formula (1), has a crystallization and precipitation amount of graphite suppressed to less than 0.3% by area ratio, and has 1 to 15% of MC carbide by area ratio; and the centrifugally cast composite roll for rolling does not have a cast defect having a diameter of ϕ4 mm or more at a boundary between the outer layer and the inner layer,

50×N+V<9.0  (1).