There is provided according to the present invention a wear-resistant compound roll comprising an outer layer (8) and a shaft portion (10) produced by a centrifugal casting method. The outer layer (8) and the shaft portion (10) are metallurgically bonded to each other, and the outer layer (8) is made of an iron-base alloy having a composition (by weight %) consisting essentially of 1-4 % of C, 3 % or less of Si, 1.5 % or less of Mn, 4 % or less of Ni, 2-15 % of Cr, 8 % or less of Mo, 20 % or less of W, 2-10 % of V and balance substantially Fe and inevitable impurities, the value of C (%) + 0.4 V (%) being 6.0 or less. This compound roll has excellent wear resistance without casting defects in the boundary between the outer layer (8) and the shaft portion (10).

Wear-resistant compound roll

PURPOSE:To improve the rolling life of a roll and to manufacture the roll economically, by diffusion joining a rolling annular body, formed by sintered hard metal or high speed steel, etc. to a ring base body, formed by a low-carbon low-alloy steel consisting of a matrix of ferrite, under a hot hydrostatic pressure. CONSTITUTION:A composite roll 1 is constituted of rolling annular-bodies 2 having desired calibers, formed in its outer peripheral surface, and a ring base body 3 having the bodies 2, built in it by exposing their outer peripheral surfaces. The bodies 2 and the body 3 are diffusion joined together under a hot hydrostatic pressure. That is, the powder of high wear-resistant material to be formed into the annular body 2 for rolling, is press packed in the recessed grooves 4 formed along the outer peripheral surface of body 3, and is provided with canning treatment before HIP treatment, to obtain a composite ring stock 1', which is formed into a composite ring roll 1 by providing it with desired caliber work. In this way, a roll excellent in durability is economically manufactured.

Composite ring roll

A composite sleeve for use in a hot-rolling roll for H-section steel and channel steel comprises a working layer adapted to contact the material to be rolled and composed of two layers, i.e., a first outer layer made of one of adamite with graphite, spheroidal graphite cast iron and adamite having high resistance to sticking, and a second outer layer made of adamite or high chromium iron having high resistance to wear; and an inner layer adapted to be out of contact with the material and made of spheroidal graphite cast steel or spheroidal graphite cast iron having high toughness. The first outer layer covers the second outer layer, and the second outer layer covers the inner layer, the three layers of the first outer layer, the second outer layer and the inner layer being joined together by melting.

Composite sleeve for use in rolling rolls for H-section steel and channel steel

A forged roll for use, inter alia, in the cold rolling industry and a method of producing a forged roll as described. The roll has a steel composition, by weight, with 0.8 to less than 1% C, 0.2 to 0.5% Mn, 0.2 to 2.0% Si, 7.0 to 13.0% Cr, 0.6 to 1.6% Mo, more than 1.0 to 3.0% V, the remainder being Fe and impurities. The steel is tempered martensite with retained austenite at less than 5% per volume with eutectic carbides of less than 5% by volume, a hardness between 780-840 HV, and internal compressive stresses of between −300 to −500 MPa.

Forged roll meeting the requirements of the cold rolling industry and a method for production of such a roll

A compound roll comprising a shell portion made of a hard cast iron having excellent wear resistance and resistance to surface roughening and a core portion made of a tough cast iron or cast steel, the cast iron of the shell portion having a composition consisting essentially, by weight ratio, of 2.5-3.5 % of C, 0.5-1.5 % of Si, 0.5-1.5 % of Mn, 0.1 % or less of P, 0.05 % or less of S, 3.0-5.0 % of Ni, 1.0-2.5 % of Cr, 0.1-1.5 % of Mo and balance Fe and inevitable impurities, an average diameter of primary precipitated particles constituting a matrix of the metal structure of the shell portion being 80 µm or less in a range from a surface to a depth of 50 mm when determined by an image analysis method on the primary precipitated particles having diameters exceeding 30 µm, and the primary precipitated particles satisfying the formula: m2 1.2 mi, wherein m1 is an average diameter of the primary precipitated particles at the surface of the shell portion, and m2 is an average diameter of the primary precipitated particles at the depth of 50 mm, is produced by supplying a melt for the shell portion at a temperature T satisfying the formula: Tc - 20 ° C ≤ T Tc + 70 ° C, wherein Tc is a primary crystal-forming temperature of the melt for the shell portion, to a hollow cylindrical mold rotatable around its longitudinal axis, at such a speed that an average shell portion-forming speed in the mold is 2-40 mm/min.

Compound roll and method of producing same

PURPOSE:To make a work roll for hot rolling withstand large Hertz stress during rolling and to enhance the wear resistance by manufacturing the roll with a Cr-Mo-V cast steel contg. a specified amount of V. CONSTITUTION:A work roll for hot rolling is manufactured with a cast steel contg. 0.6-1.2% C, =0.65. The roll is heat treated by oil hardening at 1,050-1,075 deg.C and tempering at 510 or 550 deg.C. Fine V carbide particles are uniformly dispersed in the tempered martensite structure, and a work roll for hot rolling with >=61 HRC hardness and superior wear resistance is obtd. This roll withstands >=200kg/ mm. Hertz stress.

Work roll for hot rolling

PURPOSE:To obtain the titled work roll material having high hardness, toughness and impact resistance and satisfying high brightness by adding C, Si, etc. to Fe to provide a specified composition and establishing relation represented by a specified equation between W and Mo in the composition. CONSTITUTION:The titled work roll material consists of, by wt., 1.3-1.6% C, 0.5-2.5% Si, 0.4-0.7% Mn, 4.5-5.5% Cr, 1-4% Mo, 1-3.5% W, 4-5.5% V and the balance Fe and has the relation of 5%<=2XMo%+W%<=10% between Mo and W. This material prevents vanadium carbide from falling off unlike a conventional steel material, and it has high hardness, toughness and impact resistance. This material is a kind of steel optimum for use as the titled work roll material.

High brightness work roll material for sendzimir mill

PURPOSE: To provide backup rolls with excellent wear-and spalling resistance for rolling by controlling the C content and limiting the amts. of Si, Mn, Cr, Mo, V, etc. to be added. COPYRIGHT: (C)1978,JPO&Japio

Kimihiko Akahori

Papers

Work roll for hot rolling

High brightness work roll material for sendzimir mill

Backup roll for rolling