Medium plate mill work roll and manufacturing method thereof

Abstract

The invention discloses a working roll of a medium-plate mill and a manufacturing method thereof, and belongs to the technical field of rolling equipment of medium plates. The working roll comprises an outer layer and a core part, wherein the outer layer comprises the following chemical components by weight percentage: 0.60% to 1.20% of C, 0.40% to 1.20% of Si, 0.40% to 1.20% of Mn, 0.08% or less of P, 0.03% or less of S, 4.00% to 12.00% of Cr, 0.40% to 1.20% of Ni, 1.00% to 5.00% of Mo, 1.00% to 5.00% of V and 1.00% to 5.00% of W, and the balance being Fe and unavoidable impurities. Hardness, abrasion resistance and fatigue resistance of the working roll of the medium-plate mill are improved, the working roll has high strength, good hot-cracking resistance, thermal shock resistance and other comprehensive performance, and the working roll can adapt to harsh rolling conditions of the medium-plate mill.

Description

technical field [0001] The invention relates to the field of plate rolls, in particular to a work roll of a plate mill and a manufacturing method thereof. Background technique [0002] The rolling force of the medium plate mill is relatively large, especially for the work rolls of the large medium plate mill. There is a relative sliding phenomenon between the middle and the rolled steel plate, which causes the wear of the roll and the poor shape of the plate. The roll is required to have high hardness and wear resistance; Working under load, the repeated compressive stress and tensile stress of the work rolls will induce thermal cracks, which require the work rolls to have high thermal conductivity, small thermal expansion coefficient and elastic coefficient; Fatigue strength, so the structure of the roll should be stable at high temperature. [0003] At present, high-nickel-chromium materials are widely used in medium-plate rolling mills. For example, the medium-plate hig...

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Problems solved by technology

[0003] At present, high-nickel-chromium materials are widely used in medium-plate rolling mills. For example, the medium-plate high-chromium steel and its manufacturing method published by the Chinese invention patent CN105568136A, the metallographic structure of the high-nickel-chromium material is: bainite + a small amount of martensite And retained austenite + carbide + a small amount of graphite, this kind of bainite-based matrix roll has relatively poor stability and low thermal cracking resistance. When the roll surface temperature is greater than 70 ° C, the roll The outer tissue will undergo phase transformation, and at the same time, additional phase transformation stress will be generated

[0004] In addition, due to the high carbon content in the roll material, the form of the carbides tends to form large and fish-bone carbides with obvious orientation, and the form of graphite is short flakes, which weaken the crack arrest of the roll. ability, it will cause cracks on the surface of the work roll and cause the surface quality of the steel to deteriorate

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