Wear-resistant type strong-widening roller for strip steel

Abstract

The invention discloses a wear-resistant type strong-widening roller for strip steel and belongs to the field of narrow strip steel production equipment. A roller work layer adopts a high-chrome-molybdenum-vanadium-series alloy material which comprises 2.0-3.0% of C, 0.4-1.0% of Si, 0.6-1.0% of Mn, 8-32% of Cr, 0.8-1.8% of Ni, 0.8-2.0% of Mo and 0.2-1.2% of V; and the roller shape adopts a sine curve. The roller is used for a narrow strip steel rough rolling rack and has the effects of being high in strip steel blank forced widening efficiency and capable of eliminating loosening of steel blank centers and improving the plate quality; the roller has super-strong wear resistance, and thus the online time is 2-3 times that of a traditional NiCrMo roller; the roller has good characteristics of the hot cracking resistance and the fatigue weight losing resistance, the dismounted reconditioning restoration quantity of the roller is reduced by 40% compared with a traditional NiCrMo roller, and the plate face quality is obviously improved; and the comprehensive service life is prolonged to be three times or more that of the traditional roller, and the comprehensive ton-of-steel cost is reduced by 30%.

Description

technical field [0001] The invention relates to an anti-abrasion-type strip-steel strong-spreading roll, which belongs to the field of narrow-strip steel production equipment. Background technique [0002] The existing traditional super-stretching rolls usually use materials containing C3.0-3.5, Si0.5-1.5, Mn0.4-0.9, Cr0.5-1.5, Ni0.6-4.0, Mo0.2 -0.6, Mg0-0.08 NiCrMo alloy nodular cast iron or infinitely chilled cast iron outer layer material is made of integral casting or centrifugal composite casting. The tensile strength of traditional NiCrMo alloy rolls is usually ≤350MPa. [0003] The traditional cast iron material is used for rough rolling with deep-groove strong expansion roll rolling. Regardless of ductile cast iron or infinitely chilled cast iron, the outer structure contains 1-3% graphite phase structure; due to the cooling rate of graphite The impact of the influence is greater, and the graphite structure of the outer layer is often finer and the amount of graphit...

AI Technical Summary

Problems solved by technology

In terms of performance, the surface layer is prone to slipping and is not easy to bite into, and the hardness of the inner layer is reduced. The wear resistance, thermal crack resistance, and roughness resistance of the inner layer are reduced, resulting in a greatly reduced overall service life.

[0004] The main problems in the use of traditional cast iron materials for rough rolling of strong stretch rolls with deep passes are: severe thermal cracking on the pass surface, frequent meat loss in the pass, heavy roll repairs, short online time, and poor roll shape. Poor holding capacity and high cost per ton of steel

Therefore, traditional high-alloy rolls in the environment of continuous rolling narrow-strip roughing mills (bite angle 20-23%, low rolling speed 0.4-1.0m / s, small roll diameter 550-580mm) ① cannot solve the problem of rolling A series of problems such as slipping during use, ② hot cracking in low-speed rolling, ③ rapid temperature rise of the roll caused by low-speed rolling, and a series of problems such as stress breakage of the roll. Therefore, the production of narrow strip steel, especially for rough rolling and strong expansion, has always used traditional NiCrMo rolls. Ductile iron material

[0006] The traditional strong stretching roll type usually adopts trapezoidal convex pass or compound arc pass. The main problem is that the single pass widening efficiency is low (1.5-3%), and the number of widening racks usually required is relatively small. Many (5 passes); the design of the roll shape is based on experience, and the shaping process of different rolling specifications requires multiple trials and explorations, with long cycles and low efficiency; the original porosity in the center of the billet cannot be eliminated in the optimal temperature range, and the genetic factors of porosity It is not easy to eliminate in the intermediate and finishing stands, etc.

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