Integrated cast steel supporting roller

Abstract

The invention relates to an improvement on a material and a quenching mode for an integrated cast steel supporting roller. The integrated cast steel supporting roller is characterized by consisting of a supporting roller body and a mandrel cast steel material, wherein the mandrel cast steel material comprises the following components in percentage by weight: 0.4 to 0.6 percent of C, 0.3 to 0.6 percent of Si, less than or equal to 0.03 percent of P, less than or equal to 0.02 percent of S, less than or equal to 0.3 percent of Ni, 4.8 to 5.2 percent of Cr, 0.5 to 0.7 percent of Mo, 0.1 to 0.2 percent of V, 0.1 to 0.2 percent of Ti, 0.005 to 0.1 percent of B, 0.01 to 0.03 percent of Ca, 0.6 to 0.9 percent of Mn and the balance of iron and inevitable impurities; and the roller body is quickly heated by adopting a differential temperature furnace in heat treatment, and quenching is performed after the temperature of a working layer reaches the quenching requirement. The defects that the conventional 50Cr5MoV cast blank grains are thick, loose and not compact are overcome; and the tissue grains of the obtained supporting roller are fine, the issue is bainite, and the supporting roller basically has no pearlite tissue, so the strength, toughness and quenching capacity of the supporting roller are improved, and the service life is prolonged. The working layer is subjected to effective thorough quenching by differential temperature quick quenching, so the service life of the working layer of the supporting roller is prolonged; the mandrel tissue of the inner layer is not changed, and the quenching basically does not affect the performance of the mandrel, so the strength of the mandrel is ensured, and the mandrel has high strong toughness; and the whole service life of the supporting roller is prolonged by 30 percent compared with that of the conventional 50Cr5MoV supporting roller.

Description

technical field [0001] The invention improves the material and quenching method of an integral cast steel support roll, and in particular relates to an integral cast steel support roll with a dense mandrel structure and better strength and toughness. Background technique [0002] The back-up roll provides strong rolling force to the work roll, so the working layer of the back-up roll body is required to have high hardness and high wear resistance; the mandrel requires high strength and high toughness. One type of back-up roll in the prior art is cast with the same material such as 50Cr5MoV, and then the different properties of the working layer of the roll body and the mandrel are obtained through overall heat treatment. However, for the same material, it is objectively difficult to meet the different performance requirements of the working layer of the roll body and the mandrel at the same time to obtain different performance requirements inside and outside through the over...

AI Technical Summary

Problems solved by technology

Although the composite back-up roll is made of suitable materials according to the different requirements of the working layer and the core, the composite structure, firstly, the two different materials in the composite process of centrifugal casting are prone to poor metallurgical bonding, which is easy to cause in the process of use. The working layer peels off; the second is the iron-based material of the core, its strength is lower than that of the steel base, and it is still easy to break the roll

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