High-speed steel roll and preparation method thereof by centrifugal compounding in electromagnetic field

Abstract

The invention relates to a high-speed steel roll and a preparation method thereof by centrifugal compounding in an electromagnetic field, belonging to the technical field of preparation of the high-speed steel roll. The components of a working layer material of the high-speed steel roll are as follows (in weight percent): 1.5 to 2.5 percent of C, 4.0 to 6.0 percent of V, 4.0 to 6.0 percent of W, 1.5 to 4.5 percent of Mo, 2.0 to 4.0 percent of Cr, 0.04 to 0.18 percent of Zr, 0.001 to 0.003 percent of B, less than or equal to 0.5 percent of Si, less than or equal to 0.5 percent of Mn, and the balance of Fe and impurity elements; and in the impurity elements, the required contents of S, P and O are respectively less than 0.01 percent, less than 0.01 percent and less than 0.0010 percent. The roll is cast by adopting a centrifugal compounding method in a pulse electromagnetic field, the frequency of the pulse magnetic field is 0.1 to 10Hz, and the peak strength of a central magnetic field of a cast mold is 1 to 10T. The roll has a plurality of precipitation strengthening phases, and the applied pulse magnetic field leads the strengthening phases and matrix crystal grains to be refined effectively and leads the strengthening phases to be distributed in a dispersed manner, thus overcoming the segregation of alloy elements and greatly improving the performance of the roll.

Description

technical field [0001] The invention belongs to the technical field of preparation of high-speed steel rolls, and in particular relates to a high-performance high-speed steel roll and a centrifugal composite preparation method thereof under an electromagnetic field. Background technique [0002] Roll is a key wear-resistant part consumed in large quantities in steel rolling production, and its quality directly affects the quality of rolled steel products, labor productivity and production costs. Due to the extremely harsh service conditions of the roll, it is required that the roll must withstand quite strong force and heat. In addition to having high strength and toughness to prevent the roll from breaking during use, the surface of the roll should also have good wear resistance and heat resistance. , a single roll material is difficult to meet the requirements of hot rolls. Composite rolls composed of roll core materials with good strength and toughness and roll body mate...

AI Technical Summary

Problems solved by technology

[0004] To reduce the problem of alloying elements and the segregation of carbides formed during roll casting by centrifugal composite preparation, there are currently two main methods: one method is to add an element that can form composite carbides with elements that are easy to segregate in high-speed steel , when the density of the composite carbide is similar to that of the iron matrix, the segregation of elements and their carbides can be reduced. For example, a Chinese patent (authorized announcement number CN100369681C, a high-speed steel composite roll and its manufacturing method) discloses a W-free Elements of high-speed steel composite rolls, by adding Nb elements, VC is converted into (Nb, V)C composite carbides, which can control the segregation / segregation of V and VC. The deficiency of this method is mainly that Nb elements improve the steel The quenching temperature reduces the temperature at which the secondary hardening peak appears, and the composite carbides are thick, which causes the roll to peel off easily during use. In addition, the Nb element is relatively rare and expensive, which obviously increases the cost of the roll; another method is through field control, China Both the patent (application number: 200410004744.7, electromagnetic centrifugal casting high-speed steel composite roll method) and the Chinese patent (authorized announcement number: CN100500919C) both propose to apply a steady magnetic field outside the mold to generate electromagnetic stirring to reduce the macroscopic appearance of alloy elements and carbides. Segregation, the electromagnetic stirring caused by the constant magnetic field can weaken the segregation of alloying elements and their carbides in the radial direction of the roll, but the constant magnetic field used in this invention is weak (less than 0.2T), compared to the centrifugal force of centrifugal casting, The electromagnetic stirring effect caused by the constant magnetic field is only a weak stirring of the melt. In addition, the electromagnetic stirring caused by the constant magnetic field is in a single fixed direction. Cohesion and coarseness will worsen the effect of the magnetic field. Therefore, the existing technology cannot completely solve the problem of segregation of alloy elements in the centrifugal compounding process.

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