Cast steel back-up roller and preparation method thereof

Abstract

The invention discloses a cast steel back-up roller and a preparation method thereof, and belongs to the technical field of steel rolling rollers. High alloy steel taken as a working layer material of a roller and graphitic steel taken as a core material of the roller are completely metallurgically bonded to each other. The high alloy steel material comprises the following chemical components in percent by weight: 0.4 to 0.6 percent of C, 0.4 to 0.6 percent of Si, 0.5 to 0.7 percent of Mn, 4.5 to 5.5 percent of Cr, 1.0 to 1.2 percent of Ni, 0.6 to 0.8 percent of Mo, 0.03 to 0.08 percent of Re, less than or equal to 0.35 percent of P, less than or equal to 0.030 percent of S and the balance of Fe; and the graphitic steel material comprises the following chemical components in percentage byweight: 1.4 to 1.6 percent of C, 1.7 to 1.9 percent of Si, 0.4 to 0.6 percent of Mn, 0.5 to 0.7 percent of Ni, less than 0.2 percent of Cr, less than 0.2 percent of Mo, less than 0.035 percent of P, less than 0.030 percent of S, and the balance of Fe. The cast steel back-up roller and the preparation method thereof have the advantages that: the online service life of the roller and the operating rate of a rolling mill are greatly improved; simultaneously, the serious consequence of scrap caused by abnormal nodularizing and poor bonding of the roller due to high-temperature tapping and high-temperature casting of the molten iron of nodular cast iron is avoided; and the manufacturing cost of the roller is reduced.

Description

technical field [0001] The invention belongs to the technical field of steel rolling rolls, and in particular provides a cast steel backing roll and a preparation method thereof, which are mainly applicable to the manufacture of cast steel backing rolls used in strip steel rolling. Background technique [0002] With the rapid development of the iron and steel industry, my country's current production capacity of hot-rolled plate and strip mills including narrow strip steel has reached 280 million tons. Rolls are an important component that is consumed in large quantities in rolling steel production, that is to say, no rolls are not produced. Therefore, the quality of the roll not only affects the surface quality of the rolled material, but also affects the operating rate of the rolling mill, which directly restricts the economic benefits of the enterprise. In the existing production technology, the back-up rolls used in these rolling mills usually adopt integrally cast alloy...

AI Technical Summary

Problems solved by technology

Common problems in the use of back-up rolls are destructive damage such as cracks on the roll surface, peeling, and shoulder drop. According to statistics, the consumption of such abnormal damage accounts for more than 40% of the consumption of the entire back-up roll every year. have a great impact on the economic benefits of

The main reason for these problems is that due to the low alloy content, coarse matrix structure, low contact fatigue resistance and poor toughness of the existing back-up roll materials, they are subject to the repeated alternating of the strong rolling pressure of the rolling mill and the reverse bending force of the work roll during use. Under the action, the fatigue stress and shear stress on the roll surface exceed the strength limit of the material, resulting in destructive damage such as cracks, peeling and shoulder drop

Although the "a high-alloy centrifugal composite cast steel back-up roll and its manufacturing method" described in the patent application: 2009 1 0001054.9 is feasible in the selection of the material of the roll working layer, the disadvantages of this invention on the one hand are The tensile strength of the core of the roll is low, and the roll is prone to breakage during use; on the other hand, the production rate of the inventive technology is low during the implementation process, which increases the manufacturing cost of the roll and reduces the market competitiveness of the product

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