Semi-high speed steel break-down (BD) roller and manufacturing method thereof

Abstract

The invention discloses a semi-high speed steel break-down (BD) roller and a manufacturing method thereof, particularly relates to a roller applied to a profile steel rail beam BD rolling mill and belongs to the technical field of roller manufacturing. The whole roller is made of semi-high speed steel. The alloy components of the roller comprise, by weight, 0.3-1.5% of C, 0.2-1.4% of Si, 0.2-1.0% of Mn, 1.5-5.0% of Cr, 0-1.0% of Ni, 0.5-2% of Mo, 0.5-1.5% of W, 0-1.5% of V, and the balance Fe and inevitable impurities. The manufacturing method comprises the steps of raw material smelting, integral casting, heat preservation and demolding, heat pretreatment and heat treatment. According to the heat treatment, the high-temperature quenching technique and the high-temperature tempering technique are adopted. According to the structure of the roller, 3% or less of granular carbides are distributed on tempered sorbite, the macro-hardness of the roller is controlled to be HSD50-70, the abrasion resistance is high, the tensile strength is equal to or higher than 800 MPa, the crack extension resistance is high, and the roller is good in roller surface quality under the off-machine condition and small in abrasion under the on-machine condition; and the requirements of rail beam rolling can be well met, and especially the requirements for high strength, high abrasion resistance, high impact resistance and high hot cracking resistance of the roller in the rail beam rolling process can be well met.

Description

technical field [0001] The invention relates to a semi-high-speed steel BD roll and a manufacturing method thereof, in particular to a roll applied to a profiled rail beam BD mill, and belongs to the technical field of roll manufacturing. Background technique [0002] my country's section steel production has a long history, various varieties and specifications, and a wide range of uses. It occupies a very important position in steel rolling production. According to statistics, there are more than 1,500 types of section steel in various shapes, and more than 4,000 sizes and specifications. In my country, section steel is widely used in basic constructions such as energy, transportation, farmland water conservancy, and housing construction, accounting for about 50% of my country's total steel output. [0003] Section steel rolling mills can be divided into three categories according to their use and product specifications: large rail and beam mills, small and medium-sized ste...

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Problems solved by technology

[0004] With the development of the steel industry, profiled rail beam BD (billet opening) rolling mills put forward higher requirements for the wear resistance, strength, and thermal fatigue resistance of the rolls. Rolls made of alloy steel, forged steel, and alloy ductile iron, due to the Large wear, short roll changing cycle, relatively low safety factor of roll use, poor roll surface quality of the unloading machine, etc., have gradually failed to meet the needs of users

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