Manufacturing method for high-vanadium high-speed steel composite roll

Abstract

The invention discloses a manufacturing method for a high-vanadium high-speed steel composite roll suitable for a narrow strip rolling mill. The manufacturing method comprises the steps that an outer layer of a roll body is poured by adopting a centrifugal pouring method, and after the outer layer of the roll body is poured with high-vanadium high-speed liquid steel, inert gas is continuously pumped into a cavity of the outer layer of the roll body; a centrifuge stops rotating when the outer layer temperature of high-vanadium high-speed steel reaches 1220-1280 DEG C, the inert gas is stopped being blown in, and then liquid iron in the core of the roll body is poured through mould closing. According to the manufacturing method for the high-vanadium high-speed steel composite roll, the bonding rate of the high-vanadium high-speed steel of the outer layer and the liquid iron in the core is significantly improved, the binding rate is improved from 40 percent to 100 percent, the bonding strength is improved from about 350 Mpa in the past to about 450 Mpa, and therefore the anti-stripping performance of a roll body bonding layer of the high-vanadium high-speed steel roll is greatly improved; meanwhile, the element amount formed by carbide on the corrosion outer layer of the liquid iron of the core is removed, therefore, roll neck tissues are improved, the tensile strength of the roll neck is improved, and the roll breakage phenomenon in use is effectively and completely eradicated.

Description

technical field [0001] The invention relates to a manufacturing method of rolls, in particular to a manufacturing method of high-vanadium high-speed steel composite rolls suitable for narrow-strip mills. Background technique [0002] The roll is a key wear-resistant part consumed in large quantities in steel rolling production, and its quality directly affects the quality of steel rolling, labor productivity and product profit. With the rapid development of the world's steel rolling industry, higher requirements are put forward for the service life of the rolls. The traditional high-chromium cast iron rolls with better wear resistance can no longer meet people's requirements. At present, the materials used to produce rolls mainly include cast steel, alloy semi-steel, spherical graphite cast steel, chilled cast iron, alloy ductile iron, high-speed steel, high-chromium steel, high-chromium cast iron, and cemented carbide. Among these materials, High-speed steel has been aroun...

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Problems solved by technology

[0006] A large amount of vanadium is added to high-vanadium high-speed steel. Since vanadium is easily oxidized above 600°C, when the outer layer of molten iron is poured into the cavity, because the inner surface of the cavity is in contact with air, a large amount of vanadium in the outer layer of molten iron will It is oxidized to form vanadium oxide, which not only reduces the absorption rate of vanadium, but also has a high melting point, which makes it difficult to combine the outer molten iron with the core molten iron. The combination rate is about 40%, which is very low; The molten iron in the layer contains a large amount of carbide-forming elements such as V, W, and Cr, while the molten iron in the core is ductile iron. The density and material of V, W, and Cr are very different from that of ductile iron, so there is bound to be a large amount of carbonization at the bonding layer. The density and material of V, W, Cr carbides are also very different from those of ductile iron, which makes the strength of the bonding layer very low, and it is easy to peel off from the bonding layer during use, and the bonding quality is difficult to guarantee; moreover, the molten iron in the core The molten iron in the outer layer is corroded, causing a large amount of carbide elements to enter the core, which eventually leads to low strength of the roll journal and prone to roll breakage during use

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