A cold-packing production process of high-density, high-purity fine-grained ball steel

Abstract

The invention discloses a cold-packing production process of high-density and high-purity fine-grained ball steel, comprising the following processes: molten iron pre-desulfurization-converter smelting-LF furnace refining-RH vacuum treatment-continuous casting-big round billet casting Billet slow cooling-heating-rolling-cooling-high temperature slow cooling in the pit-exit finishing-packing and storage. The heating of the present invention adopts the temperature control of the cold charging of the ball-milled steel round billet, and adopts the combination of differential temperature rolling and single-pass high-pressure rolling, which increases the deformation of the core of the billet and improves the internal compactness of the steel. and grain size. The grinding ball steel produced by the patent of the present invention has excellent low-magnification structure (center porosity≤1.0 level, general porosity≤0.5 level), high purity (type A inclusions≤1.0 level, B type inclusions≤0.5 level, C type inclusions Inclusions ≤ 0.5 grade, D-type inclusions ≤ 1.0 grade), fine austenite grains (austenite grain size ≥ 6.5 grades) advantages. The produced grinding ball steel has good impact toughness and high fatigue life through the conventional rolling process.

Description

technical field [0001] The invention belongs to the technical field of steel for wear-resistant balls, and particularly relates to a cold-packing production process of high-density, high-purity, fine-grain grinding ball steel. Background technique [0002] Although high carbon content can improve the wear resistance of steel ball steel, when such steel balls are rolled, if the carbide cannot be diffused at high temperature by high temperature heating for a long time, massive carbides will be precipitated in the structure. Lumpy carbides can have a very adverse effect on the wear resistance and fatigue properties of steel balls. [0003] For the breaking of steel balls, it is mainly affected by two aspects: on the one hand, the breaking of the steel ball during the manufacturing process; on the other hand, the breaking of the steel ball during use. cost of the ball. [0004] The control of broken balls in the production process of steel balls mainly lies in the adjustment o...

AI Technical Summary

Problems solved by technology

[0005] Although the current hot charging or hot delivery process can reduce the production cost to a certain extent, because the steel billet has not undergone phase transformation and recrystallization process, the as-cast structure is coarse, which will be inherited to the subsequent rolling products. At the same time, in the hot charging Or in the hot delivery process, the hydrogen in the slab cannot diffuse in time, so that hydrogen exists in the rolled material. If the subsequent rolled material is not cooled properly, fatal defects "white spots" will appear inside the steel

Furthermore, the implementation of the hot charging or hot delivery process has high requirements for the connection between steelmaking and steel rolling processes. As long as one party fails or the matching is smooth, the other party will be forced to interrupt, which will result in hot blanks having to choose cold charging. craft

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