A kind of shrinkage process of cemented carbide roller ring with secondary thermal processing

Abstract

The invention discloses a secondary heating contracting process for a hard alloy roll collar. The hard alloy roll collar is arranged in the center position of a graphite baseplate printed with a coating; a graphite fixing sleeve on the graphite baseplate is positioned on the outer layer of the hard alloy roll collar; an alumina powder protection ring is compacted between the hard alloy roll collar and the graphite fixing sleeve; the hard alloy roll collar, the alumina powder protection ring, the graphite fixing sleeve and the graphite baseplate are integrally placed in a pressure sintering furnace, wherein the vacuum degree in the pressure sintering furnace is 0.105MPa, the sintering temperature in the pressure sintering furnace is controlled to be 1350-1470 DEG C, and the whole sintering process curve time is 19-22h; within the heating time, argon at an injection rate of 8-15L / min is injected into the pressure sintering furnace, argon with pressure of 3.0-4.0MPa is infiltrated, the infiltration time lasts for 15-20min, the heat preservation sintering is performed for 20min, and then cooling is performed along with the furnace. By using the process disclosed by the invention, the contracting amount of inner diameter of the hard alloy roll collar is 3-4 times of that in the prior art, the rate of finished products is high and the operation is convenient.

Description

technical field [0001] The invention relates to a thermal processing technology, in particular to a secondary thermal processing shrinkage process for a hard alloy roll ring fitted on a roll body in a high-speed wire or bar production line. Background technique [0002] Cemented carbide roll rings are generally used in high-speed wire rod or bar rolling mills. Due to the alloy composition, the cost of cemented carbide roll rings is relatively high. After the inner layer of the roll ring is worn out, the roll ring will be scrapped. economic loss to the business. To solve this problem, those skilled in the art have proposed many solutions, such as surfacing a layer of the same type of hard alloy layer on the inner layer, and then machining to make the diameter of the inner layer reach the required geometric size. In addition, the "scrap" cemented carbide roller ring is directly put into the heating equipment, and the inner diameter of the roller ring shrinks after high temper...

AI Technical Summary

Problems solved by technology

However, these processes / methods are not ideal and cannot meet the design requirements. The shrinkage of the inner diameter of the roller ring is in the range of 0.5-0.6mm, which is not enough, and the inner layer of the roller ring after this treatment cannot be finished. "The reutilization rate of the roller ring is very low, and the equipment cost is high

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