Heat treatment method for common hard alloy roll collar

Abstract

The invention discloses a heat treatment method for a common hard alloy roll collar, and relates to the technical field of roll collar heat treatment. After the heat treatment method is applied, the common hard alloy roll collar can be used for a low-temperature rolling working condition. The method comprises the following treatment steps: a carbon black slurry spraying agent is prepared; rough grinding is performed on the roll collar; a carbon black slurry spraying device is adopted for conducting uniform spraying operation on the roll collar; the roll collar is heated; the roll collar is rapidly cooled in an air cooling mode; and the roll collar is subjected to annealing operation, the annealing temperature is controlled to be 460-500 DEG C, the heat preservation time is controlled to be 4-6 hours, and the roll collar is slowly cooled to the room temperature along with the furnace. According to the method, the surface layer of the hard alloy roll collar is coated with the carbon black, tungsten dissolved in a hard alloy bonding phase is changed into tungsten carbide, tungsten carbide grains are rounded after heat treatment, grain fragmentation in the rolling process is reduced, the total amount of steel is remarkably increased, and meanwhile the problem of roll collar cracking during low-temperature rolling of the hard alloy roll collar is solved.

Description

technical field [0001] The invention relates to the technical field of heat treatment processing of cemented carbide roll rings, in particular to a heat treatment method for cemented carbide roll rings, which enables ordinary hard alloy roll rings to meet the low-temperature rolling conditions and can be used for low-temperature rolling screw thread steel rolling in production. Background technique [0002] With the growing infrastructure and real estate market, the demand for rebar is increasing day by day. Carbide roller ring is the most critical component and consumable in the complete set of equipment for high-speed rolling rebar, which directly affects production efficiency, production cost and rolled products. quality. In recent years, steel rolling mills have increased the rolling speed by increasing the rolling temperature of rebar and softening the rolled material; then through the strong water cooling system, a large amount of martensitic structure is produced to ...

AI Technical Summary

Problems solved by technology

However, the low-temperature rolling will significantly increase the deformation resistance of the steel bar, resulting in cracking of the roll collar and broken rolls, resulting in production safety accidents in the rolling mill, and at the same time affecting production efficiency.

[0004] At present, the existing cemented carbide roll rings have the following technical problems during low-temperature rolling: 1. Hard alloy roll rings are prone to cracking during low-temperature rolling, and there is no very suitable low-temperature rolling roll ring developed in the existing market. The usual practice is to choose a cemented carbide roll ring with a higher binder phase content to avoid cracking of the roll ring; The steel passing capacity of 1500 tons / trough has dropped to 800 tons / trough. How to increase the passing steel capacity has become a new problem that needs to be faced in actual production. To solve the above problems, our company has developed a The heat treatment method of the ring, through the method of carbon-containing coating on the surface of the cemented carbide roll ring, can significantly increase the amount of steel passed, and the amount of steel passed can be increased to more than 1,200 tons, and can evenly carry out the inner surface of the cemented carbide roll ring The operation of spraying carbon black slurry can solve the problem of cracking in low temperature rolling of cemented carbide roll rings

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