Heating processing technology for tooth punching and tempering on open large gear

Abstract

The invention discloses a heating processing technology for tooth punching and tempering on an open large gear. The heating processing technology comprises the following steps: before tempering heating process, performing coarse tooth punching on the open large gear, and uniformly reserving allowances on tooth thickness and diameter according to the diameter of the open large gear; putting the open large gear into a furnace by virtue of a lifting appliance, and then performing the heating process for tooth punching and tempering on the open large gear; when reaching the holding time, hanging the open large gear into a quenching tank so as to be subjected to oil cooling, wherein the precooling time ranges from 3 minutes to 8 minutes, the temperature of the large gear wheel ranges from 760 DEG C to 790 DEG C when the large gear enters oil, the oil cooling time ranges from 60 minutes to 90 minutes per 100mm (which means the thickness of the rim wall of the gear), and the oil outlet temperature ranges from 260 DEG C to 300 DEG C; and after quenching, performing tempering process on the open gear, and cooling the open gear to 250+ / -10 DEG C at a cooling speed of 40 DEG C to 60 DEG C per hour, and air-cooling after discharging. According to the invention, the hardness uniformity of the open large gear subjected to the heating process is enhanced, the hardness attenuation gradient of the open large gear subjected to the heating process is reduced, the deformation of the open large gear in subsequent processing is reduced, and the quality of the open large gear is improved wholly.

Description

technical field [0001] The invention belongs to the technical field of metal heat treatment, and in particular relates to an open-type large gear tooth quenching and tempering heat treatment process. Background technique [0002] In recent years, with the rapid development of the national economy, equipment in the fields of building materials, mining, metallurgy, non-ferrous metals, and electric power in my country has developed rapidly towards large-scale, and the market share and demand for large-scale machinery have also increased year by year. As one of the most critical transmission components in large-scale rotary kilns, mills and other equipment, open gear rings have heavy loads and complex working conditions, and their quality is directly related to the quality of the entire set of products. [0003] At present, the heat treatment process of open (1 / 2 structure) large gears is usually normalizing treatment or quenching and tempering treatment. The specific manufactur...

AI Technical Summary

Problems solved by technology

In the process of normalizing heat treatment, due to the slow cooling rate and uneven cooling of the gear section, deformation is easy to occur. The common types of deformation mainly include four types: cone deformation, mouth opening deformation, necking deformation and overall shrinkage. In addition, normal Fire gears have uneven hardness and large dispersion; after adopting quenched and tempered heat treatment process, the deformation has been alleviated, but there are also problems of uneven hardness and large dispersion

According to the current normalizing and quenching and tempering heat treatment requirements, there is a large amount of gear blanks, which wastes resources and increases costs