A heat treatment method for carburizing and quenching in a vacuum furnace

Abstract

The invention discloses a vacuum furnace carburizing and quenching heat treatment method which comprises the following steps: performing stress relief annealing treatment on parts; performing vibrating finishing on the parts; clamping the parts in a heat treatment tool, placing the parts in a resistance furnace through the heat treatment tool, and performing oil immersion for 2-3 hours at the temperature of 350-400 DEG C; performing multi-layer distributing on the parts through the special heat treatment tool, placing the parts in the vacuum furnace in a staggered manner, performing preheating treatment, carburizing treatment and carbonitriding and quenching treatment in sequence; transferring the quenched parts into the resistance furnace, performing low-temperature tempering on the parts in the resistance surface at the tempering temperature of 160-180 DEG C, and then performing heat preservation for 2-3 hours; performing vibrating finishing on the parts again. According to the vacuum furnace carburizing and quenching heat treatment method, the surface hardness of the parts is ensured, the wear resistance of the parts is improved, the effective hardened layer of the parts is deeper, the core toughness of the parts is improved, and the comprehensive mechanical property of the parts is good.

Description

technical field [0001] The invention relates to the technical field of heat treatment, in particular to a vacuum furnace carburizing and quenching heat treatment method. Background technique [0002] Gears are important parts in transmission machinery, and require comprehensive properties such as wear resistance, surface contact fatigue resistance and bending fatigue resistance. At present, the carburizing and quenching process is mostly used for gear heat treatment, but due to the high carburizing temperature and quenching temperature, the deformation of gear parts is relatively large. For alloy steel gear parts, the hardenability is high, and the hardness of the core exceeds 300HV5. Using the traditional multi-purpose furnace or mesh belt furnace carbonitriding process, reduce the quenching temperature to 760°C, select quenching oil with a slow cooling rate, the hardness of the alloy steel gear core is still higher than 300HV5, and the surface hardness is lower than the re...

AI Technical Summary

Problems solved by technology

At present, the heat treatment of gears mostly adopts carburizing and quenching process, but due to the high carburizing temperature and quenching temperature, the deformation of gear parts is relatively large. For alloy steel gear parts, the hardenability is high, and the hardness of the core exceeds 300HV5

Using the traditional multi-purpose furnace or mesh belt furnace carbonitriding process, reduce the quenching temperature to 760°C, select quenching oil with a slow cooling rate, the hardness of the alloy steel gear core is still higher than 300HV5, and the surface hardness is lower than the required value, up to Less than production requirements

In the traditional carburizing and quenching tooling for pinion parts, the parts are separated by gaskets, and the contact area between the gaskets and the parts is large, resulting in more soft spots on the surface of the parts after quenching

Therefore, a reasonable gear heat treatment method is designed to solve the problems of large deformation and high hardness of the alloy steel gear, which is suitable for mass production

Images