PRODUCT CATEGORIES

Vacuum Heat Treatment Furnace

Vacuum Sintering Furnace

Vacuum Brazing Furnace

Vacuum carburizing of electric motor gear

The motor gear material for the valve electric device is 20CrMo steel.

The depth of the carburized layer is required to be 0.38mm and 0.64mm respectively, and the hardness is 55~61HRC. The internal control of the motor gear with spline requires anti-seepage.

Vacuum carburizing process curves are adopted for gears with carburized layer depths of 0.38mm and 0.64mm respectively. The carburizing method adopts pulse carburizing, and each pulse time is 5 minutes, that is, the carburizing gas is filled to 2.66×104Pa pressure and kept for 5 minutes, then pumped out immediately, and the carburizing gas is diffused after the carburizing is completed. In order to reduce deformation, pre-cooling and quenching are used after carburizing and diffusion. The mass fraction of carbon content on the surface of the gear after vacuum carburizing is 0.97%-1.00%.

According to the usual use, the effective carburized layer depth is above 550HV (50HRC), and for gears requiring a carburized layer of 0.38mm, the effective carburized layer depth at the gear face b is 0.43mm, and the carburized layer at the gear b’ The effective carburized layer depth is 0.36mm, which is 95% of the minimum effective carburized layer depth standard value of 0.38mm.

For the gear with a carburized layer requirement of 0.64mm, the effective carburized layer depth at the gear face b is 0.68mm, and the effective carburized layer depth at the gear b’ is 0.52mm, which is the minimum effective carburized layer depth 81% of the standard value of 0.64mm meets the technical requirements.

The metallographic structure of the 0.38mm carburized layer after heat treatment: the carbide at the tooth top is grade 3, the martensite and retained austenite are grade 2; the carbide at the working surface of the tooth is grade 1, martensite and retained austenite The body is grade 2; the core ferrite is grade 1.

The metallographic structure of the 0.64mm carburized layer after heat treatment: the carbide at the tooth top is grade 4, the martensite and retained austenite are grade 3; the carbide at the working surface of the tooth is grade 1, martensite and retained austenite The body is grade 2; the core ferrite is grade 2.