Overview of Surface Treatment Processes for Punch Press Reducer Gears

The common surface treatment and strengthening processes for punch press reducer gears are mainly divided into the following categories:

1、 Surface hardening heat treatment technology

This type of technology significantly improves tooth surface hardness and wear resistance by altering the microstructure or chemical composition of the gear surface layer.

carburizing and quenching

Heat low-carbon steel or low-carbon alloy steel gears in a carbon rich medium to allow carbon atoms to penetrate the surface and quench, forming a high hardness martensitic structure. This process can achieve a surface hardness of 58-62HRC, with a hardening layer depth typically ranging from 0.5-2.0mm, while maintaining good toughness in the core. Due to the high contact stress and bending stress that punch press gears need to withstand, carburizing and quenching are the preferred solutions for heavy-duty gears.

nitriding treatment

At lower temperatures (480-580 ℃), active nitrogen atoms infiltrate the surface of the steel to form a nitride layer. Nitriding treatment has low temperature and minimal deformation, with a surface hardness of up to 1000-1200HV and excellent fatigue resistance, making it very suitable for precision gears that require extremely high dimensional accuracy.

Induction heating quenching

Utilize electromagnetic fields to rapidly heat and quench the surface of gears. This process has fast heating speed and minimal quenching deformation, making it particularly suitable for local hardening or surface strengthening of large gears.

Laser hardening

By selectively hardening the tooth flank with a high-energy laser beam, a uniform hardening layer can be formed on complex tooth profile geometries, while minimizing part deformation and ensuring core toughness. It is suitable for high-precision applications that require strict dimensional stability.

2、 Surface deformation strengthening technology

This type of technology does not change the chemical composition of the material, but instead generates plastic deformation on the tooth surface through mechanical action, introducing beneficial residual compressive stress, thereby greatly improving the fatigue fracture resistance.

Shot peening strengthening

Using high-speed projectile flow to impact the metal surface, causing work hardening of the tooth surface and introducing residual compressive stress. This is equivalent to putting a layer of "prestressed armor" on the gear, which can effectively counteract the tensile stress under working load and usually increase the fatigue life of the gear by 3-5 times.

Rolling processing

Apply pressure to the tooth surface using a hard roller to produce plastic deformation. Rolling not only introduces residual compressive stress, but also increases surface hardness by 10-20% and significantly reduces surface roughness (Ra can reach 0.2 μ m), thereby improving the contact fatigue strength of the tooth surface.