What is the general use of automotive transmission gears?

Gears are the structural size and material strength to withstand the external load, which requires that the material has a high strength toughness and wear resistance; because of the complexity of gear shape, gear accuracy requirements, but also the requirements of good material technology.

Common materials for forging steel, cast steel, cast iron.

1 forged steel

According to the tooth surface hardness is divided into two categories

HB < 350, called soft tooth surface

H8 > 350, known as the hard surface

L. tooth surface hardness HB < 350

Process: forging blank, rough turning, tempering, normalizing, finishing

Common materials; 45#, 35SiMn, 40CrNi, 40MnB, 40Cr

Characteristic

With better comprehensive performance, the tooth surface has a high strength and hardness, and the tooth core has good toughness.

After heat treatment, the cutting precision can reach 8.

Simple manufacturing, economy, productivity, high accuracy requirements.

2 tooth surface hardness HB > 350

When using medium carbon steel:

Process: forging blank, often, rough cut, quenching and tempering, and fine cutting, high, intermediate frequency quenching, low temperature tempering, honing or lapping agent run, electric spark run.

Commonly used materials: 45, 40CrNi, 40Cr.

Characteristic

Tooth surface hardness of HRC = 48-55, high contact strength, good abrasion resistance.

The tooth core keeps the toughness, impact resistance, high bearing capacity.

The precision of the precision is 7.

Suitable for mass production, such as: gearbox load automobile, machine speed gear.

With low carbon steel:

Forging billet, normalizing, quenching, quenching and tempering, quenching and tempering, quenching and tempering, low temperature tempering. Up to 6, 7.

Common materials; 20Cr, 20CrMnTi, 20MnB, 20CrMnTo.