Gears used in different machines have great differences in material and heat treatment process due to the differences in stress conditions and working environment.
The gears used in forestry machinery are mostly hard tooth surfaces, which can be roughly divided into two categories: gears for lifting and conveying machinery and forestry machinery; Gears for vehicles, tractors and other means of transport.
The former is made of medium carbon steel or medium carbon low alloy steel, such as 40,45,40cr, 40MnB, etc.
The hardened layer on the gear surface is medium carbon tempered martensite, and the gear surface has high hardness, high wear resistance, high fatigue strength and toughness to ensure that it can withstand large bending stress and impact force in use.
The latter mostly adopts carburized steel: 15,20,15cr, 20Cr, 20mnvb, 20CrMnTi, 20CrMnMo, 15cr2ni4w, etc.
The gear surface is tempered high carbon martensite to ensure high hardness (HRC60 ~ 63) and good wear resistance.
The core body is tempered low-carbon martensite, which makes the gear have high strength and impact toughness.