As we all know, gear is an important part of mechanical equipment. In the process of transmitting force and changing speed, there are both rolling and sliding between meshing tooth surfaces, and the tooth surface is also affected by pulsating or alternating bending stress. There are three forms:
l) The friction and wear of meshing tooth surfaces are oxidation wear, cold bite wear and hot bite wear;
2) Contact stress and contact fatigue of meshing tooth surface, and the failure forms include surface pitting, shallow peeling and coating peeling;
3) The bending stress and bending fatigue of gear, and the failure form is bending fatigue failure.
Through the analysis and Research on the failure forms of gears, it can be seen that gears are required to have excellent wear resistance, contact fatigue resistance and bending fatigue resistance. In other words, the gear has high surface hardness, high strength, good core toughness and reasonable distribution of hardened layer.