Material influence on mechanical properties of gears with alternative microstructures

Abstract Case hardening represents the most important heat treatment process to increase load carrying capacity of gear components. Beside predominantly martensitic surface layers with low proportion retained austenite, there were investigated material structures differing properties in preceding research work. In a previous publication, results three variants made 20MnCr5, which is typically used for gears, presented. The reference was conventional carburizing subsequent case hardening. second variant also gas carburized, but high austenite. last presented had bainitic structure layer. and third showed similar tooth root bending strength compared reference. numbers pitting resistance significantly higher than variant. This paper presents further investigations on influence different microstructures capacity. For this purpose, gears 18CrNiMo7‑6 tested regard their steel like too, often applied big approximately constant, whereas decreased corresponding 20MnCr5. comparison carburized 20MnCr5 variant, only large austenite resistance. took place cycle regime limited life as well fatigue regime. determined life.