Neue Randschichtgefüge carbonitrierter Bauteile und deren Festigkeitseigenschaften: Teil 2: Tragfähigkeitseigenschaften carbonitrierter Zahnräder

Up to now carbonitriding is an unusual thermo-chemical treatment for case hardening of gear wheels. In the past carbonitriding has predominantly been used for increasing the hardenability of unalloyed steel, but not for the aimed increase of the load-carrying capacity of gear wheels. Therefore the influence of carbonitriding on the load carrying capacity of gear wheels was investigated by means of experiments as well as theoretical studies. The experiments were carried out using spur gears made of three different case hardening steels. The gears were carbonitrided with different heat treatment parameters and mechanically tested. The most important gear wheels damages (tooth root breakage, pitting, wear, micro pitting as well as scuffing) were systematically investigated. The results were correlated with the different case-microstructures as well as material characteristics and compared to the state of knowledge. The article gives an overview of main results obtained from the investigation of load-carrying capacity of carbonitrided gear wheels.