Suitable material selection for large size cylindrical gears

Globalization and international supply chains constantly challenge gear- and steel manufacturers. In the case of large gear units in particular, expensive alloy contents have a direct impact on the material price. Steels with lower alloy contents and therefore cheaper steels are therefore becoming the focus of attention in order to further improve competitiveness. This article therefore compares two materials with different alloying elements and contents and thus different hardenability behaviour. For this purpose, extensive material characterizations as well as pulsator tests were carried out on case-hardened large gears. The aim of these tests was to determine the tooth root load-bearing capacity of the two material variants. Finally, the results are compared, discussed and recommendations for industrial application are derived, taking into account the hardenability of large gears.