Abstract
Because of light weight and high power of transmission, carburized and quenched gears are used as power transmission gear. Surface durability of carburized and quenched gears has been related with their tooth surface properties. The influence of abnormal carburized layer on the surface durability, however, has not been clarified. In this study, tested pinions were of two types: gear carburized and quenched after grinding, and gears carburized and quenched before grinding with two different surface roughness. In case of gears with equivalent surface roughness, the surface durability of the gear with abnormal carburized layer was longer than or almost the same as those without abnormal carburized layer. This would be because the abnormal carburized layer at the edge of tooth surface was worn during the fatigue tests.
