ABSTRACT
Significant technical advances have been made in the past decade in steel making, heat treatment, and gear design. In heat treatment, plasma carburizing and plasma nitriding have led to significant quality improvements and energy savings. Progressive tooth-by-tooth and spin induction hardening techniques are well established and have been combined with automated precision forging techniques for the production of near net shape gears with improved mechanical “fibre.” Spur gears are usually cut from bar stock before being car-burised, followed by a quench and temper heat treatment and glass bead peening. The chapter examines the fatigue of surface-hardened gears and its prevention through optimised manufacturing technology. A testing program was devised to examine the influence of gear design, material processing, heat treatment, and steel cleanliness, as well as surface engineering considerations such as surface-hardening practices, surface finish, and residual stresses.
