Carbonitriding and Hard Shot Peening of High-Strength Gears

Author:  Y.Muwa, M.Suzawa, Y.Airmi, Y.Kojima, K.Nishimura
Source:  SAE Technical Paper
Doc ID:  1988047
Year of Publication:  1988
Abstract:  
A new process for manufacturing high-strength gears has been developed to meet the requirements of automobile transmission miniaturization. The points of the process are to increase the shot peening intensity and to perform optional control of the initial (before shot peening) microstructure by heat treatment corresponding with the peening intensity in order to obtain higher residual compressive stress. The new process, named Carbonitriding and Hard Shot Peening at Mazda, brings a much higher fatigue strength than the one obtained by the conventional carburizing and shot peening process.