Design and Optimization of Fixtures for High Pressure Gas Quenching of Transmission Components

In order to achieve the desired fatigue life for transmission components, case-hardening is widely applied to transmission gears. Low Pressure Carburizing (LPC) and High Pressure Gas Quench (HPGQ) has the advantage of producing less distortion, higher fatigue strength, and better wear resistance than other quenching methods. Therefore, optimization of LPC and HPGQ promises to reduce the distortion to the minimum level, making subsequence dimension correction more predictable and in some cases unnecessary. The geometry and materials of fixture which supports the gears during LPC and HPGQ has large influence on the temperature uniformity of gears across the load. This study shows how the fixture(s) can be optimized in order to achieve temperature uniformity during HPGQ using Computational Fluid Dynamics (CFD).