17.9.2013 Pressing & Sintering

High Performance PM Components Heat Treated by Low Pressure Carburizing and Gas Quenching

High performance components are often case hardened to have high surface hardness and fatigue strength. Low pressure carburizing and gas quenching is an increasingly popular process method for conventional steels but so far not commonly used for PM steels. Besides the benefits offered for conventional steels, such as less distortion and clean parts after heat treatment, low pressure carburizing enables surface hardening of chromium alloyed PM steels which is not possible with conventional gas carburizing. This paper presents results for low pressure carburized and gas quenched PM steels. The control of the case profiles is demonstrated together with related micro structures and initial fatigue strength results are presented.