Optimization of Low Pressure Carburizing and High Pressure Gas Quenching for Cr-alloyed PM parts*

Abstract Today Low Pressure Carburizing (LPC) followed by High Pressure Gas Quenching (HPGQ) is an established process to produce high performance components for conventional steels in order to combine high surface hardness and fatigue strength. On the other hand, thanks to its ability to combine good quality and cost saving, PM process is more and more popular in the automotive industry (especially in the transmission applications as synchronizer hubs/rings, sliding sleeves, …). In order to answer the increasing application performance requirements, chromium-alloyed grades are often used because they provide a cost-efficient way to reach high mechanical properties. However these materials need specific sintering conditions and cannot be surface hardened by conventional gas carburization and oil quenching. Thus, the alternative LPC & HPGQ applied to PM parts is a very promising, cost-efficient, and environmental solution to produce high performance parts. This paper presents the last trends and results of...