09.6.2006 Pressing & Sintering

Carburizing of Low-Alloyed Chromium Materials - An Overview

Case carburizing followed by quench and temper is a well established method of reaching very high properties for components like gears and sprockets. The well established materials on Fe-Cu-Mo-Ni base can all be case hardened using standard equipment and processes. Cr-containing PM materials, with their increased sensitivity to oxidation (and local carbon level), require special considerations.  In this paper an overview of how different methods to carburise low alloyed chromium alloyed PM steels will be presented. Among methods discussed are gas carburizing, carbonitriding and vacuum carburizing. Specific emphasis is on selection of appropriate process with regard to density of the components and the formation of carbides.