Considerations when Sintering Oxidation-Sensitive PM Steels
PM²TEC 2002, in Orlando, USA. Authors: Björn Lindqvist, Koki Kanno. The majority of mass-produced PM steels are sintered in continuous belt furnaces operating at temperatures up to 1150 °C/2100 °F. The alloying elements Cu, Ni, Mo and C are normally used to obtain good material properties. However, environmental concerns and cost might restrict their use, especially Cu and Ni, as additives to PM steels, in the future. Chromium is commonly used in solid steels mainly due to low cost and good material performance, but is still rarely used for PM structural parts. One reason for this is oxidation sensitiveness. However, continuously improved sintering technology and the more frequent use of N2-based atmospheres now makes alloying with Cr more attractive for the production of high-performance PM components at a low cost. Considerations when sintering Cr-alloyed materials in different types of furnaces are given in this paper.