Ermittlung der Gleichgewichtslage von H2/CH4-Gasatmosphärer mit chrom/kohlenstoffhaltigen Stählen. Diskussion

The role of alloying elements cannot be overlooked in the heat treatment of steel under controlled atmosphere Their influence on case hardened steels which are only low alloyed has been determined through extensive studies. The results have been published by the FA (expert committee) 5/AK (working group) 4 of the AWT. Less research has been done on the physical-chemical behaviour of high alloy steels, e. g. tool steels with 12% chromium and high carbon content, regarding their equilibrium with gas atmospheres During the heat treatment of such steels, e. g. during austenitizing or during recarburizing or overcarburizing the knowledge of the interaction between the phases involved (carbides included) is necessary. This enables the correct choice of the atmosphere. The aim of this publication is to determine the carbon potential of the atmosphere which is in equilibrium with high chromium alloyed steels (tool steels). This enables an optimal processing of this kind of steels as a result of the right choice of carbon potential.