Investigation of process and steel influences on the extent of internal oxidation during gas carburising

The authors have examined the effect of various gas carburising atmospheres on internal oxidation imparted, both during the initial heat-up stage and as a function of the duration of the carburising phase, in cycles aimed at conferring a given case depth in a specific steel. They have also explored the amount and form of internal oxidation in a variety of steel grades subj ected to a standard carburising process. The results offer guidance for the heat treater on the potential for reducing internal oxidation and its detr imental consequences in terms of surface hardenability and microstructure.