Equilibration of Plain Carbon and Alloy Steels with Endothermic Carburizing Atmospheres: Part II. Oxidation of Plain Carbon and Armco Steels during Carburizing at 1000 degrees C and 1038 degrees C

Abstract

Carbon contents by the weight gain of AISI type 1010 steel foils equilibrated with CO-CO(2) mixtures at 1000 degrees C were 0.03 wt.% to 0.07 wt.% higher than those by chemical analysis at carbon potentials of 0.2 wt.% C to 0.7 wt.% C. The lower the carbon potential, the bigger the difference became. This difference of 0.05 wt.% to 0.08 wt.% was also measured when the same materials were equilibrated with CO-CO(2) mixtures at 1038 degrees C at carbon potentials below 0.4 wt.% C. Oxygen analyses of these equilibrated steel foils confirmed that those differences of 0.03 wt.% to 0.07 wt.% and 0.05 wt.% to 0.08 wt.% were mainly due to the selective oxidation of manganese. When Armco steels and type 1010 steels were equilibrated simultaneously with endothermic-base carburizing atmospheres at 1038 degrees C, oxidation was negligible and the carbon contents of the both steels were identical at carbon potentials of 0.2 wt.% C to 1.4 wt.% C.