Equilibration of Plain Carbon and Alloy Steels with Endothermic Carburizing Atmospheres: Part I. Activity of Carbon in Plain Carbon Steels

Abstract

Experimental data on the activity of carbon in commercial plain carbon steel, AISI type 1010, common shim-stock material, at 871 degrees C, 927 degrees C, 1000 degrees C, and 1038 degrees C, equilibrated with common endothermic carburizing atmospheres, were found to be generally in agreement at relatively high carbon concentrations with previously published data on pure iron equilibrated With CO-CO2 mixtures. However, noticeable differences were found at low carbon concentrations. The carbon contents of type 1010 steel were generally higher compared to those of previously published data regarding pure iron except at very high activities of carbon. The carbon contents of type 1010 steel foil specimens by weight gain were generally higher than or equal to those chemically analyzed; however, they corresponded with each other within 0.02 wt.% except at very low carbon potentials.