Application of Differential Thermal Analysis-Effluent Gas Analysis to the Determination of Nonmetallic Compounds in Steel
SourcePreliminary studies indicate that differential thermal analysis — effluent gas analysis (DTA-EGA) may find practical application in analysis of compounds present in inclusions separated from steel. In this type of differential thermal analysis, a dynamic atmosphere is used. Gaseous products of a reaction in which there is a heat content change are analyzed, generally by thermal conductivity, although the use of gas chromatography and coulometry also are discussed. From the temperature at which reaction occurs the compound can be identified, and from analysis of a gaseous product, the amount of the compound present can be determined. Calibration with carbon dioxide (CO2) evolved from calsium carbonate indicates that metal carbides may be determined with an accuracy of about 15 per cent. DTA — EGA curves are presented for titanium carbide and zirconium carbide reacting with a dynamic oxygen atmosphere to produce the oxide and CO2 and for the titanium inclusions separated from 6 low alloy steel specimens in which carbon, nitrogen, and sulfur contents were varied.