AUTOMATED-DETERMINATION OF NITROGEN IN ST EEL AS A PART OF QUALITY-ASSURING PROCESS ANALYSIS

Objective. Thanks to recent analysis- and apparatus-related developmen ts, it is possible to determine, by spark emission spectrometry, the e ntire nitrogen concentration and, by X-ray fluorescence spectrometry, the nitrogen phases in steel, as well as to automate the conventional combustion-based hot extraktion method utilised for nitrogen determina tion. The following article discusses the introduction of these new pr ocess routes, and the results achieved with them, at Krupp Hoesch Stah l AG. Summ. The analytical determination of nitrogen in steel occupies a special place within the context of quality-assured steel productio n. For this reason, importance is attached both technically and commer cially to analysis methods that are process-compatible. The aim of syn chronously providing metallurgists with data concerning the nitrogen c oncentration as well as the other elements typical in steel for proces s control purposes can be achieved by the use of modern spark emission spectrometers. Conventional nitrogen determination by the combustion- based hot extraction method continues to be indispensable because of t he partly close specification limits of modern steel grades. The combi nation of conventional nitrogen analysers with laboratory robots permi ts the complete automation of the nitrogen determination process. As t he determination of the nitrogen phases in steels is also relevant for process analysis in many cases, this aspect of nitrogen analysis is s imilarly discussed.