SPECTROMETER ANALYSIS OF NITROGEN IN STEE LS

Objective. The need for faster and more cost-effective chemical analys is of liquid steel has led to the development of nitrogen spectral ana lysis. The aim of the joint work was initially to gather first experie nce with optical emission spectral analysis modified for the analysis of nitrogen in the laboratories of the steel industry. The efficiency of the technique was also to be assessed and, where applicable, propos als submitted regarding its improvement. Summary. The efficiency of an alyzing nitrogen by optical emission spectral analysis, a new developm ent, was put to the test by six German laboratories of the iron and st eel industry within the scope of a cooperative effort. Considered in t his respect were the quality of the calibration, results from certifie d reference materials, a comparison with the hitherto practiced method of melt extraction, the analysis scatter, and long-term stability. Th e analysis of production-shop samples taken from converters, ladies an d continuously cast material containing nitrogen concentrations betwee n 15 and 110 mu g/g revealed mean differences of less than 5 mu g/g re lative to the melt extraction results. The detection limit of the tech nique was established to be at around 6 mu g/g. By taking the greatest possible care during the preparation of the samples, and with the aid of technical improvements, it was possible to achieve significant suc cesses in terms of the long-term stability.