Chemical analysis of nitrogen in steel

Abstract

The world's technological, economic and social climate has placed increasing demands on the quality of steel products. Some mechanical properties of steel are strongly dependent on even very low concentrations of gaseous elements. Nitrogen is present in all steel and irons. The nitrogen may be present both as dissolved nitrogen and as nitride precipitate, often in combination with other elements. For a complete analytical description of a steel it is not sufficient only to give the total amount of nitrogen being present but it is necessary to discern between both dissolved nitrogen and nitride precipitates. Unfortunately a single method capable of quantifying the total nitrogen and the different nitrides present in the same sample does not exist. In this paper a review of the most common techniques and methods used to determine the total nitrogen content and the different nitrogen compounds present in steel samples is presented.