Ideas for process control of inclusion characteristics during steelmaking

Abstract

An optical emission spectroscopy (OES) method has been implemented for steel sample analysis in the steel plant at Ovako Steel. It makes it possible to receive feedback on oxygen content, inclusion size and inclusion composition within less than 10 minutes from sampling. A windows-based system has also been built to provide operators with easy access to the analysis data. A large number of production samples have been examined and evaluated using the new system. The information on inclusion size distribution and oxygen content in steel samples has been shown to correlate well with the oxygen content in rolled billet samples. It is therefore believed that actions taken during ladle refining to decrease the number of inclusions or the oxygen content can affect the steel cleanness in the finished material. Thus, it can be concluded that it is possible to obtain some control over inclusion characteristics during ladle refining.