Prof Chris Pistorius visited the Department of Materials Science and Metallurgical Engineering on 18 October 2018. Chris is currently at Carnegie Mellon University in America, but used to be the Head of our Department.
Chris gave a lecture on Quantifying inclusion changes in steel:
It is important to control nonmetallic inclusions since these affect the quality of steel. The presentation reported on recent work at the Center for Iron and Steelmaking Research (at Carnegie Mellon University) that has had two major goals: improving the accuracy and speed of measuring inclusions in steel samples, and predicting inclusion changes during liquid steel processing. Automated scanning electron microscopy is a very useful tool to quantify the sizes and chemical compositions of inclusions. Instrument settings such as detection threshold, image scan rate and accelerating voltage affect the results; guidelines were given on choosing these for consistent results. A conceptually simple approach is sufficient to predict inclusion composition changes, because steel-inclusion reactions are rapid compared with steel-slag and steel-refractory reactions. A model based on mass transfer control closely tracks steel composition changes and hence predicts inclusion compositions. In addition to calculating inclusion changes, such a model can detect process upsets such as reoxidation after these have occurred.