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Brimacombe Memorial Lecture

Monday, 16 May 2022 • David L. Lawrence Convention Center
 

The AIME Keynote and AIST J. Keith Brimacombe Memorial Lecture Award was established in 1999 to honor Dr. J. Keith Brimacombe’s outstanding accomplishments in the area of process metallurgy, his dedication to the steel industry and his profound effect on people in the industry. 

2022 J. Keith Brimacombe Memorial Lecturer

P. Chris Pistorius

Center for Iron and Steelmaking Research,
Carnegie Mellon University

Modern Tools for Steelmaking Research and Optimization
Modern steelmaking is a highly competitive, data-rich industry, supported by deep fundamental data on process thermodynamics and kinetics. In my view, the role of steelmaking research is to support steelmaking process metallurgy, to identify gaps in our knowledge, and to fill those gaps. In remarks delivered 25 years ago, Keith Brimacombe noted his interest in "the application of fundamental knowledge flowing from research to optimize production and quality on the shop floor". In this presentation, I shall highlight some such examples from my own research in steel refining. Kinetic modeling of steel-slag-refractory-inclusion reactions has been successful in predicting the changes in steel and inclusion compositions during ladle refining – using the fundamental thermodynamics of solutions and reactions, together with one to three mass transfer coefficients, and without any detailed consideration of flow conditions. This approach quantifies how – for example – alumina deoxidation product transforms to magnesium oxide inclusions in highly deoxidized advanced high-strength steels. This approach does not work if the steel bath is significantly inhomogeneous, for example after calcium treatment. Immediately after calcium treatment of aluminum-killed steel, inhomogeneity of steel composition is reflected in development of a new population of calcium aluminates and dissolution of the pre-existing alumina or spinel inclusions –  different from the previously proposed mechanisms of calcium treatment, and supported by detailed analysis of inclusion compositions and sizes, by scanning electron microscopy. In contrast with the kinetic models using a few mass transfer coefficients, detailed flow modeling is needed to understand the interaction between argon bubbles, steel and slag. These models remain incomplete, because of at best partial quantification of turbulent flow, and the large range of length scales: from micron-sized inclusions to ladle dimensions of several meters. As a final example, combining tools for data visualization and analysis with metallurgical fundamentals can provide clear answers on the quantitative effect of process variables such as slag carry-over, reoxidation and stirring on refining. The common thread of these examples is that all combine metallurgical fundamentals with modern tools of calculation, microscopy, and data analysis, to quantify steelmaking.