Application of the IDS solidification and microstructure tool for quality prediction in continuous casting of steel with novel phenomenological quality criteria

Abstract

Abstract

The defects forming in continuously cast steel take place typically due to the cumulative impacts of the steel grade, machine design, and the casting practices. The steel grade alone is associated with many physical aspects affecting the sensitivity to defects. As an example, the formation of transverse corner cracks depends strongly on the type, size and number of precipitates, phase transformations, and the grain size. To evaluate the defect sensitivities of a steel grade as a function of its composition and cooling rates, a thermodynamickinetic model which calculates the physical causes is needed. In this work, the IDS tool, a thermodynamickinetic-empirical tool for continuous casting and the subsequent cooling and reheating processes, was applied for quality prediction of continuous casting, based on the steel composition and cooling rates. The prediction is based on novel phenomenological quality criteria which separately describe the different physical causes for different kinds of surface and internal cracks. An additional benefit of this system is that it provides theoretical explanations as to why certain defects are forming or would form and can be used for devising practical solutions to avoid them. This paper presents a new rule-based system, which accounts for the cumulative effects of the individual criteria, along with practical examples.