Continuous casting is the process of solidifying molten metal to produce different products such as billet, bloom, or slab. This process can be formulated mathematically in terms of conflicting objectives including productivity, yield, quality and production costs to satisfy sets of constraints such as oscillation mark depth, metallurgical length and center line segregation. The objectives are conflicting in the sense that, if the productivity is increased, there is a reduction in other performance measures. These performance specifications are greatly influenced by operating conditions such as casting speed, superheat, mold oscillation frequency, and secondary cooling conditions. The process of identifying the set points for the continuous casting operation is iterative and expensive. The uncertainties inherent in modeling the phenomena computationally behooves exploration of the solution space to determine the quality of the solution and gain insight.
In this paper, a method to explore the solution space is introduced. The method includes weight sensitivity and constraint sensitivity analysis. This analysis allows a designer to ascertain to what extent the solution is insensitive to uncertainties inherent in the modeling of the decision problem. This is a crucial step towards determining robust solutions for performance measures. The utility of the method is illustrated in providing decision support for the continuous casting operation in presence of variability in the operating parameters and conflicting end requirements, such as productivity and quality parameters.
This method can be instantiated for exploring the solution space for ladle, tundish, rolling and annealing and thereby facilitating the exploration of the solution space for critical unit operations associated with steel product manufacturing. This development has the potential to reduce the number of plant trials necessary to determine the set points for manufacturing a new product mix with a new grade of steel using the existing equipment in a steel mill. The focus in this paper is on the method and not the results per se.