The objective of the Consortium is to develop comprehensive mathematical models of the continuous casting of steel and related processes and to apply these models to improve understanding, optimize the process, and solve problems of interest to the sponsors.

Mathematical models have been developed over the past decade to simulate fluid flow, heat transfer, mass transfer, solidification, shrinkage, and stress generation in and just below the mold region of a continuous steel slab casting machine. The system of models calculates:

• Turbulent flow of molten steel delivered through a submerged, bifurcated nozzle
• Fluid flow in the mold, including multiphase effects due to argon gas injection, inclusion particle movement, and heat transfer
  
• Mass transfer, important during grade transitions
  
• Flow and heat transfer within the insulating mold powder layer
  
• Heat transfer across the mold / steel shell interfaces
  
• Thermal distortion, fatigue, and cracking of the copper mold
  
• Coupled heat flow, shrinkage, stress development, and hot tear cracking within the solidifying steel shell

The model calculations have been compared with observations using physical water models and plant measurements, and have successfully reproduced many known phenomena, in addition to making other new and interesting predictions. The work also involves the development and improvement of numerical methods and algorithms for solving these complex mathematical problems on computer workstations.

The mathematical models are being applied to investigate problems of practical importance, and to optimize process design and operation variables, which can be controlled. Fast, user-friendly versions of several of the models are in use at the sponsoring steel companies, where specific applications of the models include:

• Design of submerged entry nozzle geometry
  
• Optimization of mold taper, including variations during automatic width changes and high casting speed
• Minimization of slab downgrading due to intermixing during grade transitions
• Optimization of argon injection to control turbulent flow in the mold and the formation of surface defects
• Better understanding of the effects of mold design, process parameters, and material properties on the flow pattern, heat transfer, and stress in the mold and steel shell
• Better understanding of the mechanism of formation of various defects, including breakouts, longitudinal depressions, surface cracks, inclusion entrapment and nozzle clogging.

Taken together, these models represent a powerful tool for gaining insight into the continuous casting process, helping to improve its operation, and thereby increasing competitiveness of the industry.