Uneven Solidification during Wide-thick Slab Continuous Casting Process and its Influence on Soft Reduction Zone

A two-dimensional heat transfer model was developed to analyze the uneven solidification, particularly the shape of solidification end in wide-thick slab continuous casting process. In order to ensure the accuracy of simulation, material properties of peritectic steel were calculated by weighted averaging of phase fractions, and the boundary conditions were obtained by realistic water flux distribution on the slab transverse surface. The model was verified by nail shooting results at different locations of strand, and the absolute value of relative error was found to be no more than 2.12%. According to the simulation results, the liquid core around 1/8 location of slab width increased after the water flux was decreased around the slab corner to reduce transverse corner cracks. The soft reduction (SR) zone was optimized to reduce macro-segregation both at the slab center and 1/8th location. The plant results showed that the inner quality of wide-thick slab was significantly improved in the whole transverse section with the optimized SR zone parameters.