Application Of Heat Transfer Model In Dynamic Soft Reduction Model For Continuous Cast Bloom

Center segregation and center porosity will seriously affect the internal slab quality for continuous casting bloom. Therefore, we must actively seek the solution to reduce the center segregation and center porosity. Dynamic soft reduction is the ideal technology to eliminate the issue of center segregation and center porosity. The main parameters of soft reduction including: soft reduction zone, soft reduction amount and soft reduction rate. In this paper, numerical simulation methods are established to calculate the main parameters of soft reduction. Through on-site high, medium and low carbon slab's experimental data and the quality in a variety of possible reduction cases we got soft reduction in different parameter cases, and inspected the numerical calculation results wether it is reasonable.In view of the characteristics of soft reduction process, this paper, had established the implicit algorithm of two-dimensional heat transfer model for continuous casting bloom and programming model to calculate. The heat transfer model results and pin shooting experimental results were compared in order to ensure the accurate. Combined with the results of heat transfer model and the VAI provided solid fraction scope (fs = 0.3-0.7), this paper having calculated the soft reduction zone. Other two mian parameters soft reduction rate and soft reduction amount were calculated by the theoretical model. Through analyzed the industrial test-site of Pangang bloom, the calculated soft reduction parameters are verified.Through the comparison of model calculations and the field data, we have got the conclusions as follows:①Accurate calculation of the temperature field is basic to establish dynamic soft reduction zone model, and soft reduction parameters based on the solid fraction were calculated by the model. The solidus temperature selection is a major factor to impact the accurate of solid fraction.②Speed for the soft reduction zone is a greater impact, with speed increasing, the length of soft reduction zone are variable. The pouring temperature for the soft reduction zone was less affected.③At the same speed, the soft reduction rate along the casting direction linear narrow. The maximum and minimum values of reduction ratio at the low speed are higher than the corresponding higher speed maximum and minimum values of soft reduction ratio.④In the steel, casting section size and pressure range under certain conditions, soft reduction amount often unchanged with casting speed.⑤Through the on-site high, medium and low carbon steel slab of low magnification photographs, and data analysis, high-carbon steel has been the reduction amount values for 7-8 mm, medium carbon steel values for 4.5-6 mm, low carbon values for the 3-4.5mm to achieve the better slab qualities. The results were compared with the model results; it shows that the results are rational and effective.