Casting Defect and Process Optimization of Steel Crossing

The casting quality of crossing in a railway turnout is required to be higher because of the significant impact load on the rail. The simulation results of using different fever risers, the temperature field, solidification process and casting defects, were obtained by the implicit finite element method based on the ProCAST software. To improve the authenticity of the visualization of the casting process, a numerical simulation assumption of the mass flow rate attenuation was proposed for the overflow of molten metal from the risers during tilt pouring. The result shows that the temperature field is more uniform when the risers with exothermic energy of 1 200 kJ/kg were chosen and the defects converge to the risers in accordance with the principle of sequential solidification. Compared with insulation riser, shrinkage porosity proportion decreased from 23.10% to 17.01%, and the shrinkage cavity proportion decreased from 1.002% to 0.530%. However, changing the burned time has no obvious effect on the casting. At the same time, the process optimization scheme of risers was put forward in this study and the casting defects such as shrinkage cavity and porosity are predicted according to the 'V type' feeding area of the fever risers. This improvement has greatly improved the performance of the casting, and the passing gross tonnage could reach 300 million tons.