Research On Solidification Simulation Of 38t Ingot With Double Electrodes

Due to the impact of COVID-19 since 2020,the global economy has been severely hampered,and China has repeatedly stressed the need to strengthen national infrastructure construction.These tasks cannot be carried out without the support of power station,petrochemical industry,metallurgy,large-scale equipment manufacturing industry.With the development of the large-scale equipment,the specification and size of the ingot is needed to be more larger,and the ingot internal quality are required to be more strict.However,there still exist many types of defects and deficiencies in traditional casting methods,such as large ingots take a long time to fully solidified,the cooling rate and temperature of the ingot center area are big different from that of the outer area in the solidification process.Moreover,the segregation of solidification structure relative to small ingot,shrinkage porosity and excessive grain size are particularly prominent.This paper explores the implication of external electric current to generate enforced flow of molten steel in the center of ingot as results of the improvement of internal quality.Al Si7 alloy with Y₂O₃（artificial inclusion）were used for solidification experiments to study the effects of changing current intensity on the solidification structure,and dispersion of Y₂O₃with the application of external electric current.It was found that changing the current intensity has different refinement effects on the solidified structure,and the Nano-particles of Y₂O₃were dispersed under the application of electric current.In order to further study the influence of current change on the composition of the internal structure of the metal melt,20kg ingot of 35Cr Mo A steel was chosen.The electric current was applied before the ingot fully solidified by inserting double electrodes during solidification.The results showed that DC electric currents can significantly reduce the depth of shrinkage cavity,and improve the surface quality of ingot and element segregation.The predicted shrinkage location and porosity by Pro CAST software shows a good agreement with the experimental results.Based on the experiments and numerical simulations,the temperature fields of 38t ingot were calculated by Pro CAST.Furthermore,the effects of operating parameters on the fluid flow in a 38t ingot were simulated by multi-fields models of Ansys CFX,varying with electrode spacing,insertion depth and the intensity of electric current.