2026 KarimiSibaki PESR Nitrogen Simulation

A multiphysics numerical model was developed to simulate nitrogen alloying during laboratory-scale pressurized electroslag remelting (PESR) of high-nitrogen stainless steel. This model integrates various physical phenomena, including magnetohydrodynamic flow, heat transfer, solidification, and species transport, to analyze nitrogen absorption from Si3N4 additives on the slag-free surface. Two feeding strategies—continuous and interrupted—were assessed for their effects on nitrogen distribution during ingot growth. Findings reveal that the transport of nitrogen is influenced significantly by the interplay between interfacial nitrogen transfer rates and convective mixing in the slag and melt pool. Lorentz-force-driven recirculation enhances nitrogen dissolution and mixing in the slag, while buoyancy-driven convection regulates nitrogen redistribution in the molten metal prior to solidification. Continuous feeding results in improved nitrogen uptake by maintaining concentration gradients at the slag–metal interface, whereas interrupted feeding facilitates partial homogenization but restricts final nitrogen absorption. Both strategies demonstrate that incomplete mixing before solidification causes variations in nitrogen concentration. Results were validated against experimental data, confirming the model's effectiveness in predicting nitrogen behavior during PESR.