Numerical simulation of delayed pouring technique for a 360t heavy steel ingot

Abstract

A continuum mathematical model for the transport phenomena in the solidification systems has been established to study the central axial macrosegregation in a 360t multi concentration pouring (MCP) steel ingot. A time explicit finite difference scheme is adopted to calculate the coupling of the temperature, concentration and velocity flow fields. The flow equations are solved by the solution algorithm for transient fluid flow (SOLA) technique. Simulations of Fe-C-Si-Mn quaternary alloy are performed. The established model has been validated by comparing with the experimental result of a 360t MCP steel ingot. The simulated carbon concentration profile along the centreline of the ingot shows a fair agreement with the measurement. The influence of the delay time for the last ladle on the macrosegregation along the centreline has been investigated. Simulation results show that the delay time for the last ladle has a significant effect on the macrosegregation, especially for the positive segregation below the hot top. A novel criterion of selecting the delay time for the last ladle has been proposed to reduce the macrosegregation. By selecting the proper delay time for the last ladle, the carbon concentration along the centreline in the ingot body can be controlled within the range of the industrial limit. © Published under licence by IOP Publishing Ltd.