Optimization of the filling and solidification of large ingots

Abstract

Ingot casting is an important process for the production of special steel products e.g. for power generation and
automobile industry or offshore applications. These products must fulfill highest requirements concerning steel
cleanness and homogeneity. Concerning these requirements flow conditions and the course of solidification
during the casting process are of essential importance. Against this background systematic investigations
were performed concerning these phenomena by application of advanced physical and numerical simulation
methods. In a physical model flow conditions during the filling process were investigated via flow visualization
and laser-optical measuring systems. Important information concerning the time-dependent flow condition and
quantitative information on flow velocities were obtained. Also numerical simulation with an enhanced CFD
programme was performed in order to get further information on inclusion behavior with regard to inclusion
separation, mould powder entrainment and solidification. The influence of the feeding system design, the
filling rate as well as temperature conditions with a special view to the hot top design was assessed. Optimized
constructive and process parameters were elaborated. The results prove the potential of developing a better
controlled casting and solidification process by application of physical and numerical simulation methods.