Macrosegregation of Carbon in Heavy Steel Casting

Segregation of elements during solidification of massive steel castings and ingots is caused by their different solubility in the melt and in the newly formed solid phase. The macrosegregation of elements significantly affects the structure in terms of microstructure and macrostructure of the casting as well as on its mechanical and operational properties. This paper deals with the evaluation of macrosegregation of selected elements on a real cross-section of a heavy experimental carbon steel casting. Macrosegregation of elements was determined by spectral analysis at selected locations and compared with the ProCAST software and its results of casting solidification simulation. The macrosegregation was analysed along the height and width of a cross-section of the casting, which measured approximately 1800×600×100 mm. Over 300 points were analysed in this area of the casting. The results present mainly carbon segregation. The carbon segregation is compared to the solidification conditions expressed by the cooling rate and the time between the liquidus and solidus temperatures (mushy zone). The aim of this paper was also to verify the measured results with those calculated using commercial software. In conclusion, the measured macrosegregation of the carbon in the casting is different from the simulated macrosegregation, this fact is not negligible. The difference in measured carbon content is influenced by solidification kinetics and will significantly affect the material properties.