Macrosegregation in Steel Ingots: The Applicability of Modelling and Characterisation Techniques

The macro-scale segregation of alloying elements during casting remains a significant issue for steel ingot manufacturers, leading to the presence of defects such as A-segregates that can necessitate scrapping components, thereby increasing economic and environmental costs. This article reviews the historical context of macrosegregation phenomena, highlighting its persistence despite extensive research throughout the 20th century and the consequential demand for enhanced chemical homogeneity in steel ingots due to the growth of the nuclear power industry. The objective is to critically assess contemporary macrosegregation modelling techniques applicable to steel casting and to propose practical alternatives. Additionally, the article delves into experimental characterisation methods used for macrosegregation and presents a review of the various techniques currently available, revealing the shortcomings of existing models in effectively addressing the macrosegregation challenges in steel ingot production. The findings emphasize the necessity for continued innovation in modelling approaches and experimental techniques to better predict and manage macrosegregation during the solidification process of steel ingots.