Analytical microsegregation model to study the effect of liquidus correlation on hot cracking susceptibility

Hot cracking not only severely affects the product quality but is also a financial and safety issue during continuous casting process. Because it is considered that the initiation and propagation of cracking is associated with the microsegregation phenomenon, and cracking criteria have been proposed to evaluate the cracking tendency (Bellet et al., 2009; Eskin and Katgerman, 2007) [1,2], the solidification path is thus considered one of the critical inputs for the criteria to model analytically the microsegregation. For multicomponent steels, the liquidus correlation is usually introduced into the analytical microsegregation model as the sum effect of all individual components. The purpose of this study, is to investigate the influence of liquidus correlation on microsegregation to predict cracking susceptibility. By introducing different liquidus correlations, the modeling work has been combined with the analytical microsegregation model, including the results in two cracking criteria (RDG criterion and Kou criterion). In addition, a new liquidus correlation has been included to accommodate the high concentration in the liquid phase caused by solute segregation. According to these modeling results, the predicted solidification paths vary with the liquidus correlations, leading to the deviations on cracking susceptibility evaluated by both RDG and Kou criteria. Therefore, the liquidus correlation should be well determined when combining the cracking criteria with the analytical microsegregation model for evaluating the cracking susceptibility of multicomponent steels.