ABSTRACT

Microsegregation is an inherent phenomenon that occurs during the solidification of steel and can result in multiple casting defects. To explain and predict the microsegregation phenomenon, the analytical microsegregation model has been extensively used. However, equilibrium partition coefficients always play a critical role, and the deviations of microsegregation prediction caused by the discrepancy of equilibrium partition coefficients have been recently reported. In this study, the deviations of element redistribution and evolution of solid fraction on an advanced high-strength steel (AHSS) have been demonstrated by introducing two sets of the equilibrium partition coefficients. Based on predicted solidification paths, the hot cracking susceptibility of the steel was evaluated by using Rappaz–Drezet–Gremaud and Kou criteria, respectively. Furthermore, according to modelling results, the solidification path predicted with variable equilibrium partition coefficients is more prone to hot cracking, indicating that a higher degree of solute partition results in higher cracking susceptibility.

摘要

微观偏析是钢凝固过程中发生的一种固有现象，可导致多种铸造缺陷。为了解释和预测微偏析现象，解析微偏析模型已被广泛使用。然而，平衡分配系数始终起着关键作用，最近报道了由平衡分配系数的差异引起的微观偏析预测偏差。在这项研究中，通过引入两组平衡分配系数，证明了先进高强度钢 (AHSS) 上元素重新分布和固体分数演变的偏差。基于预测的凝固路径，分别使用 Rappaz-Drezet-Gremaud 和 Kou 标准评估钢的热裂纹敏感性。