ABSTRACT

Good knowledge of the redistribution characteristic of solute elements is essential for the design and the production of new alloying systems. Part I of this series demonstrated the deviations of microsegregation predictions on an advanced high strength steel (AHSS) caused by equilibrium partition coefficients based on the analytical microsegregation model. In this study, the aim is to conduct a feasible experiment to assess the microsegregation and solidification characteristics of the AHSS steel and to validate the effect of partition coefficients on microsegregation predictions. The SQ method (solidification followed by quenching) was adopted for validation in this study. Solid fraction evolution was obtained on the basis of quenched solidification microstructures to compare with predicted solidification paths. Subsequently, EPMA mappings were performed on quenched microstructures to generate the concentration profiles of Mn in the liquid phase, and the measured data were used to assess the predicted degree of microsegregation.

摘要

充分了解溶质元素的再分布特性对于新合金系统的设计和生产至关重要。本系列的第 I 部分展示了基于分析微偏析模型的平衡分配系数导致的高级高强度钢 (AHSS) 的微偏析预测偏差。在这项研究中，目的是进行一个可行的实验来评估 AHSS 钢的微偏析和凝固特性，并验证分配系数对微偏析预测的影响。本研究采用 SQ 方法（凝固后淬火）进行验证。在淬火凝固微观结构的基础上获得固体分数演变，以与预测的凝固路径进行比较。随后，