低碳纯净钢连铸坯凝固前沿元素微观偏析模型的研究

Study on Element Microsegregation Model at Solidifying Interface in Continuous Casting Slab of Low Carbon Clean Steel

建立了一个连铸坯凝固前沿的元素微观偏析模型,模型考虑了钢的包晶相变,以及凝固过程枝晶粗化的影响。首次对低碳（0.01%-0.09%C）纯净钢凝固前沿的元素偏析行为做了模拟研究。钢凝固过程P、S、C的偏析程度要高于Si、Mn,固相率大于0.9以后,C、S、P偏析度急剧上升。随着Mn含量的增加S元素的偏析度逐渐降低,当固相率大于0.8以后,S元素的偏析受到Mn的抑制,偏析程度开始降低。对0.01%~0.09%C的低碳纯净钢,凝固过程中钢液始终以δ相凝固,无δ-γ相变过程。

A micro segregation model of element at solidifying interface is established in this paper.The peritectic phase transformation and dendritic growth during solidification of steel is considered in the model.This is the first simulation study about the micro segregation of element at solidifying interface in low carbon（[C] is 0.01%～0.09%） clean steel.During solidification the segregation degree of P,S,C is higher than Si and Mn.As the solidification rate exceed 0.9,the segregation of C,S,P will increase rapidly.With increase of Mn content,the segregation of S will decrease gradually.While solidification rate is higher than 0.8,segregation of S is affected by Mn,and the segregation degree will begin to reduce.If the carbon content of clean steel is between 0.01~0.09%,the solidification phase is δ but not δ-γ.