The Effect of Solute Nb on the Austenite-to-Ferrite Transformation
The Effect of Solute Nb on the Austenite-to-Ferrite Transformation
复制标题
固溶铌对奥氏体向铁素体转变的影响
DOI：
10.1007/s11661-014-2659-5
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发表时间：
2015-02-01
影响因子：
2.8
通讯作者：
Militzer, Matthias
中科院分区：
文献类型：
--
作者：
Jia, Tao;Militzer, Matthias
摘要铌是一种广泛应用于钢中的微合金化元素，当铌保留在溶液中时，它主要通过溶质拖曳来阻碍贝氏体向铁素体的转变。建立定量模型预测Nb对相变动力学的影响至关重要。在目前的工作中，专门的连续冷却转变（CCT）的研究进行了低碳钢微合金化与0.047重量%的Nb从完全再结晶奥氏体状态具有相同的晶粒尺寸，但在溶液中的Nb量不同。从一个基本的角度来看，通过假设一个混合模式的反应，包括Nb的溶质阻力的亚黄铁矿到铁素体的转变动力学描述。利用Fazeli和Militzer的溶质曳力模型，从CCT数据中确定了Nb的本征界面迁移率、跨界面扩散率及其与界面的结合能。对界面参数进行了严格分析，并与扩散和晶界偏析的独立测量进行了比较。
AbstractsNiobium is a widely used micro-alloying element in steels that can retard the austenite-to-ferrite transformation primarily by solute drag when Nb remains in solution. It is critical to develop quantitative models to predict the effect of Nb on the transformation kinetics. In the present work, dedicated continuous cooling transformation (CCT) studies were performed for a low-carbon steel microalloyed with 0.047 wt pct Nb starting from fully recrystallized austenite states with the same grain size but different amounts of Nb in solution. The austenite-to-ferrite transformation kinetics is described from a fundamental perspective by assuming a mixed-mode reaction including solute drag of Nb. Using the solute drag model of Fazeli and Militzer, the intrinsic interface mobility, trans-interface diffusivity of Nb, and its binding energy to the interface have been determined from the CCT data. The interfacial parameters are critically analyzed and compared with independent measurements of diffusion and grain boundary segregation.