Unraveling the effects of Nb interface segregation on ferrite transformation kinetics in low carbon steels
Unraveling the effects of Nb interface segregation on ferrite transformation kinetics in low carbon steels
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揭示铌界面偏析对低碳钢铁素体转变动力学的影响
DOI：
10.1016/j.actamat.2021.117081
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发表时间：
2021-06
期刊：
影响因子：
9.4
通讯作者：
T. Furuhara
中科院分区：
文献类型：
--
作者：
H. Dong;Y. Zhang;G. Miyamoto;M. Inomoto;H. Chen;Z. Yang;T. Furuhara
添加少量 Nb 可以强烈减缓铁素体生长动力学。其起源归因于迁移铁素体/奥氏体界面处 Nb 偏析造成的溶质阻力效应 (SDE)。然而，由于表征技术的限制，元素偏析、SDE和界面速度之间的关系尚未定量阐明。同时，Nb和C原子之间的强亲和力会引起界面碳化物的析出，即相间析出，这可能会影响Nb的偏析行为，使问题变得更加复杂。因此，本研究定量研究了Fe-0.08C-(0.035, 0.061)Nb (mass%)模型合金中Nb偏析量、能量耗散、NbC析出物和界面速度等界面信息。结果表明，迁移铁素体/奥氏体界面处的能量耗散随着保温时间的延长或转变温度的升高而降低。 Nb 原子更喜欢在非 K-S 界面而不是靠近 K-S 界面处偏析。非K-S界面处的Nb偏析量随着时间的延长而增加，而提高块体Nb含量或降低转变温度不会导致偏析的显着增加。 Nb 偏析、能量耗散和界面速度之间的关系可以通过优化参数（即偏析能、界面厚度和跨界面扩散率）的 SDE 模型很好地再现。 NbC 相间沉淀的出现通过消耗铁素体中的 Nb 溶质来削弱 SDE，从而间接影响转变动力学。相比之下，它们的钉扎效应起着边际作用。
Addition of small amount of Nb can strongly retard the ferrite growth kinetics. The origin has been attributed to the solute drag effect (SDE) by Nb segregation at the migrating ferrite/austenite interface. However, due to limitation of characterization techniques, the relations between elemental segregation, SDE and interface velocity have not been quantitatively clarified yet. Meanwhile, the strong affinity between Nb and C atoms can induce carbide precipitation at the interface, namely interphase precipitation, which may influence the Nb segregation behavior and make the issue even more complicated. Therefore, in this study, the interface information including amount of Nb segregation, energy dissipation, NbC precipitates and interface velocity in Fe-0.08C-(0.035, 0.061)Nb (mass%) model alloys is quantitatively investigated. It reveals that the energy dissipation at the migrating ferrite/austenite interface decreases with longer holding time or higher transformation temperature. The Nb atoms prefer to segregate at the non K-S interface rather than the near K-S interface. Amount of Nb segregation at the non K-S interface increases with longer time, while raising bulk Nb content or lowering transformation temperature does not lead to a notable increment of segregation. The relations between Nb segregation, energy dissipation, and interface velocity can be well reproduced by the SDE model with optimized parameters (i.e., segregation energy, interface thickness and trans-interface diffusivity). Occurrence of NbC interphase precipitation affects the transformation kinetics indirectly by weakening the SDE via consumption of Nb solutes in ferrite. In contrast, their pinning effect plays a marginal role.
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DOI：
10.1007/s11661-004-0296-0
发表时间：
2004-04
期刊：
Metallurgical and Materials Transactions A
影响因子：
--
作者：
E. S. Humphreys;H. A. Fletcher;J. Hutchins;A. Garratt-reed;W. Reynolds;H. Aaronson;G. Purdy;G. D. Smith
通讯作者：
E. S. Humphreys;H. A. Fletcher;J. Hutchins;A. Garratt-reed;W. Reynolds;H. Aaronson;G. Purdy;G. D. Smith
影响因子：
0.8
作者：
R. Okamoto;J. Ågren
通讯作者：
R. Okamoto;J. Ågren
含 Nb Fe-C-Mn 合金循环相变过程中移动 α/γ 界面与间相沉淀碳化物之间的相互作用分析
影响因子：
9.4
作者：
Haokai Dong;Hao Chen;Wei Wang;Yongjie Zhang;Goro Miyamoto;Tadashi Furuhara;Chi Zhang;Zhigang Yang;Sybr;van der Zwaag
通讯作者：
van der Zwaag
影响因子：
1.8
作者：
T. Furuhara;T. Yamaguchi;G. Miyamoto;T. Maki
通讯作者：
T. Furuhara;T. Yamaguchi;G. Miyamoto;T. Maki
DOI：
10.1007/s11661-007-9106-9
发表时间：
2007-04
期刊：
Metallurgical and Materials Transactions A
影响因子：
--
作者：
C. Sinclair;C. Hutchinson;Y. Bréchet
通讯作者：
C. Sinclair;C. Hutchinson;Y. Bréchet