Influence of solute drag on bainite transformation in iron alloys

溶质阻力对铁合金贝氏体转变的影响

• 批准号: 14350337
• 负责人: ENOMOTO Masato
• 金额: $ 6.08万
• 依托单位: Ibaraki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350337/
• 关键词: iron alloy; diffusion; TTT-curve; ferrite transformation; solute drag; bainite

For the preceding two years ferrite transformation behaviors and carbide precipitation in Fe-C-Mo and Fe-C-Ni alloys were studied, and the mechanism for incomplete transformation was discussed. Also, a simulation model of diffusion-controlled growth of ferrite was developed incorporating solute drag due to alloying element accumulation at α/γ boundaries.In the study of the influence of magnetic field on the ferrite transformation in Fe-C-Mo alloys it was found that the bay was shifted to a shorter time and a higher temperature side by applying a magnetic field. This was attributed to the promotion of transformation kinetics below the bay because of the increase in the driving force of transformation due to the applied field. It is considered that the extent of the promotion of ferrite transformation is smaller above the bay because of the concurrent precipitation of carbides in the Fe-C-Mo alloy.Experimental data on the local condition at moving α/γ boundaries in literature were reviewed. The diffusion spike of an alloying element is often used as a criterion discriminating para-and orth-(or local) equilibrium condition at the boundary. It was found that alloying element partition occurred even in the situation in which the spike width of alloying element in austenite is less than the austenite lattice parameter. This indicates that the diffusion of alloying element significantly occurs along α/γ boundaries and in ferrite. These issues were discussed in the workshop on alloying element effects on austenite decomposition held in Stockholm in December, 2004.

近两年来，我们研究了Fe-C-Mo和Fe-C-Ni合金中铁素体的相变行为和碳化物的析出，并对不完全相变的机理进行了探讨。在研究磁场对Fe-C-Mo合金中铁素体相变影响的过程中，发现磁场使铁素体相变向更短的时间和更高的温度方向移动。这是由于转换动力学的促进下湾，因为在转换的驱动力增加，由于施加的字段。本文认为，由于碳化物在Fe-C-Mo合金中的同时析出，在晶界以上促进铁素体相变的程度较小，并对文献中有关移动α/γ晶界局部条件的实验数据进行了评述。合金元素的扩散峰常被用来作为判别边界上准平衡和局部平衡条件的标准。发现即使在奥氏体中合金元素的峰宽小于奥氏体点阵参数的情况下，合金元素也会发生分配。这表明合金元素沿沿着α/γ晶界和铁素体内扩散明显。2004年12月在斯德哥尔摩举行的合金元素对奥氏体分解的影响研讨会上讨论了这些问题。

项目成果

M.Enomoto: "Austenite formation and Decomposition (ed. E.B.Damm and M.J.Merwin)"The Minerals, Metals and Materials Society. 97-111 (2003)

M.Enomoto：“奥氏体形成和分解（E.B.Damm 和 M.J.Merwin 编辑）”矿物、金属和材料协会。

M.Enomoto, N.Maruyama, K.M.Wu, T.Tarui: "Alloying Element Accumulation at Ferrite/austenite Boundaries below the TTT-diagram bay in an Fe-C-Mo Alloy"Materials Science and Engineering. A343. 151-157 (2003)

M.Enomoto、N.Maruyama、K.M.Wu、T.Tarui：“Fe-C-Mo 合金中 TTT 图湾下方铁素体/奥氏体边界处的合金元素积累”材料科学与工程。

K.M.Wu, M.Kagayama, M.Enomoto: "Kinetics of Ferrite Transformation in an Fe-0.28mass%C-3mass%Mo Alloy"Materials Science and Engineering. A343. 143-150 (2003)

K.M.Wu,%20M.Kagayama,%20M.Enomoto:%20"动力学%20of%20Ferrite%20Transformation%20in%20an%20Fe-0.28mass%C-3mass%Mo%20Alloy"材料%20Science%20and%20Engineering.%

T.Yokomizo, M.Enomoto, O.umezawa: "Three-dimensional distribution, morphology, and nucleation site of intragranular Ferrite Formed in association with Inclusions"Materials Science and Engineering. A344. 261-267 (2003)

T.Yokomizo、M.Enomoto、O.umezawa：“与夹杂物相关的晶内铁素体的三维分布、形态和成核位点”材料科学与工程。

M.Enomoto: "Partition of Carbon and Alloying Elements during the growth of ferrous bainite"Scripta Materialia. 47. 145-149 (2002)

M.Enomoto：“铁贝氏体生长过程中碳和合金元素的分配”Scripta Materialia。