Ferrite Transformation Microstructure in Low Carbon Iron Alloys in Strong Magnetic Fields

强磁场中低碳铁合金的铁素体相变显微组织

• 批准号: 11650673
• 负责人: ENOMOTO Masato
• 金额: $ 1.92万
• 依托单位: Ibaraki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650673/
• 关键词: iron alloy; phase transformation; magnetic field; ferrite

1.An Fe-0.006mass% C alloy was isothermally held at 850, 950 and 1050℃ for 20 min in a magnetic field of 30 Tesla. After cooling the grain size of ferrite microstructure was measured. At 850℃ the ferrite grain size was somewhat smaller in specimens held in magnetic fields than that held without magnetic fields. The difference in grain size was considerably large at 950℃ which was in the ferrite-single phase region in the magnetic field (the α/γ phase boundary was raised). On the other hand, the γ→α_m (massive) transformation occurred in the specimens held without a magnetic field. At 1050℃ no significant differences in ferrite grain size were observed. These results were essentially the same when the specimens were cooled very slowly through the transformation temperature.2.The influence of magnetic fields on α/γ equilibrium phase boundaries was calculated in Fe-C-X alloys (X=Mn, Si, Ni, Mo and Cr etc.) by means of Weiss molecular field theory. Not only the magnetic moment, but also the Curie temperature of iron solid solution is affected by the presence of these elements. The results indicate that Co stabilizes the ferrite phase while Mn has the opposite effect to the largest extent of all the elements studied. However, the effects are small compared to that on Fe atoms because of (usually) smaller X concentrations in Fe-C-X alloys.

1.在磁场为30℃的条件下，Fe-0.006质量%C合金分别在850T、950T和1050T恒温保温20min。冷却后测量了铁素体显微组织的晶粒度。在850℃时，加磁场处理的铁素体晶粒尺寸比不加磁场处理的略小。950℃时晶粒度差异较大，处于铁素体-单相区(α/γ相界抬高)。另一方面，在没有磁场的情况下，样品发生了γ→α_m(质量)相变。在1050℃时，铁素体晶粒度没有明显差异。2.计算了磁场对Fe-C-X合金(X=Mn，Si，Ni，Mo，Cr等)α/γ平衡相界的影响。借助于Weiss分子场理论。这些元素的存在不仅会影响铁固溶体的磁矩，还会影响铁固溶体的居里温度。结果表明，在所研究的所有元素中，Co对铁素体相起稳定作用，而Mn的作用最大。然而，由于(通常)Fe-C-X合金中的X含量较小，这种影响比对Fe原子的影响要小。

项目成果

M.Enomoto: "Influence of Magnetic Fields on Ferrite Transformation in Iron Alloys"Materia (Bulletin of Japan Institute of Metals). in press. (2001)

M.Enomoto：“磁场对铁合金中铁素体转变的影响”材料（日本金属研究所通报）。

榎本正人: "鉄合金のフェライト変態に対する強磁場の影響"まてりあ. 40巻. (2001)

Masato Enomoto：“强磁场对铁合金铁素体转变的影响”材料40。（2001）

H.Guo and M.Enomoto: "Influence of magnetic field on α/γ equilibrium in Fe-C(-X) allogs"Matericls Tvansactions,JIM. 41. (2000)

H.Guo 和 M.Enomoto：“磁场对 Fe-C(-X) 同系物中 α/γ 平衡的影响”Matericls Tvansactions，JIM 41。（2000）

H.Guo and M.Enomoto: "Influense of Magnetic Fields on α/γ equilibrium in Fe-C(-X) Alloys"Materials Transactions,JIM. 41.no.8. 911-916 (2000)

H.Guo 和 M.Enomoto：“磁场对 Fe-C(-X) 合金中 α/γ 平衡的影响”Materials Transactions，JIM 41.no.8 (2000)。

H.Guo and M.Enomoto: "Influence of Magnetic Fields on α/γ Equilibrium in Fe-C(-X) Alloys"Mater. Trans., JIM. Vol.41. 911-16 (2000)

H.Guo 和 M.Enomoto：“磁场对 Fe-C(-X) 合金中 α/γ 平衡的影响”，Mater.，JIM，第 41 卷（2000 年）。