Verification of the Displasive-Diffusion-less Mechanism in Bainitic Phase Transformations by a High Resolution Fractography

通过高分辨率断口验证贝氏体相变中的无弥散扩散机​​制

• 批准号: 10650655
• 负责人: SHIMIZU Kenichi
• 金额: $ 2.56万
• 依托单位: Kanazawa Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650655/
• 关键词: Bainite; Phase Transformation; Atomic Diffusion Type; Displasive-Diffusionless Type; Cu-Zn-Al Alloy; High Resolution Fractography; 高分解能フラクトグラフィ; 高分解能フラクトグラフイ

The bainitic transformation is believed to finally proceed by a diffusion mechanism of atoms. However, there has also been proposed another idea where a displasive-diffusionless mechanism is operated in the nucleation stage and early stage of growth of bainitic transformations. The present investigation was carried out to verify which of the two mechanisms, diffusion or displeasures and atomic compositions of the bainitic plate and its matrix confronted along their interphase boundary on tensile-fractured surfaces, that is, by doing fractography with a high resolution scanning electron microscope (SEM) equipped with a field emission electron gun.The materials used for the verification are carbon steels (JIS S25C and S%%C) and Cu-28.3Xn-6.0Al(at .%) alloy, and the results obtained for the latter alloy will be reported below, because those for carbon steels were previously reported. In order to observe certainly a bainite plate and its matrix confronted on tensile-fractured surfaces, the volume ration of bainite plates to the matrix must be appropriate. The ratio was first examined by changing both isothermal holding temperature and time for the bainitic transformation, and 473 K and 28.8 Ks were found to be appropriate. The bainitic specimens subjected to this heat-treatment were tensile-fractured, and the fractured surfaces were observed by the high resolution fractography. Areas, where a bainite plate and its matrix seem to be confronted, were search, and EDX analyses were performed for the confronted bainite plates and matrices. As a result, it was found that atomic compositions of the plate and matrix were the same, and therefore the displasive-diffusionless mechanism is supposed to be really operated. However, more detailed examination is needed, because a little ambiguity is remained for the identification of bainite plates and matrices confronted on fractured surfaces.

据信，贝纳特转化最终是通过原子的扩散机制进行的。然而，也有人提出了另一个想法，即在成核阶段和生长的生长阶段和早期阶段，贝恩氏转化的生长机制运行。进行了本研究以验证贝恩氏板的两种机制，扩散或不满和原子组成中的哪种机制，其基质及其基质沿着其相间划分的表面沿其相间边界面临，即通过与高分辨率扫描（SEMISITIDER）相互启用（SEMISITIAL）的分裂量（通过均匀的仪表仪），该材料是他电子的carsions od the。 S25C和S %% c）和CU-28.3XN-6.0AL（AT。％）合金，以及后一种合金获得的结果，将在下面报告，因为先前报道了碳钢的碳钢。为了肯定观察贝氏板及其基质在拉伸裂缝的表面上，贝氏板的体积分量必须适当。首先通过更改晶体转化的等温保持温度和时间来检查该比率，发现473 K和28.8 KS是合适的。将受到这种热处理的贝恩质标本进行拉伸裂缝，并通过高分辨率分裂观察到断裂的表面。搜索了贝氏板及其基质似​​乎面临的区域，并对面对面的贝氏板和矩阵进行了EDX分析。结果，发现板和基质的原子组成是相同的，因此可以真正操作显示器扩散机制。但是，需要进行更详细的检查，因为鉴定出在断裂的表面上面临的贝氏板和矩阵的鉴定仍然存在一些歧义。

项目成果

清水 謙一: "変位型原子無拡散相変態に関する研究の流と学界の動き"日本鉄鋼協会誌"ふぇらむ". 3・2. 31-36 (1998)

清水健一：“关于位移型原子无扩散相变的研究动向和学术动向”日本钢铁学会杂志“Ferram”3·2（1998）。

T.Kakeshita, T.Saburi, K.Shimizu: "Kinetics of Martensitic Transformations in Some Ferrous and Non-Ferrous Alloys"Philosophical Magazine B. 80・2. 71-81 (2000)

T.Kakeshita、T.Saburi、K.Shimizu：“某些黑色金属和有色金属合金中马氏体相变的动力学”哲学杂志 B. 80・2 (2000)。

Y.Kishi, Z.Yajima, K.Shimizu & K.Morii: "Fatigue Crack Growth Properties and Scanning Electron Microscopy of Fatigue Surface of Ti-Ni-Co SMA's"Proc. Intern'l. Symp. & Exhib. On Shape Memory Mater. (Mater. Sci. Forum). 327-328. 123-126 (1999)

Y.岸、Z.矢岛、K.清水

T.Kakeshita,Y.Sato,T.Saburi,K.Shimizu et al.: "Effects of Static Magnetic Field na Hydrostatic Pressure on the Isothermal Martensitic Transformations in an Fe-Ni-Cr Alloy" Mater.Transactions,Jpn.Inst.Metals. 40,2. 107-111 (1999)

T.Kakeshita、Y.Sato、T.Saburi、K.Shimizu 等人：“静磁场和静水压力对 Fe-Ni-Cr 合金等温马氏体转变的影响”Mater.Transactions，Jpn.Inst。

Y.Kishi,Z.Yajima,K.Shimizu & K.Morii: "Effect of Microstructures on Mechanical Fatigue Crack Growth Character.of a Ti-Ni-Co Mem.Al."Intern'l.Conf.on Martensitic Transformations(ICOMAT'98). 654-657 (1999)

岸Y、矢岛Z、清水K