Takakuwa Osamu, Iwano Tatsuya, Hirayama Kyosuke, Toda Hiroyuki, Takeuchi Akihisa, Uesugi Masayuki
Department of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Graduate School of Mechanical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Sci Rep. 2024 Jun 24;14(1):14445. doi: 10.1038/s41598-024-65505-3.
Excellent strength-ductility balance in metastable Fe-Cr-Ni austenitic alloys stems from phase transformation from austenite (fcc structure) to α' martensite (bcc structure) during deformation, namely deformation-induced α' martensitic transformation (DIMT). Here, DIMT in a metastable Fe-17Cr-7Ni austenitic alloy was detected in situ and characterized in three dimensions (3D) by employing synchrotron radiation X-ray microtomography. This technique utilizes refraction contrast, which is attributable to the presence of phase boundaries between the parent austenite and the newly formed α' martensite phase. By combining microtomography and position-sensitive X-ray diffraction, we succeeded in crystallographically identifying multiple α' martensite phases continuously transformed in four groups from a single parent austenitic phase.
亚稳Fe-Cr-Ni奥氏体合金优异的强度-延展性平衡源于变形过程中奥氏体（面心立方结构）向α'马氏体（体心立方结构）的相变，即形变诱发α'马氏体相变（DIMT）。在此，通过使用同步辐射X射线显微断层扫描技术，对亚稳Fe-17Cr-7Ni奥氏体合金中的DIMT进行了原位检测并对其进行了三维（3D）表征。该技术利用了折射对比度，这归因于母相奥氏体和新形成的α'马氏体相之间相界的存在。通过结合显微断层扫描和位置敏感X射线衍射，我们成功地从晶体学角度识别出从单个母相奥氏体相中连续转变为四组的多个α'马氏体相。
