Novel -75°C SEM cooling stage: application for martensitic transformation in steel

Kaneaki Tsuzazki; Motomichi Koyama; Ryosuke Sasaki; Keiichiro Nakafuji; Kazushi Oie; Akinobu Shibata; Takashi Gondo; Hiroya Miyazaki; Hiroshi Akamine; Minoru Nishida

doi:10.1093/jmicro/dfaa051

Novel -75°C SEM cooling stage: application for martensitic transformation in steel

Microscopy (Oxf). 2021 Mar 24;70(2):250-254. doi: 10.1093/jmicro/dfaa051.

Authors

Kaneaki Tsuzazki^{1

2

3}, Motomichi Koyama^{3

4}, Ryosuke Sasaki², Keiichiro Nakafuji², Kazushi Oie², Akinobu Shibata^{1

3}, Takashi Gondo⁵, Hiroya Miyazaki⁵, Hiroshi Akamine⁶, Minoru Nishida⁶

Affiliations

¹ Research Center for Structural Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, 305-0047, Japan.
² Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
³ Elements Strategy Initiative for Structural Materials (ESISM), Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
⁴ Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan.
⁵ Mel-Build Corporation, 2-11-36 Ishimaru, Nishi-ku, Fukuoka, 819-0025, Japan.
⁶ Faculty of Engineering Sciences, Kyushu University, Kasuga, Fukuoka, 816-8580, Japan.

Abstract

Microstructural changes during the martensitic transformation from face-centred cubic (FCC) to body-centred cubic (BCC) in an Fe-31Ni alloy were observed by scanning electron microscopy (SEM) with a newly developed Peltier stage available at temperatures to -75°C. Electron channelling contrast imaging (ECCI) was utilized for the in situ observation during cooling. Electron backscatter diffraction analysis at ambient temperature (20°C) after the transformation was performed for the crystallographic characterization. A uniform dislocation slip in the FCC matrix associated with the transformation was detected at -57°C. Gradual growth of a BCC martensite was recognized upon cooling from -57°C to -63°C.

Keywords: in situ electron microscopy; ECCI; SEM; cooling stage; martensitic transformation; steel.