Grain boundary sliding during high-temperature tensile deformation in superplastic Fe-6.6Mn-2.3Al steel

Seok Hyeon Kang, Seok Won Choi, Yong Deok Im, Young Kook Lee

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

In the present study, grain boundary sliding (GBS) occurring during high-temperature deformation, i.e., a critical strain and accommodation process of GBS, was investigated using Fe-6.6Mn-2.3Al (wt%) steel, which was recently reported as a superplastic steel. For this purpose, high-temperature interrupted tensile tests were conducted at 880 °C with an initial strain rate of 1 × 10−3 s−1, and the microstructures of the tensile specimens were then observed at room temperature as a function of the true strain (ε) at 880 °C. Variations in certain microstructural features with ε, in this case the maximum intensity of the orientation distribution function, the average grain size, the void fraction, the misorientation distribution, the aspect ratio of the grains and the kernel average misorientation, found that dislocation plasticity occurred up to ε = 0.69, followed by both GBS and grain rotation. This indicates that the critical strain for GBS (εGBS) is 0.69. GBS occurred via a dislocation accommodation process, i.e., the second type of Rachinger sliding, where the original shape of the grains is maintained and subgrains do not form during GBS.

Original languageEnglish
Article number139174
JournalMaterials Science and Engineering A
Volume780
DOIs
Publication statusPublished - 2020 Apr 7

Bibliographical note

Funding Information:
This research was originally supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant number: NRF-2018R1D1A1A09083753). This research was also partially supported by Korea Institute for Advancement of Technology (KIAT) grant funded by the Korea Government (MOTIE) (P0002019, The Competency Development Program for Industry Specialist), and by the Graduate School of YONSEI University Research Scholarship Grants in 2019. We are thankful to Professor Jeongho Han (Hanyang University, Seoul) for the assistance with the thermodynamic calculations using the Thermo-Calc software in conjunction with the TCFE9 database.

Funding Information:
This research was originally supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant number: NRF-2018R1D1A1A09083753 ). This research was also partially supported by Korea Institute for Advancement of Technology (KIAT) grant funded by the Korea Government (MOTIE) ( P0002019, The Competency Development Program for Industry Specialist ), and by the Graduate School of YONSEI University Research Scholarship Grants in 2019. We are thankful to Professor Jeongho Han (Hanyang University, Seoul) for the assistance with the thermodynamic calculations using the Thermo-Calc software in conjunction with the TCFE9 database.

Publisher Copyright:
© 2020 Elsevier B.V.

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Grain boundary sliding during high-temperature tensile deformation in superplastic Fe-6.6Mn-2.3Al steel'. Together they form a unique fingerprint.

Cite this