Download file (18.6MB)
Download as zip (17.3MB)

コレクション

引用

説明:

At cryogenic temperatures, 316L austenitic stainless steels (ASSs) exhibit remarkable strength while retaining high ductility, defying conventional stress-strain trade-off. Despite extensive studies documenting the cryo-tensile properties of ASSs, the underlying mechanisms behind this phenomenon remain largely unexplored. This study systematically re-examines the tensile properties of 316L steel and the associated mechanisms across a range of low temperatures (293 K, 223 K, 123 K, and 77 K). The reasons for the superior stress-strain balance (~ 80% GPa) are discussed through electron backscatter diffraction (EBSD) microstructure characteristics. The results undoubtedly suggested that the transformation mechanisms, specifically the shift from deformation twinning to martensitic transformation (γ → ε → α; γ → α), play a crucial role in enhancing elongation at cryogenic temperatures. At these temperatures, the Gibbs free energy difference between ε-martensite and γ-austenite approaching zero, resulting in slow martensite growth. The stress-strain curves at low temperatures satisfy the Considère criterion, indicating delayed necking under these conditions. This behavior is ascribed to presence of various hierarchical microstructures, including ε, α, γ-twins, ε-twins and their intersections, which act as sources of work hardening. This study provides new insights into deformation behavior of ASSs under cryogenic conditions.

権利情報:

• Creative Commons BY-NC-ND Attribution-NonCommercial-NoDerivs 4.0 International
  

キーワード: Strength-ductility balance, Austenitic stainless steel, Martensitic transformation, Deformation twinning, Strain-hardening rate

刊行年月日: 2024-09-12

出版者: Elsevier BV

掲載誌:

• Journal of Materials Research and Technology (ISSN: 22387854) vol. 33 p. 600-611

研究助成金:

• Japan Society for the Promotion of Science 21H01659
• Japan Society for the Promotion of Science 23K13227

原稿種別: 出版者版 (Version of record)

MDR DOI:

公開URL: https://doi.org/10.1016/j.jmrt.2024.09.074

関連資料:

その他の識別子:

連絡先:

更新時刻: 2024-09-19 16:30:19 +0900

MDRでの公開時刻: 2024-09-19 16:30:20 +0900