TY - JOUR
T1 - Dynamic tension-compression asymmetry of martensitic transformation in austenitic Fe-(0.4, 1.0)C-18Mn steels for cryogenic applications
AU - Kim, Hyunmin
AU - Park, Jaeyoung
AU - Ha, Yumi
AU - Kim, Wooyeol
AU - Sohn, Seok Su
AU - Kim, Hyoung Seop
AU - Lee, Byeong Joo
AU - Kim, Nack J.
AU - Lee, Sunghak
N1 - Funding Information:
This work was supported by POSCO under a contract No. 2013Y049. The authors would like to thank to Mr. Dong Hyun Ahn of POSTECH for his help of FEM analysis works.
Publisher Copyright:
© 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
PY - 2015/6/16
Y1 - 2015/6/16
N2 - In this study, cryogenic-temperature dynamic mechanical properties of austenitic Fe-(0.4, 1.0)C-18Mn steels were evaluated by conducting dynamic tensile and compressive tests, and deformation mechanisms including tension-compression asymmetry of martensitic transformation behavior were interpreted by microstructural evolution of dynamically tensioned or compressed specimens. After the dynamic tensile test of the 0.4C-18Mn steel, the γ → ε → α′ martensitic transformation occurred at -196 C, whereas ε- or α′-martensite was not found in the 1.0C-18Mn steel. After the dynamic compressive test, on the other hand, the γ → ε martensitic transformation occurred at -196°C without the formation of α′-martensites in the 0.4C-18Mn steel. This dynamic tensile-compressive asymmetry of martensitic transformation was plausibly interpreted by austenite stability in relation with difference in molar volume, hydrostatic stress distribution, and adiabatic heating. The γ → α′ transformation was prevented under the dynamic compressive loading because the increase in molar volume was required for the γ → α′ transformation, whereas it was promoted to induce the γ → ε → α′ transformation under dynamic tensile loading.
AB - In this study, cryogenic-temperature dynamic mechanical properties of austenitic Fe-(0.4, 1.0)C-18Mn steels were evaluated by conducting dynamic tensile and compressive tests, and deformation mechanisms including tension-compression asymmetry of martensitic transformation behavior were interpreted by microstructural evolution of dynamically tensioned or compressed specimens. After the dynamic tensile test of the 0.4C-18Mn steel, the γ → ε → α′ martensitic transformation occurred at -196 C, whereas ε- or α′-martensite was not found in the 1.0C-18Mn steel. After the dynamic compressive test, on the other hand, the γ → ε martensitic transformation occurred at -196°C without the formation of α′-martensites in the 0.4C-18Mn steel. This dynamic tensile-compressive asymmetry of martensitic transformation was plausibly interpreted by austenite stability in relation with difference in molar volume, hydrostatic stress distribution, and adiabatic heating. The γ → α′ transformation was prevented under the dynamic compressive loading because the increase in molar volume was required for the γ → α′ transformation, whereas it was promoted to induce the γ → ε → α′ transformation under dynamic tensile loading.
KW - Austenitic high-Mn steel
KW - Cryogenic temperature
KW - Dynamic tensile and compressive tests
KW - TRansformation Induced Plasticity (TRIP)
KW - TWinning Induced Plasticity (TWIP)
UR - http://www.scopus.com/inward/record.url?scp=84931263675&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2015.06.021
DO - 10.1016/j.actamat.2015.06.021
M3 - Article
AN - SCOPUS:84931263675
VL - 96
SP - 37
EP - 46
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
ER -