In-Situ Neutron Diffraction Investigation of Austenite → ε-Martensite → α-Martensite Transformation and its Dynamic Effect on Macroscopic Serration in a 13%Mn Metastable Austenitic Steel

2021 ◽  
Author(s):  
Feng Li ◽  
Zhengzhi Zhao ◽  
Jurij J. Sidor ◽  
Yan Chen ◽  
Cheng Li ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Austenitic Steel ◽  
Martensite Transformation ◽  
Dynamic Effect ◽  
Metastable Austenitic Steel ◽  
Ε Martensite ◽  
In Situ Neutron Diffraction

scholarly journals In Situ Neutron Diffraction Study of Phase Transformation of High Mn Steel with Different Carbon Content

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 101
Author(s):  
Youngsu Kim ◽  
Wookjin Choi ◽  
Hahn Choo ◽  
Ke An ◽  
Ho-Suk Choi ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Neutron Diffraction ◽  
Strain Hardening ◽  
High Strain ◽  
Tensile Deformation ◽  
Austenite Phase ◽  
Transformation Rate ◽  
Ε Martensite ◽  
In Situ Neutron Diffraction

In situ neutron diffraction was employed to examine the phase transformation behavior of high-Mn steels with different carbon contents (0.1, 0.3, and 0.5 wt.%C). With increasing carbon contents from 0.1 C to 0.5 C, the austenite phase fraction among the constituent phases increased from ~66% to ~98%, and stacking fault energy (SFE) increased from ~0.65 to ~16.5 mJ/m2. The 0.1 C and 0.3 C steels underwent phase transformation from γ-austenite to ε-martensite or α’-martensite during tensile deformation. On the other hand, the 0.5 C steel underwent phase transformation only from γ-austenite to ε-martensite. The 0.3 C steel exhibited a low yield strength, a high strain hardening rate, and the smallest elongation. The high strain hardening of the 0.3 C alloy was due to a rapid phase transformation rate from γ-austenite to ε-martensite. The austenite of 0.5 C steel was strengthened by mechanical twinning during loading process, and the twinning-induced plasticity (TWIP) effect resulted in a large ductility. The 0.5 wt.% carbon addition stabilized the austenite phase by delaying the onset of the ε-martensite phase transformation.

scholarly journals In Situ Observation for Deformation-Induced Martensite Transformation during Tensile Deformation of SUS 304 Stainless Steel by Using Neutron Diffraction PART II: Transformation and Texture Formation Mechanisms

2021 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Yusuke Onuki ◽  
Shigeo Sato
Keyword(s):  
Stainless Steel ◽  
Neutron Diffraction ◽  
Martensite Transformation ◽  
Tensile Deformation ◽  
Steel Sample ◽  
304 Stainless Steel ◽  
Formation Mechanisms ◽  
Ε Martensite ◽  
Main Components

Herein, the texture developments of γ austenite, ε martensite, and α’ martensite during the tensile deformation of SUS 304 stainless steel were observed by using the in situ neutron diffraction technique. Combined with the microstructure and local orientations measured by electron backscattered diffraction (EBSD), the mechanisms involved in the deformation-induced martensite transformation (DIMT) in the SUS 304 stainless steel were examined based on the neutron diffraction results. The results revealed that the ε martensite inherited the texture of the γ austenite, that is, their main components could be connected by Shoji–Nishiyama orientation relationship. The variant selection was qualitatively evaluated based on the Schmid factors of the {111}⟨2¯11⟩ slip systems. The results revealed that the ε→α’ transformation occurred easily in the steel sample. Consequently, the volume fraction of the α’ martensite phase observed by EBSD was higher than that observed by neutron diffraction. In addition, at a true strain of 0.42, a packet structure consisting of two α’ martensite variants was observed in the steel sample. However, the original orientation of the variants did not correspond to the main components in the γ or ε phases. This suggests that the two α’ martensite variants were transformed directly from the lost component of the γ matrix. These results indicate that the γ→ε→α’ DIMT was first activated in the steel sample, after which the γ→α’ DIMT was activated at the later stage of deformation.

Study of tempering behavior of lath martensite using in situ neutron diffraction

2015 ◽  
Vol 107 ◽  
pp. 29-32 ◽  
Author(s):  
Z.M. Shi ◽  
W. Gong ◽  
Y. Tomota ◽  
S. Harjo ◽  
J. Li ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Lath Martensite ◽  
In Situ Neutron Diffraction

In situ neutron diffraction study of fatigue behavior of CrFeCoNiMo0.2 high entropy alloy

2021 ◽  
Vol 139 ◽  
pp. 107371
Author(s):  
Haiyan He ◽  
Bing Wang ◽  
Dong Ma ◽  
Alexandru D. Stoica ◽  
Zhenduo Wu ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Fatigue Behavior ◽  
Neutron Diffraction Study ◽  
High Entropy Alloy ◽  
High Entropy ◽  
In Situ Neutron Diffraction
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