In situ neutron diffraction investigation on the phase transformation sequence of kaolinite and halloysite to mullite

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.

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Tracing Phase Transformation and Lattice Evolution in a TRIP Sheet Steel under High-Temperature Annealing by Real-Time In Situ Neutron Diffraction

Crystals ◽

10.3390/cryst8090360 ◽

2018 ◽

Vol 8 (9) ◽

pp. 360 ◽

Cited By ~ 6

Author(s):

Dunji Yu ◽

Yan Chen ◽

Lu Huang ◽

Ke An

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Neutron Diffraction ◽

Real Time ◽

Retained Austenite ◽

Sheet Steel ◽

Carbon Diffusion ◽

Structure Evolution ◽

In Situ Neutron Diffraction

Real-time in situ neutron diffraction was used to characterize the crystal structure evolution in a transformation-induced plasticity (TRIP) sheet steel during annealing up to 1000 °C and then cooling to 60 °C. Based on the results of full-pattern Rietveld refinement, critical temperature regions were determined in which the transformations of retained austenite to ferrite and ferrite to high-temperature austenite during heating and the transformation of austenite to ferrite during cooling occurred, respectively. The phase-specific lattice variation with temperature was further analyzed to comprehensively understand the role of carbon diffusion in accordance with phase transformation, which also shed light on the determination of internal stress in retained austenite. These results prove the technique of real-time in situ neutron diffraction as a powerful tool for heat treatment design of novel metallic materials.

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Texture Evolution and Phase Transformation in Titanium Investigated by In-Situ Neutron Diffraction

Metallurgical and Materials Transactions A ◽

10.1007/s11661-011-0667-2 ◽

2011 ◽

Vol 42 (6) ◽

pp. 1444-1448 ◽

Cited By ~ 11

Author(s):

D. Ma ◽

A. D. Stoica ◽

K. An ◽

L. Yang ◽

H. Bei ◽

...

Keyword(s):

Phase Transformation ◽

Neutron Diffraction ◽

Texture Evolution ◽

In Situ Neutron Diffraction

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An in-situ neutron diffraction study of a multi-phase transformation and twinning-induced plasticity steel during cyclic loading

Applied Physics Letters ◽

10.1063/1.4919455 ◽

2015 ◽

Vol 106 (17) ◽

pp. 171911 ◽

Cited By ~ 11

Author(s):

Ahmed A. Saleh ◽

Donald W. Brown ◽

Elena V. Pereloma ◽

Bjørn Clausen ◽

Christopher H. J. Davies ◽

...

Keyword(s):

Phase Transformation ◽

Cyclic Loading ◽

Neutron Diffraction ◽

Diffraction Study ◽

Neutron Diffraction Study ◽

Multi Phase ◽

In Situ Neutron Diffraction

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Characterization of the deformation and phase transformation behavior of VC-free and VC-containing FeMnSi-based shape memory alloys by in situ neutron diffraction

Materials Science and Engineering A ◽

10.1016/j.msea.2017.07.077 ◽

2017 ◽

Vol 703 ◽

pp. 314-323 ◽

Cited By ~ 9

Author(s):

C. Leinenbach ◽

A. Arabi-Hashemi ◽

W.J. Lee ◽

A. Lis ◽

M. Sadegh-Ahmadi ◽

...

Keyword(s):

Phase Transformation ◽

Neutron Diffraction ◽

Shape Memory Alloys ◽

Shape Memory ◽

Transformation Behavior ◽

Phase Transformation Behavior ◽

In Situ Neutron Diffraction

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In-Situ Neutron Diffraction Study of Strain-Induced Martensite Formation in 304L Stainless Steel at a Cryogenic Temperature

MRS Proceedings ◽

10.1557/proc-840-q7.4 ◽

2004 ◽

Vol 840 ◽

Cited By ~ 1

Author(s):

Kaixiang Tao ◽

James J. Wall ◽

Donald W. Brown ◽

Hongqi Li ◽

Sven C. Vogel ◽

...

Keyword(s):

Stainless Steel ◽

Phase Transformation ◽

Neutron Diffraction ◽

Diffraction Study ◽

Atomic Plane ◽

Neutron Diffraction Study ◽

304L Stainless Steel ◽

Martensite Formation ◽

In Situ Neutron Diffraction

ABSTRACTIn-situ, time-of-flight neutron diffraction was performed to investigate the martensitic phase transformation during quasi-static uniaxial compression testing of 304L stainless steel at 300K (room temperature) and 203K. In-situ neutron diffraction study enabled the bulk measurement of intensity evolution for each hkl atomic plane during the austenite (fcc) to martensite (hcp and bcc) phase transformation. The neutron diffraction patterns show that the martensite phases started to develop at about 2.5% applied strain (600 MPa applied stress) at 203K. However, at 300K, the martensite formation was not observed throughout the test. Furthermore, from changes in the relative intensities of individual hkl atomic planes, the selective phase transformation can be well understood and the grain orientation relationship between the austenite and newly-forming martensite phases can be determined. The results show that the fcc grain families with {111} and {200} plane normals parallel to the loading axis are favored for the “fcc to hcp” and “fcc to bcc” transformations, respectively.

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