Effect of bainitic transformation temperature on the mechanical behavior of cold-rolled TRIP steels studied with in-situ high-energy X-ray diffraction

AbstractIn-situ high-energy X-ray diffraction experiments with high temporal resolution during rapid cooling (280 °C s−1) and isothermal heat treatments (at 450 °C, 500 °C, and 550 °C for 30 minutes) were performed to study austenite decomposition in two commercial high-strength low-alloy steels. The rapid phase transformations occurring in these types of steels are investigated for the first time in-situ, aiding a detailed analysis of the austenite decomposition kinetics. For the low hardenability steel with main composition Fe-0.08C-1.7Mn-0.403Si-0.303Cr in weight percent, austenite decomposition to polygonal ferrite and bainite occurs already during the initial cooling. However, for the high hardenability steel with main composition Fe-0.08C-1.79Mn-0.182Si-0.757Cr-0.094Mo in weight percent, the austenite decomposition kinetics is retarded, chiefly by the Mo addition, and therefore mainly bainitic transformation occurs during isothermal holding; the bainitic transformation rate at the isothermal holding is clearly enhanced by lowered temperature from 550 °C to 500 °C and 450 °C. During prolonged isothermal holding, carbide formation leads to decreased austenite carbon content and promotes continued bainitic ferrite formation. Moreover, at prolonged isothermal holding at higher temperatures some degenerate pearlite form.

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Low temperature macro- and micro-mechanical behavior of an ultrafine-grained metastable 304 austenitic stainless steel investigated by in situ high-energy X-ray diffraction

Materials Science and Engineering A ◽

10.1016/j.msea.2021.141295 ◽

2021 ◽

pp. 141295

Author(s):

Chengsi Zheng ◽

Qiannan Zhen ◽

Yongqiang Wang ◽

Na Li

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Low Temperature ◽

Mechanical Behavior ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

Ultrafine Grained ◽

304 Austenitic Stainless Steel

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Mechanical behavior in boron-microalloyed CoCrNi medium-entropy alloy studied by in situ high-energy X-ray diffraction

Materials Science and Engineering A ◽

10.1016/j.msea.2020.139600 ◽

2020 ◽

Vol 788 ◽

pp. 139600

Author(s):

Yajuan Shi ◽

Yan-Dong Wang ◽

Shilei Li ◽

Runguang Li ◽

Youkang Wang

Keyword(s):

Mechanical Behavior ◽

High Energy ◽

X Ray Diffraction ◽

X Ray

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The In Situ Study on the Micro-Structural Characters of IF Steel at Early Stage of Recrystallization Using High-Energy X-Ray

Materials Science Forum ◽

10.4028/www.scientific.net/msf.575-578.972 ◽

2008 ◽

Vol 575-578 ◽

pp. 972-977

Author(s):

He Tong ◽

Yan Dong Liu ◽

Q.W. Jiang ◽

Y. Ren ◽

G. Wang ◽

...

Keyword(s):

Annealing Temperature ◽

Early Stage ◽

High Energy ◽

Fiber Texture ◽

Interstitial Free ◽

If Steel ◽

X Ray Diffraction ◽

X Ray ◽

Cold Rolled

High-energy synchrotron diffraction offers great potential for experimental study of recrystallization kinetics. A fine experimental design to study the recrystallization mechanism of Interstitial Free (IF) steel was implemented in this work. In-situ annealing process of cold-rolled IF steel with 80% reduction was observed using high-energy X-ray diffraction. Results show that, the diffraction intensity of {001}<110> and {112}<110> belong to α-fiber texture component decreased with the annealing temperature increased while {111}<110> did nearly not change and {111}<112> increased; the FMTH decreasing and d-space changing with annealing temperature increasing indicated that the residual stress relaxed completely during recovery.

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Multi length scale characterization of austenite in TRIP steels using high-energy X-ray diffraction

Powder Diffraction ◽

10.1017/s0885715613000237 ◽

2013 ◽

Vol 28 (2) ◽

pp. 77-80 ◽

Cited By ~ 1

Author(s):

R. Blondé ◽

E. Jimenez-Melero ◽

L. Zhao ◽

J.P. Wright ◽

E. Brück ◽

...

Keyword(s):

Volume Fraction ◽

Tensile Tests ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

Trip Steels ◽

Stable Austenite ◽

Scale Characterization ◽

The Stability

The martensitic transformation behavior of the meta-stable austenite phase in low alloyed TRIP steels has been studied in situ using high-energy X-ray diffraction during deformation. The stability of austenite has been studied at different length scales during tensile tests and at variable temperatures down to 153 K. A powder diffraction analysis has been performed to correlate the macroscopic behavior of the material to the observed changes in the volume fraction of the phases. Our results show that at lower temperatures the deformation induced austenite transformation is significantly enhanced and extends over a wider deformation range, resulting in a higher elongation at fracture. To monitor the austenite behavior at the level of an individual grain a high-resolution far-field detector was used. Sub-grains have been observed in austenite prior to transformation.

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In Situ Investigation of Bulk Nucleation by X-Ray Diffraction

Materials Science Forum ◽

10.4028/www.scientific.net/msf.467-470.81 ◽

2004 ◽

Vol 467-470 ◽

pp. 81-86 ◽

Cited By ~ 3

Author(s):

A.W. Larsen ◽

C. Gundlach ◽

Henning Friis Poulsen ◽

L. Margulies ◽

Q. Xing ◽

...

Keyword(s):

High Energy ◽

Triple Junctions ◽

X Ray Diffraction ◽

Nucleation Kinetics ◽

X Ray ◽

Bulk Nucleation ◽

In Situ Investigation ◽

Cold Rolled ◽

Non Destructive

A new method for in-situ studies of nucleation in bulk metals based on high energy synchrotron radiation is presented. Copper samples cold rolled 20% are investigated. The crystallographic orientations near triple junctions are characterized using non-destructive 3DXRD microscopy before, during, and after annealing for 1 hour at 290°C. This method allows in-situ identification of new nuclei and the deformed material, which spawns the nuclei. Also, since data is acquired during annealing nucleation kinetics can be studied.

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