Suppression of twinning and phase transformation in an ultrafine grained 2 GPa strong metastable austenitic steel: Experiment and simulation

Shen, Y.F.; Jia, Nan; Wang, Y. D.; X, Sun; Zuo, Liang; Raabe, Dierk

doi:10.1016/j.actamat.2015.06.053

Cited by 88 publications

(20 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The other two materials (Type-III and Type-IV), both of which use NC layers as strengthening agent, show a slight degraded toughness compared to the CG 304 SS. Importantly, we observe that the toughness and ductility achieved in all of our gradient samples are substantially better than those of various high-strength 304 SS reported in the literature [12][13][14][15][16][17][18][19], including NC [15], UFG [14], UFG embodied with NTs [18], martensite-strengthened structure [12,13,16], and the mixture of the NC, UFG and martensite [17,19]. These data underscore generally the advantageous properties of gradient materials.…”

Section: Tensile Propertiessupporting

confidence: 55%

See 1 more Smart Citation

Gradient twinned 304 stainless steels for high strength and high ductility

Chen

Liu

Wang

et al. 2016

Materials Science and Engineering: A

View full text Add to dashboard Cite

Gradient materials often have attractive mechanical properties that outperform uniform microstructure counterparts. It remains a difficult task to investigate and compare the performance of various gradient microstructures due to the difficulty of fabrication, the wide range of length scales involved, and their respective volume percentage variations. We have investigated four types of gradient microstructures in 304 stainless steels that utilize submicrotwins, nanotwins, nanocrystals, ultrafine-and coarse-grains as building blocks. Tensile tests reveal that the gradient microstructure consisting of submicrotwins and nanotwins has a persistent and stable work hardening rate and yields an impressive combination of high strength and high ductility, leading to a toughness that is nearly 50% higher than the coarse-grained counterpart. Ex-and in-situ transmission electron microscopy indicates that nanoscale and submicroscale twins help to suppress and limit martensitic phase transformation via the confinement of martensite within the twin lamellar. Twinning and detwinning remain active during tensile deformation and contribute to the work hardening behavior. We discuss the advantageous properties of using submicrotwins as the main load carrier and nanotwins as the strengthening layers over those coarse and nanocrystalline grains. Our work uncovers a new gradient design strategy to help metals and alloys achieve high strength and high ductility.

show abstract

Section: Tensile Propertiessupporting

confidence: 55%

“…Enhancing its strength has been the focus of many past studies (see refs. [12][13][14][15][16][17][18][19][20]). Unfortunately, strength and toughness are generally mutually exclusive [21].…”

Section: Introductionmentioning

confidence: 99%

Gradient twinned 304 stainless steels for high strength and high ductility

Chen

Liu

Wang

et al. 2016

Materials Science and Engineering: A

View full text Add to dashboard Cite

show abstract

“…5(h)). So far, the mechanical behaviors of low SFE alloys as determined by the dynamic interactions among these typical microstructures have been investigated largely from theoretical viewpoints and experimental evidences (Choi et al, 2015;Gutierrez-Urrutia et al, 2010;Shen et al, 2015;Steinmetz et al, 2013). The fact that our MAMD simulations consist with the existing studies provides a validation of the proposed meta-atom method.…”

Section: Stacking Faults In Twip Steelsmentioning

confidence: 80%

Atomistic simulation for deforming complex alloys with application toward TWIP steel and associated physical insights

Wang

Liu

et al. 2017

Journal of the Mechanics and Physics of Solids

View full text Add to dashboard Cite

A B S T R A C TThe interest in promoting deformation twinning for plasticity is mounting for advanced materials. In contrast to disordered grain boundaries, highly organized twin boundaries are beneficial to promoting strength-ductility combination. Twinning deformation typically involves the kinetics of stacking faults, its interplay with dislocations, as well as the interactions between dislocations and twin boundaries. While the latter has been intensively studied, the dynamics of stacking faults has been rarely touched upon. In this work, we report new physical insights on the stacking fault dynamics in twin induced plasticity (TWIP) steels. The atomistic simulation is made possible by a newly introduced approach: meta-atom molecular dynamics simulation. The simulation suggests that the stacking fault interactions are dominated by dislocation reactions that take place spontaneously, different from the existing mechanisms. Whether to generate a single stacking fault, or a twinning partial and a trailing partial dislocation, depends upon a unique parameter, namely the stacking fault energy. The latter in turn determines the deformation twinning characteristics. The complex twin-slip and twin-dislocation interactions demonstrate the dual role of deformation twins as both the dislocation barrier and dislocation storage. This duality contributes to the high strength and high ductility of TWIP steels.

show abstract

“…Therefore, the main purpose of this work is to develop a microstructure‐motivated phenomenological model of stress‐driven twinning kinetics and to verify it by in situ observations performed on magnesium and its alloys. The concept of twin nucleation driven by stress that controls the evolution of the twin volume fraction is implicit in a recent model proposed by Shen et al for an ultrafine‐grained austenitic steel 304. It goes back to the twin nucleation model of Mahajan and Chin .…”

Section: Motivation and Backgroundmentioning

confidence: 99%

A Phenomenological Model of Twinning Kinetics

et al. 2016

View full text Add to dashboard Cite

We present a model of deformation twinning based on the idea that twin generation is a stress-driven process. Using simple, yet sensible, assumptions regarding the grain size distribution, an equation for the variation of the twin volume fraction with the flow stress is obtained. The model is validated for the case of Mg alloy ZK60 through measurements of the evolving volume fraction of twins by means of direct video observation of the specimen surface and by monitoring the acoustic emission signals.

show abstract

Suppression of twinning and phase transformation in an ultrafine grained 2 GPa strong metastable austenitic steel: Experiment and simulation

Cited by 88 publications

References 66 publications

Gradient twinned 304 stainless steels for high strength and high ductility

Gradient twinned 304 stainless steels for high strength and high ductility

Atomistic simulation for deforming complex alloys with application toward TWIP steel and associated physical insights

A Phenomenological Model of Twinning Kinetics

Contact Info

Product

Resources

About