Comparative study of stress and strain partitioning behaviors in medium manganese and transformation-induced plasticity-aided bainitic ferrite steels

2022 ◽  
Vol 210 ◽  
pp. 114463
Author(s):  
Tomohiko Hojo ◽  
Motomichi Koyama ◽  
Bakuya Kumai ◽  
Yuki Shibayama ◽  
Ayumi Shiro ◽  
...  
Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 299
Author(s):  
Adriana Eres-Castellanos ◽  
Carlos Garcia-Mateo ◽  
Francisca G. Caballero

Displacive stress and strain induced transformations are those transformations that occur when the formation of martensite or bainitic ferrite is promoted by the application of stress or strain. These transformations have been shown to be one of the mechanisms by which the mechanical properties of a microstructure can be improved, as they lead to a better ductility and strength by the transformation induced plasticity effect. This review aims to summarize the fundamental knowledge about them, both in fully austenitic or in multiphase structures, pointing out the issues that—according to the authors’ opinion—need further research. Knowing the mechanisms that govern the stress and strain induced transformation could enable to optimize the thermomechanical treatments and improve the final microstructure properties.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qiuliang Huang ◽  
Ran Shi ◽  
Ondrej Muránsky ◽  
Hossein Beladi ◽  
Saurabh Kabra ◽  
...  

Abstract By time-of-flight (TOF) neutron diffraction experiments, the influence of segregation-induced microstructure bands of austenite (γ) and martensite (α′ ) phases on the partitioning of stress and strain between these phases was investigated. Initially, tensile specimens of a Co-added stainless steel were heat treated by quenching and partitioning (Q&P) processing. Tensile specimens were subsequently loaded at 350 °C parallel to the length of the bands within the apparent elastic limit of the phase mixture. Lattice parameters in both axial and transverse directions were simultaneously measured for both phases. The observation of a lattice expansion for the γ phase in the transverse direction indicated a constraint on the free transverse straining of γ arising from the banded microstructure. The lateral contraction of α′ imposed an interphase tensile microstress in the transverse direction of the γ phase. The multiaxial stress state developed in the γ phase resulted in a large deviation from the level of plastic strain expected for uniaxial loading of single phase γ. Since segregation-induced banded microstructures commonly occur in many engineering alloys, the analysis of stress and strain partitioning with the present Q&P steel can be used to interpret the observations made for further engineering alloys with two-phase microstructures.


2011 ◽  
Vol 172-174 ◽  
pp. 1183-1188 ◽  
Author(s):  
Fateh Fazeli ◽  
Tao Jia ◽  
Matthias Militzer

Bainite is an essential constituent in the microstructure of many advanced high strength steels, e.g. ferrite-bainite dual-phase, transformation induced-plasticity (TRIP) and complex phase (CP) steels. A complex thermo-mechanical processing is employed in industry such that following ferrite formation a desired fraction of bainite can be obtained during austenite decomposition. In order to evaluate robust processing routes it would be very useful to have a bainite transformation model with predictive capabilities. In this work a transformation start criterion for bainite is proposed by defining a critical driving pressure concept. Subsequent bainite formation kinetics from a mixture of ferrite-austenite is described using phenomenological modelling methodologies. In particular, the predictive capabilities of two approaches will be critically discussed, i.e. (i) the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model in conjunction with Rios treatment of the additivity rule and (ii) a nucleation-growth based model that describes simultaneous formation of bainitic ferrite and carbides. Using experimental transformation data for TRIP and CP steels, status and limitations of these models will be delineated.


2018 ◽  
Vol 157 ◽  
pp. 02016 ◽  
Author(s):  
Lenka Jakubovičová ◽  
Milan Vaško ◽  
Milan Sága ◽  
Peter Kopas

The article presents the theoretical and computational analysis of the fatigue tested specimens loaded by bending and torsion. The testing device allows loading by constant turn of the clamping parts. The stress and strain magnitude in test depends on the material characteristics and shape of the specimen. The calculations are realized by finite element method (FEM). The obtained results are verified with the experimental measurement applying the optical system ARAMIS.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qiuliang Huang ◽  
Ran Shi ◽  
Ondrej Muránsky ◽  
Hossein Beladi ◽  
Saurabh Kabra ◽  
...  

An amendment to this paper has been published and can be accessed via a link at the top of the paper.


Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 944 ◽  
Author(s):  
Faisal Qayyum ◽  
Aqeel Afzal Chaudhry ◽  
Sergey Guk ◽  
Matthias Schmidtchen ◽  
Rudolf Kawalla ◽  
...  

Crystal plasticity simulations help to understand the local deformation behavior of multi-phase materials based on the microstructural attributes. The results of such simulations are mainly dependent on the Representative Volume Element (RVE) size and composition. The effect of RVE thickness on the changing global and local stress and strain is analyzed in this work for a test case of dual-phase steels in order to identify the minimal RVE thickness for obtaining consistent results. 100×100×100 voxel representative volume elements are constructed by varying grain size and random orientation distribution in DREAM-3D. The constructed RVEs are sliced in depth up to 1, 5, 10, 15, 20, 25, 30, 40, and 50 layers to construct different geometries with increasing thickness. Crystal plasticity model parameters for ferrite and martensite are taken from already published data and assigned to respective phases. Although the global stress/strain behavior of different RVEs is similar (<5% divergence), the local stress/strain partitioning in RVEs with varying thickness and grain size shows a considerable variation when statistically compared. It is concluded that two-dimensional (2D) RVEs can be used for crystal plasticity simulations when global deformation behavior is of interest. Whereas, it is necessary to consider three-dimensional (3D) RVEs, which have a specific thickness and number of grains for determining stabilized and more accurate local deformation behavior. This estimation will help researchers in optimizing the computation time for accurate mesoscale simulations.


Author(s):  
V. Helpa ◽  
E. Rybacki ◽  
L. F. G. Morales ◽  
G. Dresen

2006 ◽  
Vol 15-17 ◽  
pp. 744-749 ◽  
Author(s):  
Jérémie Bouquerel ◽  
Kim Verbeken ◽  
Bruno C. De Cooman ◽  
Yvan Houbaert ◽  
Patricia Verleysen ◽  
...  

Low alloy multiphase TRansformation Induced Plasticity (TRIP) steels offer an excellent combination of a large uniform elongation and a high strength. This results from the composite behaviour of the different phases that are present in these steels: polygonal ferrite, bainitic ferrite and a martensite/austenite constituent. In order to obtain a clear understanding of the behaviour of the different constituents within the multiphase steel, they were prepared separately. The stress-strain relationship of the different single phase and multiphase steels were simulated with physically based micromechanical models. The model used to describe the stress-strain curves of the separate phases is based on the Mecking-Kocks and Seeger-Kocks theories and uses physical properties such as the microstructural properties and the chemical composition of the different phases. Strain-induced transformation kinetics, based on a generalized form of the Olson-Cohen law, were used to include the influence of the transformation of the metastable austenite. Static stress-strain properties of multiphase steels were modelled by the successive application of a Gladman type mixture law for two-phase steels. The model yields detailed information of stress and strain partitioning between the different phases during a static tensile test. A model for the dynamic stress-strain properties of ferritic steels is also proposed.


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