Restoration Mechanism and Sub-Structural Characteristics of Duplex Stainless Steel with an Initial Equiaxed Austenite Morphology during Post-Deformation Annealing

2021 ◽  
Vol 882 ◽  
pp. 64-73
Author(s):  
Pawan Kumar ◽  
Peter Hodgson ◽  
Hossein Beladi ◽  
Amit Roy Chowdhury ◽  
Mamookho Elizabeth Makhatha ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Static Recrystallization ◽  
Structural Characteristics ◽  
Electron Backscattered Diffraction ◽  
Grain Coarsening ◽  
Static Recovery ◽  
Second Stage ◽  
Third Stage ◽  
Restoration Mechanism

Uni-axial compression (UAC) tests and further post deformation annealing (PDA) were done for 23Cr-6Ni-3Mo duplex stainless steel (DSS). The initial morphology was equiaxed (EQ) in nature. In the first stage of PDA, austenite showed limited static recrystallization (SRX) followed by static recovery (SRV); however ferrite showed static recovery (SRV). In the second stage of PDA, the austenite showed grain coarsening followed by disintegration of substructures (DIS); and ferrite revealed mostly SRV leading to grain coarsening. The third stage of PDA envisages substructural disintegration of unstable substructure leading to saturation in both austenite and ferrite. The sub-structural characteristics were provided by Electron backscattered diffraction (EBSD) and its post processing were done by using HKL Channel 5 software.

scholarly journals Novel Mechanical Characterization of Austenite and Ferrite Phases within Duplex Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1352
Author(s):  
Hossein Besharatloo ◽  
Marcel Carpio ◽  
José-María Cabrera ◽  
Antonio Manuel Mateo ◽  
Gemma Fargas ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
High Speed ◽  
Mapping Technique ◽  
Small Scale ◽  
Processing Conditions ◽  
Excellent Correlation ◽  
Electron Backscattered Diffraction ◽  
Interphase Boundaries

The microstructure and micromechanical properties of the constitutive phases of a particular duplex stainless steel in various processing conditions have been characterized. Hardness (H), elastic modulus (E) and H/E cartography maps were obtained by using a high-speed nanoindentation mapping technique. Small-scale H and E evolution at different processing conditions has been investigated by statistical analysis of a large number of nanoindentations (10,000 imprints per sample). Two mechanically distinct phases, ferrite (α) and austenite (γ), were deconvoluted from this dataset using Ulm and Constantinides’ method, with the remaining values assigned to a third mechanical phase linked to composite-like (containing α/γ interphase boundaries) regions. These mechanical property phase assessments were supplemented by overlaying crystallographic phase maps obtained by electron backscattered diffraction. An excellent correlation between microstructure and small-scale mechanical properties was achieved, especially when considering the ratio H/E.

Micro Flash Welding of Super Duplex Stainless Steels

2007 ◽  
Vol 539-543 ◽  
pp. 3979-3984
Author(s):  
Toshio Kuroda ◽  
Kenji Ikeuchi ◽  
Takeshi Terajima
Keyword(s):  
Stainless Steel ◽  
Solid State ◽  
Duplex Stainless Steel ◽  
Stainless Steels ◽  
Welding Time ◽  
Butt Welding ◽  
Second Stage ◽  
Solid State Bonding ◽  
Super Duplex Stainless Steels ◽  
Flash Welding

Super duplex stainless steels were welded using new flash butt welding technology of temperature controlling system. The super duplex stainless steel (329J4L) and conventional duplex stainless steel (329J3L) were used. The samples were mounted in the dies using a Gleeble thermal simulator and flash but welding was made. The specimens were heated up to 1373K for 10sec, 20sec and 30sec. Flash butt welding has consisting of a two stage processes of a flash action and a contact resistance. First stage was a flash welding process and second stage was a solid state bonding process. The cross sectional microstructure of the weld bond region showed two types of a deposited fine particles region and a solid state bonding region. The grain growth was hardly observed in the weld region and the heat-affected zone. For further increasing joining efficiency of solid state bonding at the second stage, the welding time at 1373K was increased from 5 sec to 180sec. The bonding area increased with increasing welding time at 1373K and successfully welded for conventional duplex stainless steel.

scholarly journals Static Softening Behavior and Modified Kinetics of Al 2219 Alloy Based on a Double-Pass Hot Compression Test

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3862
Author(s):  
Lei Liu ◽  
Yunxin Wu ◽  
Hai Gong ◽  
Abdulrahaman Shuaibu Ahmad ◽  
Fang Dong ◽  
...  
Keyword(s):  
Compression Test ◽  
Static Recrystallization ◽  
Reduction Rate ◽  
Electron Backscattered Diffraction ◽  
Double Pass ◽  
Static Recovery ◽  
Step Rate ◽  
Softening Mechanism ◽  
Deformation Parameters ◽  
Static Softening

In this paper, the static softening mechanism of a 2219 aluminum alloy was studied based on a double-pass isothermal compression test. For the experiment, different temperatures (623 K, 723 K, and 773 K), strain rates (0.1/s, 1/s, and 10/s), deformation ratios (20%, 30%, and 40%), and insulation periods (5 s, 30 s, and 60 s) were used. Based on the double-pass flow stress curves obtained from the experiment, the step rate expressed by the equivalent dynamic recrystallization fraction is dependent on the deformation parameters, which increases with the increase in strain rate and insulation time, while it decreases with the increase in temperature and strain. Based on the microstructure observed using electron backscattered diffraction (EBSD), the static softening mechanism of the Al 2219 alloy is mainly static recovery and incomplete static recrystallization. A new expression for the static recrystallization fraction is proposed using the reduction rate of the sub-grain boundary. The dependent rule on the deformation parameters is consistent with the step rate, but it is of physical significance. In addition, the modified static recrystallization kinetics established by the new SRX fraction method was proven to have a good modeling and prediction performance under given deformation conditions.

Identification by Electron Microdiffraction of Intermetallic Phases in a Duplex Stainless Steel

1990 ◽  
Vol 48 (2) ◽  
pp. 494-495
Author(s):  
A. Redjaïmia ◽  
J.P. Morniroli ◽  
G. Metauer ◽  
M. Gantois
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Convergent Beam Electron Diffraction ◽  
Intermetallic Phases ◽  
Small Particles ◽  
Parallel Beam ◽  
Diffraction Patterns ◽  
Average Size ◽  
Convergent Beam ◽  
Electron Microdiffraction

2D and especially 3D symmetry information required to determine the crystal structure of four intermetallic phases present as small particles (average size in the range 100-500nm) in a Fe.22Cr.5Ni.3Mo.0.03C duplex stainless steel is not present in most Convergent Beam Electron Diffraction (CBED) patterns. Nevertheless it is possible to deduce many crystal features and to identify unambiguously these four phases by means of microdiffraction patterns obtained with a nearly parallel beam focused on a very small area (50-100nm).From examinations of the whole pattern reduced (RS) and full (FS) symmetries the 7 crystal systems and the 11 Laue classes are distinguished without ambiguity (1). By considering the shifts and the periodicity differences between the ZOLZ and FOLZ reflection nets on specific Zone Axis Patterns (ZAP) which depend on the crystal system, the centering type of the cell and the glide planes are simultaneously identified (2). This identification is easily done by comparisons with the corresponding simulated diffraction patterns.

The Coherence of Mary Barton: Romance, Realism, and Utopia

2015 ◽  
Vol 5 (3) ◽  
pp. 185-200
Author(s):  
Robert Z. Birdwell
Keyword(s):  
Thomas Carlyle ◽  
The Novel ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Three Stages ◽  
Mode Of Production

Critics have argued that Elizabeth Gaskell's first novel, Mary Barton (1848), is split by a conflict between the modes of realism and romance. But the conflict does not render the novel incoherent, because Gaskell surpasses both modes through a utopian narrative that breaks with the conflict of form and gives coherence to the whole novel. Gaskell not only depicts what Thomas Carlyle called the ‘Condition of England’ in her work but also develops, through three stages, the utopia that will redeem this condition. The first stage is romantic nostalgia, a backward glance at Eden from the countryside surrounding Manchester. The second stage occurs in Manchester, as Gaskell mixes romance with a realistic mode, tracing a utopian drive toward death. The third stage is the utopian break with romantic and realistic accounts of the Condition of England and with the inadequate preceding conceptions of utopia. This third stage transforms narrative modes and figures a new mode of production.

DETECTION OF THE SIGMA PHASE IN A DUPLEX STAINLESS STEEL THROUGH MEASUREMENTS OF MAGNETIC PERMEABILITY

2019 ◽  
Author(s):  
Edgard Silva ◽  
Francisco Eduardo Mendes da Silva ◽  
Amanda Medeiros ◽  
Ana Paula Alves Pacheco ◽  
IZAURA VIEGAS ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Magnetic Permeability ◽  
Sigma Phase
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