scholarly journals Initial Deformation Behaviors in Lean Duplex Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 936
Author(s):  
Rosa Kim ◽  
Cheoljun Bae ◽  
Jongryoul Kim
Keyword(s):  
Microstructural Analysis ◽  
Stacking Faults ◽  
Initial Deformation ◽  
Tension Tests ◽  
Deformation Behaviors ◽  
Dislocation Behavior ◽  
Austenite Grains ◽  
Mechanical Twins ◽  
Strain Hardening Behavior ◽  
Predominant Effect

The deformation behaviors of the austenite phase in lean duplex stainless steels were investigated through uniaxial tension tests with different amounts of deformation. Microstructural analysis showed that in the initial deformation stage the deformation in austenite grains had a predominant effect on the strain hardening behavior of the LDX-2101 steel. The initial deformation in the austenite grains was found to be mainly accommodated by the formation of stacking faults. As the deformation increased further, mechanical twins were generated by the initial stacking faults and sequentially interacted with dislocations to accommodate the strain. The analysis of dislocation behavior revealed that the deformation twinning process followed the three-layer twin formation mechanism.

Microstructural Analysis of Type 304 Metal Sleeve

2011 ◽  
Vol 702-703 ◽  
pp. 959-962
Author(s):  
Shintaro Ohtani ◽  
Satoshi Morooka ◽  
Osamu Umezawa
Keyword(s):  
Layer Structure ◽  
Microstructural Analysis ◽  
High Strength ◽  
Dual Phase ◽  
Drawing Direction ◽  
Strain Induced Martensite ◽  
Austenite Grains ◽  
Grain Width ◽  
Type 304 ◽  
Pancaked Austenite

In order to form thin metal sleeve with the thickness of 0.03 mm, type 304 austenitic steel sheet was deeply drawn to a cup and spinning method applied to its body. The sleeve shows high strength with a dual-phase microstructure of fine austenite and transformed martensite. Pancaked austenite and martensite grains were highly elongated along RD (drawing direction) in the layer structure, and their grain width was about 100 nm. Dynamically recovered austenite grains were highly aligned from {101} to {101}. The strain-induced martensite grains mainly showed two components of {001} and {111}. Recover and recrystallization of the sleeve appeared at the temperature from 873 K to 1073 K. Annealed at 1073 K the austenite grains were mostly recrystallized with intensifying {101}, and the martensite grains were also reverse-transformed to austenite.

Microstructure of laser-ablated superconducting La2CuO4Fx thin films on SrTiO3

2001 ◽  
Vol 16 (11) ◽  
pp. 3309-3316 ◽  
Author(s):  
G. Kong ◽  
M. O. Jones ◽  
J. S. Abell ◽  
P. P. Edwards ◽  
S. T. Lees ◽  
...  
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Microstructural Analysis ◽  
Stacking Faults ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Elemental Fluorine ◽  
Deposit Surface ◽  
Film Substrate ◽  
Post Deposition

Thin films of lanthanum cuprate were grown on SrTiO3 substrates by pulsed laser deposition and made superconducting (Tc ∼ 38 K) through the process of post-deposition fluorination using elemental fluorine. A microstructural analysis showed that the [110] zone of the film grows parallel to the [100] zone of the SrTiO3 substrate, reducing the lattice mismatch from 37.5% to 2.4%. At the film–substrate interface there is an intermediate layer 3–4 nm thick and twin-related grains emanate from this region. Stacking faults are present in the bulk of the film, with misoriented subgrains present at the deposit surface.

Microstructural analysis of nickel hydroxide: Anisotropic size versus stacking faults

2005 ◽  
Vol 20 (4) ◽  
pp. 334-344 ◽  
Author(s):  
Montse Casas-Cabanas ◽  
Maria Rosa Palacín ◽  
Juan Rodríguez-Carvajal
Keyword(s):  
Powder Diffraction ◽  
Nickel Hydroxide ◽  
Size Effects ◽  
Microstructural Analysis ◽  
Stacking Faults ◽  
Finite Size ◽  
Line Broadening ◽  
Peak Broadening ◽  
Transmission Electron ◽  
Microstructural Model

Two different approaches for studying sample’s contributions to diffraction-line broadening are analyzed by applying them to several nickel hydroxide samples. Both are based in the refinement of powder diffraction data but differ in the microstructural model used. The first one consists in the refinement of the powder diffraction pattern using the FAULTS program, a modification of DIFFaX, which assigns peak broadening mainly to the presence of stacking faults and treats finite size effects by convolution with a Voigt function. The second method makes use of the program FULLPROF, which allows the use of linear combinations of spherical harmonics to model peak broadening coming from anisotropic size effects. The complementary use of transmission electron microscopy has allowed us to evaluate the best approach for the Ni(OH)2 case. In addition, peak shifts, corresponding to reflections 10l (l≠0) were observed in defective nickel hydroxide samples that can be directly correlated with the degree of faulting.

scholarly journals The Deformation Behaviors and Mechanism of the High-Temperature Mechanical Properties of a Ni48W35Co17 Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1755
Author(s):  
Guoliang Xie ◽  
Wenli Xue ◽  
Yilei Fu ◽  
Kai Feng ◽  
Rui Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Microstructural Analysis ◽  
Tensile Sample ◽  
High Temperature Mechanical Properties ◽  
Precipitated Phase ◽  
Heavy Alloys ◽  
The Matrix ◽  
Deformation Behaviors ◽  
Strength And Plasticity

Investigations of the plastic deformation mechanisms of Ni-W-based heavy alloys varying with increasing temperatures are very important for the development of hot forming processes and applications at elevated temperatures. In this study, the continuous variation of strength and plasticity of a novel Ni-W-based heavy alloy with increasing temperatures was investigated. The tensile strength of a Ni48W35Co17 sample at 600 °C was 471 MPa, which was 47% lower than that at 100 °C. A variation in an abnormal decrease in elongations at temperatures from 400 °C to 800 °C was found in this alloy. The elongation rate of the sample tensile at 600 °C was 19%, which was 73% lower than that at 100 °C. A microstructural analysis revealed that the number of twins in the sample tensile at a temperature higher than 600 °C increased considerably compared with the sample tensile at lower temperatures, indicating that the dislocation slips were suppressed during the high-temperature stretching process. The precipitates of the NiW phase were found in the 600 °C tensile sample, which was not clearly observed in the 400 °C tensile sample, suggesting that dislocation slips were affected by the formation of these precipitates. Moreover, the orientation relationship between the matrix and NiW phase was (200)Ni//(240)NiW and [001]Ni//[001]NiW. The tiny precipitated phase was the main reason for the plasticity decrease of the alloy with the temperature increase.

scholarly journals Differences in Deformation Behaviors Caused by Microband-Induced Plasticity of [0 0 1]- and [1 1 1]-Oriented Austenite Micro-Pillars

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1179
Author(s):  
Yuan-Yuan Cui ◽  
Yun-Fei Jia ◽  
Fu-Zhen Xuan
Keyword(s):  
Strain Hardening ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Uniaxial Compression Test ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Deformation Behaviors ◽  
Micro Pillars ◽  
Strain Hardening Behavior ◽  
Good Agreement

A uniaxial compression test and scanning/transmission electron microscopy observations were performed to investigate the differences in mechanical behavior and deformed microstructure between focused ion beam-manufactured [1 1 1]- and [0 0 1]-oriented austenite micro-pillars with 5 μm diameter from duplex stainless steel. After yielding, the strain hardening of two orientation micro-pillars increased sharply as a result of the formation of a microband, namely microband-induced plasticity, MBIP. The same phenomenon could be observed in a [0 0 1]-oriented pillar due to the activation of the secondary slip system, while slight strain hardening behavior was observed in the [1 1 1] orientation because of the refinement of the microband. Furthermore, the trend of the calculated strain hardening rates of both [1 1 1]- and [0 0 1]-oriented micro-pillars were in good agreement with the experimental data. This study proved that MBIP can be helpful for the mechanical property enhancement of steels.

Dynamic Growth of Ultra-Fine Austenite Grains Deformed above Ad3 Temperature in a Nb-V-Ti Steel

2010 ◽  
Vol 89-91 ◽  
pp. 657-662 ◽  
Author(s):  
S.J. Yao ◽  
Lin Xiu Du ◽  
Xiang Hua Liu ◽  
Guo Dong Wang
Keyword(s):  
Grain Boundary ◽  
Hot Deformation ◽  
True Strain ◽  
Grain Boundary Sliding ◽  
Macroscopic Deformation ◽  
Deformation Behaviors ◽  
Boundary Sliding ◽  
Dynamic Growth ◽  
Austenite Grains ◽  
Holding Temperature

Generally, three typical behaviors are recognized in hot-deformation of austenite. However, considering that those austenite grains involved in single-pass deformation are mostly on the scale of dozens of micrometers or even much larger than that, it is meaningful to investigate hot-deformation behaviors of austenite grains smaller than 10μm. In the current paper, austenite grains of different sizes were prepared through repetitive treatment of rapid reheating and quenching with changing the holding temperature and/or holding time. Kinds of true stress-true strain curves at 900oC and 950oC indicate that austenitic deformation can be gradually coordinated by grain boundary behaviors, such as grain boundary sliding and/or diffusion. Simultaneously, the macroscopic deformation is more likely to be dominated through co-operation grain boundary sliding (CGBS).

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