scholarly journals Effects of Crystal Orientation and Grain Boundary Inclination on Stress Distribution in Bicrystal Interface of Austenite Stainless Steel 316L

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Fu-qiang Yang ◽  
He Xue ◽  
Ling-yan Zhao ◽  
Xiu-Rong Fang ◽  
Hai-bing Zhang
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Elastic Modulus ◽  
Grain Boundary ◽  
Single Crystals ◽  
Crystal Orientation ◽  
Stress And Strain ◽  
Face Centered Cubic ◽  
Stainless Steel 316L ◽  
Load Direction

Nuclear structural material austenitic stainless steel 316L is a polycrystalline composed of single crystals with a face-centered cubic (FCC) structure, and the intergranular stress corrosion cracking (IGSCC) is closely related to the crystal orientation. A constitutive model is presented to assess the elastic response of anisotropic behavior of single crystals in 316L in this study. With a bicrystal model built by the finite element method, the effects of crystal orientation and grain boundary (GB) inclination on the stress state nearby a symmetric tilt GB were discussed under the constant-displacement condition. The results indicate that when tensile axes are perpendicular to the GB, the stress and strain are equal at the GB and inside the grain, and the crystal misorientation has little effects on the stress and strain distribution. If the GB is not perpendicular to the load direction, the GB inclination angle will change the equivalent elastic modulus along the load direction and result in a larger stress in the grain with larger equivalent elastic modulus, but the stress tends to be equal inside the two grains. The grain size effects verification shows that the conclusions are independent of grain size.

scholarly journals On the Role of Grain Size and Carbon Content on the Sensitization and Desensitization Behavior of 301 Austenitic Stainless Steel

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1193 ◽  
Author(s):  
Kolli ◽  
Javaheri ◽  
Kömi ◽  
Porter
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Grain Boundary ◽  
Carbon Content ◽  
Double Loop ◽  
Boundary Carbide ◽  
Self Healing ◽  
Chromium Depletion ◽  
Electrochemical Potentiokinetic Reactivation

The effect of grain size in the range 72 to 190 μm and carbon content in the range 0.105–0.073 wt.% on the intergranular corrosion of the austenitic stainless steel 301 has been investigated. Grain boundary chromium depletion has been studied directly using energy dispersive X-ray spectroscopy combined with scanning transmission electron microscopy and indirectly using double loop electrochemical potentiokinetic reactivation tests. In addition, chromium depletion has been modelled using the CALPHAD Thermo-Calc software TC-DICTRA. It is shown that the degree of sensitization measured using the double loop electrochemical potentiokinetic reactivation tests can be successfully predicted with the aid of a depletion parameter based on the modelled chromium depletion profiles for heat treatment times covering both the sensitization and de-sensitization or self-healing. Additionally, along with intergranular M23C6 carbides, intragranular M23C6 and Cr2N nitrides that affect the available Cr for grain boundary carbide precipitation were also observed.

Influence of Annealing on the Microstructure and Mechanical Properties of Electrodeposited Nanocrystalline Nickel

2011 ◽  
Vol 683 ◽  
pp. 103-112 ◽  
Author(s):  
B. Yang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Elastic Modulus ◽  
Grain Boundary ◽  
Boundary Structure ◽  
Boundary State ◽  
Microstructure And Mechanical Properties ◽  
Grain Boundary Structure ◽  
Average Grain Size ◽  
Different Grain Size

The evolution of the microstructure and mechanical properties of electrodeposited nanocrystalline Ni with different annealing procedures was studied systematically. For the annealed specimens hardness decreases with increasing average grain size but the dependence changes at different grain size ranges. The specimens annealed at a low temperature show higher hardness compared to the as-deposited nanocrystalline Ni, despite an increased measured average grain size. In association with this hardening an increase in elastic modulus and a decrease in microstrain was observed after annealing. With increasing annealing temperature both the tensile strength and the fracture strain were observed to decrease, this is companied with a transition from ductile to brittle in the fracture surfaces. These results indicated that the mechanical behaviour of nanocrystalline Ni depends not only on the average grain size but also on the grain boundary structure. A change in the grain boundary state arising from annealing may be responsible for the observed increase in hardness and elastic modulus as well as the deterioration of tensile properties.

scholarly journals Molecular Dynamics as a Means to Investigate Grain Size and Strain Rate Effect on Plastic Deformation of 316 L Nanocrystalline Stainless-Steel

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3223 ◽  
Author(s):  
Abdelrahim Husain ◽  
Peiqing La ◽  
Yue Hongzheng ◽  
Sheng Jie
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Stainless Steel ◽  
Grain Boundary ◽  
Strain Rate ◽  
Deformation Mechanism ◽  
Grain Boundary Sliding ◽  
Plastic Deformation Mechanism ◽  
Grain Sizes ◽  
Critical Grain Size

In the present study, molecular dynamics simulations were employed to investigate the effect of strain rate on the plastic deformation mechanism of nanocrystalline 316 L stainless-steel, wherein there was an average grain of 2.5–11.5 nm at room temperature. The results showed that the critical grain size was 7.7 nm. Below critical grain size, grain boundary activation was dominant (i.e., grain boundary sliding and grain rotation). Above critical grain size, dislocation activities were dominant. There was a slight effect that occurred during the plastic deformation mechanism transition from dislocation-based plasticity to grain boundaries, as a result of the stress rate on larger grain sizes. There was also a greater sensitive on the strain rate for smaller grain sizes than the larger grain sizes. We chose samples of 316 L nanocrystalline stainless-steel with mean grain sizes of 2.5, 4.1, and 9.9 nm. The values of strain rate sensitivity were 0.19, 0.22, and 0.14, respectively. These values indicated that small grain sizes in the plastic deformation mechanism, such as grain boundary sliding and grain boundary rotation, were sensitive to strain rates bigger than those of the larger grain sizes. We found that the stacking fault was formed by partial dislocation in all samples. These stacking faults were obstacles to partial dislocation emission in more sensitive stress rates. Additionally, the results showed that mechanical properties such as yield stress and flow stress increased by increasing the strain rate.

scholarly journals Comparison between experiment and computer modelling of plane-strain simple-shear ice deformation

1994 ◽  
Vol 40 (134) ◽  
pp. 46-55
Author(s):  
C.J. L. Wilson ◽  
Y. Zhang
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Simple Shear ◽  
Computer Modelling ◽  
Boundary Migration ◽  
Stress And Strain ◽  
Grain Boundary Migration ◽  
Lattice Orientation ◽  
Polycrystalline Ice ◽  
Good Agreement

AbstractAn examination of both experiments and computer models of polycrystalline ice undergoing a simple shear suggests that there is good agreement. The model has correctly reproduced the deformational and microstructural features caused by glide on (0001) in the ice aggregates. This success is particularly prominent for those ice grains with a lattice orientation suitable for hard or easy glide or kinking, and where there is a sub-horizontal с axis and a larger grain-size. A limitation may be that the model cannot explicitly simulate recrystallization and grain-boundary migration, which are two other important processes operating jointly with glide in experimentally deformed ice. However, through the use of the models, it is possible to show how kinematic factors can control the processes of recrystallization. The localization of recrystallization in the polycrystalline ice aggregate is determined by the stress and strain variations between neighbouring grains.

scholarly journals Comparison between experiment and computer modelling of plane-strain simple-shear ice deformation

1994 ◽  
Vol 40 (134) ◽  
pp. 46-55 ◽  
Author(s):  
C.J. L. Wilson ◽  
Y. Zhang
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Simple Shear ◽  
Computer Modelling ◽  
Boundary Migration ◽  
Stress And Strain ◽  
Grain Boundary Migration ◽  
Lattice Orientation ◽  
Polycrystalline Ice ◽  
Good Agreement

AbstractAn examination of both experiments and computer models of polycrystalline ice undergoing a simple shear suggests that there is good agreement. The model has correctly reproduced the deformational and microstructural features caused by glide on (0001) in the ice aggregates. This success is particularly prominent for those ice grains with a lattice orientation suitable for hard or easy glide or kinking, and where there is a sub-horizontalсaxis and a larger grain-size. A limitation may be that the model cannot explicitly simulate recrystallization and grain-boundary migration, which are two other important processes operating jointly with glide in experimentally deformed ice. However, through the use of the models, it is possible to show how kinematic factors can control the processes of recrystallization. The localization of recrystallization in the polycrystalline ice aggregate is determined by the stress and strain variations between neighbouring grains.

scholarly journals The elastic modulus of columnar-grain fresh-water ice

1994 ◽  
Vol 19 ◽  
pp. 13-18 ◽  
Author(s):  
Lorne W. Gold
Keyword(s):  
Grain Size ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Temperature Dependence ◽  
Fresh Water ◽  
Compressive Loading ◽  
Stress And Strain ◽  
Strain Rates ◽  
Water Ice ◽  
Columnar Grain

An analysis is presented of stress and strain measurements made during an investigation of the characteristics of cracks formed in columnar-grain, type S2 fresh-water ice, during uniaxial, compressive loading at the nominal strain rates of 10−3, 10−4 and 10−5s−1, and temperatures of −5°, −10°, −20° and −30°C. The analysis shows that for this range of strain rate and temperature, ice behaves as an anelastic solid. Results are given for the time, grain-size and temperature dependence of the elastic modulus in the plane perpendicular to the long direction of the grains. They are shown to be in reasonable agreement with results of an earlier study of the anelastic behaviour of the same type of ice. It is suggested that the grain-size and temperature dependence of the elastic moduli of ice for this range of strain rate and temperature may be due, in part, to the dependence of the relaxation time on these variables.

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