scholarly journals Studying Deformation Behaviors in Austenitic Stainless Steels within a Temperature Range of 143 K < T < 420 K

2021 ◽  
pp. 22-30
Author(s):  
S. A Barannikova ◽  
A. M Nikonova ◽  
S. V Kolosov
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Strain Localization ◽  
Work Hardening ◽  
Deformation Localization ◽  
Linear Hardening ◽  
Jerky Flow ◽  
Temperature Range ◽  
Α Phase ◽  
Flow Stage

This work deals with studying staging and macroscopic strain localization in austenitic stainless steel 12Kh18N9T within a temperature range of 143 K < T < 420 K. The visualization and evolution of macroscopic localized plastic deformation bands at different stages of work hardening were carried out by the method of the double-exposure speckle photography (DESP), which allows registering displacement fields with a high accuracy by tracing changes on the surface of the material under study and then comparing the specklograms recorded during uniaxial tension. The shape of the tensile curves σ(ε) undergoes a significant change with a decreasing temperature due to the γ-α'-phase transformation induced by plastic deformation. The processing of the deformation curves of the steel samples made it possible to distinguish the following stages of strain hardening, i.e. the stage of linear hardening and jerky flow stage. A comparative analysis of the design diagrams (with the introduction of additional parameters of the Ludwigson equation) and experimental diagrams of tension of steel 12Kh18N9T for different temperatures is carried out. The analysis of local strains distributions showed that at the stage of linear work hardening, a mobile system of plastic strain localization centers is observed. The temperature dependence of the parameters of plastic deformation localization at the stages of linear work hardening has been established. Unlike the linear hardening, the jerky flow possesses the propagation of single plastic strain fronts that occur one after another through the sample due to the γ-α' phase transition and the Portevin-Le Chatelier effect. It was found that at the jerky flow stage, which is the final stage before the destruction of the sample, the centers of deformation localization do not merge, leading to the neck formation.

Stages of Plastic Deformation in Metallic Nanocrystals

2011 ◽  
Vol 683 ◽  
pp. 183-187 ◽  
Author(s):  
Nina Koneva ◽  
Eduard Kozlov
Keyword(s):  
Plastic Deformation ◽  
Work Hardening ◽  
Pure Copper ◽  
Paper Analysis ◽  
Deformation Localization ◽  
Tension And Compression ◽  
Average Size ◽  
20 Nm ◽  
First Time ◽  
The Relationship

In this paper, analysis of work hardening laws for grains with sizes on nano- and microlevel is carried out. The work is based on experimental data of deformation behavior of mainly pure copper at room temperature (RT). A special attention is given to the interval of grains with the average size between 20 nm and 230 nm. Work hardening stages of active plastic deformation during tension and compression are characterized. The dependence of work hardening coefficients on the average grains size at the nanoscale in the II, IV and VI stages is revealed for the first time. Mechanisms of deformation in the range of grains sizes between 10 nm and 1000 nm are categorized. The relationship between work hardening stages and deformation mechanisms is discussed. The stage of deformation where deformation localization takes place is determined.

scholarly journals Influence of Temperature and Plastic Strain on Deformation Mechanisms and Kink Band Formation in Homogenized HfNbTaTiZr

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 81
Author(s):  
Hans Chen ◽  
Theresa Hanemann ◽  
Sascha Seils ◽  
Daniel Schliephake ◽  
Aditya Srinivasan Tirunilai ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Kink Band ◽  
Deformation Mechanisms ◽  
Large Temperature ◽  
Plastic Strains ◽  
Compression Tests ◽  
Band Formation ◽  
Influence Of Temperature ◽  
Temperature Range

Due to its outstanding ductility over a large temperature range, equiatomic HfNbTaTiZr is well-suited for investigating the influence of temperature and plastic strain on deformation mechanisms in concentrated, body centered cubic solid solutions. For this purpose, compression tests in a temperature range from 77 up to 1073 K were performed and terminated at varying plastic strains for comparison of plastic deformation behavior. The microstructure and chemical homogeneity of a homogenized HfNbTaTiZr ingot were evaluated on different length scales. The compression tests reveal that test temperature significantly influences yield strength as well as work hardening behavior. Electron backscatter diffraction aids in shedding light on the acting deformation mechanisms at various temperatures and strains. It is revealed that kink band formation contributes to plastic deformation only in a certain temperature range. Additionally, the kink band misorientation angle distribution significantly differs at varying plastic strains.

scholarly journals The effect of plastic deformation on martensite decomposition process in Ti-6Al-4V alloy

2020 ◽  
Vol 321 ◽  
pp. 12034
Author(s):  
Maciej Motyka ◽  
Waldemar Ziaja ◽  
Anna Baran-Sadleja ◽  
Karol Slemp
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloys ◽  
Scientific Literature ◽  
Thermal Analyses ◽  
Compressive Load ◽  
Two Phase ◽  
Temperature Range ◽  
Α Phase ◽  
Heat Treated ◽  
Kinetics Of

Microstructure and mechanical properties of heat treated martensitic two-phase α+β titanium alloys are in major perspective determined by results of martensite decomposition during tempering. The process of martensitic α’(α”) phase decomposition in titanium alloys, although utilized in industry for years, has not been sufficiently characterized in the scientific literature. Especially aspects of plastically deformed martensite decomposition is poorly described. Preliminary research results of water quenched Ti-6Al-4V alloy, subsequently cold deformed in compression and tempered at the temperature range of 600-900ºC for 1 and 2 h indicated that α’(α”) martensite undergoes strain hardening and deformed martensite laths exhibit tendency towards fragmentation and spheroidization during tempering at 900ºC. In the present paper, also α’(α”) martensite decomposition under compressive load applied at the temperature range of 600-900ºC is considered too. Based on light and scanning electron microscopy observations, thermal analyses and XRD measurements, the effect of plastic deformation on kinetics of martensite decomposition and morphology of α phase formed in the process is analysed.

scholarly journals Кинетика развития паттернов макролокализации пластического течения металлов

2018 ◽  
Vol 60 (7) ◽  
pp. 1358
Author(s):  
Л.Б. Зуев ◽  
С.А. Баранникова ◽  
Б.С. Семухин
Keyword(s):  
Plastic Deformation ◽  
Acoustic Emission ◽  
Plastic Strain ◽  
Plastic Flow ◽  
Strain Localization ◽  
Plastic Distortion ◽  
Localization Zone ◽  
Distortion Tensor ◽  
The Relationship

AbstractThe features of the macroscopic inhomogeneity of plastic deformation in the form of autowaves with a pulsating amplitude are analyzed, and data on the localization of sources of acoustic emission at different stages of plastic flow in the stretching of fcc mono- and polycrystals are presented. The relationship between the local components of the plastic distortion tensor in the strain localization zone is traced. The role of acoustic phenomena accompanying the localization of plastic strain in the development of the process of plastic deformation is considered.

Hardening Palladium Using Hydrogen as a Catalytic Alloying Element

2015 ◽  
Vol 365 ◽  
pp. 262-265 ◽  
Author(s):  
Yu Zeng Chen ◽  
X.Y. Ma ◽  
X.H. Shi ◽  
Feng Liu
Keyword(s):  
Plastic Deformation ◽  
Dislocation Density ◽  
Plastic Strain ◽  
Work Hardening ◽  
Dynamic Recovery ◽  
Alloying Element ◽  
Subsequent Removal ◽  
New Strategy ◽  
Cold Rolled ◽  
Deformation Level

Work hardening is one of the most widely used methods in strengthening metals by increasing dislocation density, which can be achieved by raising plastic strain and/or suppressing dynamic recovery of the dislocations upon plastic deformation. Based on the analyses on the data reported in our previous work in cold-rolled Pd-H system (Scripta Materialia, Vol. 68 (2013), p. 743), we propose a new strategy in hardening Pd using hydrogen as a catalytic element. It is shown that since the introduction of hydrogen facilitates dislocation formation and increases the dislocation density in Pd upon plastic deformation, subjected to a same deformation level and subsequent removal of hydrogen, Pd can obtain a higher hardness compared to that without hydrogenation before deformation. It is further pointed out that the proposed strategy may, in addition, be applied to other metals, which can dissolve a relatively large amount of hydrogen, e.g. magnesium, nickel and niobium.

Deformation Behavior and Plastic Strain Localization of Nanostructured Materials Produced by Severe Plastic Deformation

2009 ◽  
Vol 633-634 ◽  
pp. 107-119 ◽  
Author(s):  
Evgeny V. Naydenkin ◽  
Galina P. Grabovetskaya
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Severe Plastic Deformation ◽  
Strain Localization ◽  
Deformation Behavior ◽  
Grain Boundary Sliding ◽  
Deformation Bands ◽  
Localized Deformation ◽  
Plastic Strain Localization ◽  
Structure Heterogeneity

The literature on the deformation behavior and plastic strain localization inherent to nanostructured metallic polycrystals produced by severe plastic deformation techniques is reviewed. The effects of the texture, structure heterogeneity and state of grain boundaries on the special features and evolution of mesoscopic and macroscopic localized deformation bands are investigated. The role of grain-boundary sliding in the development of mesoscopic plastic deformation bands is discussed.

scholarly journals Kinetics of Plastic Deformation Localization Bands in Polycrystalline Nickel

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1440
Author(s):  
Svetlana A. Barannikova ◽  
Mikhail V. Nadezhkin
Keyword(s):  
Plastic Deformation ◽  
Constant Strain Rate ◽  
Correlation Method ◽  
Deformation Bands ◽  
Total Deformation ◽  
Polycrystalline Nickel ◽  
Deformation Localization ◽  
Jerky Flow ◽  
Time Period ◽  
Localized Plastic Deformation

Jerky flow has recently aroused interest as an example of complex spatiotemporal dynamics resulting from the collective behavior of defects in Al- and Mg-based alloys under loading. This paper presents the results of the study of the macroscopic strain localization kinetics in Nickel 200 (99.5 wt % purity). Uniaxial tension of flat samples is monitored at room temperature in the load–unload mode at a constant strain rate and total deformation increment up to 5%. The stress–strain curves reveal jerky flow from the yield point to the formation of the neck. The digital speckle correlation method evidences the movement of localized plastic deformation bands under the conditions of the Portevin–Le Chatelier effect (PLC). It is shown that stress drops during jerky flow in Ni are accompanied by the formation of morphologically simple single PLC bands. It is established that, with an increase in total deformation, the number of PLC bands and their velocity of motion along the sample decrease, while their time period increases. Moreover, an increase in total deformation leads to an increase in the parameters of the force response (i.e., time period and stress drop magnitude). It is found that the criterion of damage for PLC bands as a function of the total strain has a sigmoidal shape.

Plastic Deformation in Microtomed Sections

1971 ◽  
Vol 29 ◽  
pp. 458-459
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Applied Stress ◽  
Elastic Strain ◽  
High Strain ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Structure ◽  
Geometrical Constraints

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.

On effect of surface hardening on impact and abrasive wear resistance of Hadfi eld steel

2020 ◽  
pp. 252-255
Author(s):  
V.I. Bolobov ◽  
V.S. Bochkov ◽  
E.V. Akhmerov ◽  
V.A. Plashchinsky ◽  
E.A. Krivokrisenko E.A.
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Work Hardening ◽  
Surface Hardening ◽  
Cold Work ◽  
Abrasive Wear Resistance ◽  
Hadfield Steel ◽  
Mining Equipment ◽  
Effect Of Surface

On the example of Hadfield steel, as the most common material of fast-wearing parts of mining equipment, the effect of surface hardening by plastic deformation on their impact and abrasive wear resistance is considered. Wear test is conducted on magnetic ironstone as typical representative of abrasive and hard rock. As result of wear of initial samples with hardness of ∼200 HB and samples pre-hardened with different intensities to the hardness of 300, 337 and 368 HB, it is found that during the initial testing period, the initial samples pass the “self-cold-work hardening” stage with increase in hardness to ∼250 HB, which remains virtually unchanged during further tests; the hardness of the pre-hardened samples does not change significantly throughout the tests. It is established that the rate of impact-abrasive wear of pre-hardened samples is significantly (up to 1.4 times) lower than the original ones that are not subjected to plastic deformation, and decreases with increasing degree of cold-work hardening. Preliminary surface hardening by plastic deformation can serve as effective way to increase the service life of fast-wearing working parts of mining equipment.

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