Dependence of nonuniformity of plastic deformation on stressed state and test temperature

1978 ◽  
Vol 10 (5) ◽  
pp. 565-568
Author(s):  
R. F. Merenkova ◽  
P. F. Koshelev ◽  
V. V. Grot
Keyword(s):  
Plastic Deformation ◽  
Stressed State ◽  
Test Temperature

Effect of Hydrogen on the Apparent Yield Stress—Research on the Cause of Hydrogen Induced Delayed Plasticity

CORROSION ◽  
1981 ◽  
Vol 37 (9) ◽  
pp. 514-521 ◽  
Author(s):  
Wu-Yang Chu ◽  
Shi-Qun Li ◽  
Chi-Mei Hsiao ◽  
Shur-Yahn Ju
Keyword(s):  
Plastic Deformation ◽  
Tensile Strength ◽  
Yield Stress ◽  
Test Temperature ◽  
Stress Reduction ◽  
Stress Gradient ◽  
Tensile Specimen ◽  
Low Alloy Steels ◽  
Wide Range ◽  
Alloy Steels

Abstract The effect of hydrogen on the apparent yield stress, which is a necessary exterior stress to cause the local macroscopic plastic deformation, was investigated for various carbon and low alloy steels with a wide range of tensile strength. Smooth tensile, bent beam, and precracked WOL specimens were used. The results show that the effect of hydrogen on the yield strength of a smooth tensile specimen is insignificant. However, for the smooth bent beam or precracked specimens with a stress gradient, hydrogen decreases the apparent yield stress considerably if the strength of steel and the amount of hydrogen entering into the specimen exceed critical values. This is the cause of hydrogen induced delayed plastic deformation and then hydrogen induced delayed cracking. The apparent yield stress of the charged specimen decreases with increasing tensile strength and the amount of hydrogen in the steel. It depends evidently on the strain rate and test temperature and is reversible, but is not related to the prestrain condition. The variation of the apparent yield stress of the charged specimens with the test temperature is not monotonous, there is a minimum near room temperature. According to these results, a possible mechanism of hydrogen induced apparent yield stress reduction has been suggested.

scholarly journals New technological potentialities of finish-strengthening by surface plastic deformation

2017 ◽  
Vol 2 (3) ◽  
pp. 25-30 ◽  
Author(s):  
Семен Зайдес ◽  
Semen Zaides ◽  
Као Нго ◽  
Сao Ngo
Keyword(s):  
Plastic Deformation ◽  
Stressed State ◽  
Strain State ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Factors Affecting ◽  
Simulation Process ◽  
Simulation Results ◽  
Definition Of ◽  
The Impact

The paper reports the results of the strengthening simulation process. A new kinematics of deforming rollers ensuring a surface plastic deformation of shafts of low rigidity was considered. On the basis of the theory of low elasto-plastic deforma-tions and a method of finite elements there were formed simulators of a strengthening process allowing the definition of a stressed state in a sample depending on the form and kinematics of an indenter. With the aid of ANSYSWB software there was considered the impact of some circuits of deformation upon a stressed state: running-in by rolling, running-in by slip, running-in by one and two rollers with the rotation with regard to a diametrical axis. On the basis of simulation results it was revealed that the basic factors affecting a stress-strain state of parts are geometry, a form, a mutual location of elements of a tool deformed and their kinematics with regard to a part worked.

scholarly journals Plastic deformation of titanium alloy Ti-6Al-4V in a complex stressed state under tension at high-strain rates

2021 ◽  
Vol 11 (3) ◽  
pp. 267-272
Author(s):  
Vladimir Skripnyak ◽  
Kristina Iohim ◽  
Evgeniya Skripnyak ◽  
Vladimir Skripnyak
Keyword(s):  
Plastic Deformation ◽  
Titanium Alloy ◽  
Stressed State ◽  
High Strain ◽  
Complex Stressed State ◽  
Strain Rates ◽  
High Strain Rates

Loss of stability for the process of plastic deformation with a complex stressed state

1991 ◽  
Vol 23 (10) ◽  
pp. 1039-1047 ◽  
Author(s):  
F. F. Giginyak ◽  
O. K. Shkodzinskii ◽  
A. A. Lebedev ◽  
V. T. Timofeev
Keyword(s):  
Plastic Deformation ◽  
Stressed State ◽  
Complex Stressed State ◽  
Loss Of Stability

Sem Examinations of Glass Knives

1970 ◽  
Vol 28 ◽  
pp. 282-283
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Tensile Loading ◽  
Resultant Force ◽  
Stress Concentrations ◽  
Edge Chipping ◽  
Surface Flaws ◽  
Edge Defects ◽  
Microscopic Surface

There are two types of edge defects common to glass knives as typically prepared for microtomy purposes: 1) striations and 2) edge chipping. The former is a function of the free breaking process while edge chipping results from usage or bumping of the edge. Because glass has no well defined planes in its structure, it should be highly resistant to plastic deformation of any sort, including tensile loading. In practice, prevention of microscopic surface flaws is impossible. The surface flaws produce stress concentrations so that tensile strengths in glass are typically 10-20 kpsi and vary only slightly with composition. If glass can be kept in compression, wherein failure is literally unknown (1), it will remain intact for long periods of time. Forces acting on the tool in microtomy produce a resultant force that acts to keep the edge in compression.

Stereo Electron Microscopy Applied to High Resolution Freeze-Etch Replicas

1970 ◽  
Vol 28 ◽  
pp. 306-307
Author(s):  
L. Andrew Staehelin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
High Resolution ◽  
Smooth Surfaces ◽  
Small Particles ◽  
Membrane Surfaces ◽  
Wide Acceptance ◽  
New Information ◽  
Number Of Particles ◽  
Small Holes

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.

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