Studying the effect of elastic-plastic strain and hydrogen sulphide on the magnetic behaviour of pipe steels as applied to their testing

The paper reports results of magnetic measurements made on samples of the 12GB pipe steel (strength group X42SS) designed for producing pipes to be used in media with high hydrogen sulphide content, both in the initial state and after exposure to hydrogen sulphide, for 96, 192 and 384 hours under uniaxial elastic-plastic tension. At the stage of elastic deformation there is a unique correlation between the coercive force measured on a minor hysteresis loop in weak fields and tensile stress, which enables this parameter to be used for the evaluation of elastic stresses in pipes made of the 12 GB pipe steel under different conditions, including a hydrogen sulphide containing medium. The effect of the value of preliminary plastic strain, viewed as the initial stress-strain state, on the magnetic behaviour of X70 pipe steels under elastic tension and compression is studied. Plastic strain history affects the magnetic behaviour of the material during subsequent elastic deformation since plastic strain induces various residual stresses, and this necessitates taking into account the initial stress-strain state of products when developing magnetic techniques for the determination of their stress-strain parameters during operation.

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METHOD FOR DETERMINING THE LIMITS OF ELASTICITY AND PROPORTIONALITY OF MATERIALS FOR SUBSEQUENT DRILLING OF WORKPIECES IN THE STRESS–STRAIN STATE

Fundamental and Applied Problems of Engineering and Technology ◽

10.33979/2073-7408-2020-341-3-164-170 ◽

2020 ◽

Vol 3 ◽

pp. 164-170

Author(s):

V.V. KUTS ◽

A.S. BYSHKIN ◽

M.S. RAZUMOV

Keyword(s):

Measurement Error ◽

Elastic Deformation ◽

Strain State ◽

Drilling Process ◽

Stress Strain ◽

Workpiece Material ◽

Stress Strain State ◽

Urgent Task ◽

Accuracy Of Measurement ◽

Proportionality Limit

Drilling holes is one of the most common operations in the manufacture of parts. As a result, improving the efficiency of this process is an urgent task. To improve the efficiency of the drilling process, a method was developed at the Southwestern University for drilling with pre–stressed–deformed material of the workpiece, in which the sample is subjected to elastic deformation at a load that does not exceed the proportionality limit of the workpiece material, that is, when the load is removed, the dimensions of the workpiece remain the same. As part of this work, an experimental device was developed and designed to determine the limits of elasticity and proportionality of materials for subsequent drilling of workpieces in a stress–strain state. This invention will improve the automation and accuracy of measurement. An example of measurement and calculation is considered. Calculation formulas for determining the measurement error are given.

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Crack Resistance of the Self-Stressed Members Reinforced with FRP Bars

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.272.244 ◽

2018 ◽

Vol 272 ◽

pp. 244-249 ◽

Cited By ~ 1

Author(s):

Volha Semianiuk ◽

Viktar V. Tur

Keyword(s):

Initial Stress ◽

Static Loading ◽

Strain State ◽

Crack Opening ◽

The Self ◽

Stress Strain ◽

Diagram Method ◽

Stress Strain State ◽

Expansion Stage ◽

Frp Bars

Fiber reinforced polymer (FRP) bars are widely used in building structures, especially that are exposed to the aggressive environment influence and other special conditions. Nevertheless, due to the low FRP (e.g. glass, basalt, aramid fibers reinforced polymers) bars modulus of elasticity, exceeding crack opening width, as well as deflections can be observed. FRP bars pretensioning is considered as an effective method of its structural performance increasing. Physico-chemical method of the FRP bars pretensioning based on the self-stressing concrete utilizing is an alternative to the mechanical method and in its turn doesn’t need for special devices and anchorage systems as well as qualified personnel. Assessment of the initial stress-strain state obtained during self-stressing concrete expansion stage in the reinforced self-stressed members is presented. Diagram method of the self-stressing parameters verification based on the static loading tests results is presented. Comparison of the initial stress-strain state obtained during concrete expansion stage and predicted by the proposed model, as well as assessment of its influence on the behavior at the static loading stage in cases of the self-stressed reinforced with FRP bars members and traditionally reinforced with steel bars self-stressed members was performed.

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Influence of the inhomogeneity of the initial stress-strain state on elastic perturbations in a solid body

Materials Science ◽

10.1007/s11003-006-0017-5 ◽

2005 ◽

Vol 41 (5) ◽

pp. 567-580

Author(s):

V. F. Chekurin ◽

O. Z. Kravchyshyn

Keyword(s):

Initial Stress ◽

Solid Body ◽

Strain State ◽

Stress Strain ◽

Stress Strain State

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Effect of initial stress/strain state on order-disorder transformation of FePt thin films

Applied Physics Letters ◽

10.1063/1.3153513 ◽

2009 ◽

Vol 94 (23) ◽

pp. 232505 ◽

Cited By ~ 66

Author(s):

S. N. Hsiao ◽

F. T. Yuan ◽

H. W. Chang ◽

H. W. Huang ◽

S. K. Chen ◽

...

Keyword(s):

Thin Films ◽

Initial Stress ◽

Strain State ◽

Stress Strain ◽

Stress Strain State ◽

Fept Thin Films

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THE INVESTIGATION OF THE INITIAL STRESS-STRAIN STATE INFLUENCE ON MECHANICAL PROPERTIES OF VISCOELASTIC BODIES

PNRPU Mechanics Bulletin ◽

10.15593/perm.mech/2019.2.02 ◽

2019 ◽

Keyword(s):

Mechanical Properties ◽

Initial Stress ◽

Strain State ◽

Stress Strain ◽

Stress Strain State ◽

Viscoelastic Bodies

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Investigation of the stress-strain state and microstructure transformation of copper busbars in the deformation zone during continuous extrusion

Izvestiya Vuzov Tsvetnaya Metallurgiya (Proceedings of Higher Schools Nonferrous Metallurgy) ◽

10.17073/0021-3438-2021-1-36-48 ◽

2021 ◽

Vol 1 (1) ◽

pp. 36-48

Author(s):

A. N. Koshmin ◽

A. V. Zinoviev ◽

A. Ya. Chasnikov ◽

G. N. Grachev

Keyword(s):

Grain Size ◽

Plastic Strain ◽

Deformation Zone ◽

Strain State ◽

Stress Strain ◽

Deformation Heating ◽

Stress Strain State ◽

The Press ◽

Metal Deformation ◽

Continuous Extrusion

The paper describes an extensive study of features peculiar to physical and mechanical processes occurring in metal in the deformation zone during the continuous extrusion of Cu-ETP rectangular busbars 10×60 mm in size. Finite element computer simulation was used to obtain the values of extrusion power parameters. It was noted that moment and force values increase to the point of filling the press chamber free space with metal reaching a maximum of 12.26 kN·m and 1.54 MN, respectively. The stress-strain state analysis of metal in the deformation zone made it possible to obtain distribution fields of accumulated plastic strain, strain rate intensity and average stresses, and to build the graph of metal temperature variation over time during extrusion. Maximum levels of accumulated plastic strain and compressive stresses are observed in the contact zone of the workpiece with the press container abutment. The most intense metal deformation heating also occurs there. The comparison of modeling and microstructural study results indicate that a significant portion of the cast structure grinding work occurs at the entrance to the deformation zone and at the abutment zone subjected to the highest level of compression stresses. Metal deformation during the die passage leads to an oriented crystal structure formed with a grain size of 25–30 μm. Sample hardness measurement results are consistent with the results of structure analysis in the studied areas of the deformation zone. When the workpiece passes through the compression container abutment section, deformation heating occurs, which leads to a decrease in hardness from 93 to 67 HV. After the metal passes through the die, recrystallization processes continue in it leading to a slight increase in grain size and, accordingly, a decrease in hardness from 79 to 74 HV, which continues until the busbar contacts a cooling medium.

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