scholarly journals Constructive and technological method of increasing durability of “choke connections”

2021 ◽  
Vol 2131 (4) ◽  
pp. 042061
Author(s):  
Y G Lyudmirskii ◽  
S S Assaulenko ◽  
S O Ageev
Keyword(s):  
Plastic Deformation ◽  
Base Metal ◽  
Strain State ◽  
Low Cycle Fatigue ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Cycle Fatigue ◽  
Static Loads ◽  
Maintenance System ◽  
Shape And Size

Abstract Welded circular seams of “choke joints”, as a rule, have deviations from the specified diameter. This leads to uneven deformation, and sometimes to the absence of deformations in some areas of the seam. With repeated static loads, destruction arises in these places. To connect to the maintenance system of connections with the base metal, used as a guide, surface plastic deformation of the zone zone is carried out. A technology and equipment have been developed that allow plastically deforming the area of transition from the weld to the base metal along the entire length of the circular weld. As a result of plastic deformation along the technological groove, the characteristics of low-cycle fatigue of welded joints are obtained, which are not inferior to the base metal. To reduce stresses in the zone of transition from the weld to the base metal, it is proposed, first, to perform a circular groove on the base metal by machining, as close as possible to the specified zone. To assess the influence of the shape and size of the groove on the stress-strain state of the zone of conjugation of the weld metal with the base metal, FEM calculations were carried out

Study of Surface Layer Hardening after Treatment Complex Tool

2020 ◽  
Vol 303 ◽  
pp. 89-96
Author(s):  
K.S. Mitrofanova
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Strain State ◽  
Experimental Studies ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Technological Inheritance ◽  
Multiple Loading ◽  
Surface Layer Hardening ◽  
Solidified Body

The results of experimental studies of the thin surface layer of samples made of steel 45 after treatment with surface plastic deformation (SPD) multiradius roller (MR-roller) are presented. On the basis of the apparatus of the mechanics of technological inheritance, taking into account the effect of the solidified body, a model of the process according to the scheme of multiple loading-unloading of metal, taking into account the phenomenology of the SPD process and the properties of the material, is created. Distributions of parameters of the stress-strain state in the deformation centre are obtained, the parameters of roughness and microhardness of the surface layer are investigated.

scholarly journals Impact of local deformation kinematics upon stressed state of surface layer

2019 ◽  
Vol 2019 (5) ◽  
pp. 32-48
Author(s):  
Семен Зайдес ◽  
Semen Zaides ◽  
И. Бобровский ◽  
I. Bobrovsky ◽  
Ван Фам ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Plastic Deformation ◽  
Strain State ◽  
Surface Plastic Deformation ◽  
Local Deformation ◽  
Surface Plastic ◽  
Deformation Kinematics ◽  
State Changes ◽  
Process Computer ◽  
Tool Motion

A kinematics of a deforming tool motion for stress-strain state changes in the point of an elastic-plastic deformation and residual stresses increase at surface plastic deformation is developed. The results of a loading process computer simulation under different conditions of a deforming tool contact with a part which give a possibility to increase the effectiveness of a new method of the finishing-strengthening of orbital surface plastic deformation are shown.

scholarly journals Assessment of stress-strain state in cylindrical parts after transverse running with flat plates

2017 ◽  
Vol 2 (5) ◽  
pp. 38-43 ◽  
Author(s):  
Семен Зайдес ◽  
Semen Zaides ◽  
Дак Фам ◽  
Dac Pham
Keyword(s):  
Plastic Deformation ◽  
Strain State ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Flat Plates ◽  
Stress Strain ◽  
Program Complex ◽  
Vertical Loading ◽  
Stress Strain State ◽  
Cylindrical Parts

For the deformation strengthening of parts like axles, pins, and bushes there is offered a method of surface plastic deformation based on blank rolling with flat plates. The method allows machining parts which do not have center holes. At transverse running a blank bending affected by transverse loading forces is excluded. With the aid of ANSYS program complex there is considered a change of a stress-strain state in cylindrical parts at transverse running. There are defined plastic and elastic cylinder deformations after loading. The distribution of residual stresses along cylinder section in the plane of vertical loading is obtained. The stress state of samples run with flat plates on equivalent stress is assessed. An efficient value of running at transverse running used as a basic parameter of surface plastic deformation is defined.

scholarly journals Numerical Study of Stress-Strain State of Workpiece in Contact Problem of Surface Mandrel Drilling

2021 ◽  
Vol 20 (3) ◽  
pp. 259-267
Author(s):  
N. S. Sivtsev ◽  
V. V. Tarasov
Keyword(s):  
Plastic Deformation ◽  
Friction Coefficient ◽  
Contact Interaction ◽  
Computational Experiment ◽  
Strain State ◽  
Numerical Study ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Stress Strain ◽  
Stress Strain State

In recent years, the economic factor has played an increasingly important role in the selection of technologies for manufacturing machine parts with specified values of normalized parameters of geometric accuracy and quality of working surfaces. As applied to surface plastic deformation processes, this is noticeably manifested in the search for effective friction control methods in the “tool – workpiece” pair, which ultimately determines the distribution pattern and the magnitude of stresses and strains in the workpiece and the tool. It is not possible to obtain a rigorous analytical solution to the problem of establishing a connection between surface conditions, friction, and the stress-strain state of the contacted bodies. In this regard, the construction of mathematical models comes to the fore, the solution of which is possible by numerical methods. The paper presents the results of a numerical study (computational experiment) of a finite-element model of workpiece deformation under various conditions of contact interaction and friction by one of the methods of surface plastic deformation – surface mandrel drilling. The friction coefficient has been chosen as the criterion for assessing the conditions of contact interaction and friction. It is shown that a change in the friction coefficient in the process of surface mandrel has no noticeable effect on the formation of a stress field in the deformable workpiece both in the axial, and in the radial and circumferential directions. At the same time, with an increase in the value of the friction coefficient in the “tool – workpiece” pair and with the associated increase in the force of mechanical resistance to deformation of the workpiece, their growth is observed. A computational experiment has confirmed the presence of non-contact deformations of the workpiece and tool during surface mandrel drilling, as well as  as a decrease in the value of residual deformations in the workpiece with a decrease in the coefficient of friction. Balance assessment of contact surface displacements in the workpiece (the inner surface of the hole to be machined) and the tool (mandrel) has shown that the deformations of the tool in the elastic region can lead to a significant decrease in the real tightness of surface mandrel drilling.

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.

Dressing of shafts by surface plastic deformation with elastic bending of a billet at machining process

2020 ◽  
pp. 62-66
Author(s):  
G.V. Muratkin ◽  
V.A. Sarafanova
Keyword(s):  
Plastic Deformation ◽  
Strain State ◽  
Residual Deformation ◽  
Surface Plastic Deformation ◽  
Machining Process ◽  
Surface Plastic ◽  
Stress Strain ◽  
Elastic Bending ◽  
Stress Strain State ◽  
Accuracy Stress

A method for dressing of non-rigid parts by surface plastic deformation is proposed, which is based on a change in the stress-strain state of the billet during finishing and hardening processing. Keywords non-rigid shaft, dressing, surface plastic deformation, technological residual deformation, accuracy, stress. [email protected]

Influence of structure and properties of surface layer on fatigue durability of hardened steels strengthened by combined electromechanical treatment

2019 ◽  
Vol 62 (6) ◽  
pp. 438-450
Author(s):  
V. P. Bagmutov ◽  
N. G. Dudkina ◽  
I. N. Zakharov ◽  
M. D. Romanenk ◽  
V. V. Chekunov
Keyword(s):  
Plastic Deformation ◽  
Fatigue Limit ◽  
Surface Hardening ◽  
Strain State ◽  
Surface Plastic Deformation ◽  
Carbon Steels ◽  
Surface Plastic ◽  
Surface Microhardness ◽  
Near Surface ◽  
Surface Metal

Using the example of hardened carbon steels (steel 45, U8), the effect of combination of various surface hardening technologies is considered (using electromechanical processing, surface plastic deformation, non-abrasive ultrasonic finishing and their combination) on changes in structural state and surface microhardness, cyclic durability of hardened specimens and fatigue failure mechanisms. The studies were carried out by the methods of optical and scanning electron microscopy and by microhardness and fatigue tests. It is shown that for the investigated steels in quenched state, a high-speed pulsed thermo-deformation effect during electromechanical processing is accompanied by an increase in the surface microhardness (by more than 50 %) and decrease in the fatigue limit (by 20 – 30 %). Such a change in properties is associated with formation in the surface layer of substantially non-equilibrium, inhomogeneous in chemical composition, ultradispersed phases with increased hardness. At the same time, in the near-surface metal volumes tempering processes of the hardened structure proceed with the formation of softening zones and tensile residual stresses, accompanied by a decrease in the microhardness in these zones and the fatigue limit of the specimens. Such effects reduce some of the materials performance characteristics during surface hardening. The ways to improve the properties of such products due to additional technological operations require further studies. Combined surface hardening (based on electromechanical processing, surface plastic deformation and non-abrasive ultrasonic finishing) of carbon steels allows, due to variations in the intensity of temperature and deformation effects, to purposefully change the structural-phase composition and stress-strain state of the surface and near-surface metal layers. As a result, it becomes possible to form a balanced complex of strength and fatigue characteristics of the samples, depending on the preliminary heat treatment of steel. The operations of surface plastic deformation and non-abrasive ultrasonic finishing after electromechanical hardening, due to intensive plastic deformation provide smoothing of the surface and healing of near-surface defects and allow correction of stress-strain state of the processed metal. It provides an increase in microhardness in the tempering zone by 20 – 25 % and the fatigue limit of the samples by 25 – 30 %. 

New methods for surface plastic deformation of low-rigidity cylindrical machine parts

2018 ◽  
Vol 2018 (8) ◽  
pp. 16-24 ◽  
Author(s):  
Семен Зайдес ◽  
Semen Zaides
Keyword(s):  
Plastic Deformation ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
High Productivity ◽  
Surface Strengthening ◽  
New Methods ◽  
Machine Parts

Technological potentialities at finish-strengthening processing of low-rigid parts of shaft- and axle types with local ways of machining impact are rather limited. In the paper there are considered new ways for strengthening allowing obtaining qualitative surface strengthening in machine parts at high productivity of an engineering procedure.

Plastic deformation of collector plates at electric motor repair

2020 ◽  
pp. 79-82
Author(s):  
D.YU. Belan ◽  
G.B. Toder ◽  
K.V. Averkov ◽  
YU.V. Titov
Keyword(s):  
Plastic Deformation ◽  
Electric Motor ◽  
Roughness Parameter ◽  
Surface Plastic Deformation ◽  
Analytical Dependence ◽  
Surface Plastic ◽  
Machined Surface ◽  
Tool Surface ◽  
Diamond Burnishing ◽  
Traction Electric Motor

A tool was developed for smoothing the plates of an electric motor collector. An analytical dependence of the roughness parameter of the machined surface on the force applied to the tool is obtained. Keywords traction electric motor, collector, diamond burnishing tool, surface-plastic deformation, repair, roughness. [email protected]

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