scholarly journals Calculation methods of investigating the surface layer of thin-walled shafts hardened by methods of surface plastic deformation

2015 ◽  
Vol 14 (3-2) ◽  
pp. 474
Author(s):  
A. S. Bukaty ◽  
A. N. Shvetsov
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Calculation Methods ◽  
Thin Walled

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.

Acoustic and Emission Control of the Hereditable Stress and Strain State of the Metal Surface Layer during Cutting and Surface Plastic Deformation

2015 ◽  
Vol 788 ◽  
pp. 3-10
Author(s):  
Valeriy Yu. Blumenstein ◽  
Fyodor I. Panteleenko ◽  
Igor V. Miroshin ◽  
Oleg A. Ostanin
Keyword(s):  
Plastic Deformation ◽  
Acoustic Emission ◽  
Surface Layer ◽  
Shear Deformation ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Deformation Degree ◽  
Emission Signal ◽  
Experimental Findings ◽  
Surface Layer Quality

Methods and experimental findings shown describe how mechanical parameters of the surface layer behavior and acoustic emission signals are interconnected.Experimental study was carried out under conditions of simple single-and dual stage compression. Graphic and analytic dependencies between the counting rate of the acoustic emission Ṅ and the shear deformation degree Λ were revealed. The findings describing dual compression show that the acoustic emission method is sensitive to the material stressing history.The dependency of the acoustic emission signal energy on the pre-stressing program was found, which helped establish that, with values of the plasticity reserve depletion being equal for all experimental specimens, the accumulated shear deformation degree Λ was different.The findings describing the hereditable physical state of the strengthened surface layer of parts during cutting and surface plastic deformation are presented in the paper. The study was carried out using the methods of property accumulation control in deformation sites depending on treatment modes with real-time monitoring of acoustic emission signals. A peculiar feature of these methods is the use of visual recording of the metal plastic flow to be further used in calculating the hereditable parameters of the surface layer quality.

OUTLOOKS IN SURFACE PLASTIC DEFORMATION USE TO DECREASE SURFACE ROUGHNESS IN ROLLING MILL PARTS STRENGTHENED WITH SVS-ELECTRODE MATERIALS

2020 ◽  
Vol 2020 (8) ◽  
pp. 4-12
Author(s):  
Aleksey Makarov ◽  
Anna Titova ◽  
A. Afonin ◽  
Alexander Kudryashov ◽  
Aleksandr Vladimirov
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Surface Layer ◽  
Rolling Mill ◽  
Mechanical Characteristics ◽  
Electrode Materials ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Electrospark Alloying ◽  
Micro Hardness

The purpose of this work consists in ensuring the required quality of micro-geometry and mechanical characteristics of a surface layer in rolling mill parts, in particular, surface roughness no more than Ra=2.5mkm and micro-hardness no less than 900 kgs/mm2. To ensure such micro-hardness in samples of 60HN steel there were applied coatings With the method of electrospark alloying with the use as an electrode synthetic hard tool materials based on titanium diboride (STIM-11) and titanium carbide (STIM-40NA) made by the method of self-propagating high-temperature synthesis. EIL-coatings made of thses materials are characterized with the thickness of 30mkm, micro-hardness up to 980 kgs/mm2, that exceeds four times micro-hardness of a non-hardened sample, and with roughness Ra=5…10mkm. To decrease roughness of EIL-coatings made of STIM materials for the first time there was used surface plastic deformation with smoothing that is a novelty of this investigation. Smoothing was carried out on a screw-cutting lathe with the aid of a flattener with TC6 tungsten-cobalt hard alloy indenter (r=6mm) at the rotational frequency n=70rev/min and at the indenter longitudinal feed S=0.05mm/rev and the smoothing force P=500N. As a result of smoothing the micro-hardness of surface layers made 990kgs/mm2, and roughness – Ra=1.6…1.8mkm. Conclusion: smoothing contributes to the decrease of surface layer roughness from 3 times (STIM-40NA) to 5.5 times (STIM-11) at the conservation of their mechanical characteristics that proves the outlook in use of such a technology for finishing parts surfaces strengthened with SVS-electrode materials by STIM method of electrospark alloying.

Influence of the deforming tool kinematics on the stress state of the surface layer during hardening of cylindrical parts

2021 ◽  
pp. 28-32
Author(s):  
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Stress State ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
The Finite Element Method ◽  
Kinematic Scheme ◽  
Local Surface ◽  
Hardening Process ◽  
Cylindrical Parts

The influence of kinematic schemes of processing by local surface plastic deformation on the intensification of the stressed state of cylindrical surfaces of parts is considered. On the basis of the finite element method by computer simulation, a mathematical model of the hardening process was obtained to determine the stress state in the surface layer for different hardening schemes. Keywords: kinematic scheme of processing, deforming tool, orbital burnishing, intensification of the stress state, residual stresses, depth of plastic deformation. [email protected], [email protected]

scholarly journals Application of the method of current functions in stationary plastic deformation processes

2020 ◽  
pp. 157-163
Author(s):  
Volodymyr Rekechynsky
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Local Heating ◽  
Surface Plastic Deformation ◽  
Contact Friction ◽  
Surface Plastic ◽  
Strain Rate Tensor ◽  
Current Function ◽  
Plastic Molding ◽  
Current Lines

A method of determining the components of the strain rate tensor based on the method of current functions is developed. It is assumed that, with an axisymmetric plastic deformation of the metal in a channel with curvilinear borders, the kinematics of the process are similar to a flat flow. Using the incompressibility equation and the differential equation of the current lines, it is established that the current function maintains a constant value along the current lines. Two infinitely close current lines are considered in the flow plane to explain the kinematic content of the current function. The expression for flow through the finite transverse-sized tube was obtained. In the absence of radial velocity components at the boundaries, we obtain the restrictions imposed on derivatives of the current functions at these boundaries. The method of calculation of kinematic deformation characteristics for established axisymmetric processes will allow to simplify the mathematical processing of the obtained results. Real processes of metal processing are always accompanied by uneven plastic molding, which affects the power and kinematic parameters, the quality of finished products. The main technological factors affecting the appearance of the inhomogeneity and the nature of its distribution are the form factor (geometric parameters of the original workpiece) and the coefficient of contact friction. The study of technological parameters affecting the distribution of non-uniformity of plastic molding will allow to create practical recommendations for reducing the influence of the above mentioned parameters to ensure more uniform plastic deformation. Due to elastic-plastic deformation and local heating, which occur during surface-plastic deformation processing, the stress-strain and physical state of the surface layer is formed. This changes the microgeometry of the surface, the physical and mechanical properties of the surface layer of the workpiece. The surface treated by methods of surface-plastic deformation, has high hardness, residual compression stresses in the surface layer, smoothed out the micro-roughness. Accordingly, increases wear resistance, fatigue strength, resistance to corrosion and more.

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