Structure of sheet blanks from VT6S titanium alloy after local deformation during pulse heating by electric current

2020 ◽  
pp. 512-519
Author(s):  
S.V. Smirnov ◽  
V.V. Ovchinnikov
Keyword(s):  
Titanium Alloy ◽  
Electric Current ◽  
Current Pulse ◽  
Pulse Heating ◽  
Pulse Current ◽  
Point Contact ◽  
Local Deformation ◽  
Vt6s Titanium Alloy ◽  
Heated State ◽  
Contact Welding

The local deformation process of blanks in the form of thin discs from VT6S titanium alloy with the use of pulse heating by electric current and deformation in heated state in the electrodes of the point contact welding machine is studied. The rational values of the process parameters (pulse current, pulse duration and precipitation force) are defi ned. Analysis of the microstructure for the VT6S alloy in its original state and after deformation with heating did not reveal signifi cant increase in grain and the formation of thick alpha layer. The increasing in the plasticity of the VT6S alloy after passing of the current pulse is established. At the same time, in the structure of the deformed zone noted the presence of double.

Effect of pulsed electric heating local deformation mode on structure of blanks made of titanium VT6S alloy

2021 ◽  
pp. 234-240
Author(s):  
S.V. Smirnov ◽  
V.V. Ovchinnikov
Keyword(s):  
Point Contact ◽  
Deformation Mode ◽  
Electric Heating ◽  
Local Deformation ◽  
Double Layers ◽  
Artificial Ageing ◽  
Heat Temperature ◽  
Heated Area ◽  
Heated State ◽  
Contact Welding

The local deformation process of blanks in the form of thin discs made of titanium VT6S alloy with the use of pulse heating with electric current without and with deformation in heated state in the electrodes of the point contact welding machine is studied. It is established that when heated without deformation, increase in the temperature of heating contributes to the growth of grain in the blank. Intense grain growth is noted at heat temperature above 750...800 °C. Intensive plastic deformation due to the compression of the blank heated area by the electrodes of the contact machine is accompanied by the formation of double layers and decrease in the size of the grain after deformation and artificial ageing.

Refinement of inclusions in molten steel by electric current pulse

2015 ◽  
Vol 31 (13) ◽  
pp. 1555-1559 ◽  
Author(s):  
W. B. Dai ◽  
J. K. Yu ◽  
C. M. Du ◽  
L. Zhang ◽  
X. L. Wang
Keyword(s):  
Electric Current ◽  
Current Pulse ◽  
Molten Steel ◽  
Electric Current Pulse

Electric Current Pulse Welding of Titanium with 18-10 Stainless Steel

2009 ◽  
Vol 83-86 ◽  
pp. 1251-1253 ◽  
Author(s):  
E.G. Grigoryev ◽  
V.N. Bazanov
Keyword(s):  
Stainless Steel ◽  
Electric Current ◽  
Current Pulse ◽  
Contact Zone ◽  
Welded Joints ◽  
High Speed ◽  
Welded Joint ◽  
Electric Current Pulse ◽  
Pulse Effect ◽  
Different Thickness

The purpose of the work was to determine the capabilities of the pulse effect of electric current and pressure to produce welded joints of various component parts of different thickness from 18-10 stainless steel and titanium. Application of electric current pulses on the surfaces of contacting metallic conductors leads to considerable changes in the surface structure. Depending on the initial state of the surfaces and parameters of the pulse effect this can result in melting without formation of joints, formation of a strong welded joint with characteristics no worse than those of welded metals, and in destruction of the contact zone. A combination of a short electric pulse with simultaneous application of mechanical pressure in the weld zone causes high-speed deformation of the contact zone. The process of joint formation itself does not cause any appreciable diffusion during welding. The greatest energy emission and the maximal heating occur on the contacting surfaces being welded with the passage of an electric current pulse through the welding zone. Simultaneously with intensive heating, and due to applied pressure, high-speed deformation of materials takes place and a strong welded joint is formed. Optimal parameters for the welding of titanium and 18-10 stainless steel have been determined on the basis of the tests conducted. Investigations into the welding of titanium and 18-10 stainless steel have shown that application of a short electric current pulse and pressure produces stronger welded joints composed of both similar and different metals of considerably different thickness.

scholarly journals Effect of Electric Current Pulse on Microstructure and Corrosion Resistance of Hypereutectic High Chromium Cast Iron

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2220 ◽  
Author(s):  
Haiyang Lv ◽  
Rongfeng Zhou ◽  
Lu Li ◽  
Haitao Ni ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Cast Iron ◽  
Electric Current ◽  
Current Pulse ◽  
Electric Current Pulse ◽  
High Chromium ◽  
High Chromium Cast Iron ◽  
Microcrack Propagation ◽  
Primary Carbides ◽  
Chromium Cast Iron

The effect of electric current pulse on the microstructure and corrosion resistance of hypereutectic high chromium cast iron was explored. The morphology of carbides in solidification microstructure was observed by an optical microscope and a scanning electron microscope and the composition was determined by an electron probe micro-analyzer. The microhardness of primary carbides and corrosion resistance of samples were also compared. Under the active of electric current pulse, the microstructure of hypereutectic high chromium cast iron was homogenized and its performance improved accordingly. On treatment by electric current, the morphology of primary carbides changed from thick long rods to hexagonal blocks or granular structures. The interlayer spacing of eutectic carbide decreased from ~26.3 μm to ~17.8 μm. Size statistics showed that the average diameter of primary carbide decreased from ~220 μm to ~60 μm. As a result, microhardness increased from 1412 HV to 1511 HV. No obvious microcrack propagation was found at the microindentation sites. The average length of microcracks decreased from ~20.7 μm to ~5.7 μm. Furthermore, corrosion resistance was remarkably enhanced. The average corrosion rate decreased from 2.65 mg/cm2·h to 1.74 mg/cm2·h after pulse current treatment.

scholarly journals Effect of High Density Electric Current Pulse on Solidification of Cu-37.4 wt.%Pb Monotectic Alloy Melt

2019 ◽  
Vol 26 (1) ◽  
pp. 34-40
Author(s):  
Teng MA ◽  
Guihong GENG ◽  
Xiaosi SUN ◽  
Xi HAO ◽  
Weixin HAO
Keyword(s):  
Wear Resistance ◽  
Electric Current ◽  
Current Pulse ◽  
Metal Cluster ◽  
High Density ◽  
Formation Mechanisms ◽  
Electric Current Pulse ◽  
Monotectic Alloy ◽  
Scanning Calorimetry ◽  
Cluster Theory

The effect of high-density electric current pulse (ECP) on the solidification of Cu-37.4 wt.%Pb monotectic alloy melt was investigated. The microstructure formation mechanisms of ECP were clarified according to liquid metal cluster theory. The results demonstrated that with ECP treatment, the microstructure of Cu-Pb monotectic alloy became finer, the distribution of Pb phase in the matrix was more even and the solute trapping was significantly apparent. Based on the metal liquid cluster theory under ECP, the solid solubility increase result might be due to the salvation clusters increase under the action of pulse current, leading to the binding force increase among solute atoms and solvent atoms. Simultaneously, the aforementioned results were verified through the Differential Scanning Calorimetry (DSC) curve analysis. The results of hardness test, anti-friction test and wear- resistance test show that the ECP can enhance the hardness, improve the properties of anti-friction and wear-resistance of the alloy.

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