Influence of Electric Current Pulses on the Microstructure and Mechanical Properties of X70 Pipeline Steel

2011 ◽  
Vol 391-392 ◽  
pp. 535-539 ◽  
Author(s):  
Wen Bin Dai ◽  
Xin Li Wang ◽  
Li Li Chen ◽  
Lin Zhao ◽  
Jing Kun Yu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electric Current ◽  
Pipeline Steel ◽  
Elongation Rate ◽  
Electric Current Pulse ◽  
X70 Pipeline Steel ◽  
Current Pulses ◽  
Electric Current Pulses ◽  
Current Densities

The effect of high electric current pulse on the microstructure and macroscopic mechanical behavior of X70 pipeline steel was studied. With the increasing of current density, the grains become refined and the tensile strength has an evident improvement without a decrease in elongation rate. The theoretical analysis shows that two kinds of refinement mechanisms, recrystallization and phase transformation, compete when the exerted current densities differ. Therefore, the ECP treatment should provide a promising method to refine materials and to improve their physical properties by using different current densities.

Effect of electric current pulse type on springback, microstructure, texture, and mechanical properties during V-bending of AA2024 aluminum alloy

2020 ◽  
pp. 1-36
Author(s):  
Nafiseh Mohammadtabar ◽  
Mohammad Bakhshi-jooybari ◽  
Hamid Gorji ◽  
Roohollah Jamaati ◽  
Jerzy A. Szpunar
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Electric Current ◽  
Current Pulse ◽  
Fiber Texture ◽  
Electric Current Pulse ◽  
Electric Pulses ◽  
Current Pulses ◽  
Electric Current Pulses ◽  
Pulse Type

Abstract The present work focused on the effect of the electric current pulse type on the springback, microstructure, texture, and mechanical properties during the V-bending process of AA2024 aluminum alloy. In order to investigate this effect, three different forming conditions including conventional V-bending and electrically assisted V-bending with square and sinusoidal pulses were considered. The results indicated that the amount of springback significantly decreased from 45.5° (for the sample formed via conventional V-bending) to 24° by applying the sinusoidal pulse. Microstructural observations revealed lower stored energy in the samples formed by electric current pulses which resulted in larger grain size compared to the samples formed without electric pulses. In addition, the result showed that the intensity of the (111)||BLD (bend line direction) fiber texture reduced after applying electric current pulses whereas it was very strong in the sample formed without electric pulses. It was suggested that the electric current pulses led to change the slip plane of the dislocations from {111} to {110} through cross slip. The applying electric current pulses decrease the ultimate tensile strength (UTS) from 471.1 MPa (for the conventional tensile test) to 448.0 and 426.7 MPa for the square and sinusoidal pulses, respectively. On the other hand, the electric pulses improved the formability of the AA2024 alloy owing to the activation of more slip systems, inhibition of dislocation pinning, the promotion of dislocation movement, and the acceleration of restoration mechanisms.

scholarly journals Effect of Annealing Process on the Mechanical Properties of X70 Pipeline Steel

2018 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Teng-wei Zhu ◽  
Cheng-liang Miao ◽  
Zheng Cheng ◽  
Zhipeng Wang ◽  
Yang Cui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Annealing Temperature ◽  
Pipeline Steel ◽  
Annealing Process ◽  
X70 Pipeline Steel ◽  
Grain Sizes ◽  
Scanning Electron

The influence of the mechanical properties of X70 pipeline steel under different annealing temperature was studied. The corresponding microstructure was investigated by the Field Emission Scanning Electron Microscopy. The results showed that the yield strength and the tensile strength both experienced from rise to decline with the increase of annealing temperature. The grain sizes were coarse and a large amount of cementite precipitated due to preserving temperature above 550 °, which induced matrix fragmentation and deteriorate the -10 ° DWTT Toughness. There were little changes on the microstructure and mechanical properties when the annealing temperature was under 500 °.

Texture and Microstructural Evolution under Electric Current Pulses in a Fe-3%Si Steel

2011 ◽  
Vol 197-198 ◽  
pp. 1104-1108 ◽  
Author(s):  
Xin Li Wang ◽  
Hong Ming Zhao ◽  
Wen Bin Dai ◽  
Xiang Zhao
Keyword(s):  
Electric Current ◽  
Microstructural Evolution ◽  
Current Density ◽  
High Current Density ◽  
Current Direction ◽  
Direction Parallel ◽  
Current Pulses ◽  
Electric Current Pulses ◽  
Current Densities ◽  
Cold Rolled

The evolution of the recrystallization texture under high current density electric current pulses (ECP) was investigated in a cold-rolled Fe-3%Si steel sheet. Results showed that the preferred nucleation always occurred in the direction parallel to the current direction at the primary stage of recrytallization. With the increment of the current density, the effect of current direction on texture and microstructural evolution was decreased. Due to the different texture component along the layer depth under different current densities, it was also found that the recrystallization nucleation was much easier to occur from the top surface.

scholarly journals Numerical Modeling and Experimental Verification for High-Speed Forming of Al5052 with Single Current Pulse

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1311
Author(s):  
Hyeong-Gyu Park ◽  
Beom-Soo Kang ◽  
Jeong Kim
Keyword(s):  
Mechanical Behavior ◽  
Thermal Effect ◽  
Electric Current ◽  
Current Pulse ◽  
High Speed ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Electric Current Pulse ◽  
Current Pulses ◽  
Electric Current Pulses

Application of electric current pulses during plastic deformation changes the mechanical behavior owing to the electro-plastic effect. The effect of electric current pulses on the Al5052 alloy is investigated in this study. In order to demonstrate the advantages of passing electric current pulses through a metal sheet during the forming process, a uniaxial tensile test with an electric current pulse was carried out using a self-designed device; this device can apply a 2-kA electric current pulse to the specimen for a short period (>100ms). The electric current increases the temperature of the specimen due to Joule heating. It is, therefore, necessary to decouple the thermal effect from the overall behavior to understand only the contribution of electric current in the mechanical behavior. Firstly, an electro-thermo-mechanical finite element study of an electrically assisted uniaxial tensile test of Al5052 alloy is performed to isolate the thermal effect. The simulated results yielded the thermal effect due to the electric current. By comparing the experimental and simulated results, the contribution of electric current is decoupled from that of thermal effect. The electric current-dependent material model is implemented into the commercial FEM code LS-DYNA using user-defined material(UMAT) subroutine. The electric current-dependent material model was used to simulate the electro-mechanical finite element analysis of the high-speed forming of an aluminum sheet with electric current pulse. Simulation results were compared with experimental results at several applied electric currents to evaluate the accuracy of the UMAT. The present work can be utilized to develop simpler constitutive models for the mechanical behavior of metals subjected to a pulsed electric current.

Effect of electric current pulses on the recrystallization kinetics of copper

1988 ◽  
Vol 22 (2) ◽  
pp. 235-238 ◽  
Author(s):  
H. Conrad ◽  
N. Karam ◽  
S. Mannan ◽  
A.F. Sprecher
Keyword(s):  
Electric Current ◽  
Recrystallization Kinetics ◽  
Current Pulses ◽  
Electric Current Pulses ◽  
Kinetics Of
Sign in / Sign up

Export Citation Format

Share Document