The Experts below are selected from a list of 5286 Experts worldwide ranked by ideXlab platform
W X Zhou - One of the best experts on this subject based on the ideXlab platform.
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friction and wear behavior of pure Carbon Strip sliding against copper contact wire under ac passage at high speeds
Tribology International, 2011Co-Authors: T Ding, G X Chen, X C Wang, W H Zhang, W X ZhouAbstract:A series of tests on the friction and wear behaviour of pure Carbon Strip/copper contact wire with alternating current were conducted on a ring-on-block sliding tester at a high speed. The electric current, normal force and sliding velocity have distinct effects on the test results. The worn scar has the smallest size without electric current. The worn scar becomes larger with increasing electric current. Arc ablation pits, dark stream-lines of arc ablation, slipping marks, spalling blocks and the copper-like layer are found on the worn surfaces. Arc erosion, abrasive wear and adhesive wear are main wear mechanisms.
T Ding - One of the best experts on this subject based on the ideXlab platform.
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effect of temperature and arc discharge on friction and wear behaviours of Carbon Strip copper contact wire in pantograph catenary systems
Wear, 2011Co-Authors: T Ding, G X Chen, J Bu, Wulin ZhangAbstract:Abstract A series of tests on friction and wear performance of pure copper rubbing against Carbon Strip under electric current have been carried out on a modified pin-on-disc friction and wear tester. The results indicate that there are temperature rise and arc discharge in the electrical sliding processes. The temperature rise of contact pairs and the intensity of arc discharge increase with the increasing of electric current. However, the friction coefficient increases firstly due to the accumulation of wear debris, and then decreases with the increasing of electric current due to the accumulation of electric heat and friction heat on contact interface. The increase in wear volume of the Carbon Strip is mainly caused by high temperature of contact pairs and arc discharge phenomenon. The test results also show that the wear volume of pin specimen with arc discharge is much greater than that without arc discharge under the same temperature. Therefore, the thermal wear due to high temperature has a distinct influence on the service life of pantograph contact Strip and arc erosion even has more significant influence. Cooling measures should be applied in pantograph/catenary systems. Especially, off-line arc discharge of the contact couple should be suppressed to the maximum extent to extend the service life of pantograph contact Strip.
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friction and wear behavior of pure Carbon Strip sliding against copper contact wire under ac passage at high speeds
Tribology International, 2011Co-Authors: T Ding, G X Chen, X C Wang, W H Zhang, W X ZhouAbstract:A series of tests on the friction and wear behaviour of pure Carbon Strip/copper contact wire with alternating current were conducted on a ring-on-block sliding tester at a high speed. The electric current, normal force and sliding velocity have distinct effects on the test results. The worn scar has the smallest size without electric current. The worn scar becomes larger with increasing electric current. Arc ablation pits, dark stream-lines of arc ablation, slipping marks, spalling blocks and the copper-like layer are found on the worn surfaces. Arc erosion, abrasive wear and adhesive wear are main wear mechanisms.
G X Chen - One of the best experts on this subject based on the ideXlab platform.
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effect of the vibration on friction and wear behavior between the Carbon Strip and copper contact wire pair
Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2012Co-Authors: H J Yang, G X Chen, Shuang Zhang, Wulin ZhangAbstract:This article reports an experimental study on the friction and wear behavior of Carbon Strip sliding against copper contact wire under strong electric current utilizing a high-speed block-on-ring tester. The dynamic mechanism of electric arc generation was investigated. Scanning electron microscopy was used to observe morphology of worn surfaces of the Carbon Strips. The results show that arc discharge has a certain correlation with low-frequency vibration of the Carbon Strip. The arc discharge frequency and the average single arc discharge energy initially decrease and then tend to stable with increasing normal load at different speeds. The wear rate increases first and then decreases and has the minimum when the load is equal to 100 N especially. Moreover, the wear rate steadily increases with increase in arc discharge energy and is almost directly proportional to arc discharge energy. Arc erosion was a dominant wear mechanism occurred in Carbon Strip sliding against copper contact wire at a low load, a...
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effect of temperature and arc discharge on friction and wear behaviours of Carbon Strip copper contact wire in pantograph catenary systems
Wear, 2011Co-Authors: T Ding, G X Chen, J Bu, Wulin ZhangAbstract:Abstract A series of tests on friction and wear performance of pure copper rubbing against Carbon Strip under electric current have been carried out on a modified pin-on-disc friction and wear tester. The results indicate that there are temperature rise and arc discharge in the electrical sliding processes. The temperature rise of contact pairs and the intensity of arc discharge increase with the increasing of electric current. However, the friction coefficient increases firstly due to the accumulation of wear debris, and then decreases with the increasing of electric current due to the accumulation of electric heat and friction heat on contact interface. The increase in wear volume of the Carbon Strip is mainly caused by high temperature of contact pairs and arc discharge phenomenon. The test results also show that the wear volume of pin specimen with arc discharge is much greater than that without arc discharge under the same temperature. Therefore, the thermal wear due to high temperature has a distinct influence on the service life of pantograph contact Strip and arc erosion even has more significant influence. Cooling measures should be applied in pantograph/catenary systems. Especially, off-line arc discharge of the contact couple should be suppressed to the maximum extent to extend the service life of pantograph contact Strip.
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friction and wear behavior of pure Carbon Strip sliding against copper contact wire under ac passage at high speeds
Tribology International, 2011Co-Authors: T Ding, G X Chen, X C Wang, W H Zhang, W X ZhouAbstract:A series of tests on the friction and wear behaviour of pure Carbon Strip/copper contact wire with alternating current were conducted on a ring-on-block sliding tester at a high speed. The electric current, normal force and sliding velocity have distinct effects on the test results. The worn scar has the smallest size without electric current. The worn scar becomes larger with increasing electric current. Arc ablation pits, dark stream-lines of arc ablation, slipping marks, spalling blocks and the copper-like layer are found on the worn surfaces. Arc erosion, abrasive wear and adhesive wear are main wear mechanisms.
Koji Kato - One of the best experts on this subject based on the ideXlab platform.
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Effect of arc discharge on the wear rate and wear mode transition of a copper-impregnated metallized Carbon contact Strip sliding against a copper disk
Tribology International, 1999Co-Authors: Shunichi Kubo, Koji KatoAbstract:Wear of the contact Strip on the pantograph of electric railway vehicles is governed mainly by arc discharge occurring simultaneously with break of contact between the Strip and trolley wire. As a step to clarify the wear mechanism of metallized Carbon contact Strips under the occurrence of contact break arc discharge, a detailed sliding wear test of 30 min duration was carried out for the combination of a copper-impregnated Carbon Strip and a copper disk at a sliding speed of 100 km/h. The worn surfaces of the Strip and disk were observed every 5 min. The voltage drop and electric current were measured throughout the test, and the occurrence and energy of the arc discharge were evaluated for each revolution of the disk. The wear process is considered in terms of the wear mode transition, and the effect of arc discharge on the mode transition and wear rate of the Strip is discussed.
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effect of arc discharge on wear rate of cu impregnated Carbon Strip in unlubricated sliding against cu trolley under electric current
Wear, 1998Co-Authors: Shunichi Kubo, Koji KatoAbstract:The wear of contact Strip on the pantograph of electric railway vehicle is mainly governed by arc discharge occurring simultaneously with contact break between Strip and trolley wire. Sliding wear tests were carried out under electric current for the combination of Cu-impregnated baked Carbon Strip and Cu trolley at a sliding speed of 100 km/h. Voltage drop and current were measured at a frequency of 48 kHz and electric power, total time duration and accumulated energy of discharge were evaluated for each test Strip. Plot of wear rate of Strip against arc discharge energy shows a proportional relationship between them.
L I Yiyi - One of the best experts on this subject based on the ideXlab platform.
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modelling of microstructural evolution and prediction of mechanical properties of plain Carbon Strip steel in hot rolling process
Journal of Materials Science & Technology, 2004Co-Authors: Xiaochun Sha, M O Chunli, L I Dianzhong, L I YiyiAbstract:Based on hot rolling production line of Strip steel, the off-line in-house software, termed as ROLLAN (Rolling Analysis), is developed. The code is mainly used to predict the evolution of temperature, rolling force, fraction and grain size of recrystallization, fraction and grain size of phase transformation and final mechanical properties. Almost all the processing parameters affecting microstructure and mechanical properties in the schedule from reheating to the coiling process are considered in detail. Self-learning coefficient is adopted to adjust the deviation between predicted and measured temperatures, such as roughing exit temperature (RT2), finishing exit temperature (FT7) and coiling temperature (CT). Due to the application of low-speed-threading,increasing-speed-rolling and decreasing-speed delivery process during finishing rolling and different cooling condition, after coiling the thermal-mechanical history of different position, along Strip longitudinal direction is different resulting in inhomogeneous mechanical properties. So the segments are divided along longitudinal direction to identify the variation of microstructure and mechanical properties. An example of plain Carbon Strip steel Q235 with various thickness is used to compare the calculated mechanical properties with measured ones. For the specific grade of Q235, the maximum deviation of tensile strength is less than 10.3 MPa, the yield strength is less than 13.2 MPa, and elongation is less than 1.99%. Further work will focus on the on-line application and consider the effect of macrosegregation and sulfur content of cast slab.