The Experts below are selected from a list of 40128 Experts worldwide ranked by ideXlab platform
Pengfei Li - One of the best experts on this subject based on the ideXlab platform.
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study of weld formation in swing arc Narrow Gap vertical gma welding by numerical modeling and experiment
The International Journal of Advanced Manufacturing Technology, 2018Co-Authors: Guoxiang Xu, Jiayou Wang, Lin Li, Pengfei LiAbstract:A three-dimensional unified model is proposed to simulate the weld pool dynamic behavior in swing arc Narrow Gap vertical GMA welding with allowing for swing feature of arc heat source and joint configuration. Both the moving direction of arc and its inclination are considered by transformation of coordinate system. The model can simulate the weld pool sagging process reasonably. Based on the calculated and experimental results, the mechanism of weld formation in swing arc vertical-up welding is studied. The weld pool size and the peak temperature of liquid metal are reduced largely in the case of swing arc, which leads to the faster solidification of weld pool and is the major factor responsible for suppression of weld pool sagging. Meanwhile, upward component of arc force and the enhanced support force from solidified metal bulge benefits the weakness of downward flow of liquid metal. With increasing the swing frequency, weld cross section geometry tends to be symmetrical and weld bead surface becomes smoother. When the swing frequency is higher than 0.6 Hz, the satisfied weld formation can be obtained.
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numerical analysis of heat transfer and fluid flow in swing arc Narrow Gap gma welding
Journal of Materials Processing Technology, 2018Co-Authors: Guoxiang Xu, Jiayou Wang, Pengfei LiAbstract:Abstract A three-dimensional model is developed for swing arc Narrow Gap welding process considering the effect of moving trajectory of arc and joint geometric shape, which can calculate the temperature field and fluid flow in transient state. The arc heat source model also allows for the inclination of arc in the plane perpendicular to weld beam and the variation of the arc moving direction through coordinate system transformation, its distribution parameters being determined based the arc behavior captured by a high speed video system. The droplet heat transfer is assumed as the process of liquid metal with high temperature flowing into the weld pool from the certain area above it. The major forces acing on liquid molten pool, including arc pressure, arc plasma drag force, electromagnetic force, surface tension, Marangoni stress and buoyancy force are taken into account in this model. The characteristics of weld pool dynamic behavior and temperature profile are analyzed and the effect of different welding parameters on them is discussed. In swing arc Narrow Gap GMA welding, there exists a large vortex in the whole weld pool cross section and fluid flow pattern is beneficial to the growth of sidewall penetration depth. The width of high-temperature region outside weld pool is smaller than that of non-swing arc welding process. The arc swing frequency has minor influence on the cooling rate.
Jiayou Wang - One of the best experts on this subject based on the ideXlab platform.
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study of weld formation in swing arc Narrow Gap vertical gma welding by numerical modeling and experiment
The International Journal of Advanced Manufacturing Technology, 2018Co-Authors: Guoxiang Xu, Jiayou Wang, Lin Li, Pengfei LiAbstract:A three-dimensional unified model is proposed to simulate the weld pool dynamic behavior in swing arc Narrow Gap vertical GMA welding with allowing for swing feature of arc heat source and joint configuration. Both the moving direction of arc and its inclination are considered by transformation of coordinate system. The model can simulate the weld pool sagging process reasonably. Based on the calculated and experimental results, the mechanism of weld formation in swing arc vertical-up welding is studied. The weld pool size and the peak temperature of liquid metal are reduced largely in the case of swing arc, which leads to the faster solidification of weld pool and is the major factor responsible for suppression of weld pool sagging. Meanwhile, upward component of arc force and the enhanced support force from solidified metal bulge benefits the weakness of downward flow of liquid metal. With increasing the swing frequency, weld cross section geometry tends to be symmetrical and weld bead surface becomes smoother. When the swing frequency is higher than 0.6 Hz, the satisfied weld formation can be obtained.
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numerical analysis of heat transfer and fluid flow in swing arc Narrow Gap gma welding
Journal of Materials Processing Technology, 2018Co-Authors: Guoxiang Xu, Jiayou Wang, Pengfei LiAbstract:Abstract A three-dimensional model is developed for swing arc Narrow Gap welding process considering the effect of moving trajectory of arc and joint geometric shape, which can calculate the temperature field and fluid flow in transient state. The arc heat source model also allows for the inclination of arc in the plane perpendicular to weld beam and the variation of the arc moving direction through coordinate system transformation, its distribution parameters being determined based the arc behavior captured by a high speed video system. The droplet heat transfer is assumed as the process of liquid metal with high temperature flowing into the weld pool from the certain area above it. The major forces acing on liquid molten pool, including arc pressure, arc plasma drag force, electromagnetic force, surface tension, Marangoni stress and buoyancy force are taken into account in this model. The characteristics of weld pool dynamic behavior and temperature profile are analyzed and the effect of different welding parameters on them is discussed. In swing arc Narrow Gap GMA welding, there exists a large vortex in the whole weld pool cross section and fluid flow pattern is beneficial to the growth of sidewall penetration depth. The width of high-temperature region outside weld pool is smaller than that of non-swing arc welding process. The arc swing frequency has minor influence on the cooling rate.
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groove sidewall penetration modeling for rotating arc Narrow Gap mag welding
The International Journal of Advanced Manufacturing Technology, 2015Co-Authors: Wenhang Li, Jiayou Wang, Jing Wu, Yunhong JiAbstract:It is important to predict the groove sidewall penetration for Narrow Gap MAG welding quality control. In this paper, we present a hybrid model to describe the groove sidewall penetration dynamics. First, sensing system was set up to obtain and fuse the signal from arc sensor, visual sensor, and sidewall penetration sensor. Next, the center position of the rotating arc was varied to generate the experimental data. Due to the fact that sidewall penetration on the left side varies greater than that on the right side, a support vector machine (SVM)-based dynamic model was built to predict the penetration on the left side and a cubic polynomial regression model for the right side. The model developed in this paper can be applied to the further penetration control.
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a swing arc system for Narrow Gap gma welding
Isij International, 2012Co-Authors: Jiayou Wang, Ping Fu, Rongjin Su, F. YangAbstract:A novel swing arc system was developed to realize high quality Narrow Gap GMA welding at low cost. This system uses a motor of hollow axis to turn directly the micro-bent conductive rod and then to weave circularly the arc around itself axis of torch, and can automatically search for the midpoint of symmetrical swing trail and detect precisely swing frequency in real time. Three mathematical models are also presented to calculate precisely key swing variables from torch structure and process parameters. Experimental results show that weld surface curvature and the penetration into groove sidewalls increase and weld sectional thickness decreases with increasing swing frequency and at-sidewall staying time of arc, while bottom shape of bead varies from single to twin peaks. This swing arc process thus improved obviously Narrow Gap weld formation.
Guoxiang Xu - One of the best experts on this subject based on the ideXlab platform.
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study of weld formation in swing arc Narrow Gap vertical gma welding by numerical modeling and experiment
The International Journal of Advanced Manufacturing Technology, 2018Co-Authors: Guoxiang Xu, Jiayou Wang, Lin Li, Pengfei LiAbstract:A three-dimensional unified model is proposed to simulate the weld pool dynamic behavior in swing arc Narrow Gap vertical GMA welding with allowing for swing feature of arc heat source and joint configuration. Both the moving direction of arc and its inclination are considered by transformation of coordinate system. The model can simulate the weld pool sagging process reasonably. Based on the calculated and experimental results, the mechanism of weld formation in swing arc vertical-up welding is studied. The weld pool size and the peak temperature of liquid metal are reduced largely in the case of swing arc, which leads to the faster solidification of weld pool and is the major factor responsible for suppression of weld pool sagging. Meanwhile, upward component of arc force and the enhanced support force from solidified metal bulge benefits the weakness of downward flow of liquid metal. With increasing the swing frequency, weld cross section geometry tends to be symmetrical and weld bead surface becomes smoother. When the swing frequency is higher than 0.6 Hz, the satisfied weld formation can be obtained.
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numerical analysis of heat transfer and fluid flow in swing arc Narrow Gap gma welding
Journal of Materials Processing Technology, 2018Co-Authors: Guoxiang Xu, Jiayou Wang, Pengfei LiAbstract:Abstract A three-dimensional model is developed for swing arc Narrow Gap welding process considering the effect of moving trajectory of arc and joint geometric shape, which can calculate the temperature field and fluid flow in transient state. The arc heat source model also allows for the inclination of arc in the plane perpendicular to weld beam and the variation of the arc moving direction through coordinate system transformation, its distribution parameters being determined based the arc behavior captured by a high speed video system. The droplet heat transfer is assumed as the process of liquid metal with high temperature flowing into the weld pool from the certain area above it. The major forces acing on liquid molten pool, including arc pressure, arc plasma drag force, electromagnetic force, surface tension, Marangoni stress and buoyancy force are taken into account in this model. The characteristics of weld pool dynamic behavior and temperature profile are analyzed and the effect of different welding parameters on them is discussed. In swing arc Narrow Gap GMA welding, there exists a large vortex in the whole weld pool cross section and fluid flow pattern is beneficial to the growth of sidewall penetration depth. The width of high-temperature region outside weld pool is smaller than that of non-swing arc welding process. The arc swing frequency has minor influence on the cooling rate.
C. L. Yang - One of the best experts on this subject based on the ideXlab platform.
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Molten pool behaviors and weld forming characteristics of all-position tandem Narrow Gap GMAW
The International Journal of Advanced Manufacturing Technology, 2016Co-Authors: C. L. YangAbstract:A tandem gas metal arc welding system was utilized for Narrow Gap welding in three welding positions: flat, vertical down, and overhead welding position. The two arcs worked in two independent molten pools respectively. The molten pool behaviors were investigated and the weld forming characteristics were revealed. The results suggest the molten pool behaviors in different welding positions are different due to the action of gravity. In flat welding position, the molten pool surface is concave. In vertical down welding position, more fusion metal flow to the head of molten pool, and the molten pool is asymmetric, and the molten pool surface is more concave than that in flat welding position. In overhead welding position, more fusion metal flow to the tail of the molten pool, and the surface of the pool is convex. High quality welds for various welding positions can be acquired with an appropriate ratio of welding speed to wire feed speed.
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molten pool behaviour and weld forming mechanism of tandem Narrow Gap vertical gmaw
Science and Technology of Welding and Joining, 2016Co-Authors: Xinghua Cai, C. L. Yang, Sanbao Lin, Chenglei Fan, Wei Zhang, Y W WangAbstract:A tandem gas metal arc welding system was utilised for Narrow Gap welding in vertical down position. In the welding process, the two pulses are asynchronous and two arcs worked in the same molten pool. The molten pool forming process was investigated, and the results suggest that an asymmetric pool was generated, which resulted in the asymmetry of the weld bead. This condition could be improved by decreasing the distance between the two wires. The forces acting on the molten pool and the droplet were analysed. It is pointed out that, in vertical welding with low welding speed, more fusion metal flows down to the head of the molten pool due to the gravity, which leads to the reduction of the penetration depth. Based on the results, a multilayer welding was conducted with a high welding speed and a close distance between two wires, and a high quality weld was acquired.
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prediction and optimization of weld bead geometry in oscillating arc Narrow Gap all position gma welding
The International Journal of Advanced Manufacturing Technology, 2015Co-Authors: W. H. Xu, C. L. YangAbstract:Oscillating arc Narrow Gap all-position gas metal arc (GMA) welding is primarily applied for the construction of large metal structure with the advantages of high efficiency and quality. According to the characteristic of weld shape, oscillating arc Narrow Gap all-position welding process can be divided into two parts, namely 0–180° and 180–360°, and in this paper the welding process of part 180–360° was researched. The statistical models for weld geometry were developed to predict and optimize weld bead geometry by using response surface methodology (RSM) based on central composite design (CCD), and the developed models were checked for their adequacy and significance by ANOVA. Then, the effects of wire feed rate, travel speed, dwell time, oscillating amplitude, and welding position on weld bead dimension were studied. Finally, the optimal welding parameters at welding positions from 180° to 360° were obtained by numerical optimization using RSM.
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statistical modelling of weld bead geometry in oscillating arc Narrow Gap all position gma welding
The International Journal of Advanced Manufacturing Technology, 2014Co-Authors: W. H. Xu, X Q Zhuo, C. L. YangAbstract:In this work, the oscillating arc Narrow Gap all-position gas metal arc (GMA) welding process was developed to improve efficiency and quality in the welding of thick-walled pipes. The statistical models of Narrow Gap all-position GMA weld bead geometry were developed using response surface methodology (RSM) based on central composite design (CCD). The developed models were checked for their adequacy and significance by ANOVA, and the effects of wire feed rate, travel speed, dwell time, oscillating amplitude and welding position on weld bead dimension were studied. Finally, the optimal welding parameters at welding positions of 0° to 180° were obtained by numerical optimization using RSM.
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application of rotating arc system to horizontal Narrow Gap welding
Science and Technology of Welding and Joining, 2009Co-Authors: C. L. Yang, Y Q ZhangAbstract:A rotating arc system for Narrow Gap horizontal welding was developed for solving the problem that the molten pool sagged due to the gravity. The characteristic of the system was that the synchronous rotation of nozzle and wire was generated by eccentric sleeve driven by motor. This process not only may reduce welding effective heat input due to an increase in the welding instantaneous velocity but also may disperse arc force which could counteract the gravity of upper side of molten metal. Both the two aspects were beneficial for horizontal weld formation. Experimental results indicated that shapely horizontal joint could be obtained in appropriate rotating parameters. The asymmetry of joint formation indicated that the heat affected zone width and microstructure in upper side were larger than that in lower side. The effective heat input difference near each side caused by the instantaneous velocity difference was the main reason why the formation characteristics occurred.
Gang Zhang - One of the best experts on this subject based on the ideXlab platform.
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arc characteristics and metal transfer behavior in Narrow Gap gas metal arc welding process
Journal of Materials Processing Technology, 2017Co-Authors: Gang ZhangAbstract:Abstract During the constant-voltage welding machine employed welding process, a common phenomenon of arc attachment point moving from the bottom of the Narrow Gap to the sidewalls occurs, and metal transfer behavior appears greatly different. A mechanism that the arc inherent-self regulation combines the minimum arc voltage principle was proposed to elaborate the arc climbing up process along the sidewalls. The arc shape was approximately classified into three patterns by the change of arc conductive path, and the amount of the arc conductive path and its distributive symmetry determine the action of the electromagnetic force on the droplet as well as the metal transfer mode. As the number of the arc conductive paths increases, and the conductive paths distribute symmetrically, the necking process of the droplet detachment occurs more easily, and the metal transfer from globular mode to spray mode becomes more smoothly. Simulation results match the experiments and verify the mechanism proposed. In a constant-current welding power source adopted condition, the arc climbing up phenomenon cannot be observed, and a stable welding process is obtained.
