scholarly journals Control of Droplet Transition in Underwater Welding Using Pulsating Wire Feeding

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1715 ◽  
Author(s):  
Ning Guo ◽  
Lu Huang ◽  
Yongpeng Du ◽  
Qi Cheng ◽  
Yunlong Fu ◽  
...  
Keyword(s):  
Short Circuit ◽  
Droplet Transfer ◽  
Frequency Condition ◽  
Feeding Mode ◽  
Cored Wire ◽  
Underwater Wet Welding ◽  
Withdrawal Speed ◽  
Feeding Process ◽  
The Wire ◽  
Wire Feeding

Underwater wet welding technology is widely used. Because the stability of droplet transfer in underwater wet welding is poor, the feasibility of improving the droplet transfer mode has been discussed from various technical directions. In this work, the characteristics of pulsating wire feeding were studied in the pulsating wire feeding mode by investigating the effects of changing the pulsating frequency, the wire withdrawal speed, and the wire withdrawal quantity on the droplet transfer process and the welding quality. With the aim of improving weld forming and welding stability, the authors selected the coefficient of variation and the ratio of unstable droplet transfer as the indexes to evaluate the effect of droplet transfer control. The pulsating wire feeding process of underwater wet flux-cored wire was analyzed in depth, and the following conclusions were drawn: using the pulsating wire feeding mode and after comparing and analyzing the pulsed wire feeding process under the same frequency condition, the authors found that the forming and stability were better under the conditions of slower withdrawal speed and smaller withdrawal quantity. The short-circuit transition ratio decreased steadily with the increase of pulsating wire feeding frequency, the rejection transition ratio first rose and then decreased, and the splash ratio first decreased and then rose.

Study on Metal Transfer and Welding Spatter Characteristics of Basic Flux Cored Wire

2013 ◽  
Vol 477-478 ◽  
pp. 1369-1372 ◽  
Author(s):  
Yong Wang ◽  
Ying Qiao Zhang ◽  
Bao Wang ◽  
Zhi Jun Wang
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Welding Current ◽  
Metal Transfer ◽  
Welding Parameters ◽  
Droplet Transfer ◽  
Cored Wire ◽  
Basic Flux ◽  
Key Factor ◽  
Slag Column

The metal transfer behaviors of basic flux cored wire at different arc voltage and welding current and the resultant welding spatter were investigated by using a high speed camera. Two modes of metal transfer are found: globular repelled transfer (lower welding parameters) and small droplet transfer (higher welding parameters). The former is accompanied by large granular spatter, large droplet itself explosion spatter and electric explosive spatter of short-circuit, and spatter in the latter is reduced obviously. But if the slag column is found in the two models, spatter could be dropped evidently owing to its significant guiding role for metal transfer. Therefore the slag column is the key factor of reducing welding spatter.

Physical Modeling Test on Gas Rotary Lance for Wire-Feeding

2013 ◽  
Vol 655-657 ◽  
pp. 190-194
Author(s):  
Qing Hua Yan ◽  
Lie Qiang Xiong
Keyword(s):  
Physical Modeling ◽  
Present Condition ◽  
Simulation Test ◽  
Cored Wire ◽  
Characteristic Curves ◽  
Pressure Water ◽  
The Wire ◽  
Wire Feeding ◽  
Water Simulation

On ca-cored wire feeding in ladle, there are surface feeding stage and inner feeding stage. China is still in the surface feeding stage. The gas rotary lance was developed for the present condition of the wire feeding devices in China. The water simulation test and the pressure water simulation test were carried through. The vortex on the surface of the liquid and the cavity, the recirculation and rotary in the liquid were observed in the water simulation test. The characteristic curves of the lance coupled with the different wires were disclosed. The lance can be used with the guide pipe directly.

Study on Short-Circuit Transition Welding System Based on Push-Pull Wire Feeder

2012 ◽  
Vol 569 ◽  
pp. 320-323
Author(s):  
Peng Fei Huang ◽  
Chang Wu Wang ◽  
Zhen Yang Lu ◽  
Li Lai Bai
Keyword(s):  
Power Supply ◽  
Short Circuit ◽  
Current Mode ◽  
Fast Response ◽  
Feeding System ◽  
Ac Servo ◽  
The Wire ◽  
Wire Feeding ◽  
Ac Servo Motor ◽  
Welding System

A welding system based on a push- pull wire feeder was designed and how it works was analyzed. The system included the welding power supply, the wire feeding system, and the coordination controller. The power supply used a current mode PWM IC UC3846 as the controller, which made sure the security and the dynamitic responsibility of the system. The critical fact to realize the push-pull wire feeding system was that a small inertia and fast response AC servo motor was selected. TMS320F2808 was used as the core coordination controller of the system, which made the welding power source and the wire feeding system work coordinately. The motor will pull the wire back when the arc was in the period of short-circuiting, and push the wire forward when the arc was in arc period. The results proved the system can meet the welding demands.

scholarly journals Cell/Module Integration Technology with Wire-Embedded EVA Sheet

2021 ◽  
Vol 11 (9) ◽  
pp. 4170
Author(s):  
Jeong Eun Park ◽  
Won Seok Choi ◽  
Donggun Lim
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Power ◽  
Short Circuit ◽  
Optical Loss ◽  
Manufacturing Cost ◽  
Power Module ◽  
Manufacturing Method ◽  
Front Electrode ◽  
The Wire

Silicon wafers are crucial for determining the price of solar cell modules. To reduce the manufacturing cost of photovoltaic devices, the thicknesses of wafers are reduced. However, the conventional module manufacturing method using the tabbing process has a disadvantage in that the cell is damaged because of the high temperature and pressure of the soldering process, which is complicated, thus increasing the process cost. Consequently, when the wafer is thinned, the breakage rate increases during the module process, resulting in a lower yield; further, the module performance decreases owing to cracks and thermal stress. To solve this problem, a module manufacturing method is proposed in which cells and wires are bonded through the lamination process. This method minimizes the thermal damage and mechanical stress applied to solar cells during the tabbing process, thereby manufacturing high-power modules. When adopting this method, the front electrode should be customized because it requires busbarless solar cells different from the existing busbar solar cells. Accordingly, the front electrode was designed using various simulation programs such as Griddler 2.5 and MathCAD, and the effect of the diameter and number of wires in contact with the front finger line of the solar cell on the module characteristics was analyzed. Consequently, the efficiency of the module manufactured with 12 wires and a wire diameter of 0.36 mm exhibited the highest efficiency at 20.28%. This is because even if the optical loss increases with the diameter of the wire, the series resistance considerably decreases rather than the loss of the short-circuit current, thereby improving the fill factor. The characteristics of the wire-embedded ethylene vinyl acetate (EVA) sheet module were confirmed to be better than those of the five busbar tabbing modules manufactured by the tabbing process; further, a high-power module that sufficiently compensated for the disadvantages of the tabbing module was manufactured.

Droplet transfer behavior of narrow gap laser wire filling welding

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940045 ◽  
Author(s):  
Z. Zhang ◽  
R. Wang ◽  
G. Gou ◽  
H. Chen ◽  
W. Gao
Keyword(s):  
Welding Speed ◽  
High Speed ◽  
Transition Period ◽  
High Speed Photography ◽  
Narrow Gap ◽  
Droplet Transfer ◽  
Transfer Behavior ◽  
Feeding Speed ◽  
Wire Feeding ◽  
Droplet Transition

In this paper, we study the droplet transition behavior of narrow gap laser wire filling welding under the condition of changing welding speed and wire feeding speed, and it was observed by high-speed photography. It was found that with the increase of welding speed, the frequency of droplet transfer was reduced and the transition period was prolonged. With the increase of wire feeding speed, the wire was not fully melted and finally inserted into the molten pool.

Arc Characteristics and Droplet Transfer Analysis of Disconnect Impulse Arc Welding for Repairing Surface Default of Metal Parts

2014 ◽  
Vol 941-944 ◽  
pp. 2026-2029 ◽  
Author(s):  
Jun Wei Yang ◽  
Jia Xu Teng ◽  
Qing Zhang ◽  
Ling Dong Meng
Keyword(s):  
Arc Welding ◽  
Droplet Transfer ◽  
Metal Parts ◽  
Transfer Characteristics ◽  
Camera Systems ◽  
Arc Characteristics ◽  
Wire Material ◽  
Metallurgical Bonding ◽  
Arc Current ◽  
The Wire

The wire material and the workpiece was fused together by the transient arc heat from disconnect impulse, to achieve metallurgical bonding. The process of arc striking and the arc was very short in disconnect impulse arc welding. The image signals of disconnect impulse arc and droplet transfer were acquired using speed camera systems. Then, the arc and the droplet transfer characteristics in repairing the metal defects process were discussed. The results showed that the process of arc striking was only 0.5-1ms in disconnect impulse arc welding. The maintain arc time must be matched with the arc current, the longer maintain arc time the less the arc current was likely to be.

scholarly journals Characteristics of Magnetic Field Assisting Plasma GMAW-P

2020 ◽  
Vol 99 (1) ◽  
pp. 25s-38s
Author(s):  
JIANG YU ◽  
◽  
BO WANG ◽  
HONGTAO ZHANG ◽  
PENG HE ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Current ◽  
Plasma Welding ◽  
Droplet Transfer ◽  
Spray Transfer ◽  
The Wire ◽  
Indirect Arc ◽  
The Magnetic Field

The droplet transfer and voltage-current characteristics of gas metal arc welding (GMAW) in single-pulsed GMAW (single GMAW-P), plasma pulsed GMAW (plasma GMAW-P), and plasma-GMAW-P with a magnetic field were studied using the synchronous acquisition system of high-speed camera and electric signals. The results showed the plasma arc and magnetic field had a significant effect on the droplet transfer process. The indirect arc of the plasma and gas metal arc emerged in the pulse peak phase causing a shunt phenomenon of the GMAW current. The period of the indirect arc was increased under the action of the magnetic field. In hybrid plasma GMAW-P, when the GMAW current did not exceed 140 A, several pulsed one-drop free transfers occurred and the droplet transfer period decreased with the increase in the plasma welding current; when the GMAW current exceeded 140 A, and the plasma welding current was less than 180 A, spray transfer was formed. The droplet transfer transformed into a projected transfer when the plasma welding current increased to 180 A. In plasma-GMAW-P hybrid welding with a magnetic field, the magnetic field had a slight effect on the transfer period. When the GMAW current did not exceed 140 A, the droplet transfer was mainly repelled transfer. The detaching location was on the right side of the wire when the magnetic field current was less than 3 A. When the magnetic field current exceeded 3 A, it was below or on the left side of the wire. When the GMAW current exceeded 140 A and the magnetic field current was less than 5 A, spray transfer was formed, but the droplet transfer mode transformed into a projected transfer with a magnetic field current of 5 A.

scholarly journals EVALUATION OF THE EFFICIENCY OF THE DEVICE FOR LIMITING TENSION OF THE WIRE IN A SHORT CIRCUIT

2017 ◽  
Vol 60 (4) ◽  
pp. 309-319
Author(s):  
I. I. Sergey ◽  
E. G. Panamarenka ◽  
Ya. A. Potachits
Keyword(s):  
Computer Program ◽  
Short Circuit ◽  
Great Length ◽  
Structural Elements ◽  
Method Of Calculation ◽  
Overhead Lines ◽  
Stage Of Development ◽  
Initial Stage ◽  
The Wire ◽  
Short Circuit Currents

The intensity of the electrodynamic action of currents of a short circuit on the flexible conductors of overhead lines depends on the magnitude of currents of short-circuit. The commis sioning of new capacities is inevitably accompanied by an increase in short circuit currents in the nodes of the grid, so the need to limit peaks of tension arising in a short-circuit can acquire a special relevance at a certain stage of development of the power system. At short circuit currents over 40 kA the mechanical force and displacement of the wires can have a decisive influence on the structural performance of flexible bus as of single wires as well as of split phases. In this regard there is a need for the development and use of new structural elements enhancing electrodynamic stability of flexible busbars of outdoor switchgear. One such element is a tension damper. The damper is installed between the portal and the insulator string and limits the transmission of undesirable forces on the portals in a short circuit. The numerical method of calculation of dynamics of flexible wires of switchgear and overhead lines in a short-circuit taking into account influence of a tension damper has been developed. This method was used for modification of the computer program of calculation of electrodynamic stability. With the aid of the computer program it was demonstrated that the installation of the tension damper makes it possible to cut off peaks of the tension of wire in a short circuit at the initial stage of movement of the conductors. However, in spans of a great length after the actuation of the damper the occurrence of new bursts of tension is possible due to the sudden stop of the wire. 

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