scholarly journals Multiple Output Analysis for Advanced Waveform and Controlled Short-circuit MIG/MAG Variants

2021 ◽  
Author(s):  
Régis Henrique Gonçalves e Silva ◽  
Daniel Galeazzi ◽  
Pedro Correa Jaeger Rocha ◽  
Alberto Bonamigo Viviani ◽  
Rafael Albino Bernardi
Keyword(s):  
High Speed ◽  
Manufacturing Industry ◽  
Short Circuit ◽  
Basic Research ◽  
Metal Transfer ◽  
Current Control ◽  
Output Analysis ◽  
Process Characterization ◽  
Interdisciplinary Approaches ◽  
Physical Phenomena

Abstract The latest advancements of MIG/MAG welding technologies have experienced a steep evolution in functionality, reliability and ever-growing process and weld controllability, within widely interdisciplinary approaches and driven by demanding trends of Advanced Manufacturing (Industry 4.0). Technologic development can be optimized through basic research, which focuses on understanding the physical phenomena involved in metal transfer, weld pool behavior and bead geometric formation and their correlation with each other and with the process´s variables. In this context, the objective of this work is to compare different waveforms of the short-circuiting MIG / MAG process with current control, namely CCC and SOFT, with the conventional process version, evaluating the influence of the electrical parameters on process stability and the general morphology of the weld beads. Analysis of metal transfer by means of high-speed filming and thermal analysis by infrared thermography supported conventional oscillogaphic monitoring for process characterization. Spatter emission assessment by means of image analysis was performed as well. The process´s versions with current control resulted in better operational weldability, geometric control of the bead and lower spatter emission.

Arc characteristics and metal transfer behavior of CMT+P process for Q235 steel of titanium-steel composite plate

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940040
Author(s):  
Yang Wang ◽  
Zhongyin Zhu ◽  
Guoqing Gou ◽  
Lin Peng ◽  
Yali Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Welding Process ◽  
Metal Transfer ◽  
Pulse Period ◽  
Cold Metal Transfer ◽  
Q235 Steel ◽  
Spray Transfer ◽  
Transfer Mode ◽  
Transfer Behavior

The cold metal transfer (CMT) with addition of pulses (CMT[Formula: see text]P) process is a new CMT welding method. This paper uses a high-speed camera and electrical signal synchronization acquisition system to perform a CMT[Formula: see text]P welding test on a 10 mm thick Q235 steel plate, and performs arc characteristic and droplet transfer behavior in the welding process. It has been founded that under relatively small currents and voltages, the CMT[Formula: see text]P transfer mode is a combination of a projected transfer mode with one droplet in the pulse period and a short circuit transfer mode during the CMT period. The process is stable with little spatter; at relatively large currents and voltages, the transition mode is the combination of pulse transfer, spray transfer and short circuit transfer. It results in one or more droplets that enter the pool both in pulse transfer in the spray transfer mode during the pulse period and in the short circuit transfer mode during the CMT period in a weld cycle.

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.

scholarly journals The Effect of the Use of PTFE as a Covered-Electrode Binder on Metal Transfer

2015 ◽  
Vol 20 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Cláudio Turani Vaz ◽  
Alexandre Queiroz Bracarense
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Welding Current ◽  
Metal Transfer ◽  
Outer Edge ◽  
Polymer Binder ◽  
Electrode Binder ◽  
Covered Electrodes ◽  
Weld Metal Microstructure ◽  
Metal Microstructure

AbstractStudies have shown that when used as binders for basic covered electrodes, polymers produce a weld metal microstructure with a high acicular ferrite content. The reasons identified for this behavior include changes in the shielding atmosphere and metal transfer mode. To investigate the effect of polymers on metal transfer, voltage oscillograms and high-speed films were recorded during welding with standard-binder and polymer-binder E7018 electrodes using different welding currents. Electrodes tips collected after the arc had been abruptly interrupted were examined metallographically. For electrodes with a polymer binder, the short-circuit frequency was lower regardless of the welding current used and decreased as welding current increased. In many events characterized as short circuits in the voltage oscillograms for polymer-binder electrodes, metal transfer in fact occurred without any arc interruption. The angle between the outer edge of the metal drop and the inner edge of the coating crater showed that the polymer increased the intensity of the plasma jet, and the pinch effect observed during welding using the polymer-binder electrode indicated that there were changes in surface tension and electromagnetic force.

Two-Phase Short Circuit in the Power Grid Powered by a Transformer with a Y/Δ-11 Winding Connection

2020 ◽  
pp. 25-30
Author(s):  
Aleksandr S. Serebryakov ◽  
Vladimir L. Osokin ◽  
Sergey A. Kapustkin
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Relay Protection ◽  
Electric Circuit ◽  
Operational Reliability ◽  
Research Purpose ◽  
Industrial Complex ◽  
Two Phase ◽  
Short Circuit Currents ◽  
Secondary Winding

The article describes main provisions and relations for calculating short-circuit currents and phase currents in a three-phase traction transformer with a star-triangle-11 connection of windings, which feeds two single-phase loads in AC traction networks with a nominal voltage of 25 kilovolts. These transformers provide power to the enterprises of the agro-industrial complex located along the railway line. (Research purpose) The research purpose is in substantiating theoretical equations for digital intelligent relay protection in two-phase short circuits. (Materials and methods) It was found that since the sum of instantaneous currents in each phase is zero, each phase of the transformer works independently. We found that this significantly simplifies the task of analyzing processes with a two-phase short circuit. In this case, the problem of calculating short-circuit currents in the traction network can be simplified by reducing it to the calculation of an ordinary electric circuit with three unknown currents. (Results and discussion) The article describes equations for calculating short-circuit resistances for one phase of the transformer when connecting the secondary winding as a star or a triangle. The currents in the phases of the transformer winding at short circuit for the star-triangle-11 and star-star-with-ground schemes are compared. It was found that when calculating short-circuit currents, there is no need to convert the secondary winding of the traction transformer from a triangle to a star. (Conclusions) It was found that the results of the research can be used in the transition of relay protection systems from electromagnetic relays to modern high-speed digital devices, which will increase the operational reliability of power supply systems for traction and non-traction power consumers.

Effects of Wire Rotating Frequency on Metal Transfer Process in Rotating Arc Narrow Gap Horizontal GMAW

2011 ◽  
Vol 189-193 ◽  
pp. 3395-3399 ◽  
Author(s):  
Ning Guo ◽  
Yan Fei Han ◽  
Chuan Bao Jia ◽  
Yong Peng Du
Keyword(s):  
Transfer Process ◽  
High Speed ◽  
Stable Process ◽  
Welding Process ◽  
Metal Transfer ◽  
Welding Parameters ◽  
High Speed Photography ◽  
Narrow Gap ◽  
Weld Formation ◽  
Rotating Arc

The metal transfer process with different welding parameters in rotating arc narrow gap horizontal welding is successfully observed by the high-speed photography system. The effects of wire rotating frequency on metal transfer process in rotating arc narrow gap horizontal welding are novelly explored. The metal transfer with different wire rotating frequency presents different modes. The results indicate that the droplet transfer has stable process with the rotating frequency of 5-20 Hz. And the weld formation is quite shapely. But with the high rotating frequency of 50 Hz, the metal transfer process is not acceptable and the weld formation is very pool. Metal transfer process is one of the most important factors of effecting the weld formation in rotating arc horizontal welding process besides the molten pool behavior and welding thermal circles.

Effect of Current Waveform on Metal Transfer in Controlled Short Circuiting Gas Metal Arc Welding

2013 ◽  
Vol 718-720 ◽  
pp. 202-208 ◽  
Author(s):  
Mao Ai Chen ◽  
Yuan Ning Jiang ◽  
Chuan Song Wu
Keyword(s):  
Transfer Process ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Welding Current ◽  
Metal Transfer ◽  
Arc Voltage ◽  
Metal Arc Welding ◽  
Maximum Stability ◽  
The Stability ◽  
Welding Inverter

With high-speed welding inverter and precisely controlling the welding current with arc-bridge state, advanced pulse current waveforms can be produced to optimize the transfer characteristics of short circuiting transfer welding. In this paper, the images of droplet/wire, and the transient data of welding current and arc voltage were simultaneously recorded to study the influence of peak arcing current, background arcing current and tail-out time on the stability of short circuiting transfer process. It was found that maximum short circuiting transfer stability is reached under specific welding conditions. Any deviation from these conditions will cause abnormal rises in arc voltage indicating instantaneous arc extinguishing and greater spatter. Optimal welding conditions were obtained to achieve the maximum stability of short circuiting metal transfer process.

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