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.

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.

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.

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.

The Impact of Adscititious Longitudinal Magnetic Field on CO2 Welding Process

2012 ◽  
Vol 538-541 ◽  
pp. 1447-1450 ◽  
Author(s):  
Shu Yuan Jiang ◽  
Xiao Wei Wang ◽  
Huan Ming Chen ◽  
Pin Liu
Keyword(s):  
Magnetic Field ◽  
High Speed ◽  
Longitudinal Magnetic Field ◽  
Short Circuit ◽  
Welding Process ◽  
Welding Current ◽  
High Speed Photography ◽  
Current Decay ◽  
Co2 Welding ◽  
The Impact

Aiming at the welding arc can act with the magnetic field, has electrical quasi-neutral and electrical conductivity. This paper introduced an adscititious longitudinal magnetic field to control the CO2 welding process and used the Hanover Welding Quality Analyzer to acquire the real-time welding signal. Meanwhile, the short circuit behavior of CO2 welding under the adscititious longitudinal magnetic field, was monitored with the High-speed Photography System. The results show that when the excitation current in an optimal range, the welding current decay and the frequency of short circuit transition is uniform and faster, smaller droplet size and the welding process is more stability than welding without adscititious magnetic field.

Prediction Model of Droplet Size in Low-Current GMAW

2013 ◽  
Vol 652-654 ◽  
pp. 2299-2302
Author(s):  
Jun Xiao ◽  
Guang Jun Zhang
Keyword(s):  
Prediction Model ◽  
Droplet Size ◽  
High Speed ◽  
Welding Current ◽  
Experimental System ◽  
Metal Transfer ◽  
Constant Current ◽  
Future Research ◽  
Feed System ◽  
Globular Transfer

A low-current GMAW experimental system is established using a constant current power supply and a controlled wire feed system. The metal transfer behavior and the droplet growing process in low-current GMAW are investigated by using a high-speed camera, and the welding current and voltage are monitored by a data acquisition set. The metal transfer in low-current GMAW can be classified into three modes: short-circuiting transfer, long-arc short-circuiting transfer and large globular transfer. The arc voltage is the primary factor that affects the metal transfer mode. The droplets growing in low-current GMAW are observed and analyzed. The maximum detaching size of the droplet and the corresponding growing time with different welding current are calculated from the recorded image sequences of metal transfer. Based on such results, a prediction model of the droplet size is thus established, which will be used in the future research on pulsed laser-enhanced GMAW.

scholarly journals Analysis of the Arc Current of CMT Brazing Process

2018 ◽  
Vol 26 (42) ◽  
pp. 103-108
Author(s):  
Miloš Mičian ◽  
Milan Marônek
Keyword(s):  
Short Circuit ◽  
Welding Current ◽  
Metal Transfer ◽  
Point Of View ◽  
Cold Metal Transfer ◽  
Digital Oscilloscope ◽  
Software Applications ◽  
Cmt Welding ◽  
Arc Current ◽  
Cold Metal

Abstract The system with short circuiting metal transfer in comparison to common MIG/MAG process was introduced as CMT (Cold Metal Transfer) process by the Fronius company in 2004. The paper deals with the arc current analysis of the CMT process during MIG brazing of automotive components. The TPS 5000 CMT power source together with VR 7000 CMT wire feeder, Robacta Drive CMT welding torch and CuAl 5 Ni 2, Ø1 mm filler metal were used. In order to monitor the welding current, the galvanic separator WS 1.0, digital oscilloscope ETC M621 and IBM notebook with software applications ETC Scope M621 were engaged. A current waveform in the stage D at the time of 5s from the brazing process beginning within duration of 50 ms was closely analysed. The analysis revealed the total ratio of the arc burning to the total brazing time to be approximately 26%. The starting and ending phases of short-circuit were performed at decreased current (approximately 34 to 38 % of the current value during arc burning), which was very positive from the transient effect point of view, and could not be proclaimed for the conventional short-circuit droplet transfer modes.

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.

Effect of Helium Addition in Argon Shielding Gas on Metal Transfer Behavior in Gas Metal Arc Welding of Aluminum

2013 ◽  
Vol 545 ◽  
pp. 219-224 ◽  
Author(s):  
Pakpoom Jittavisuttiwong ◽  
Bovornchok Poopat
Keyword(s):  
Short Circuit ◽  
Welding Current ◽  
Metal Transfer ◽  
Gas Mixture ◽  
Spray Transfer ◽  
Arc Voltage ◽  
Pure Argon ◽  
Transfer Mode ◽  
Transfer Behavior ◽  
Current Region

Helium is widely used as mixing with argon for a shielding gas in GMAW process of Aluminum in order to improve weld quality and increase heat transfer to the weld pool. It has been known that helium could affect metal transfer behavior; however, its behavior has not been well understood. In this study, an analysis of the metal transfer behavior in the GMAW of aluminum was studied. The main objective is to study the effect of Helium on metal transfer in two main regions, short circuit (low welding current region) and spray transfer (high current region). The composition of 5 types of shielding gases were pure argon, 75%Ar + 25%He, 50%Ar + 50%He, 25%Ar + 75%He and pure helium. The welding parameters were fixed at 90A/17.0V, 100A/18.2V, 140A/24.6V and 180A/27.6V. Aluminum plates were welded bead-on-plate in a flat position. The metal transfer behavior was analyzed by using acoustic signals and arc voltage signals. For the result, at low welding current of 90A and 100A with pure argon, short-circuit transfer mode was observed. Adding helium in gas mixture gave no effect in metal transfer mode in low welding current regions but the metal transfer rate was slightly increased. At high welding currents of 140A and 180A with pure argon, spray transfer mode was observed and when increasing helium in gas mixture resulted in changing from spray transfer to combined mode of spray-globular. In these high welding currents, adding helium in gas mixture resulted in decreasing the metal transfer rate since helium gas tended to promote globular metal transfer. Acoustic signal and arc voltage signal can be used effectively in determining modes of metal transfer.

Effect of Laser Beam on Double Wire Pulsed MIG Welding Process

2011 ◽  
Vol 130-134 ◽  
pp. 4169-4173
Author(s):  
Li Yan Lou ◽  
Huan Li ◽  
Xu You Wang ◽  
Wei Wang ◽  
Ying Gao
Keyword(s):  
Laser Beam ◽  
High Speed ◽  
Welding Process ◽  
Welding Current ◽  
Metal Transfer ◽  
Wave Form ◽  
Hybrid Welding ◽  
Transfer Mode ◽  
Metal Transfer Mode ◽  
Set Up

Based on the coupling of laser beam and double arcs, a novel process was investigated. This research set up the laser-double wire pulsed MIG hybrid welding system. Meanwhile the current and voltage sensors were used to detect welding current and arc voltage wave-form and high-speed videography system was used to observe the metal transfer process and arc behavior. The three signals were acquired synchronously. The results showed that the synergic action of the three different heat sources leads to a change in metal transfer mode. It was revealed that the metal transfer mode was two droplets per pulse in laser-double wire hybrid welding process while one droplet per pulse in double wire welding process with the same certain experiment parameters. And we also discovered that the arcs were attracted strongly by the laser beam.

An Arc Welder Monitoring System Research and Design of High-Speed Camera Trigger

2013 ◽  
Vol 712-715 ◽  
pp. 1792-1797
Author(s):  
Zhi Yong Jiang
Keyword(s):  
Monitoring System ◽  
High Speed ◽  
Short Circuit ◽  
Welding Current ◽  
Gas Shielded Arc Welding ◽  
High Speed Camera ◽  
Co2 Gas ◽  
Trigger Circuit ◽  
Research And Design ◽  
Camera Shutter

Based on CO2 gas shielded arc welding of short circuit transfer welding current waveform changes with microcontroller core control with TTL counter as a basic circuit, the design an arc welder monitoring system the high-speed camera composition trigger circuit to solve the high-speed camera shutter trigger open the question of and actual monitoring system is verified.

Sign in / Sign up

Export Citation Format

Share Document