Analysis and Evaluation for Usability of the Lime Titania Type Structural Steel Covered Electrode

2010 ◽  
Vol 154-155 ◽  
pp. 1217-1222
Author(s):  
Yong Wang ◽  
Bao Wang ◽  
Li Song ◽  
Zhi Jun Wang
Keyword(s):  
Structural Steel ◽  
Probability Density ◽  
Principal Component ◽  
Metal Transfer ◽  
Spray Transfer ◽  
Analysis And Evaluation ◽  
Transfer Mode ◽  
Voltage Variation ◽  
Electric Parameters ◽  
Information Values

Metal transfer mode of the lime titania type structural steel covered electrode is a mixed one that coexists as the globular short-circuiting transfer, the flux-wall guided transfer, the explosive transfer and the spray transfer. Constitute of the metal transfer modes has a direct effect on usability of the covered electrode. Using the Analysator Hannover, the welding electric parameters are measured and analyzed. Four characteristic information values correlated with usability of the covered electrode are extracted, such as the sum of probability density of the short-circuiting voltage, variation coefficient of the arc voltage, the sum of probability density of the big short-circuiting current and the short-circuiting frequency, and then method of the principal component analysis is applied to determining evaluation index of usability of the covered electrode. Usability of the covered electrode is quantitatively evaluated. It offers a new method for scientifically evaluating usability of the lime titania type structural steel covered electrode.

Analysis and Evaluation for Usability of the Low Hydrogen Type Structural Steel Covered Electrode

2008 ◽  
Vol 575-578 ◽  
pp. 684-689
Author(s):  
Yong Wang ◽  
Bao Wang ◽  
Jun Hua Gao
Keyword(s):  
Structural Steel ◽  
Principal Component ◽  
Welding Current ◽  
Mean Value ◽  
Metal Transfer ◽  
Analysis And Evaluation ◽  
Transfer Mode ◽  
The Mean ◽  
The One ◽  
Information Values

Metal transfer mode of the low hydrogen type structural steel covered electrode is the one that coexists as the globular short-circuiting transfer and the fine droplet transfer in the flux-bridge. Component of the metal transfer modes has a direct effect on usability of the covered electrode. The oscillograms of the arc voltage and the welding current gained using the traditional photoelectric oscillograph can only qualitatively describe the general characteristics of metal transfer, but can’t make a quantitative analysis. Using the ANALYSATOR HANNOVER, the welding electrical parameters are measured and analyzed. Four characteristic information values correlated with usability of the covered electrode, such as the frequency of the globular short-circuiting transfer, the globular short-circuiting time, the mean value of the globular short-circuiting time and the mean value of the weighted arcing time, are extracted. The method of principal component analysis is applied to determining the evaluation index for usability of the covered electrode. Thereby quantitative evaluation for usability of the covered electrode is realized. A new method is offered for scientifically evaluating usability of the low hydrogen type structural steel covered electrode.

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.

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.

Mechanically assisted droplet transfer process in gas metal arc welding

2002 ◽  
Vol 216 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Y Wu ◽  
R Kovacevic
Keyword(s):  
Transfer Process ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Droplet Transfer ◽  
Macroscopic Appearance ◽  
Transfer Mode ◽  
Metal Arc Welding ◽  
Separate Control

Gas metal arc welding has been generally accepted as the preferred joining technique due to its advantages in high production and automated welding applications. Separate control of arc energy and arc force is an essential way to improve the welding quality and to obtain the projected metal transfer mode. One of the most effective methods for obtaining separate control is to exert an additional force on the metal transfer process. In this paper, the droplet transfer process with additional mechanical force is studied. The welding system is composed of an oscillating wire feeder. The images of molten metal droplets are captured by a high-speed digital camera, and both the macroscopic appearance and the cross-sectional profiles of the weld beads are analysed. It is shown that the droplet transfer process can be significantly improved by wire electrode oscillation, and a projected spray transfer mode can be established at much lower currents. By increasing the oscillation frequency, the droplet transfer rate increases while the droplet size decreases. In addition, the improvement in the droplet transfer process with wire oscillation leads to an enhancement of the surface quality and a modification of the geometry of the weld beads that could be of importance for overlay cladding and rapid prototyping based on deposition by welding.

scholarly journals Analysis of Metal Transfer and Weld Forming Characteristics in Triple-wire Gas Indirect Arc Welding

2021 ◽  
Author(s):  
Liming Liu ◽  
Zeli Wang ◽  
Tianyi Zhang ◽  
Xianli Ba
Keyword(s):  
Electromagnetic Force ◽  
Arc Welding ◽  
Metal Transfer ◽  
Force Model ◽  
High Deposition Rate ◽  
Transfer Mode ◽  
Conductive Channel ◽  
Forming Characteristics ◽  
Metal Transfer Mode ◽  
Indirect Arc

Abstract Triple-wire gas indirect arc welding (TW-GIA) has the advantages of low heat input and high deposition rate. However, the simultaneous melting of triple wires makes the metal transfer mode complicated. The unknown of the metal transfer mode restricts the development of this technology. In this paper, high-speed camera systems and electrical signal acquisition sensors were used to explore the TW-GIA metal transfer mode. The static force model and the arc conductive channel model were used to discuss the droplet force and energy conversion characteristics respectively. Results showed that the TW-GIA metal transfer modes can be divided into: short-circuit transfer (SCT), main wire projected transfer + side wire globular transfer (PGT), main wire streaming transfer + side wire projected transfer (SPT) and main wire streaming transfer + side wire streaming transfer (SST). Moreover, the process parameter ranges corresponding to the four modes were summarized. Due to the stable arc and the uniform metal transfer process, SPT and SST can form desirable weld seam. The gravity and z-axis components of electromagnetic force are the main forces that promote metal transfer. The x-axis and y-axis components of the electromagnetic force deviate the metal transfer path from the arc coverage. Due to the change of arc conductive channel, the energy transferred from TW-GIA to the base metal is less than that of GMAW, showing the advantages of small welding deformation, narrow heat affected zone and grain refinement.

scholarly journals 3D Numerical Study of External Axial Magnetic Field-Controlled High-Current GMAW Metal Transfer Behavior

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5792
Author(s):  
Lei Xiao ◽  
Ding Fan ◽  
Jiankang Huang ◽  
Shinichi Tashiro ◽  
Manabu Tanaka
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Numerical Study ◽  
Metal Transfer ◽  
Temperature Fields ◽  
Dominant Factor ◽  
Conductive Heat ◽  
High Current ◽  
Spray Transfer ◽  
Transfer Behavior

For gas metal arc welding (GMAW), increasing the welding current is the most effective way to improve welding efficiency. However, much higher current decreases the welding quality as a result of metal rotating-spray transfer phenomena in the high-current GMAW process. In this work, the external axial magnetic field (EAMF) was applied to the high-current GMAW process to control the metal transfer and decrease the welding spatters. A unified arc-droplet coupled model for high-current GMAW using EAMFs was built to investigate the metal rotating-spray transfer behavior. The temperature fields, flow fields in the arc, and droplet were revealed. Considering all the heat transferred to the molten metal, the Joule heat was found to be the dominant factor affecting the droplet temperature rise, followed by the anode heat. The conductive heat from the arc contributed less than half the value of the other two. Considering the EAMFs of different alternating frequencies, the arc constricting effects and controlled metal transfer behaviors are discussed. The calculated results agree well with the experimental high-speed camera observations.

The Effect of Voltage and Metal Transfer Mode on Particulate Fume Size During the GMAW of Plain Carbon Steel

2010 ◽  
Vol 54 (9-10) ◽  
pp. R249-R256 ◽  
Author(s):  
Zoran Sterjovski ◽  
John Norrish ◽  
Brian J. Monaghan
Keyword(s):  
Carbon Steel ◽  
Plain Carbon Steel ◽  
Metal Transfer ◽  
Transfer Mode ◽  
Metal Transfer Mode

Dynamic Metal Transfer Behavior in Double-Wire DP-GMAW of Aluminum Alloy Under Different Pulse Phases

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Kaiyuan Wu ◽  
Jiatong Zhan ◽  
Xuanwei Cao ◽  
Xiaobin Hong ◽  
Peimin Xie
Keyword(s):  
High Speed ◽  
Droplet Diameter ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Double Pulse ◽  
Droplet Growth ◽  
Al Alloy ◽  
Spray Transfer ◽  
Pulse Phase ◽  
Transfer Behavior

Abstract The effects of pulse phase and pulse stage on the metal transfer characteristics in double-wire double pulse gas metal arc welding (DP-GMAW) of aluminum (Al) alloy were studied using high-speed camera images and current and voltage waveforms. In addition, the effects of various forces on dynamic metal transfer behavior were analyzed under different pulse phases and pulse stages. The results show that the spray transfer mode can be obtained in both the alternating pulse phase (APP) and synchronous pulse phase (SPP). The transfer pattern of the leading and trailing droplets is alternating in the APP, but changes to simultaneous metal transfer in the SPP, mainly owing to influence of the pulse phase on droplet growth. The transfer type is one drop double pulse (ODDP) during the strong pulse stage and one drop triple pulse (ODTP) during the weak pulse stage, regardless of the pulse phase. The pulse phase does, however, affect the Lorentz force between the leading and trailing droplets, causing droplet collision in the SPP, which results in a poorer weld bead appearance compared with in the APP. Finally, the droplet diameter was found to be similar during different pulse phases and pulse stages.

Numerical Analysis of Arc Plasma with Metal Transfer in GMAW

2008 ◽  
Vol 580-582 ◽  
pp. 359-362
Author(s):  
Yoshinori Hirata ◽  
K. Ohnishi
Keyword(s):  
Metal Transfer ◽  
Time Dependent ◽  
Arc Plasma ◽  
Metal Drop ◽  
Spray Transfer ◽  
Drop Detachment ◽  
Globular Transfer ◽  
Arc Shape ◽  
The Moment ◽  
Kinetics Of

A numerical model of time-dependent gas shielded metal arc is described, which was developed in order to make clear the kinetics of arc plasma together with metal transfer. It is possible to calculate and visualize time-dependent temperature and fluid flow field of argon shielded metal arc plasma with the grow-up and the subsequent detachment of the liquid metal drop at the wire tip. Numerical calculation shows that the arc shape in globular transfer abruptly changes at the moment of metal drop detachment. Whereas, the spray transfer arc seems to be stable and almost does not fluctuate with metal transfer.

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