A Study on the Weld Bead Characteristics in Pulsed Gas Metal Arc Welding With Rotating Arc

2004 ◽  
Author(s):  
P. Srinivasa Rao ◽  
O. P. Gupta ◽  
S. S. N. Murty
Keyword(s):  
Arc Welding ◽  
Gma Welding ◽  
Gas Metal Arc Welding ◽  
Bead Geometry ◽  
High Productivity ◽  
Metal Arc Welding ◽  
Welding Torch ◽  
Welding Steel ◽  
Rotating Arc ◽  
Selection Of

Pulsed Gas Metal Arc Welding is widely used in industries because of its high productivity. The bead geometry obtained in welding steel is far from ideal and needs to be improved. It is experimentally observed that the beads are either convex or the penetration is deep and narrow. Both these conditions are undesirable. Proper selection of pulse parameters can improve the wetting, but the penetration remains finger type penetration. An arc rotation mechanism is developed which can be adapted to any conventional GMA welding torch. The beads deposited with rotating arc are flat and the penetration is semi-circular. It is observed that the penetration is maximum only at a particular rotating arc speed.

Metal Transfer in Double-Electrode Gas Metal Arc Welding

2007 ◽  
Vol 129 (6) ◽  
pp. 991-999 ◽  
Author(s):  
Kehai Li ◽  
YuMing Zhang
Keyword(s):  
Base Metal ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
High Melting ◽  
High Productivity ◽  
Spray Transfer ◽  
Metal Arc Welding ◽  
Double Electrode ◽  
Melting Current

Gas metal arc welding (GMAW) is the most widely used process for metal joining because of its high productivity and good quality, but analysis shows that the fundamental characteristic restricts conventional GMAW from further increasing the welding productivity. A novel GMAW process, refereed to as double-electrode GMAW or DE-GMAW, thus has been developed to make it possible to increase the melting current while the base metal current can still be controlled at a desired level. This fundamental change provides an effective method to allow manufacturers to use high melting currents to achieve high melting speed and low base metal heat input. A series of experiments have been conducted to uncover the basic characteristics of this novel process. Results obtained from analyses of high-speed image sequences and recorded current signals suggest that DE-GMAW can lower the critical current for achieving the desired spray transfer, shift the droplet trajectory, reduce the diameter of the droplet, and increase the speed and (generation) rate of the droplets.

Effects of Welding Current on Metal Transfer and Weld Pool Dynamics in Gas Metal Arc Welding

2006 ◽  
Author(s):  
J. Hu ◽  
H. L. Tsai ◽  
P. C. Wang
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Gma Welding ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Dominant Factor ◽  
Transient Temperature ◽  
Transfer Mode ◽  
Metal Arc Welding ◽  
Metal Transfer Mode

In gas metal arc welding (GMAW), current is one of the most important factors affecting the mode of metal transfer and subsequently the weld quality. Recently, a new technology using pulsed currents has been employed to achieve the one droplet per pulse (ODPP) metal transfer mode with the advantages of low average currents, a stable and controllable droplet generation, and reduced spatter. In this paper, the comprehensive model recently developed by the authors was used to study the influences of different current profiles on the droplet formation, metal transfer, and weld pool dynamics in GMA, welding. Five types of welding currents were studied, including two constant currents and three waveform currents. In each type, the transient temperature and velocity distributions of the arc plasma and the molten metal, and the shapes of the droplet and the weld pool were calculated. The results showed that a higher electromagnetic force was generated at a higher current and becomes the dominant factor that detaches the droplet from the electrode tip. A smaller droplet size and a higher droplet frequency were obtained for a higher current. The model has demonstrated that a stable ODPP metal transfer mode can be achieved by choosing a current with proper waveform for given welding conditions.

scholarly journals Metal Transfer Mechanisms in Hot-Wire Gas Metal Arc Welding

2020 ◽  
Vol 99 (11) ◽  
pp. 281s-294s
Author(s):  
P. P. G. RIBEIRO ◽  
◽  
P. D. C. ASSUNÇÃO ◽  
E. M. BRAGA ◽  
R. A. RIBEIRO ◽  
...  
Keyword(s):  
Cross Sections ◽  
Arc Welding ◽  
High Speed ◽  
Gas Metal Arc Welding ◽  
Melting Rate ◽  
Bead Geometry ◽  
Hot Wire ◽  
High Speed Imaging ◽  
Metal Arc Welding ◽  
Full Factorial

The hot-wire gas metal arc welding (HW-GMAW) process is widely used to increase the melting rate of a secondary wire through Joule heating without significantly increasing the total heat input to the substrate. Because there is limit-ed knowledge regarding the associated arc dynamics and its influence on bead geometry, the present study considers how these are affected by the hot-wire polarity (negative or positive), hot-wire feed rate, and hot-wire orientation using a two-factor full factorial experiment with three replicates. During welding, high-speed imaging synchronized with current and voltage acquisition to study the arc dynamics. After this, each replicated weld was cut into three cross sections, which were examined by standard metallography. The preliminary results suggest that the arc was stable within the range of process parameters studied. The arc polarity played a role on arc position relative to the hot wire, with a decrease in penetration depth observed when the arc was attracted to the hot wire.

Virtual Reality Welder Training

2006 ◽  
Vol 22 (03) ◽  
pp. 126-138 ◽  
Author(s):  
Nancy C. Porter ◽  
J. Allan Cote ◽  
Timothy D. Gifford ◽  
Wim Lam
Keyword(s):  
Neural Network ◽  
Virtual Reality ◽  
Real Time ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Travel Speed ◽  
Virtual Reality Technology ◽  
Metal Arc Welding ◽  
Welding Torch

Based on the orientation and travel speed of a welding torch, virtual reality technology simulates gas metal arc welding in near-real time using a neural network.

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