A Study on Prediction of Welding Current in Gas Metal arc Welding Part 1: Modelling of Welding Current in Response to Change of Tip-to-Workpiece Distance

Author(s):  
J W Kim ◽  
S J Na
Author(s):  
C D Yoo ◽  
Y S Yoo ◽  
H-K Sunwoo

The arc length has been detected through the arc because the welding current and voltage vary linearly with the arc length. In this work, the relationship between the arc light intensity and arc length is investigated through analytic modelling. The arc light intensity is derived as a function of the arc length and welding current using the heat balance in the plasma. Experiments are carried out to verify the proposed model and to find out the effects of welding conditions on the arc light intensity in gas metal arc welding (GMAW). The arc light intensity varies proportionally to the arc length and signal quality is enhanced with a fast weaving speed. The predicted results of the arc light intensity show reasonably good agreement with the experimental data.


2004 ◽  
Vol 127 (3) ◽  
pp. 590-597 ◽  
Author(s):  
Guo Xu ◽  
William W. Schultz ◽  
Elijah Kannatey-Asibu

A numerical model is developed to simulate the short-circuiting metal transfer process during gas metal arc welding (GMAW). The energy equation and the Marangoni convection are considered for the first time in analyzing the short-circuiting time. A front-tracking free surface method explicity tracks the profile of the liquid bridge. The electromagnetic field, distribution of velocity, pressure, and temperature are calculated using the developed model. Effects of welding current, surface tension temperature coefficient, and initial drop volume on short-circuiting duration time are examined. The results show that both the electromagnetic force and Marangoni shear stress play significant roles in short-circuiting transfer welding.


2011 ◽  
Vol 339 ◽  
pp. 440-443 ◽  
Author(s):  
Shu Jun Chen ◽  
Chang Hui Liu ◽  
Yang Yu ◽  
Shao Jun Bai

This study proposed preset pulsed magnetic field acting on process of the short circuiting transfer. It is a controlled horizontal magnetic field which attached at the very beginning of contact between the wire and the weld pool during welding. It was found that there exists optimum conditions of magnetic field with which preset pulsed magnetic field could accelerate the rupture of the liquid bridge and reduce the peak value of welding current in the period of short circuiting transfer. This lead to energy accumulation lowered at the last phase of the short circuiting transfer and spatter loss reduced resulting from explosive short circuit rupture, in the meantime, it could improve the regularity and stability of the short circuiting transfer as well as the weld shaping quality.


2011 ◽  
Vol 25 (6) ◽  
pp. 1-8
Author(s):  
Phuc Thinh Doan ◽  
Pandu Sandi Pratama ◽  
Suk-Yoel Kim ◽  
Hak-Kyeong Kim ◽  
Hwang-Yeong Yeun ◽  
...  

2021 ◽  
Vol 100 (4) ◽  
pp. 121-131
Author(s):  
R. A. RIBEIRO ◽  
◽  
P. D. C. ASSUNÇÃO ◽  
E. B. F. DOS SANTOS ◽  
E. M. BRAGA ◽  
...  

The electrical current required for a transition from globular to spray droplet transfer during gas metal arc welding (GMAW) is determined by the specified wire feed speed in the case of constant-voltage power supplies. Generally, in narrow groove welding, spray transfer is avoided, be-cause this transfer mode can severely erode the groove sidewalls. This work compared the globular-to-spray transition mechanism in cold wire gas metal arc welding (CW-GMAW) vs. standard GMAW. Synchronized high-speed imaging with current and voltage samplings were used to characterize the arc dynamics for different cold wire mass feed rates. Subsequently, the droplet frequency and diameter were estimated, and the parameters for a globular-to-spray transition were assessed. The results suggest that the transition to spray occurs in CW-GMAW at a lower current than in the standard GMAW process. The reason for this difference appears to be linked to an enhanced magnetic pinch force, which is mainly responsible for metal transfer in higher welding current conditions.


Sign in / Sign up

Export Citation Format

Share Document