Eur. Phys. J. Appl. Phys. 43, 111-122 (2008)
https://doi.org/10.1051/epjap:2008106

Gas influence on the arc shape in MIG-MAG welding

¹ Institute of Physics, Jagellonian University, ul. Reymonta 4, 30-459 Krakow, Poland
² LASEP, Faculté des Sciences-Bourges, Université d'Orléans, BP 4043, 18028 Bourges Cedex, France
³ CTAS - Air Liquide Welding, Rue d'Epluches, Saint-Ouen l'Aumône, France

Corresponding author: stephane.pellerin@univ-orleans.fr

Received: 14 February 2008
Accepted: 19 May 2008
Published online: 24 June 2008

Abstract

Composition of the applied shielding gas has a strong influence on physical properties of the plasma and parameters of the welding process. In particular, increase of the percentage of carbon dioxide in argon results in an increase of the transition current value while changing from the globular to spray mode of metal transfer during the welding process. In order to explain this phenomenon, the MIG/MAG welding arc plasma was investigated for different mixtures of argon and carbon dioxide in the shielding gas. Applying a fast camera, recording distribution of spectral lines of the plasma components, we noticed some phenomena not described yet in the literature. Especially, there is a limit in the percentage of relative concentration CO₂/Ar beyond which the arc shape is significantly modified.