The method presented in this paper is based on the measurement of oxygen on the surface of the base metal to enable a quantitative assessment of the contamination in the shielding gas. The gas used in arc processes affected arc properties and simultaneously protected the welding pool. The contamination of the shielding gases, e.g. with atmospheric air, damages the properties of the weld joint. The contamination in the shielding gas is not only dependent on the purity of the utilized gas, but also on the components of the welding torch. The level of contamination in the gas produced by the torch had been analyzed so far only by empirical evaluation of the quality and appearance of the welding seam. The measurement of oxygen on the surface of the base metal is a simple and accurate method to analyze the level of contamination in the shielding gas. This method allows a quantitative assessment even in the presence of the arc. This work shows the possibilities of using this method for the development and analysis of arc welding processes using the example of TIG and MIG / MAG torches.
Arc; shielding gas; contamination; oxygen; torch
