Papers by Keyword: ATIG Welding

Abstract: The ATIG welding which is the high productivity version of conventional TIG welding, parallel with productivity increasing has some advantageous effect both on HAZ and weld joint grain structure. In this paper the effect of ATIG welding on austenite/ferrite ratio in duplex steel will be represented with experimental results performed on 8 mm thick 2205 type duplex steel. As collateral benefit through these results new evidences are originated to prove the “reversed Marangoni effect” theory.

Abstract: Welding experiences are demonstrated, which were developed on 2205 type duplex and 2509 type superduplex stainless steels (DSS and SDSS). The welded joints were produced by activated TIG welding and laser beam welding. For the ATIG process, which is a special kind of the TIG-welding, silica powder was used as activating flux. Microstructural characterizations were applied for the measurement of ferrite/austenite phase ratio in the weldments. The welded joints were thermally aged at temperature of 400 °C. The phase transformations produced during thermal ageing were investigated by optical and scanning electron microscopy and thermoelectric power measurement. Investigations show that the thermal ageing induced phase transformations are similar at ATIG-welded weldment and DSS base material, but the incubation time is significantly shorter in the weldment than in the base material when laser welding is applied.

Abstract: The TIG welding has a high disadvantage against the substantially high productivity welding procedures. This is why there were continuously going on several trials to improve the productivity of the TIG welding. The Activated Tungsten Inert Gas welding (ATIG welding) is one of these trials. Application experiments of ATIG welding on austenitic stainless steel plates will be presented. The main problems which appear when using the ATIG welding are the choosing of tungsten electrode, the suggested fitting of parts for the joining, portioning of the activating flux and the sensitivity for the measure of flux. They are extremely important to apply the ATIG welding and the results will be presented by this work. In the second half of this paper the comparison of the productivity differences between TIG and ATIG welding; mechanical properties, microstructure and corrosion resistance of welded joints will continue. Finally the evaluating the results and trying to classify the ATIG welding amongst the modern and most productive welding procedures is detailed. Furthermore advises for using the ATIG welding for suitable applications are represented.