Papers by Keyword: A-TIG

Abstract: Tungsten Inert Gas Welding (TIG) is a welding process that has low weld penetration and low heat intensity of the electric arc. This affects the low productivity of processes. To overcome this drawback, Activated Tungsten Inert Gas Welding has been developed. This study investigates Al-7 series plates using the A-TIG welding process. Different kinds of fluxes, TiO2 and Al2O3 are used with a ratio of 1:1 mixture of both these powders. This mixture was applied on Al-7075 plates to enhance weld characteristics. Activated flux has been used to improve the weld depth. The effects of various process parameters (welding current (I), welding speed(V), and gas flow rate were analysed and compared with the TIG welding method. Activated Tungsten Inert Gas (A-TIG) welding canincrease the joint penetration and weld depth width ratio compared to conventional TIG welding. The main objective of this work is to enhance weld penetration, improve mechanical properties (tensile strength and elongation), and assess metallurgical changes in Al-7075 joints using A-TIG welding with TiO₂ and Al₂O₃ mixed fluxes.

Abstract: A-TIG welding is a new variant of high-efficiency TIG weld technology, the weld penetration can be improved by using surface activating fluxes. In the present work, 12 mm thick stainless steel plates were welded by A-TIG method utilizing self-developed oxide-based composite activating flux. Results showed that for 12 mm thick stainless steel plates, weld joint of full penetration and one-side welding with back formation and good weld appearance could be achieved by A-TIG welding. Furthermore, compared with traditional TIG welding, the microstructure of A-TIG weld was finer, directivity of dendritic crystals near weld bond line was weaker, and mechanical properties of weld joints was also superior.

Abstract: Using A-TIG to welding thick plate duralumin alloy and designing rationally welding processing for Y groove butt plates welding of duralumin alloy. Using repeated measurements of dot to get transverse and vertical welding deformation under different current of A-TIG after welding. This paper analyzed the influence of different current on welding deformation and the features of A-TIG welding deformation. The result showed that transverse deformation was the uniformity along weld direction but was not uniform along weld vertical direction. Transverse deformation was larger when it was nearer to weld. Vertical deformation of middle position of weld was smaller than the part of arc starting and arc suppression. The result also showed that the deformation increased as the current increased.

Abstract: The aim of this study was to investigate the effect of activated fluxes on the weld morphology, angular distortion, and mechanical properties obtained with activated tungsten inert gas (TIG) process applied to the welding of 6 mm thick mild steel and stainless steel plates. A novel variant of the TIG welding, specific oxides were applied to mild steel and stainless steel through a thin layer of the flux to produce a butt joint. The CaO, SiO2, Fe2O3, and Cr2O3 fluxes used were packed in powdered form. The experimental results indicated that the SiO2, Fe2O3, and Cr2O3 fluxes can increase joint penetration and weld depth-to-width ratio. The reversed Marangoni convection are considered to the main factors for increasing penetration of A-TIG on dissimilar welds in this study. Furthermore, TIG welding with SiO2 powder can significantly reduce the angular distortion of the dissimilar weldment.

Abstract: The performance of dissimilar activated tungsten inert gas (A-TIG) welding on the welds morphology, angular distortion, and mechanical properties in dissimilar metal plates were investigated. Autogenous TIG welding process was applied to the JIS G3131 mild steel and type 316L stainless steel through a thin layer of activating flux to produce a butt-joint weld. CaO, SiO₂, Fe₂O₃, and Cr₂O₃ fluxes were used as the activating fluxes. The experimental results indicated that the SiO₂, Fe₂O₃, and Cr₂O₃ fluxes can increase joint penetration in both of the 316L stainless steel and the JIS G3131 mild steel. The CaO flux only can increase the joint penetration of the mild steel. The reversed Marangoni convection are considered to the main factors for increasing penetration of A-TIG on dissimilar welds in this study. Furthermore, TIG welding with SiO₂ powder can significantly reduce the angular distortion and increase the tensile strength of the dissimilar weldment.

Abstract: This paper studied and framed TIG and A-TIG welding procedure of LY12 aluminum alloy and analyzed the metallurgical structure and hardness of weld zone of TIG and A-TIG under different welding current. The result showed the strengthening phase which separated out from the basal body of TIG weld zone was obviously fewer than A-TIG and the strengthening phase of TIG obviously decreased when welding current increased. Compared with TIG weld zone, surface activating flux changed the metallurgical structure of A-TIG weld zone and the strengthening phase of A-TIG weld zone was more than TIG. The strengthening phase of A-TIG weld zone did not obviously decreased when welding current increased that implied the strengthening phase of A-TIG did not obviously dissolve into the basal body as TIG and only coarsened with the increase of welding current. The hardness experiment of weld zone showed that the hardness of A-TIG weld zone was higher than TIG and the hardness of 60%NaF+40%SiO2 activating flux of A-TIG weld zone was higher than 40%NaF+60%SiO2 activating flux.

Abstract: In order to investigate the effect of active fluxes on weld penetration, angular distortion and weld morphology in gas tungsten arc welding (GTAW), three types of oxide fluxes-CaO, TiO₂ and Al₂O₃-were used in the welding of 5mm think stainless steel plates. Those powders were applied through a thin layer of the flux to produce a bead on plate welds. The results showed that compared with conventional TIG welding, increased weld penetration and reduced angular distortion of the weld piece were obtained with the application of active fluxes. However, the weld morphology was not changed significantly when the powders were coated on the surface of steel. It was also found that each of the powders has a fittest range in penetration increment. Whether the rate of the coating run out of the range, the effects of these active fluxes on the increased weld penetration were not obvious. The CaO flux has a narrow effective range for deep penetration, while the Al₂O₃ powder does have no effect on A-TIG penetration. The mechanism of those different performances has not been found out. According to the investment, the mechanism of active fluxes for the increased weld penetration and reduced angular distortion is related to the contraction of the arc.