Investigations on effect of three single component activating fluxes on penetration of super duplex stainless steel welded by activated TIG welding process

Abstract

In this research, an attempt has been made to study the weldability newlineaspects of UNS S32750 super duplex stainless steel using Activated Tungsten newlineInert Gas (A-TIG) welding. Three activation fluxes, namely MnO2, ZnO, and newlineSiO2, were employed in the welding process, and the A-TIG welding setup was newlinemeticulously detailed to enhance weld quality by preventing plate movement. newlineThe experimental joints were prepared using the base material and the newlinethree activation fluxes, with different offset configurations. The effects of these newlinevariations on the welding process and resulting joints were explored through newlinevarious characterizations, including tensile testing, microhardness evaluation, newlinemacro, and microstructural examination, fatigue testing, and simulation studies. newlineThe experimental joints were prepared using the base material and the three newlineactivation fluxes, with different offset configurations and designations newlineintroduced to explore the effects of these variations on the welding process and newlinethe resulting joints. A range of characterizations on the A-TIG welded joints newlinewas conducted, including tensile testing, microhardness evaluation, macro, and newlinemicrostructural evaluation, fatigue testing, and simulation studies. newlineThe simulation studies were used to identify the heat flow mechanisms newlinein A-TIG welding. Finite element modelling and thermal analysis was used to newlinevisualize temperature distribution in different zones of the welded joints. newlineActivation fluxes were used to control temperature and improve welding newlineoutcomes. The macrostructure of the UNS S32750 super duplex stainless steel newlineA-TIG welded joints was discussed, including variations in bead width and newlinepenetration under the influence of different activation fluxes. Microstructural newlineevaluation was conducted using optical microscopy and scanning electron newlinemicroscopy (SEM). newline