ACTIVATED FLUX GAS TUNGSTEN ARC WELDING OF STEELS

Abstract

Stainless Steel, a widely used material in today's world needs to be fabricated properly. Tungsten Inert Gas welding is incorporated to weld the steels because of its high quality results and productivity. TIG welding also provides control of heat input which is the most important consideration in steels to maintain its properties and high quality of the product .But there is limitation of maximum thickness i.e. 3mm that can be welded through TIG process. To overcome this limitations a novel variant of TIG welding known as Activated Flux Gas Tungsten Arc welding was developed by Paton Welding Institute where a coating of activated flux paste is coated on the material to be welded which can increase the weld penetration by 300%. In the present study, austenitic stainless steel and ferritic stainless steel is welded for reaching the optimized composition of flux and welding parameters achieving the penetration of 15mm in austenitic stainless steel and 10mm in ferritic stainless steel. - Further microscopic and metallographic characterizations like Scanning electron microscopy, X-Ray diffraction, Electron dispersion spectra, Mapping, toughness, tensile, hardness and corrosion are carried out to check the soundness and suitability of the welds which are elaborated in the results and discussions chapter. Further conclusions are discussed proving the joint be sound and reliable with no negative impact of surface active elements on the base material. Penetration in austenitic stainless steel is observed to be increased by more than 300% and 252% in ferritic stainless steel. Various tests are concluded for different thicknesses of material welded. Future scope is also discussed giving a possibility of further enhancement in penetration and properties of welds