Austenitic stainless steel (ASS) is widely fabricated by tungsten inert gas (TIG) welding for aesthetic look and superior mechanical properties while compared to other arc welding process. Hitherto, the limitation of this process is low depth of penetration and less productivity. To overcome this problem activated tungsten inert gas (A-TIG) welding process is employed as an alternative. In this investigation the welding performance of conventional TIG welding is compared with A-TIG process using TiO2 and SiO2 flux with respect to weld bead geometry. The experimental investigation on A-TIG welding of ASS-201 grade shows TiO2 flux helps in achieve higher penetration as compared to SiO2 flux. While welding with SiO2 the hardness in HAZ and weld region higher than that of TIG welding process.

Austenitic Stainless Steel has improved mechanical properties and great corrosion resistance thereby it is extensively used in fabrication industries. The aim of our work is to compare the mechanical property and macrostructural of TIG and A-TIG welding process on Nitrogen alloyed stainless steel and find out the best oxide flux to be used before welding to improve the macrostructure, penetration, weld width, and tensile strength of butt joint. Five dissimilar fluxes i.e. SiO2, MnO2, TiO2, ZnO and CaO were used during A-TIG welding. Experiments were performed at same welding speed but at different welding current in both TIG and A-TIG welding. In the whole process SiO2 and TiO2 helps to get full penetration of 5mm at 200A welding current while least penetration of 3.16mm obtained during TIG method. Welding parameters giving the best penetration profile was chosen to perform welding on butt joint for assessment of strength. Test coupon of TiO2 had greater strength (698N/mm2) as well as percentage elongation (34.5).

Chromium manganese austenitic stainless steel is exhibiting an admirable amalgamation of higher strength and stress corrosion resistance. This economical steel is developed to fulfill the requirement of a variety of consumers for high temperature and structural applications. Hitherto, the limitation associate with the TIG welding process is a low depth of penetration which reduces productivity. Activated tungsten inert gas welding (ATIG) is the best suitable option to overcome this problem and satisfy the sustainable welding requirement. Welding procedure has been developed for chromium manganese austenitic stainless steel during ATIG welding using a box behken design (BBD) to improve penetration depth and productivity. The activated flux using SiO2 and TiO2 flux indicates improvement in penetration 5.3 mm and 5.1 mm as compared to TIG welding. The ATIG welded test coupon has strength and hardness of 495 MPa and 195 HV when using SiO2 flux, and 487 MPa and 190 HV when using TiO2 flux, compared to 435 MPa and 165 HV for the TIG welded test coupon. ATIG welds have higher strength and hardness because of their finer grain size when compared to TIG welded test coupons.

Cladding is widely used in manufacturing industries for the production of pressure vessel by depositing thick layer of filler material for providing corrosion resistant-surface. The use of metal cored wire in gas metal arc welding (GMAW) process is popular due to its higher deposition rate and productivity. This work investigates the effect of process parameters on the deposition of cladding layer with ER 309L metal core wire (as filler material) on a corrosion resistant material (IS 2062). The welding parameters viz., wire feed rate (WFR), voltage (V), welding speed (S) and nozzle to plate distance (NTD) are employed as process parameters while penetration (P), bead width (W), reinforcement (R), weld penetration shape factor (WPSF) and weld reinforcement form factor (WRFF) as welding responses. The predictive model developed for P, W, R, WPSF, and WRFF using the response surface methodology (RSM) approach is found adequate at 95% confidence interval. The validation results for the developed model results in a model accuracy (MA) of 92.82%, 96.34%, 91.47% 88.98% and 87.75% for model P, W, R, WPSF, and WRFF respectively and it shows higher predictability and accuracy. The process parameters are optimized simultaneously with integrated optimization approach using RSM with Jaya algorithm and obtain optimal solution in less than 20 number of iterations. The minimum fitness value obtained as 1.3008 at an optimal parameter setting of WFR = 12 m min−1, V = 26 V, S = 280 mm min−1, NTD = 10 mm. The validation result at the optimal parameter setting results in an improvement of 6.45%, 11.29%, 13.58%, 16.07%, 15.38% is noted for P, W, R, WPSF, and WRFF respectively.

Hastelloy C-276 is a nickel-based alloy with high strength and corrosion resistance at cryogenic to high temperatures. The issue of Hastelloy C-276 shallow penetration by Tungsten Inert Gas (TIG) welding was addressed in the current investigation by applying A-TIG welding with variable oxide flux. In the current investigation, constant welding conditions were used to perform TIG and A-TIG welding using SiO2, TiO2, and a 50% mixture of SiO2+TiO2 flux. The weld bead width and depth of penetration of the weld bead profile were measured, and the mechanical and metallurgical properties of the weld metal was investigated. SiO2 flux attained the highest D/W ratio and depth of penetration during A-TIG welding when compared to other fluxes used. A-TIG welding using SiO2 flux improved the depth of penetration and the D/W ratio by 118% and 263%, respectively, in comparison with conventional TIG welding. Additionally, the A-TIG welded sample with SiO2 flux had an ultimate tensile strength of 738.295 MPa and a percentage of elongation of 52.75%.