Parameter optimization and experimental validation of A-TIG welding of super austenitic stainless steel AISI 904L using response surface methodology

Abstract

Super austenitic stainless steel (SASS) is a premium stainless steel (SS) variant which finds applications in challenging environments. One of the premium grades of SS that falls under the said category is AISI 904L. Autogenous activated flux tungsten inert gas (A-TIG) welding is an established technique for fabricating sound steel joints which offers various advantages. In this context, this research aims to identify an optimum set of input process parameters to effectively employ A-TIG welding to fabricate 10 mm thick joints of SASS AISI 904L plates by employing bead on plate welding trials. The input parameters varied for the trials are welding current, torch travel speed, and percentage of Argon gas present in a mixture of Argon and Helium – which is the shielding gas used, while the responses were the depth of weld penetration (DOP) and weld bead width (BW). For finalizing the combinations of input parameters and the run order of the welding trials, the design of experiments (DOE) was performed using central composite design (CCD) of response surface methodology (RSM). After performing the trials, the DOP and BW attained were measured and the data thus generated were analyzed to study the influence of varying input parameters on the two responses. Analysis of variance (ANOVA) was then performed to check the input parameter's level of significance. RSM's desirability approach was used for numerical optimization to attain maximum DOP and a moderate BW. A linear regression equation generated can be used to precisely predict DOP and BW for any random values of input parameters. The bead on plate trial's validation study displayed root mean squared error (RMSE) values of 0.328 and 0.653 for DOP and BW respectively, The RMSE values of DOP and BW of the joint fabricated with optimized parameters was 0 and 0.311 respectively.

Mechanical and Corrosion Properties of Friction Stir Welded and Tungsten Inert Gas Welded Phosphor Bronze

“…Tungsten inert gas (TIG) welding was conducted using direct current single polarity (DCSP) from a power source characterised by drooping V-I static characteristics. A tungsten electrode of type A 203, typically sharpened to a cone angle of 60° with a flat tip ranging from 0.125 to 0.50mm, was employed [34]. The machine used for the TIG operation is a DC inverter TIG welder (model: PI 180 MT, manufacture: Powercon Electronics, Amperage range -10-180 A, welding rods -Phosphor bronze).…”

Analysis and optimization of the automated TIG welding process parameters on SS304 incorporating Taguchi optimization technique

“…The little serious circular segment given by the sharp anode is great for excellent and accurate welding. Since the cathode will not be consumed during welding, the TIG welder does not need to adjust the intensity input from the circular segment as the metal is stored from the softening electrode [6]. Garg et al (2019) analyzed that by increasing the welding current on SS304 TIG welding operation, more input heat is generated whereas to sort out the excess heat, extended power is utilized to cool the base metal.…”

“…The little serious circular segment given by the sharp anode is great for excellent and accurate welding. Since the cathode will not be consumed during welding, the TIG welder does not need to adjust the intensity input from the circular segment as the metal is stored from the softening electrode [6].…”

Process parameter optimization of hot-wire TIG welding of 10 mm thick type 316LN stainless steel plates

“…They found that reduced welding voltage significantly affected weld joint hardness and bending strength. Sunny et al, 18 and Sharma and Dwivedi 19 have optimized TIG welding parameters using RSM for super austenitic stainless steel AISI 904L. They developed a second-order quadratic model based on RSM to predict DOP and BW.…”