Effect and Optimization of Welding Parameters and Flux Baking on Weld Bead Properties and Tensile Strength in Submerged Arc Welding of HSLA 100 Steel

Submerged arc welding (SAW) has certain advantages of easy control of process parameters, no atmospheric contamination, deep and stable penetration, higher welding speeds and almost no radiation which makes this process to be the preferred choice among different welding processes. In the present work, effect of welding parameters, welding current, welding voltage, welding speed and flux condition (baked/unbaked) was studied for submerged arc welding on high-strength low alloy steel (HSLA steel) plates. The output responses measured were weld bead reinforcement, depth of penetration, ultimate tensile strength (UTS) and percentage elongation. D-optimal design was used as design of experiment technique to generate experimental design matrix. The mathematical model for responses were developed in terms of input welding parameters. The developed mathematical models were analyzed using ANOVA (F test). Optimization of input parameters is also performed to obtain the optimum values of output responses. From the results, it was concluded that welding current is the most significant parameter among the selected parameters controlling all the responses. All responses increase with an increase in welding current and decrease with an increase in welding speed. Interaction among welding parameters plays significant role in deciding the final weld bead characteristics.