Optimization of welding parameters for BCTW-GIA single-pass welding using RSM

Bypass coupling triple-wire indirect arc (BCTW-GIA) welding technology was applied to single-pass welding for medium and thick plates. The regression models between process variables and target responses were built with response surface methodology (RSM) based on central composite design (CCD). The effect of significant process variables namely bypass current, groove gap, plate thickness, and welding speed on penetration-to-width ratio (P/W) of weld joint and tensile strength (TS) was evaluated. Guiding process parameters were determined with numerical optimization for BCTW-GIA single-pass welding of 8 mm, 10 mm, and 12 mm thickness steel plates. With the advice parameters, the average tensile strength of the weldments with three thickness were 558 MPa, 539 MPa, and 547 MPa. The true P/W of butt joints was also in desirable range. That the error between predicated value and experiment value was no more than 10% emphasized the positive effect of regression model of TS and P/W.