Taguchi Optimization Technique of Weld Bead Geometrical Parameters using Submerged Arc Butt Weld in Mild Steel

Abstract

Submerged arc welding (SAW) is usually classified as a pure slag shielded process. It is used extensively in industry to fabricate pressure vessels, pipe lines, marine vessels, bridge girders etc. Weld bead geometry is a critical component in determining weld quality, since it is determined by the mechanical characteristics of the weld metal, particularly tensile strength. Weld metal mechanical strength is influenced not only by metal composition but also by weld bead shape. In the present study attempt has been made to study the optimal process parameters for submerged arc welded mild steel plates for bead geometry and tensile strength. The experimental plan was developed using a design of experiment (DOE) with four parameters (arc voltage, welding current, travel speed, and nozzle to plate distance) and five levels (Taguchi orthogonal design). Twenty-five specimens are made to determine the joint's bead width, penetration, and tensile strength. The analysis of variance (ANOVA) approach is used to determine the magnitude of the impact of factors such as welding current, arc voltage, nozzle to plate distance, and trolley speed on bead width, depth of penetration, and weld strength on particular outputs such as bead width, depth of penetration, and weld strength.