The Optimization of Automated Based Shielded Metal Arc Welding Parameters on Welded Pool Geometry of Mild Steel Welded Joint Using Taguchi Technique

Abstract

Shielded metal arc welding (SMAW) primarily used for metal processing fields with advantages of low costing. However, the low welding quality and welding speed accuracy are main issues on the conventional SMAW. These issues can significantly influence to geometry shapes and appearance such as bead width and penetration, which determines degree of strength in the mechanical properties of weldment. Thus, in this study, the automated based shielded metal arc welding (ABSMAW) used to weld sheets of mild steel AISI1080 to evaluate bead width and penetration using different welding parameters. During the research, the parameters focused on welding speed range from 3.19 to 4.6 mm/s with manipulating the welding angle and electrode diameter (45° to 60° and 2.6 to 4.0 mm). The configuration of workpiece was clamped in the butt joint of closed square to weld. The samples were ground and cross-sectioned to view the welded pool geometry with etching material. The Taguchi method used to analyze the bead width and penetration using the signal/noise (S/N) ratio diagram. This experiment found the inverse relationship among the welding speed, bead width and penetration that means the welding speed increases, then the bead width and penetration decrease. In contrast, the welding angle increases, then the bead width and penetration increase. The optimum value of bead width and penetration are produced by welding speed of 3.19 mm/s, welding angle of 60° and electrode diameter of 4.0 mm.