EXPERIMENTAL INVESTIGATION OF WELDING PARAMETERS ON MECHANICAL PROPERTIES AND CHEMICAL COMPOSITION OF GMAW BUTT-WELDED PIPE JOINTS

Gas Metal Arc Welding (GMAW) is widely used in manufacturing due to its high productivity and versatility. However, the quality of butt-welded pipe joints strongly depends on the selection of welding parameters. This study investigates the influence of welding current, voltage, and travel speed on the tensile strength, hardness, and chemical composition of S235JR pipe joints welded with GM-70S filler wire. Experiments were designed using the Taguchi method with an orthogonal array of nine tests. Tensile test results indicated that the welding condition M7 (100A, 20V, 4.6mm/s) achieved the maximum tensile strength of 454 MPa. Hardness measurements indicated the metal zone achieved higher values than other regions. Chemical analysis revealed that changes in Mn and C content correlated with hardness and tensile strength. Overall, the Taguchi method proved effective for optimizing welding parameters, minimizing defects, and improving the reliability of butt-welded pipe joints in industrial applications