Effect of low frequency vibration-assisted shielded metal arc welding on the properties of mild steel

Vibration-assisted welding (VAW) has emerged to be a feasible alternative to thermal and post-weld vibration treatments for arc welds in order to minimize stress concentrations and distortions thereby improving mechanical characteristics. Limited research is available considering low frequency vibration. The main objective is to develop an experimental setup to analyze the properties of welded connections made with shielded metal arc welding (SMAW) using low-frequency mechanical vibrations. Mild steel (MS) plates with dimensions of 100 mm by 50 mm and thickness of 5 mm are considered in this study. Heat inputs of 80 Amps, 100 Amps and 120 Amps were taken into consideration as input current. Vibration was varied between 0 and 100 Hz at every 20 Hz interval to study the Hardness, Tensile Strength and Impact Strength of welded joints. Microstructure of welded MS plates has been analyzed using SEM analysis. Experimental results revealed improved mechanical properties due to the application of low-frequency vibrations that may tend to increase the welding speed thus reducing time and enabling stronger, durable and reliable welded joints. A fine grain structure is seen for Low-frequency vibration-assisted welded butt joints implying improved mechanical properties due to excitation of weld pool.