Indian Journal of Science and Technology

Abstract

Objectives: In the present article, the effect of inducing auxiliary vibration into the weld pool during welding has been investigated and the work has been aimed to understand the fundamental role of vibration in controlling the weld pool microstructure and mechanical properties. Methods/ Statistical Analysis: Shielded Metal Arc Welding (SMAW) process, which is one of the most widely process, has been used for preparation of weld specimen. In present study a new concept of vibratory setup has been designed which stir the molten metal of the weld-pool before it solidifies during the welding operation. The vibratory setup is capable to produce a resonance frequency of 300 Hz with maximum amplitude of 0.5 mm. Findings: To study the effect of vibration on mechanical properties of the weld joints tensile test and microhardness test has been conducted. The test result shows the improvement in microhardness properties and the Ultimate tensile strength increases by 80 MPa. The yield strength and percentage elongation of vibratory welded joints also get increased as compare to the welded joints prepared using conventional welding operation. Present investigation propose that inducing auxiliary vibrations into the weld pool results into grain refinement of the weld zone which is attributed not mainly to dendrite fragmentation but impeding of the dendritic growth. The microstructure study of vibratory welded joints shows the small size of grains as compare to the conventional welded joints. Application/Improvement: Based upon the results obtained the present experimentation provides an alternative vibratory welding mechanism for enhancement of mechanical properties by shaking the weldpool only during welding operation. 
Keywords: Auxiliary Vibrations, Frequency, SMAW Process, Tensile Properties, Vibratory Welding Technique