Effect of vibratory welding process on hardness of dissimilar welded joints

This paper presents the effect of vibratory dissimilar TIG (Tungsten Inert Gas) welding process on hardness of welded joins with respect to change of vibratory parameters. In this study, new vibratory setup with two metal engravers is used to give mechanical vibrations to the specimens to be welded.
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Effect of vibratory welding process on hardness of dissimilar welded joints Engineering Solid Mechanics (2017) 133-138 Contents lists available at GrowingScience Engineering Solid Mechanics homepage: www.GrowingScience.com/esmEffect of vibratory welding process on hardness of dissimilar welded jointsJ. Kalpanaa, P. Srinivasa Raob and P. Govinda Raoc*a Assistant Professor, Dept. of Mechanical Engineering, SSCE, Chilakapalem, Andhra Pradesh, Indiab Professor, Dept. of Mechanical Engineering, Centurion University, Parlakhemundi, Odisha, Indiac Associate Professor, Dept. of Mechanical Engineering, GMRIT, Rajam, Andhra Pradesh, IndiaA R T I C L EI N F O ABSTRACT Article history: This paper presents the effect of vibratory dissimilar TIG (Tungsten Inert Gas) welding process Received 6 October, 2016 on hardness of welded joins with respect to change of vibratory parameters. In this study, new Accepted 20 February 2017 vibratory setup with two metal engravers is used to give mechanical vibrations to the specimens Available online to be welded. Finally, the effect of mechanical vibrations with the variation of vibration 20 February 2017 Keywords: parameters is studied on the hardness at the weld bead and heat effected zone (HAZ) of welded Vibratory welding joints. Tungsten Inert Gas (TIG) welding Vibratory parameters Weld bead and Heat affected zone (HAZ) © 2017 Growing Science Ltd. All rights reserved.1. Introduction To overcome the disadvantages in normal welding process, vibratory assisted welding has beenintroduced for improving mechanical properties of welded joints. In vibratory welding, a force isapplied periodically to the specimens during welding process. Due to this periodic force, weld pool isstirred to refine the grain structure in order to enhance the weld joint properties. Lu et al. (2007)investigated to improve the quality of full welded valve by the application of vibratory weldconditioning (VWC) and the effect of VWC on the welded joint properties was studied. In their study,cylinders with different thicknesses have been welded by submerged arc welding (SAW) and theexperiment results showed that the vibration applied during welding reduces the residual deformationand stress. The yield strength, as well as the tensile strength, does not change distinctively in vibratorySAW (V-SAW) when compared with that in normal SAW (N-SAW), but the bend property wasimproved in V-SAW. They also conducted fracture toughness tests using single edge notch bend* Corresponding author.E-mail addresses: govind09.p@gmail.com (P.Govinda Rao)© 2017 Growing Science Ltd. All rights reserved.doi: 10.5267/j.esm.2017.2.003134(SENB) specimens and demonstrated that the fracture surfaces of failed weld metal (WM) specimensare characterized by dimple-like structures. The depth and the density of these dimples are increasedafter the vibration applied in welding. River marking, the characteristic of cleavage fracture, is observedin the heat-affected zone (HAZ) specimens. Teng et al. (2002) showed that the stress concentrations usually occur at structural geometrydiscontinuities, e.g. weld toes, and crack like defects. These stress concentration sites may serve forcrack initiation and cracks that are propagating may lead to failure. Rao et al. (2015a) proposed a newvibratory welding technique for inducing mechanical vibrations into the weld pool during weldingprocess. The designed vibratory setup produces the required vibrations at frequency with the amplitudeand acceleration in terms of voltages. An increase in the flexural strength, impact strength, ultimatetensile strength and hardness of the weld pieces at the heat affected zone (HAZ) is observed. Theincrease in mechanical properties is attributed to, as the weld pool solidifies, grains are not only limitedin size but also dendrites are broken before they grow large in size and forms refined microstructure.This mechanism is responsible for the improvement in flexural strength, ultimate tensile strength,impact strength and hardness of welded joints. From the experimental results it is clear that themechanical properties are improved considerably with the increase in the acceleration and amplitudeof the specimens. Mechanical propertie ...