Effect of Mig Welding Input Process Parameters on Weld Bead Geometry on Hsla Steel

The various welding parameters such as welding speed, voltage and gas flow rate were varied on HSLA steel and the effects of these parameters on weld bead geometry such as penetration, width & height have been studied. Mathematical equations have been developed using factorial technique. And the result of various effects are shown in tables. (Numerical Values). INTRODUCTION Wide variety of steels has been developed, amongst which, IS304 series are particularly used for general structural purposes, for sheet applications in automotive industries and in military also. In this series, IS304 being an important grade has been identified for welding. Automatic gas metal arc welding (GMAW) was used for the process of welding because of its high reliability, all position capability, ease of use, low cost and high productivity . The mixture of 80% Argon 18% Carbon Dioxide and 2% Oxygen was used as shielding gas. REVIEW OF LITERATURE Among all the welding processes, the chief advantages in using Gas metal arc welding (GMAW) for surfacing are high reliability, all position capability, ease of use, low cost and high productivity {14,16}. With the growing emphasis on the use of automated and robotic system MIG welding, with its all position capabilities, GMAW has been employed increasingly in mechanized surfacing in industry{1,6} Large amount of published work has been available on these aspects of investigation for steel welds, employing conventional MIG/MAG and submerged arc (SA) welding processes { 2,4,5,7,9,10,11,17,18,19,21}. It is reported that the strength of a welded joint is largely determined by the dimensions and shape of its bead. Ravendra and Parmar {22} have built mathematical models using the fractional factorial technique to predict the weld –bead geometry and shape relations penetration, width, reinforcement height, width to penetration ratio and percentage dilution). The base metal was a 13 mm thick low carbon structural steel plate. The parameters of the FCWA process considered in this work were arc voltage, welding current, welding speed, gun angle and nozzle to plate distance. They have developed models which can be used either to predict the bead geometry or to determine a combination or a range of parameters to obtain the desired bead geometry dimensions within the factors domain. Furthermore, these models can also be used in a production system for automatic control of welding conditions. Kim et al.{12} have studied the inter relationship between robotic CO2 arc welding parameters and bead penetration by developing mathematical models using factorial techniques to predict the desired bead penetration. Kim et al. {13} have employed factorial design to correlate the robotic GMAW process Parameters (welding voltage, welding speed and arc current) to three responses ( bead width, bead height and penetration) or optimization purposes. The material used was plates of AS 1204 mild steel adopting the bead on plate technique. EXPERIMENTAL SETUP Introduction:MIG (Metal Inert Gas) welding, also known as MAG ( Metal Active Gas ) and in the USA as GMAW ( Gas Metal Arc Welding), is a welding process that is now widely used for welding a variety of materials, ferrous and non ferrous. The essential feature of the process is the small diameter electrode wire, which is fed continuously into the arc from a coil. As a result this process can produce quick and neat welds over a wide range of joints. Mohd. Shoeb et al. / International Journal of Engineering Science and Technology (IJEST) ISSN : 0975-5462 Vol. 5 No.01 January 2013 200