Parametric optimization of activated Tig welding of hot rolled steel is 5986 using taguchi method

Abstract

The present investigation aims to optimized and develop input parameters for joining of Hot newlinerolled steel using activated tungsten inert gas (A-TIG) welding process. Three combinations of newlinefluxes were prepared to decide suitable flux for Hot rolled steel. The design of experiment was newlinecarried out for optimization of welding parameters to achieve the desired depth of penetration. The newlinesquare butt weld joints were fabricated on 8 mm thick plates employing A-TIG welding using newlinedeveloped flux and optimized process parameters employing single side welding procedure. The newlineUltimate Tensile testing hardness test and impact tests were carried out on the base metal and weld newlinejoint. The strengths, ductility and impact toughness of the joints were found to be comparable with newlinethat of the base metal. newlineGas Tungsten Arc Welding (GTAW), also called Tungsten Inert Gas welding (TIG) is one newlineof the main welding methods which have been widely used in industries for the welding of newlinestainless steel, titanium alloy, and other nonferrous metals for its high weld quality and lower newlineequipment Investment. The major limitation of TIG welding of steel is mainly the limited newlinethickness of material which can be welded in a single pass and that has a lower production rate. newlineTherefore, enhancements in the depth of penetration in weld bead have long been sought in steel newlineweldments produced by TIG welding process. These limitations have been overcome by newlineintroducing oxide powders at the joint during the TIG welding process which is called Activated newlineTungsten Inert Gas Welding (A-TIG). newlineHot rolled steel is used in a range of automobile products it has excellent forming and newlinewelding characteristics. Post-weld annealing is not required when welding thin sections. It has newlineexcellent corrosion resistance in a wide range of atmospheric environments and many corrosive newlinemedia. newlineIn the present work, TIG Welding was carried out on Hot Rolled steel plates of 8 mm newlinethickness. In the first phase, the specimens were welded as bead on plate. The Taguchi method is newlinethe technique is used to determine the level of influence of the independent variables on the newlinedependent variables. The independent variables have been taken for this study are 5 of welding newlineparameters,viz three different types of flux composition combination of two compound TiO2 And newlineSiO2 flux, three set of welding voltage, welding current, gas flow rate, root gap is used. The newlinedependent variables are tensile strength (TS), Hardness (HR), Impact strength (IS), Depth of newlinePenetration (DP), Bead Width (BW), of the weld morphology are used. The SEM images of the newlinemacro structures of weld morphology were compared. The results obtained from the macro newlinestructures of weld morphology indicated that the higher depth of penetration has been achieved in newlinethe specimens welded with A-TIG welding process when compared with Conventional TIG newlinewelding process. The results obtained from the Taguchi, L27 O.A. technique indicated that the newlineactivating flux showed the maximum percentage of contribution in weld morphology. newlineIn Next phase of this study was to determine the influence of two component fluxes on the newlineweld morphology of A-TIG weldments of Hot Rolled steel plates. The activating fluxes such as newlineTiO2 and SiO2, were applied with different proportions to the specimens. Experimental results newlineindicated that using 60% TiO2 +40% SiO2 flux combination leads to a significant increase in joint newlinepenetration and the aspect ratio. newline