Welding J Final Report.pdf

COMPARISION OF TIG WELDING AND ACTIVATED TIG WELDING

J Component - Project Report MEE 2011 Welding Engineering Winter Semester 2018 - 2019

Submitted to School of Mechanical Engineerring VIT University, Vellore – 632 014

By  17BME0357 PRASHANTH REDDY  17BME0127 VISHNU TEJA.V  16BME0932 PAVAN KUMAR

Faculty In-charge Prof. G.Rajamurugan ( SMEC, VIT University)

Name of the Student 1. PRASHANTH REDDY 17BME0357

Contribution 1. Brought the commercial aluminium metal sheeet of 100 *180*6mm dimentions . 2. made the cutting of the aluminium sheet by using machine cuttter. 3. Review 1 of the project were proposed.

2. VISHNU TEJA.V 17BME0127

1. Cutting of the aluminium sheet into pieces with the help of jigsaw blade into 100*50*6mm dimentions. 2. Prepared the paste by adding the mixture of titanium and acetone. 3. Report of the final project were written.

3. PAVAN KUMAR 4. 16BME0932

1. After the completion of the cutting aluminium sheet into strips ,he made milling to each piece. 2. brought the aluminium Filler rods to weld the strips .(total of 6 wires). 3. Review 2 of the project were proposed.

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Table of Contents 1. Abstract .................................................................................................................................... 3 2. Introduction………………………………................................................................................ 3 3. Literature (workdone sofar in this area)…………………………………………………………….7 4. Objectives…………………………………………………………………………………………...10 5. Experiemtal details ………………………............................................................................... 11 6. Results and Discussion…………………….............................................................................. 17 7. Summary and Conclusions.......................................................................................................... 18 8. Future scope………………........................................................................................................ 18 9. References ............................................................................................................................ 19

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1.Abstract: In this study, Two different welding processes have been considered:conventional fusion welding processes:TIG and Activated TIG welding were applied to 5 mm thick plates of pure aluminium.Tungsten Inert Gas (TIG) welding is also known as Gas Tungsten Arc Welding (GTAW) process which is an arc based welding process that uses the arc between a nonconsumable tungsten electrode and a workpiece with the help of a shielding gas. The TIG welding is used to produce high quality welds and isone of the most popular technologies for welding in manufacturing industries. The main disadvantage of TIG welding process is low weld penetration. The purpose of this review was to look into various techniques that may improve the weld penetration and weld quality in a TIG welding. In this review we discuss the influence of ATIG (Activated Flux TIG) Welding.It was observed during the review that use of flux or fluxes and pulsed current method improve the weld penetration with weld quality.

2.Introduction: A activating TIG welding (A-TIG welding), is put forward. The effects of welding parameters on weld penetration and width are studied using pure aluminium as base metal. The results indicate that the weld penetration of A-TIG welding can increase above 2 times of that of the traditional TIG welding in the same welding conditions and the weld width reduce dramatically. Using ATIG welding process, the 5mm thickness pure aluminum can be fully penetrated without making a groove. Welding efficiency is obviously improved. Welding specifications of the activated and common TIG welding have influence on the weld penetration and width of A-TIG welding.

Aluminium: Pure aluminium is obtained from bauxite, is relatively expensive to produce, and is too soft and weak to act as a structural material. To overcome its low strength it is alloyed with elements such as magnesium. Many different alloys exist and have found their primary use in the aircraft industry where their relatively high strength/low weight ratio is a marked advantage; aluminium is also a ductile material. In structural engineering aluminium sections are used for fabricating lightweight roof structures, window frames, etc. Page 3 of 21

i)

Tungsten inert gas welding(TIG):

Fig Principle of TIG Welding. Tungsten inert gas welding(TIG) is the arc based process between a tungsten electrode and workpiece .Because between of its simplicity ,good weld appearance ,low initial cost and feasibility to join bigger structures, this process is commonly used to join reactive materials like aluminum =,stainless steel,magnesium etc. However the disadvantages of this process is relatively low penetration capability and hence it is not consider as cost competitive. It is well understood from fig that TIG(GTAW) has the least penetration capability when compared with the other processes. Generally TIG welding process can be used to weld material thickness up to 3 mm in single pass. Hence higher thickness plates cannot be welded autogenously. Higher thickness materials are joined by multipass welding which needs joint preparation and filler additions. To improve the weld penetration in titanium alloys, in 1960, Paton Electric Welding Institute has called ATIG (ACTIVATED FLUX TIG) process in which a thin layer of activating flux is applied on the surface of the material prior to welding . However the composition of the flux is not published .Since then ATIIG has attracted the attention of researchers to investigate the mechanism of deep penetration and development of flux for different materials .

EBW

LBW (absorbed) LBW (refected)

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GTAW

SMAW

GMAW

SAW

EBW-Electron Beam Welding LBW-Laser Beam Welding SAW-Submerged Arc Welding GMAW-Gas Metal Arc Welding SMAW-Shielded Metal Arc Welding FCAW-Flux Cored Arc Welding GTAW Gas Tungsten Arc Welding

ii) Activated Tungsten Arc Welding(ATIG): Activated GTAW process that increases the penetration was first proposed by Paton Electric Welding Institute in the 1960s. The commonly used fluxes are TiO2, SiO2, Cr2O3, ZrO2 halide fluxes. These fluxes can be prepared by using different kind of component oxides packed in the powdered form with about 30-60 μm particle size. To produce a paint-like consistency, these powders are mixed with acetone, methanol, ethanol etc. The coating density of the flux should be about 5-6 mg/cm². A thin layer of the flux is brushed on to the surface of the joint to be welded prior to welding followed by application of welding arc for melting the base metal. Application of these fluxes results in

a) increasing the arc voltage compared with conventional GTAW process under identical conditions of arc length, welding current which in turn burns the arc hotter and increases the joint penetration and weld depth-to width ratio, which helps in reducing the angular distortion of the weldment

b) increasing the constriction of the arc which increases the current density at the anode and the arc force action on the weld pool.The arc constriction also facilitates the development of weld of Page 5 of 21

high depth to width ratio. Increase in depth of the penetration in turn increases the rate of lateral heat flow from the weld pool to the base metal. Increased rate of heat flow from the weld pool causes grain refinement owing to the high cooling rate and low solidification time. High depth to width ratio, effect imparted to the weld pool by activated fluxes is found similar to the high energy density process. Activated flux assisted GTA welding processes have been developed for joining of titanium and aluminium for nuclear and aerospace applications. The commercial fluxes tend to produce a surface slag residue which is required to be removed.

A-GTAW is a kind of welding with a thin layer of fine flux covered on the surface of the base material. Prior to welding, flux mixed with acetone is applied on the surface of the workpiece to be welded. The acetone evaporates within seconds leaving a layer of flux on the surface. During A-GTAW, a part or all of the fluxes is molten and vaporized. As a result, greatly increased penetration weld with good mechanical property can be obtained.

TIG welding can be used in all positions. It is normally used for root pass(es) during welding of thick pipes but is widely being used for welding of thin walled pipes and tube tungsten arc process is being employed widely for the precision joining of critical components which require controlled heat input. The small intense heat source provided by the tungsten arc is ideally suited to the controlled melting of the material. Since the electrode is not consumed during the process, as with the MIG or MMA welding processes, welding without filler material can be done without the need for continual compromise between the heat input from the arc and the melting of the filler metal. As the filler metal, when required, can be added directly to the weld pool from a separate wire feed system or manually, all aspects of the process can be precisely and independently controlled i.e. the degree of melting of the parent metal is determined by the welding current with respect to the welding speed, whilst the degree of weld bead reinforcement is determined by the rate at which the filler wire is added to the weld pool. In TIG torch the electrode is extended beyond the shielding gas nozzle. The arc is ignited by high voltage, high frequency (HF) pulses, or by touching the electrode to the workpiece and withdrawing to initiate the arc at a preset level of current. Selection of electrode composition and size is not completely independent and must be considered in relation to the operating mode and the current level. Electrodes for DC welding are pure tungsten or tungsten with 1 or 2% thoria, the thoria being added to improve electron Page 6 of 21

emission which facilitates easy arc ignition. In AC welding, where the electrode must operate at a higher temperature, a pure tungsten or tungsten-zirconia electrode is preferred as the rate of tungsten loss is somewhat lesser than with thoriated electrodes and the zirconia aids retention of the ‘balled' tip.

3.Literature review(workdone sofar in this area):

Sanjeev kumar et. al [5] attempted to explore the possibility for welding of higher thickness plates by TIG welding. Aluminium Plates (3-5mm thickness) were welded by Pulsed Tungsten Inert Gas Welding process with welding current in the range 48-112 A and gas flow rate 7 -15 l/min. Shear strength of weld metal (73MPa) was found less than parent metal (85 MPa). From the analysis of photomicrograph of welded specimen it has been found that, weld deposits are form co-axial dendrite micro-structure towards the fusion line and tensile fracture occur near to fusion line of weld deposit.

Tseng et. al [6] investigated the effect of activated TIG process on weld morphology, angular distortion, delta ferrite content and hardness of 316 L stainless steel by using different flux like TiO2, MnO2, MoO3, SiO2 and Al2O3. To join 6 mm thick plate author uses welding current 200 Amp, welding speed 150 mm/min and gas flow rate 10 l/min. From the experimental results it was found that the use of SiO2 flux improve the joint penetration, but Al2O3 flux deteriorate the weld depth and bead width compared with conventional TIG process.

Ahmed Khalid Hussain et. al [7] investigated the effect of welding speed on tensile strength of the welded joint by TIG welding process of AA6351 Aluminium alloy of 4 mm thickness. The strength of the welded joint was tested by a universal tensile testing machine. Welding was done on specimens of single v butt joint with welding speed of 1800 -7200 mm/min. From the experimental results it was revealed that strength of the weld zone is less than base metal and tensile strength increases with reduction of welding speed.

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Song et. al [8] successfully joined dissimilar metals of 5A06 Al alloy and AISI 321 stainless steel of thickness 3 mm by TIG welding-brazing with different filler materials. TIG welding– brazing was carried out by AC-TIG welding source with welding current 135 A, arc length 3.0– 4.0mm, welding speed 120 mm/min and argon gas flow rate 8–10 lit/min. It was found hat addition of Si preventing the build-up of the IMC layer, minimising its thickness. The author also investigated (Song et. al 2009) spreading behaviour of filler metal on the groove surface and microstructure characteristics for butt joint. For the experimentation welding current in the range of 90-170 A and welding speed in the range of 100-220 mm/min, were used for 2 mm thick plate.

Wang et. al [9] studied the influences of process parameters of TIG arc welding on the microstructure, tensile property and fracture of welded joints of Ni-base super-alloy. For welding plate width of 1.2-1.5 mm, welding current in the range of 55-90 A, with variable welding speed in the range 2100-2900 mm/min was used. From experimental result it was observed that, the heat input increases with increase of welding current and decrease of welding speed.

Kumar and Sundarrajan [10] performed pulsed TIG welding of 2.14 mm AA5456 Al alloy using welding current (40-90) A, welding speed (210-230) mm/min. Taguchi method was employed to optimize the pulsed TIG welding process parameters for increasing the mechanical properties and a Regression models were developed. Microstructures of all the welds were studied and correlated with the mechanical properties. 10-15% improvement in mechanical properties was observed after planishing due to or redistribution of internal stresses in the weld.

Preston et.al [11] developed a finite element model to predict the evolution of residual stress and distortion dependence on the yield stress-temp for 3.2 mm 2024 Al alloy by TIG welding.

Urena et. al [12] investigated the influence of the interfacial reaction between the Al alloy (2014) matrix and SiC particle reinforcement on the fracture behaviour in TIG welded Al matrix composites. TIG welding was carried out on 4 mm thick AA2014/SiC/Xp sheets using current setting in the range of 37-155 A and voltage of 14-16.7 V. From experimental results it was found that, the failure occurred in the weld metal with a tensile strength lower than 50% of the parent material. Fracture of the welded joint was controlled by interface deboning through the interface reaction Layer. Probability of interfacial failure increases in the weld zone due to formation of Aluminium-carbide which lowers the matrix/reinforcement interface strength. Page 8 of 21

Sivaprasad et.al [13] performed TIG welding of 2.5 mm thick Nickel based 718 alloy using welding current in the range of 44-115 A, voltage 13-15 V and welding speed 67 mm/min. the influence of magnetic arc oscillation on the fatigue behaviour of the TIG weldments in two different post-weld heat treatment conditions were studied.

Indira Rani et. al [14] investigated the mechanical properties of the weldments of AA6351 during the GTAW /TIG welding with non-pulsed and pulsed current at different frequencies. Welding was performed with current 70-74 A, arc travel speed 700-760 mm/min, and pulse frequency 3 and 7 Hz. From the experimental results it was concluded that the tensile strength and YS of the weldments is closer to base metal. Failure location of weldments occurred at HAZ and from this we said that weldments have better weld joint strength.

Raveendra et. al [15] done experiment to see the effect of pulsed current on the characteristics of weldings by GTAW. To weld 3 mm thick 304 stainless steel welding current 80-83 A and arc travel speed 700-1230 mm/min. More hardness found in the HAZ zone of all the weldings may be due to grain refinement. Higher tensile strength found in the non-pulsed current weldings. It was observed that UTS and YS value of non-pulsed current were more than the parent metal and pulsed current weldings.

Sakthivel et.al [16] studied creep rupture behaviour of 3 mm thick 316L austenitic stainless steel weld joints fabricated by single pass activated TIG and multi-pass conventional TIG welding processes. Welding was done by using current in the range of 160-280 A, and welding speed of 80-120 mm/min. Experimental result shows that weld joints possessed lower creep rupture life than the base metal. It was also found that, single pass activated TIG welding process increases the creep rupture life of the steel weld joint over the multi-pass TIG weld joints.

Wang Xi-he et. al [17] performed TIG welding of SiCp /6061 Al composites without and with Al-Si filler using He-Ar mixed as shielding gas. For the welding authors uses gas flow rate 6.9 l/min, welding speed 1800 mm/min, current-60 A. The results show that addition of 50 vol.% helium in shielding gas improves the arc stability, and quality of welding improves when the Al– Si filler is added. The microstructure of the welded joint shows non-uniformity with SiC particles distributing in the weld centre.

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Karunakaran et. al [18] performed TIG welding of AISI 304L stainless steel and compare the weld bead profiles for constant current and pulsed current setting. Effect of welding current on tensile strength, hardness profiles, microstructure and residual stress distribution of welding zone of steel samples were reported. For the experimentation welding current of 100-180 A, welding speed 118.44 mm/min, pulse frequency 6 Hz have been considered. Lower magnitude of residual stress was found in pulsed current compared to constant current welding. Tensile and hardness properties of the joints enhanced due to formation of finer grains and breaking of dendrites for the use of pulsed current.

Narang et. al [19] performed TIG welding of structural steel plates of different thickness with welding current in the range of 55 -95 A, and welding speed of 15-45 mm/sec. To predict the weldment macrostructure zones, weld bead reinforcement, penetration and shape profile characteristics along with the shape of the heat affected zone (HAZ), fuzzy logic based simulation of TIG welding process has been done.

Kumar and Sundarrajan [20] performed pulsed TIG welding of 2.14 mm AA5456 Al alloy using welding current (40-90) A, welding speed (210-230) mm/min. Taguchi method was employed to optimize the pulsed TIG welding process parameters for increasing the mechanical properties and a Regression models were developed. Microstructures of all the welds were studied and correlated with the mechanical properties. 10-15% improvement in mechanical properties was observed after planishing due to or redistribution of internal stresses in the weld.

4.objective of the work: From the literature review, it is found that welding of Aluminium is a big challenge by conventional arc welding process. Again repeatability of welding depends on its control on welding speed and other processing parameters. In this work to perform welding of 6 mm Aluminium plate . TIG welding setup was made .both TIG and A-TIG are performed on the different plates. To get better strength welding of the Aluminium plate also done from both side. Effect of welding speed and applied current on the tensile strength of weld joint, micro hardness of the weld pool and macrostructure of the joint was analysed.

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5.Experiemtal details:

Experimental Work and Methodology: For the present work, experimentation was done in two phase. In first phase, butt welding of Al plate (3 mm thickness) done at one side with different current setting and welding speed. In second phase, butt welding of Al plate done both side by varying welding speed and current setting . Experimental procedure: 

Commercial Aluminium plate of thickness 6 mm was selected as work piece material for the present experiment. Al plate was cut with dimension of 100 mm x 50 mm with the help of jigsaw.



Oprated the milling to the each strips after the jigsaw to make sure surface is plain with no defects.

Fig champering of the metal strips individuvally . 

Before the welding, grinding done at the edge to smooth the surface to be joined. After that surfaces are polished with emery paper to remove any kind of external material. After sample preparation, Aluminium plates are fixed in the working table with flexible clamp side by side and welding done so that a butt join can be formed .

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Fig .the metal strips before the welding with the champering of 2X45 degree. 

TIG welding with Alternate Current (AC) was used in experiments as it concentrates the heat in the welding area. Zirconiated tungsten electrodes of diameter 3.4 mm was taken as electrode for this experiment. The end of the electrode was prepared by reducing the tip diameter to 2/3 of the original diameter by grinding and then striking an arc on a scrap material piece. This creates a ball on the end of the electrode.



Generally an electrode that is too small for the welding current will form an excessively large ball, whereas too large an electrode will not form a satisfactory ball at all.



The power source required to maintain the TIG arc has a drooping or constant current characteristic which provides an essentially constant current output when the arc length is varied over several millimeters. Hence, the natural variations in the arc length which occur in manual welding have little effect on welding current. Open circuit voltage of power source ranges from 60 to 80 V.

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Fig showing the rectifier to operate the power source to doTIG welding (AC)

Table 1: Welding parameters for the experiments :

Parameters

Range

Welding current

130 A

Voltage

(30-50 )v

Speed

Manual around(3.5-4) mm/s

Gas flow rate

(8-10) l/min.

Current type

AC

Electrode Diameter

(1.6-2.4)mm

Dimension

120mm*50mm*6mm

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Titanium powder is added with the acetone to make the paste and it is applied on the both sides of the metal strips on the champered side of the metal to get the activated TIG process done .

Fig. showing the mixure (titanium and acetone),added to strips as flux to do A-TIG 

TIG Welding torch- Torch is fixed with the movable tractor unit. A tungsten electrode is fixed in the torch and Ar gas is flow through this.



TIG welding machine– This is the main part of TIG welding setup by which controlled amount of current and voltage is supplied during welding.



A Rectifier (made by FRONIUS) with current range 10-180 A and voltage up to 230 V, depending on the current setting has been used.



Gas cylinder- For TIG welding Ar gas is supplied to the welding torch with a particular flow rate so that an inert atmosphere formed and stable arc created for welding. Gas flow is control by regulator and valve. Page 14 of 21

 Work holding table- a surface plate (made of grey cast iron) is used for holding the work piece so that during welding gap between the tungsten electrode and work piece is maintained. Proper clamping has been used to hold the work piece.

Fig. welding of the joints by using the filler rod in left hand and welding torch In right hand .

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Fig completion of the weld.  After the welding ,the welding strips are cooled for 1 hour in normal temperature

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6.RESULTS AND DICUSSION: The arc results in the vaporisation of the flux applied on the target. The presence of alkali metal with substantially lower ionisation potential results in preferential ionisation of these elements. These ions conduct the current across the arc. At the outer envelope of the arc, where the temperatures are sufficiently low, the cat ions condense to form atoms increasing the resistance to the flow of current. This increase the current density along the axis increasing the electromagnetic force. The increase in electromagnetic force is sufficiently high to reverse the flow of metal overcoming the effect of surface tension temperature gradient resulting in inward flow of the metal and a narrow weld pool. The hardness of the welded region which done by A-TIG welding is less than that of the conventional TIG welding.

f

Fig a and b showing the weld joints of the A-TIG and TIG respectively. Page 17 of 21

7.CONCLUSION: The A-TIG process (TIG welding with active flux) consists in depositing a thin layer of flux on the workpiece surface just before welding. The layer deposition can be done by brushing or spraying over the surface and welding is performed after it dries out. It is found that with this process it is possible to increase productivity (travel speed) up to three times higher compared to the conventional TIG process. The flux that we used for the experiment is the mixture of titanium powder with acetone. The two aluminium plates(5mm) are welded by both TIG and A-TIG methods. Then their properties are compared. It is found that the A-TIG welding is strong and it is penetrated to more depth than the normal TIG welding. We can also use magnesium and calcium in the place of titanium as flux. A-TIG welding basically involves the penetration capability of arc. A-TIG welding produces a steeper temperature gradient across the weld than conventional welding. With all these we conclude that A-TIG welding has higher productivity than conventional TIG welding.

SCOPE FOR THE FUTURE WORK In these project differentiating both ATIG and TIG we concluded, 

Effect of other process parameters like tilt angle, tool material etc may be studied.



Different design of the tool could be used to investigate the effect of the tool design. The study could be extended to lap joints and investigated in the same way. Development of better tool profile, which is economical, may deliver better results.



Thermocouple may be used to measure the temperature at different zonesHAZ and base metal.



Study can be conducted on the preheating of base material with help of TIG torch.

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8.Referances: [1] en.wikipedia.org/wiki/GTAW [2] www.weldwell.co.nz/site/weldwell [3] http://www.azom.com/article.aspx?ArticleID=1446 [4] www.micomm.co.za/portfolio/alfa [5] Kumar, S.(2010) Experimental investigation on pulsed TIG welding of aluminium plate. Advanced Engineering Technology.1(2), 200-211. [6] Tseng, K. H., & Hsu, C. Y. (2011). Performance of activated TIG process in austenitic stainless steel welds. Journal of Materials Processing Technology, 211(3), 503-512. [7] Hussain, A. K., Lateef, A., Javed, M., & Pramesh, T. (2010). Influence of Welding Speed on Tensile Strength of Welded Joint in TIG Welding Process. International Journal of Applied Engineering Research, Dindigul, 1(3), 518-527 [8] Song, J. L., Lin, S. B., Yang, C. L., & Fan, C. L. (2009). Effects of Si additions on intermetallic compound layer of aluminum–steel TIG welding–brazing joint. Journal of Alloys and Compounds, 488(1), 217-222. [9] Wang, Q., Sun, D. L., Na, Y., Zhou, Y., Han, X. L., & Wang, J. (2011). Effects of TIG Welding Parameters on Morphology and Mechanical Properties of Welded Joint of Ni-base Superalloy. Procedia Engineering, 10, 37-41. [10] Kumar, A., & Sundarrajan, S. (2009). Optimization of pulsed TIG welding process parameters on mechanical properties of AA 5456 Aluminum alloy weldments. Materials & Design, 30(4), 1288-1297. [11] Preston, R. V., Shercliff, H. R., Withers, P. J., & Smith, S. (2004). Physicallybased constitutive modelling of residual stress development in welding of aluminium alloy 2024. Acta Materialia, 52(17), 4973-4983. [12]Urena, A., Escalera, M. D., & Gil, L. (2000). Influence of interface reactions on fracture mechanisms in TIG arc-welded aluminium matrix composites. Composites Science and Technology, 60(4), 613-622. [13] Sivaprasad, K., & Raman, S. (2007). Influence of magnetic arc oscillation and current pulsing on fatigue behavior of alloy 718 TIG weldments. Materials Science and Engineering: A, 448(1), 120-127. Page 19 of 21

[14] Indira Rani, M., & Marpu, R. N.(2012). Effect of Pulsed Current Tig Welding Parameters on Mechanical Properties of J-Joint Strength of Aa6351. The International Journal of Engineering And Science (IJES),1(1), 1-5. [15]Narang, H. K., Singh, U. P., Mahapatra, M. M., & Jha, P. K. (2011). Prediction of the weld pool geometry of TIG arc welding by using fuzzy logic controller. International Journal of Engineering, Science and Technology, 3(9), 77-85. [16]T. Sakthivel ⇑ , M. Vasudevan, K. Laha, P. Parameswaran, K.S. Chandravathi, M.D. Mathew, A.K. Bhaduri , Creep rupture strength of activated-TIG welded 316L(N) stainless steel Journal of Nuclear Materials. [17]Wang, Q., Sun, D. L., Na, Y., Zhou, Y., Han, X. L., & Wang, J. (2011). Effects of TIG Welding Parameters on Morphology and Mechanical Properties of Welded Joint of Ni-base Superalloy. Procedia Engineering, 10, 37-41. [18] Narang, H. K., Singh, U. P., Mahapatra, M. M., & Jha, P. K. (2011). Prediction of the weld pool geometry of TIG arc welding by using fuzzy logic controller. International Journal of Engineering, Science and Technology, 3(9), 77-85. [19] Karunakaran, N. (2012). Effect of Pulsed Current on Temperature Distribution, Weld Bead Profiles and Characteristics of GTA Welded Stainless Steel Joints. International Journal of Engineering and Technology, 2(12). [20] Kumar, A., & Sundarrajan, S. (2009). Optimization of pulsed TIG welding process parameters on mechanical properties of AA 5456 Aluminum alloy weldments. Materials & Design, 30(4), 1288-1297.

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