• International Journal of Technology (IJTech)
  • Vol 13, No 3 (2022)

Investigation on Weld Characteristic, Welding Position, Microstructure, and Mechanical Properties in Orbital Pulse Current Gas Tungsten Arc Welding of AISI 304L Stainless Steel Pipe

Investigation on Weld Characteristic, Welding Position, Microstructure, and Mechanical Properties in Orbital Pulse Current Gas Tungsten Arc Welding of AISI 304L Stainless Steel Pipe

Title: Investigation on Weld Characteristic, Welding Position, Microstructure, and Mechanical Properties in Orbital Pulse Current Gas Tungsten Arc Welding of AISI 304L Stainless Steel Pipe
Agus Widyianto, Ario Sunar Baskoro, Gandjar Kiswanto

Corresponding email:


Cite this article as:
Widyianto, A., Baskoro, A.S., Kiswanto, G., 2022. Investigation on Weld Characteristic, Welding Position, Microstructure, and Mechanical Properties in Orbital Pulse Current Gas Tungsten Arc Welding of AISI 304L Stainless Steel Pipe. International Journal of Technology. Volume 13(3), pp. 473-483

918
Downloads
Agus Widyianto Department of Automotive Engineering Education, Faculty of Engineering, Universitas Negeri Yogyakarta, Jl. Colombo No.1, Karang Gayam, Caturtunggal, Kab. Sleman 55281, Indonesia
Ario Sunar Baskoro Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Jl. Prof. Dr. Sumitro Djojohadikusumo Kampus UI Depok 16424, Indonesia
Gandjar Kiswanto Department of Mechanical Engineering, Faculty of Engineering, Universitas Indonesia, Jl. Prof. Dr. Sumitro Djojohadikusumo Kampus UI Depok 16424, Indonesia
Email to Corresponding Author

Abstract
Investigation on Weld Characteristic, Welding Position, Microstructure, and Mechanical Properties in Orbital Pulse Current Gas Tungsten Arc Welding of AISI 304L Stainless Steel Pipe

Orbital pipe welding is carried out in this study by Pulse Current Gas Tungsten Arc Welding (PC-GTAW) without metal filler (autogenous) of AISI 304L stainless steel pipe. The dimensions of the specimen are 114 mm outside diameter and the thickness of 3 mm. This study investigates the effect of pulse current parameters, weld position, and pulse width on the characteristics of weld geometry, mechanical properties, and microstructure. The welding method used in this study is the continuous current and pulse current. The mean current of each parameter is the same at 100 ± 0.5 Amperes, but in the pulse current, there are variations in peak current, base current, peak current time, and the base current time. The welding speed used is constant at 1.4 mm/s. The result of weld geometry on the outside of pipe has shown that the flat (0°) position is concave and the overhead (180°) position is convex due to the influence of gravity. The microstructure indicates that the fine cellular dendritic structures appear at PC-GTAW. The PC-GTAW can produce good mechanical properties such as the tensile strength and the micro-hardness. The tensile strength of the specimen is reduced 14.23 % from the base metal at parameter 65-B and the flat position.

Orbital pipe welding; PC-GTAW; AISI 304L; Weld characteristic

Introduction

    Austenitic stainless steel (ASS) is a type of material that is widely used in manufacturing. This material is used in the manufacture of pipes, power plants, refineries, pressure vessels, nuclear reactors, automobiles and offshore structures (Karunakaran, 2012). AISI 304L and 316L stainless steel is the type of ASS materials often used in the industry (Alcock & Baufeld, 2017; Jujur et al., 2015). One of the advantages of this material is that it has corrosion-resistant properties at high temperatures and high pressures and has good mechanical properties (Xu et al., 2017). In general, welding of austenitic stainless steel can be performed by using Gas Tungsten Arc Welding (GTAW) or Gas Metal Arc Welding (GMAW).  Gas Tungsten Arc Welding (GTAW) is one of the most widely used welding methods used in industrial sectors due to its ability to join materials such as similar or dissimilar metal materials connected with high-quality joints. During the welding process, the specimen melts due to the heat from the welding arc generated  process, the specimen melts due to the heat from the welding arc generated between the non-consumable tungsten electrodes (Kou, 2003).
    Welding of 304L stainless steel alloy using GTAW without added (autogenous) material is susceptible to the phenomenon of hot cracking. Hot cracks are cracks due to heat during the welding process and the type of welded joint (James et al., 2020). Many researchers have studied on hot cracking that often occurs in austenitic stainless steels (Alcantar-Modragón et al., 2021; James et al., 2020; Mirshekari et al., 2014). One method to reduce hot cracking in GTAW welding is to use pulse current.
The depth of penetration and width of the weld bead are factors that can directly affect weld quality. In the GTAW process, it can be increased by raising the weld current. However, an increase in weld current can result in an increase in distortion due to the high heat input (Okano & Mochizuki, 2017). Stainless steel, especially the austenite stainless steel (ASS) type, has the highest thermal expansion coefficient and the lowest thermal conductivity compared to carbon steel and other alloy steel (Tseng & Hsu, 2011). One other method to reduce the heat input that occurs due to an increase in weld current is by welding pulse current (Pal & Pal, 2011). With pulse current welding, many parameters  can be set including peak current, base current, time peak current, and time base current (Dorn et al., 2009). In orbital pipe welding, the use of pulse currents can reduce the effect of gravity during the welding process.
    In previous research, Aesh (Aesh, 2007) reported on welding with the continuous current to observe the weld geometry on GTA welding, Gunaraj and Murugan (2000) on SMA welding. Pipe welding has been carried out by researchers such as Lothongkum et al. (2001) studied on orbital welding of stainless steel and the influence of pulsed current on microstructure and weld bead quality. The variation in the welding process and welding parameter to improve the weld characteristics of 304LN stainless steel pipe have been reported by Kulkarni et al. (2008). Baskoro et al. (2011) developed a system to detect and control the weld penetration from the weld pool and optimize it with PSO and GA. Karunakaran (2012) stated that the results of mechanical properties from welding with pulsed current were higher than the continuous current. In addition, the use of pulsed current can reduce porosity and reduce residual stress that occurs after the welding process (Kulkarni et al., 2008). The results of a review conducted by Pal Kamal & Pal Surjya K. (2011) stated that welding with the pulsed current is one method to reduce the heat input received by the material. The choice of pulsed current parameters is crucial due to this will determine the characteristics of the weld bead formed during the welding process (Palani & Murugan, 2006). The effect of pulsed current at the welding position of 6-12 h has been reported by Lothongkum et al. (2001). Next, Daniel et al. (Figueirôa et al., 2017) indicated that the welding position affects the weld geometry and mechanical properties of low carbon steel. The welding position can determine the welding results visually on the orbital pipe welding if the pipe was seen from a horizontal orientation.
    Several of the above studies show that the use of welding methods with pulsed currents has a positive impact on weld geometry and mechanical properties. Most of the above studies only vary the pulse current regardless of the magnitude of the heat input or the average current. This affects the weld geometry that was formed and its mechanical properties. Therefore, based on the above research, no research pays attention to the amount of heat input and the mean current in the use of pulse currents in orbital pipe welding. In orbital pipe welding, there is a welding position that needs attention due to the influence of gravity. So, the use of pulsed currents is suitable for reducing the effect of gravity, and the weld geometry can still be controlled. Stainless steel pipe type 304L (AISI 304L) is used in this study. This material is widely used in industries due to it has corrosion-resistant properties. Therefore, further investigation is needed on the effect of orbital pipe welding on weld characteristics, mechanical properties, and microstructure of each welding position.

Conclusion

This study investigates the effect of orbital PC-GTAW on weld characteristics, welding position, microstructure, and mechanical properties of AISI 304L stainless steel pipe. In the orbital pipe welding, the weld geometry on the flat (0°) and overhead (180°) positions were strongly influenced by gravity. However, in the descendant vertical (90°) and ascendant vertical (270°) positions weren’t too affected by gravity. The weld geometry on the outside of the pipe formed at the flat (0°) position was concave, at the overhead (180°) position was convex, and at the descendant vertical (90°) and ascendant vertical (270°) positions it tends to be flat. The higher the peak current, the geometry of the weld formed will be deeper in penetration at several pipe positions in the orbital pipe welding. PC-GTAW can produce smaller width of HAZ than CC-GTAW due to in the PC-GTAW, the cooling rate is faster, and heat input can be controlled. The orbital PC-GTAW of AISI 304L produced good mechanical properties. The tensile strength of each parameter and welding position was not much different from the base metal, the largest decrease in the parameter 65-B at the flat (0°) position of 14.23% from BM. The micro-hardness value will rise when in the HAZ region, and then it will descend when entering the PMZ region and back up again when in the WM region. The micro-hardness value in PMZ has the smallest value compared to the other zones.

Acknowledgement

    This research is supported by the Master Program to Doctorate for Scholar Excellent (PMDSU) program of the Ministry of Research & Technology and High Education (RISTEK DIKTI) 2018 with contract number 6265/UN2.R3.1/HKP05.00/2018.

References

Aesh, M.A., 2007. Optimization of Weld Bead Dimensions in GTAW of Aluminum–Magnesium Alloy. Materials and Manufacturing Processes, Volume 16(5), pp. 725–736.

Alcantar-Modragón, N., Garcia, V.G., Reyes-Calderon, F., Villalobos-Brito, J.C., Vergara-Hernández, H.J., 2021. Study of Cracking Susceptibility in Similar and Dissimilar Welds Between Carbon Steel and Austenitic Stainless Steel Through Finger Test and FE Numerical Model. The International Journal of Advanced Manufacturing Technology, Volume 116, pp. 2661–2686

Alcock, J., Baufeld, B., 2017. Diode Laser Welding Of Stainless Steel 304L. Journal of Materials Processing Technology, Volume 240, pp. 138–144

Baskoro, A.S., Masuda, R., Suga, Y., 2011. Comparison of Particle Swarm Optimization and Genetic Algorithm for Molten Pool Detection in Fixed Aluminum Pipe Welding. International Journal of Technology, Volume 2(1), pp. 74–83

Casalino, G., Angelastro, A., Perulli, P., Casavola, C., Moramarco, V., 2018. Study on The Fiber Laser/TIG Weldability of AISI 304 and AISI 410 Dissimilar Weld. Journal of Manufacturing Processes, Volume 35, pp. 216–225

Dorn, L., Devakumaran, K., Hofmann, F., 2009. Pulsed Current Gas Metal Arc Welding Under Different Shielding And Pulse Parameters; Part 1: Arc Characteristics. ISIJ international, Volume 49(2), pp. 251–260

Figueirôa, D.W., Pigozzo, I.O., Silva, R.H.G.E., Santos,T.F.D.A., Urtiga Filho, S.L., 2017. Influence of Welding Position and Parameters in Orbital Tig Welding Applied to Low-Carbon Steel Pipes. Welding international, Volume 31(8), pp. 583–590

Giridharan, P., Murugan, N., 2009. Optimization of Pulsed GTA Welding Process Parameters for The Welding of AISI 304L Stainless Steel Sheets. The International Journal of Advanced Manufacturing Technology, Volume 40(5-6), pp. 478–489

Gunaraj, V., Murugan, N., 2000. Prediction and Optimization of Weld Bead Volume for The Submerged Arc Process—Part 1. Welding journal, Volume 79(10), pp. 286s–294s

James, M.N., Matthews, L., Hattingh, D.G., 2020. Weld Solidification Cracking in A 304L Stainless Steel Water Tank. Engineering Failure Analysis, Volume 115, pp. 104614

Jujur, I.N., Sah, J., Bakri, A., Wargadipura, A.H.S., 2015. Analysis of Oxide Inclusions on Medical Grade 316L Stainless Steel Using Local Raw. International Journal of Technology, Volume 7, pp. 1184–1190

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 Science, Volume 2 (12), pp. 19081916

Kou, S., 2003. Welding Metallurgy. New Jersey, USA, Volume 431(446), pp. 223–225

Kulkarni, S., Ghosh, P.K., Ray, S., 2008. Improvement of Weld Characteristics by Variation in Welding Processes And Parameters in Joining of Thick Wall 304LN Stainless Steel Pipe. ISIJ international, Volume 48(11), pp. 1560–1569

Kumar, R., Anant, R., Ghosh, P., Kumar, A., Agrawal, B., 2016. Influence of PC-GTAW Parameters on The Microstructural and Mechanical Properties of Thin AISI 1008 Steel Joints. Journal of Materials Engineering and Performance, Volume 25(9), pp. 3756–3765

Kumar, T.S., Balasubramanian, V., Sanavullah, M., 2007. Influences of Pulsed Current Tungsten Inert Gas Welding Parameters on The Tensile Properties of AA 6061 Aluminium Alloy. Materials & Design, Volume 28(7), pp. 2080–2092

Kusuma, A.P., Suhadi, A., Priadi, D., Siradj, E.S., 2017. Effect of annealing temperature on microstructure and mechanical properties of ultrafine grained brass produced by equal channel angular pressing. International Journal of Technology, Volume 8(1), pp. 58–65

Lothongkum, G., Viyanit, E., Bhandhubanyong, P., 2001. Study on The Effects Of Pulsed TIG Welding Parameters on Delta-Ferrite Content, Shape Factor and Bead Quality in Orbital Welding of AISI 316L Stainless Steel Plate. Journal of Materials Processing Technology, Volume 110(2), pp. 233–238

Manikandan, M., Arivazhagan, N., Rao, M.N., Reddy, G.M., 2014. Microstructure and Mechanical Properties of Alloy C-276 Weldments Fabricated by Continuous and Pulsed Current Gas Tungsten Arc Welding Techniques. Journal of Manufacturing Processes, Volume 16(4), pp. 563–572

Mirshekari, G.R., Tavakoli, E., Atapour, M., Sadeghian, B., 2014. Microstructure and Corrosion Behavior of Multipass Gas Tungsten Arc Welded 304L Stainless Steel. Materials & Design, Volume 55, pp. 905–911

Okano, S., Mochizuki, M., 2017. Transient Distortion Behavior During TIG Welding of Thin Steel Plate. Journal of Materials Processing Technology, Volume 241, pp. 103–111

Pal, K., Pal, S. K., 2011. Effect of Pulse Parameters on Weld Quality in Pulsed Gas Metal Arc Welding: A Review. Journal of Materials Engineering and Performance, Volume 20(6), pp. 918–931

Palani, P., Murugan, N., 2006. Selection of Parameters of Pulsed Current Gas Metal Arc Welding. Journal of Materials Processing Technology, Volume 172(1), pp. 1–10

Purnama, D., Winarto, W., Sofyan, N., Prihastomo, A., Ito, K., 2020. Microstructure and Mechanical Properties of Ah-36 Steel Weldment Welded Using Magnesium Modified E6013 Electrode. International Journal of Technology, Volume 11(1), pp. 48–59

Tseng, K.H., Hsu, C.Y., 2011. Performance of Activated TIG Process in Austenitic Stainless Steel Welds. Journal of Materials Processing Technology, Volume 211(3), pp. 503–512

Widyianto, A., Baskoro, A.S., Kiswanto, G., 2020. Effect of Pulse Currents on Weld Geometry and Angular Distortion in Pulsed GTAW of 304 Stainless Steel Butt Joint. International Journal of Automotive and Mechanical Engineering, Volume 17(1), pp. 7687–7694

Xu, J., Chen, J., Duan, Y., Yu, C., Chen, J., Lu, H., 2017. Comparison of Residual Stress Induced by TIG and LBW in Girth Weld of AISI 304 Stainless Steel Pipes. Journal of Materials Processing Technology, Volume 248, pp. 178–184