Effect of Heat Input on Microstructural and Mechanical Properties of AISI 304 Welded Joint Via MIG Welding

Document Type : Original Article


University Polytechnic, Jamia Millia Islamia,New Delhi, India


In this experimental work, AISI 304 was welded via metal inert gas (MIG) welding process with Argon (Ar) as shielding gas. In the present study, AISI 304 was subjected to different heat input using a standard 308L electrode. Weld quality i.e. ultimate tensile strength, toughness, microhardness, and microstructure of AISI 304 were examined. Microstructures of welded joints were studied using scanning electron microscopy (SEM), linked to the SEM was used to determine the chemical composition of phases formed at the joint interface and from the result, it was revealed that at low heat input ultimate tensile strength is higher than those at medium and low heat input. From the result, it was also observed that grain coarsening extent in the HAZ increases with an increase in the heat input. It was also found that the fractures of toughness samples were brittle in nature which shows the low ductility and brittle fracture. Weld zone microstructure exhibited skeletal δ-ferrite in austenite matrix with various ferrite contents. Microhardness of weld bead was found to decrease with increases in the heat input. It was also observed that at medium heat input there was an improvement in tensile strength, elongation, and hardness due to finer grain structure and smaller inter-dendritic spacing.


1.     Handbook, W., "Fundamentals of welding", American Welding Society, Miami,  Vol. 1, (1976), 9-11.
2.     Rizvi, S.A., "Advanced welding technology, SK Kataria and Sons. (2010)
3.     Takuda, H., Mori, K., Masachika, T., Yamazaki, E. and Watanabe, Y., "Finite element analysis of the formability of an austenitic stainless steel sheet in warm deep drawing", Journal of Materials Processing Technology,  Vol. 143, (2003), 242-248. DOI.10.1016/S0924-0136(03)00348-0
4.     Viswanathan, R. and Bakker, W., "Materials for ultrasupercritical coal power plants—boiler materials: Part 1", Journal of Materials Engineering and Performance,  Vol. 10, No. 1, (2001), 81-95.https://doi.org/10.1361/105994901770345394
5.     Lakshminarayanan, A., Shanmugam, K. and Balasubramanian, V., "Effect of autogenous arc welding processes on tensile and impact properties of ferritic stainless steel joints", Journal of Iron and Steel Research International,  Vol. 16, No. 1, (2009), 62-68.https://doi.org/10.1016/S1006-706X(09)60012-1
6.     Abioye, T., "The effect of heat input on the mechanical and corrosion properties of aisi 304 electric arc weldments", Current Journal of Applied Science and Technology,  Vol. 20, No. 5, (2017), 1-10. DOI: 10.9734/BJAST/2017/32846
7.     Saha, S., Mukherjee, M. and Pal, T.K., "Microstructure, texture, and mechanical property analysis of gas metal arc welded aisi 304 austenitic stainless steel", Journal of Materials Engineering and Performance,  Vol. 24, No. 3, (2015), 1125-1139. DOI:10.1007/s11665-014-1374-0
8.     Hsieh, R.-I., Pan, Y.-T. and Liou, H.-Y., "The study of minor elements and shielding gas on penetration in tig welding of type 304 stainless steel", Journal of Materials Engineering and Performance,  Vol. 8, No. 1, (1999), 68-74.DOI:10.1361/105994999770347188
9.     Saluja, R. And Moeed, K., "Effects of process parameters and alloying elements on micro-hardness distribution in pulse arc 304l austenitic stainless steel welded plates", Journal of Engineering Science and Technology,  Vol. 14, No. 4, (2019), 2271-2291.
10.   Kurt, H.İ. and Samur, R., "Study on microstructure, tensile test and hardness 304 stainless steel jointed by tig welding", International Journal of Science and Technology,  Vol. 2, No. 2, (2013), 163-168.
11.   Moradi, M., Salimi, N., Ghoreishi, M., Abdollahi, H., Shamsborhan, M., Frostevarg, J., Ilar, T. and Kaplan, A.F., "Parameter dependencies in laser hybrid arc welding by design of experiments and by a mass balance", Journal of Laser Applications,  Vol. 26, No. 2, (2014), 022004. http://dx.doi.org/10.2351/1.4866675
12.   Moradi, M., Ghoreishi, M. and Rahmani, A., "Numerical and experimental study of geometrical dimensions on laser-tig hybrid welding of stainless steel 1.4418", Journal of Modern Processes in Manufacturing and Production,  Vol. 5, No. 2, (2016), 21-31.
13.   Khorram, A., Jafari, A. and Moradi, M., "Effect of linear heat input on the morphology and mechanical properties of ti-6al-4v welded using a com 2 laser", Lasers in Engineering (Old City Publishing),  Vol. 40,  (2018).
14.   Çaligülü, U., Dikbaş, H. And Taşkin, M., "Microstructural characteristic of dissimilar welded components (aisi 430 ferritic-aisi 304 austenitic stainless steels) by CO2 laser beam welding (lbw)", Gazi University Journal of Science,  Vol. 25, No. 1, (2012), 35-51.
15.   Tewari, S. and RIZVI, S., "Effect of different welding parameters on the mechanical and microstructural properties of stainless steel 304h welded joints", International Journal of Engineering, Transactions A: Basics, Vol. 30, No. 10, (2017), 1592-1598. doi: 10.5829/ije.2017.30.10a.21
16.   Gupta, S.K., Raja, A.R., Vashista, M. and Yusufzai, M.Z.K., "Effect of heat input on microstructure and mechanical properties in gas metal arc welding of ferritic stainless steel", Materials Research Express,  Vol. 6, No. 3, (2018), 036516.
17.   Paulraj, P. and Garg, R., "Effect of welding parameters on mechanical properties of gtaw of uns s31803 and uns s32750 weldments", Manufacturing Review,  Vol. 2, No. 29, (2015), DOI:10.1051/mfreview/2015032.
18.   Gharibshahiyan, E., Raouf, A.H., Parvin, N. and Rahimian, M., "The effect of microstructure on hardness and toughness of low carbon welded steel using inert gas welding", Materials and Design,  Vol. 32, No. 4, (2011), 2042-2048.https://doi.org/10.1016/j.matdes.2010.11.056
19.   Hsieh, C.-C., Lin, D.-Y., Chen, M.-C. and Wu, W., "Microstructure, recrystallization, and mechanical property evolutions in the heat-affected and fusion zones of the dissimilar stainless steels", Materials Transactions,  Vol. 48, No. 11, (2007), 2898-2902. doi:10.2320/matertrans.MRA2007162
20.   Ogundimu, E., Akinlabi, E. and Erinosho, M., "Effect of welding current on mechanical properties and microstructure of tig welding of type-304 austenite stainless steel", in Journal of Physics: Conference Series, IOP Publishing. Vol. 1378, No. 3, 032022.
21.   Moi, S.C., Pal, P.K., Bandyopadhyay, A. and Rudrapati, R., "Effect of heat input on the mechanical and metallurgical characteristics of tig welded joints", Journal of Mechanical Engineering Vol. 16, No. 2, (2019), 29-40.
22.   Li, J.-Y., Sugiyama, S. and Yanagimoto, J., "Microstructural evolution and flow stress of semi-solid type 304 stainless steel", Journal of Materials Processing Technology,  Vol. 161, No. 3, (2005), 396-406. DOI: 10.1016/j.jmatprotec.2004.07.063
23.   Unnikrishnan, R., Idury, K.S., Ismail, T., Bhadauria, A., Shekhawat, S., Khatirkar, R.K. and Sapate, S.G., "Effect of heat input on the microstructure, residual stresses and corrosion resistance of 304l austenitic stainless steel weldments", Materials Characterization,  Vol. 93, (2014), 10-23.
24.   Taiwade, R.V., Patil, A.P., Ghugal, R.D., Patre, S.J. and Dayal, R.K., "Effect of welding passes on heat affected zone and tensile properties of aisi 304 stainless steel and chrome-manganese austenitic stainless steel", ISIJ International,  Vol. 53, No. 1, (2013), 102-109. http://dx.doi.org/10.1016/j.matchar.2014.03.013
25.   Kumar, S. and Shahi, A., "Effect of heat input on the microstructure and mechanical properties of gas tungsten arc welded aisi 304 stainless steel joints", Materials and Design,  Vol. 32, No. 6, (2011), 3617-3623. DOI: 10.1016/j.matdes.2011.02.017
26.   Mosa, E., Morsy, M. and Atlam, A., "Effect of heat input and shielding gas on microstructure and mechanical properties of austenitic stainless steel 304l", International Research Journal of Engineering and Technology,  Vol. 4, No. 12, (2017), 370-377.
27.   Tabish, T., Abbas, T., Farhan, M., Atiq, S. and Butt, T., "Effect of heat input on microstructure and mechanical properties of the tig welded joints of aisi 304 stainless steel", International Journal of Scientific and Engineering Research,  Vol. 5, No. 7, (2014), 1532-1541.