Comparative Analysis of GTAW, LBW, and FSW Welding Techniques for Dissimilar Weld Joints of SS 304 and Mild Steel (E 250A) Plates

Abstract

Dissimilar metal welding is a crucial process in industries requiring the joining of materials with different properties to optimize performance and cost. This study focuses on a comparative analysis of three advanced welding techniques: Gas Tungsten Arc Welding (GTAW), Friction Stir Welding (FSW), and Laser Beam Welding (LBW) for joining stainless steel (SS 304) and mild steel (E 250A) plates. These materials are commonly used in structural and industrial applications due to their mechanical strength, corrosion resistance, and cost-effectiveness. The analysis evaluates the weldability, mechanical properties, and microstructural characteristics of joints produced by each technique. Key performance metrics such as tensile strength, hardness, microstructural behavior, and residual stress distribution are compared. The study aims to identify the most suitable welding technique for dissimilar joints of SS 304 and mild steel, balancing mechanical performance, process efficiency, and economic feasibility. The results will provide valuable insights for industries involved in manufacturing, automotive, and construction, guiding the selection of optimal welding techniques for hybrid material assemblies.

Introduction

The text reviews dissimilar metal welding (DMW), focusing on joining SS 304 stainless steel with mild steel, a combination widely used in industries such as power generation, petrochemical plants, and automotive manufacturing. DMW is more complex than similar-metal welding because it requires balancing the differing thermal, mechanical, and metallurgical properties of two base metals and the filler material. Weld quality depends on bead geometry, mechanical properties, microstructure, corrosion resistance, and fatigue behavior, all of which are strongly influenced by welding process parameters.

The study aims to fabricate and compare SS 304–mild steel joints using three welding techniques—Gas Tungsten Arc Welding (GTAW), Laser Beam Welding (LBW), and Friction Stir Welding (FSW)—under optimized conditions. Welds are evaluated through non-destructive testing, microstructural analysis, hardness measurements, mechanical performance, and statistical analysis (ANOVA) to identify the most effective process for defect-free, high-strength joints.

The literature review highlights the strengths and limitations of each process. GTAW offers excellent control and flexibility through filler metal selection, but suffers from high heat input, wide heat-affected zones (HAZ), residual stresses, and carbon migration. LBW provides very low heat input, narrow HAZ, minimal distortion, and high strength, but is costly, requires precise joint fit-up, and may produce brittle martensitic structures. FSW, as a solid-state process, avoids melting-related defects, minimizes carbon migration, and produces refined microstructures with superior fatigue performance, though it requires specialized tools, high forces, and careful process control.

The key research gap identified is the lack of a comprehensive, direct comparison of GTAW, LBW, and FSW for SS 304–IS 2062 mild steel joints under uniform conditions. The study seeks to determine which process offers the best balance of mechanical performance, microstructural integrity, and economic feasibility for industrial application.

Conclusion

The following key conclusions can be drawn from the present study: 1) The dissimilar welding of SS 304 and MS is feasible using both fusion and solid-state processes with proper parameter optimization. 2) FSW provides the most homogeneous microstructure, minimal residual stress, and superior mechanical properties among the three techniques. 3) LBW serves as a promising intermediate option, combining precision and good joint strength with minimal distortion. 4) GTAW remains an economical and accessible process but requires post-weld heat treatment to improve strength and reduce HAZ width. 5) The correlation between grain refinement and mechanical enhancement highlights the critical role of thermal cycles and material flow behavior in dissimilar welds.

References

[1] Ahmed, T., Ali, S., & Khan, M. A. (2019). Comparative study on TIG and laser beam welding of SS304 to mild steel. Materials & Design, 180, 107943. [2] Babu, S., & Balasubramanian, V. (2017). Optimization of friction stir welding parameters for stainless-steel–mild-steel joints. Journal of Manufacturing Processes, 28, 440–451. [3] Bhole, S. D., Nemade, K. R., & Pati, S. (2012). Effect of nickel filler on SS–MS welds. Welding Journal, 91(3), 77S–83S. [4] El-Batahgy, A. M., Ahmed, E., & Nassar, H. (2017). Effect of laser parameters on microstructure and hardness of dissimilar joints. Optics & Laser Technology, 92, 42–51. [5] Kou, S. (2003). Welding Metallurgy (2nd ed.). Wiley-Interscience. Kumar, R., Reddy, N. R., & Rao, P. (2020). Parametric study on TIG welding of austenitic stainless steels. Procedia Manufacturing, 48, 545–552. [6] Mishra, R. S., & Ma, Z. Y. (2005). Friction stir welding and processing. Materials Science and Engineering: R: Reports, 50(1–2), 1–78. [7] Ramesh, K., Patel, A., & Gupta, S. (2020). Effect of PWHT on dissimilar stainless-mild steel joints. Journal of Materials Engineering and Performance, 29(5), 3167–3175. [8] Rao, G., & Srinivasan, A. (2016). Mechanical characterization of TIG welded SS304–MS joints. International Journal of Advanced Manufacturing Technology, 87(9–12), 3371–3380. [9] Siva Prasad, R., Murugan, N., & Ravi, K. (2018). Laser beam welding of austenitic stainless steel to mild steel. Optics and Laser Engineering, 100, 95–103. [10] Soundararajan, V., Kumar, S., & Manoharan, P. (2021). Microstructural analysis of friction-stir-welded dissimilar joints. Journal of Materials Processing Technology, 293, 117056. [11] Gupta, R., Patil, S., & Rao, P. (2021). Microstructural evolution and mechanical behavior of friction stir welded dissimilar stainless–carbon steel joints. Journal of Materials Processing Technology, 298, 117281. [12] Kumar, S., Yadav, A., & Singh, K. (2021). Comparative assessment of TIG and laser welding on stainless steel–mild steel joints. Materials Today: Proceedings, 44, 1306–1313. [13] Patel, V., & Singh, P. (2023). Effect of process parameters on microstructural and mechanical properties of friction stir welded dissimilar metals. Journal of Manufacturing Processes, 92, 456–467. [14] K. Mehta, Effect of welding parameters on intermetallic phase formation in dissimilar welds. [15] H. Clemens et al., Impact of double-pass laser welding on microstructure and mechanical properties. [16] L. Zanotto et al., Electrochemical analysis of dissimilar stainless steel welds: A corrosion perspective. [17] P. Kumar, Laser Beam Welding (LBW): Principles, applications, and trends in modern manufacturing, 2021. [18] G. R. Mohammed et al., Influence of heat input on weld quality of dissimilar stainless steels. [19] Tunde Isaac Ogendengbe: Investigation of mechanical properties and parametric optimization of the dissimilar GTAW of AISI 304 stainless steel and low carbon steel, October 2018 [20] Fabio Giudice, Sevcereino Missori: A Review on Fusion Welding of Dissimilar Ferritic/Austenitic Steels: Processing and Weld Zone Metallurgy, 4th May 2024.

Copyright

Copyright © 2026 Smt. Ms. K. Tejaswi, Rachakonda Benarji. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.