PSI - Issue 68

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2025) 000–000

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ScienceDirect

Procedia Structural Integrity 68 (2025) 1024–1030

European Conference on Fracture 2024 Influence of GTAW and SMAW Techniques on the Mechanical Behavior of S275JR Low Carbon Manganese Steel Welded Joints Ibrahim R. Awad a , Hamed A. Abdel-Aleem b , Ahmed Gaafer c , Mahmoud Khedr c, d, * a Department of Mechanical Engineering, Lyle School of Engineering, Southern Methodist University, 3101 Dyer Street, Dallas, TX 75205, USA b Central Metallurgical Research and Development Institute (CMRDI), Helwan 11722, Egypt c Kerttu Saalasti Institute, Future Manufacturing Technologies (FMT), University of Oulu, Nivala FI-85500, Finland d Mechanical Engineering Department, Faculty of Engineering at Shoubra, Benha University, Cairo 11629, Egypt Abstract In the present study, the weldability of S275JR low carbon manganese steel using gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) at respective heat inputs of 321.18 and 304.63 J/mm, was investigated. The welded joints' microstructural evolution and mechanical properties were assessed through optical microscopy, hardness, and tensile testing. The weld metal microstructure comprises various structures such as ferrite and pearlite. The hardness distribution revealed higher values in the heat-affected zone (HAZ) of GTAW joints (270 HV), compared to SMAW joints (257 HV). Results show that SMAW joints exhibited higher ultimate tensile strength (532 MPa) and joint efficiency (98.8%) compared to GTAW joints, which achieved an ultimate tensile strength 502 MPa and a joint efficiency of 93.2%. Both joints fractured at the HAZ during tensile testing, indicating its critical influence on the welded joint performance. It is recommended that various ranges of heat inputs be employed during welding the S275JR via GTAW and SMAW techniques to control and optimize welding parameters. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers a b c d © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers

Keywords: Low carbon manganese steel; Gas tungsten arc welding; Shielded metal arc welding; Microstructure; Hardness; Tensile behavior.

* Corresponding author. Tel.: +358-417913505. E-mail address: Mahmoud.khedr@oulu.fi. 1. Introduction

The welding of low-carbon steel (LCS) is a critical aspect of various industrial applications, and the choice of welding technique can significantly impact the quality and performance of the fabricated joint (Khedr et al., 2023). In

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers 10.1016/j.prostr.2025.06.165