Irsel, Gurkan2024-06-122024-06-1220220921-50931873-4936https://doi.org/10.1016/j.msea.2021.142320https://hdl.handle.net/20.500.14551/24306This study reports the investigation of the microstructural and mechanical characterizations of low carbon steel EN10025 S235JR welded with tungsten inert gas welding (TIG or GTAW) and shielded metal arc welding (SMAW). TIG and SMAW microstructures in fusion regions were compared in this context, and their effect on mechanical properties was examined. Experiments were carried out using optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), and mechanical tests, such as tensile, vickers microhardness (HV 0.1), bending, and charpy V-Notch impact tests. In the optical investigation, the base metal's average grain size was measured as 12 +/- 2 mu m. After the TIG and SMAW processes, the average grain size in the HAZ was measured to be 20 +/- 3 mu m and 15 +/- 2 mu m, respectively. Therefore, the mechanical testing results were appropriately correlated with the microstructure analysis. The Vickers microhardness gradually increased from the base metal approaching the heat-affected zone for both welding methods. The highest hardness value was measured in the TIG welding center and was 430 +/- 12 HV. In the SMAW center, the maximum hardness was measured as approximately 230 +/- 5 HV, and the hardness of the base metal was approximately 120 +/- 8 HV. The microhardness in the TIG weld zone significantly increased because of the presence of delta-ferrite (delta-ferrite) and Widmansta center dot tten ferrite (WF) in the microstructure. Mechanical strength analysis showed that the ultimate tensile strength (UTS) of the specimen extracted from the longitudinal direction of the TIG weldment was 652 +/- 10 MPa and that the UTS of the SMAW weldment was 591.40 MPa. The bending test showed that the bending force of the specimen extracted from the longitudinal direction of the TIG weldment was approximately 57% higher than that of the SMAW weldment. Finally, TIG welding has superior properties in terms of strength, higher quality weld, and smooth weld bead appearances.en10.1016/j.msea.2021.142320info:eu-repo/semantics/closedAccessTIG (GTAW)SMAWMicrostructureMechanical PropertiesXRDLow Carbon SteelS235JRBehaviorParametersToughnessArticle830Q1WOS:0007256989000022-s2.0-85119499710Q1