Comparative Analysis of Electrode Performance and Thermal Treatments in SMAW of Dissimilar Metal Joints

AISI 316 stainless steel and ASTM A516 alloy steel weldment characteristics investigated according to filler materials and post weld heat treatment performance.The welding was performed using shielded metal arc welding (SMAW) with two types of filler metals, E7018 and E310, and PWHT was carried out at three temperatures: 600, 630, and 650.Welded joints' mechanical performance encompassed tensile and bending tests, and micro-hardness measurements, in addition to microstructural and fractographical examination employed for this purpose.Results evidenced that tensile strength and elongation of welded steel using E7018 electrode were 518 MPa and 28.1%, respectively, which showed relatively high strength.The results show steel welded with E310 electrode had higher mechanical properties, with the best balance between strength and ductility.In addition, post welding heat treatment improving mechanical properties by minimizing residual stress and refining grain structure.E7018 welded joints failure load increased to 86 KN after PWHT and the ultimate tensile strength increased to 525 MPa, further, microstructure analysis of optical microscope and scanning electron microscope shows PWHT has good effect on ductility improvement and hardness reduction.New microstructures with finer grain size and increased ferrite phase observed, which enhanced tensile and bend strength.