Stress Corrosion Cracking of MIG Welded Mild Steel Joints in 3.5% NaCl Solution Under Different Loads

In recent decades, Stress Corrosion Cracking has garnered significant attention as a potential threat to the secure functioning of welded joints. This study investigates stress corrosion cracking in mild steel joints welded using MIG, immersed in a 3.5% NaCl solution under varying loads. Material characterization is performed using a Scanning Electron Microscope and X-ray Diffraction to identify the mechanism of Stress Corrosion Cracking. The results indicate that the initiation of stress corrosion cracking occurs when the load exceeds 250 N in the weldment area. Pitting corrosion contributes to initiation, while selective dissolution plays a role in propagating stress corrosion cracking in mild steel exposed to a 3.5% NaCl solution. The presence of compressive residual stress resulting from machining the gauge section of the specimens suppresses the initiation of cracks. This study provides insights for designing structures that are resistant to SCC in corrosive environments.