Effects of mechanical stress on the corrosion behaviour of an austenitic stainless steel welded joint – Stress corrosion cracking susceptibility

The susceptibility to stress corrosion cracking of 316 L welds was investigated in a moderately aggressive electrolyte, performing long-term U-Bend tests at the OCP. Micro-cracks were observed in the heat-affected zone (HAZ), initiating at pits. This was due to the increased susceptibility to pit initiation under tensile stress of the HAZ, which was also the most deformed zone in terms of plastic deformation. Accelerated U-Bend tests, carried out applying a fixed current density, made it possible to reproduce in a short time the main damage modes observed after 9 months at OCP, but led to the growth of large cavities. • Assessment of the susceptibility of 316 L welds to stress corrosion cracking (SCC). • Long-term U-Bend tests performed at OCP in a moderately aggressive electrolyte. • Micro-cracks observed mainly in the heat-affected zone and initiated at pits. • The tensile stress promoted pit initiation in the weld root, mainly in the HAZ. • Accelerated tests reproduced in a short time the main damage modes observed at OCP.