Role of residual stresses induced by U-bending on stress corrosion cracking susceptibility of F304 stainless steel

The present study was performed on the stress corrosion cracking of F304 stainless steel immersed in boiling magnesium chloride solution. Earlier, the Stress Corrosion Cracking behaviour (SCC) of induced residual stress on F304 stainless steel has not been stated widely in the literature. Researchers have used different techniques to understand SCC behaviours. However, the ASTM G36 method is extensively used for SCC testing under U-bend. In this work, the residual stresses were induced by U-Bend, and then the SCC behaviour of F304 Stainless steel was observed in a chloride environment of boiling MgCl2.6 H2O. The combined effect of residual stress and corrosion environment were applied with the help of the U-bend technique. Further, the upper surface of the U-bend was focused on as an investigation area. XRD Stress Analyser measured the residual stresses. The selected spot of stress analysis was the upper surface, end of U-bend curvature, and lower end. Moreover, the heat treatment process was performed to reduce the effect of machining. The results reveal the SCC susceptibility, the magnitude of residual stresses, and elements composition around the cracked surfaces. Similarly, the study also highlights SCC behaviour under the influence of boiling magnesium chloride.