Effect of surface grinding on chloride induced SCC of 304L

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 658; pp. 50 - 59
• Main Authors: Zhou, Nian, Pettersson, Rachel, Lin Peng, Ru, Schönning, Mikael
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 21.03.2016
• Subjects: Austenitic stainless steel 304L; Austenitic stainless steels; Chlorides; Cracks; Deviation; Grinding; Grounds; Residual stress; Steel Forming and Surface Engineering; Stress corrosion cracking; Stålformning och ytteknik; Surface grinding; Austenitic stainless steel 304L; Stress corrosion cracking; Grinding; Residual stress
• ISSN: 0921-5093; 1873-4936; 1873-4936
• DOI: 10.1016/j.msea.2016.01.078

The effect of surface grinding on the stress corrosion cracking (SCC) behavior of 304L austenitic stainless steel in boiling magnesium chloride has been investigated. SCC tests were conducted both without external loading and with varied levels of four-point bend loading for as-delivered material and for specimens which had been ground parallel or perpendicular to the loading direction. Residual stresses due to the grinding operation were measured using the X-ray diffraction technique. In addition, surface stress measurements under applied load were performed before exposure to evaluate the deviation between actual applied loading and calculated values according to ASTM G39. Micro-cracks initiated by a high level of tensile residual stress in the surface layer were observed for all the ground specimens but not those in the as-delivered condition. Grinding along the loading direction increased the susceptibility to chloride induced SCC; while grinding perpendicular to the loading direction improved SCC resistance. Surface tensile residual stresses were largely relieved after the initiation of cracks.