The metastable pitting corrosion of 2205 duplex stainless steel under bending deformation

The effects of tensile and compressive deformation introduced by the bending deformation on metastable pitting corrosion of 2205 duplex stainless steel were studied by microstructure characterization and electrochemical tests. The results demonstrated that both tensile and compressive deformation resulted in severer plastic strains in ferrite than that in austenite, caused the inclusions debonding from matrix and the surrounding micro-cracks. The decrease in critical pitting temperature and pitting potential provides the degradation evidence of the deformed steel. Compared with the as-received samples, bending deformation promoted the initiation frequency and growth rate of metastable pits. It also revealed that higher metastable pitting initiation rate and pit growth under compressive deformation than tensile deformation. The preferential initiation sites and transients' behavior of metastable pitting were discussed herein. (C) 2020 Elsevier B.V. All rights reserved.