Pitting and Electrochemical corrosion behaviour of 316L austenitic stainless steel subjected to warm deformation

摘要

Electrochemical and pitting corrosion behaviour of undeformed,deformed and annealed after deformation of the 316L stainless steel have been investigated by using electrochemical corrosion test methods.The results indicated that pitting occurred in undeformed sample,while the small pits were observed in deformed and annealed sample after immersion test in 10% FeCl3 solution.Microstructural characterization of undeformed,deformed and corroded sample were analysed by optical microscope and SEM.A Potentiodynamic polarization test in PWR environment was performed to evaluate the electrochemical behaviour of samples after deformation and heat treatment.The results showed that the corrosion rate decrease after heat treatment of deformed samples because heat treatment after deformation form a more protective oxide film on the surface of samples as compared to oxide film form on the surface of undeformed sample.The E_(corr)shifted toward the passive direction with increase in annealing temperature after deformation.The shift of E_(corr)towards the passive direction indicates a more protective passive film formed on the surface of heat treated samples after deformation.