Cold deformation for ameliorating the corrosion resistance of 654SMO in a high-temperature simulated seawater environment: the combined effect of texture and twinning boundaries

The influence of cold rolling deformation on the electrochemical and corrosion behavior of 654SMO super-stainless steel in a high-temperature 3.5% NaCl solution was investigated by potentiodynamic curves, EIS, Mott–Schottky plots and XPS. Results of the electrochemical experiments and surface analyses showed that 654SMO under 33.3% reduction had a maximum deterioration in corrosion properties. After heavy deformation (55.6% and 66.7%), the corrosion resistance of 654SMO improved. XRD and EBSD were performed to illustrate the potential mechanism for the improvement in corrosion resistance. Results showed that there was no strain-induced martensite transformation for steels even under 66.7% deformation, and the dislocation density increased monotonically with an increasing deformation. The cold rolling texture of steels could be described by high Goss, S, brass and copper textures with a low brass-R component. Misorientation analysis and grain boundary characterization obtained from EBSD showed that a large number of mechanical twins formed in steels under 55.6% and 66.7% reductions. A hypothesis was proposed that the combined effect of the strong rolling texture and ∑3 twin boundaries ameliorated the corrosion resistance of 654SMO under large deformations.