Relating General and Phase Specific Corrosion in a Super Duplex Stainless Steel with Phase Specific Microstructure Evolution

Abstract

Controlled near plane strain deformation was imposed on a super duplex stainless steel. Subsequent characterization involved extensive microtexture measurements, and measurements of general corrosion and corrosion behavior (and nature of the passive film) of the individual phases. The general corrosion was controlled by the corrosion performance of the austenite phase, and corresponding microtextural developments. Corrosion resistance in the austenite phase, as well as the general corrosion, improved until a true strain of 0.26 and then dropped. Enhanced corrosion resistance coincided with slip band formation and generation of low-angle boundaries. Beyond a strain of 0.26, shear bands and associated lattice curvatures plus high-angle boundaries led to a clear degradation in the corrosion behavior.