Corrosion resistance improvement of 430 stainless steel via plastic deformation induced uniform substructure

In this work, the influence of cold deformation rate on the microstructure evolution and corrosion behavior of 430 ferritic stainless steel in sodium chloride environment were studied by electron backscatter diffraction analysis, transmission electron microscopy analysis, scanning electron microscopy analysis, electrochemical analysis and X-ray photoelectron spectroscopy. Cold deformation changed the internal structure of the alloy, including grain boundary angle and special grain boundary. The corrosion resistance of the alloy was improved by low-speed deformation at a rate of 0.03 mm & sdot;s-1, which was mainly due to the increase of low angle grain boundaries and low coincidence site lattices, the uniform distribution of dislocations and the formation of a more stable passivation film. Deformation at a high rate of 3 mm & sdot;s-1 reduced the corrosion resistance of the alloy, which was attributed to the uneven distribution of dislocation density inside the alloy.