Influence of cold deformation on pitting corrosion resistance of ISO NBR 5832-1 austenitic stainless steel used for orthopedic implants

The aim of this work is to evaluate the effect of cold deformation on the electronic properties of the passive film on the ISO NBR 5832-1 austenitic stainless steel and its pitting resistance. The tested stainless steel was cold rolled to 50% of its initial thickness and the electronic properties of the passive film on this material were evaluated and compared with that of the same material as received, that is, without cold deformation. The electronic properties of the passive film were characterized by the Mott-Schottky approach and the pitting resistance by polarization curves. The effect of the frequency adopted in the Mott-Schottky analysis was also investigated. The results showed that the deformed material presented higher concentration of dopants, and higher pitting susceptibility compared with the material without deformation.