A Systematic Application of the Potentiostatic Scratch Method in Order to Determine the Pitting Corrosion Resistance of Traditional and Advanced Stainless Alloys
The potentiostatic scratch method has been systematically applied to rank the pitting corrosion (PC) resistance of commercial and laboratory austenitic, superaustenitic, and extra low interstitial ferritic stainless steels in chloride solutions simulating the aggressivity of the human body and seawater. This technique was generally shown to be reliable and reproducible when the pits were associated with the scratched regions. In this case, it was possible to confirm that deformation‐induced martensitic transformation does not have any effect upon the PC behavior of metastable austenitic stainless steels. On the contrary, when the pits are formed on the unscratched regions, the scratch technique does not provide an accurate way of determining the pitting potential. In this latter case, the nonmetallic inclusions seem to be more critical sites for pitting development than the bare scratched regions.