Sintered stainless steels (SS) are used widely because of their good combination of mechanical properties and corrosion resistance, raw material savings, dimensional accuracy, and good finishing that makes machining unnecessary. Typical applications are in anti-block system rings, filters, and components for the food processing industry. However, sintered SS have lower corrosion resistance than their wrought counterparts in several aggressive environments. Interconnected porosity affects electrochemical behavior, increases reaction surface, and promotes the formation of cells with local pH variation, which hinders steel passivity. Sintering is the most important process for obtaining good corrosion resistance.