Corrosion Resistance of Co-containing Maraging Stainless Steel

Corrosion resistance behavior of Co-containing maraging stainless steels was investigated. Neutral salt spray and polarization test showed that maraging stainless steel with high Co content showed poor corrosion behavior. Microstructure observation proved that segregation of Cr in the matrix deteriorated its corrosion resistance. The surface morphology of the aged maraging stainless steel with high Co content indicated that during passivation process, the newly formed passive film with sinusoidal distribution readily destroyed by the corrosive medium, hence, causing poor corrosion resistance. Moreover, through first-principles calculation it was proved that Co increased Fe–Fe ferromagnetic interaction which facilitated the formation Cr-rich clusters.