Corrosion and cavitation-corrosion resistance of 95Kh18 steel

1. In the active area of the anodic polarization curve the corrosion of 95Kh18 steel under static and cavitation conditions occurs with active solution of the martensite. In the passive area under static conditions strong passivation of the steel is observed and in cavitation a less resistant passive condition indicating dynamic equilibrium of the activation and passivation processes. 2. The phase γ→α-transformation occurring in cavitation in 95Kh18 steel reduces some-what its corrosion resistance but significantly increases the total cavitation-corrosion resistance. 3. The degree and character of the cavitation-corrosion failure of 95Kh18 steel hardened from different temperatures are determined by the degree of localization of plastic deformation. Coarse slip in the steel with stable austenite leads to greater erosion of the specimen and the formation of a more developed relief than for the steel with metastable austenite subjected to more uniform plastic deformation. 4. The corrosion resistance of 95Kh18 steel in cavitation under conditions of the experiment conducted (5 M H3PO4 solution and a passivating polarization potential of 0.5 V) is determined primarily by the capacity for passivation. In this case the mechanicochemical effect obviously plays a lesser role.