Caustic Stress Corrosion of Nickel Base and Iron-Nickel Base Corrosion Alloys

In the caustic environment of NaOH aqueous solution, Ni-Cr alloy and Ni-Fe-Cr alloy have good stress corrosion resistance. Under a given medium, the stress corrosion behavior of the alloy is affected by the content of Cr and Ni in the alloy. Heat treatment conditions are constrained. The test results in Figures 2-49 and 2-50 show that under the service conditions of pressurized water containing caustic soda, the stress corrosion resistance of stainless steel and nickel-based corrosion-resistant alloys is affected not only by the Ni content but also by the Cr in the alloy. The effect of the content is that in the austenitic stainless steel, the stress corrosion resistance of the Cr 25%-containing 310 is higher than that of the Cr-containing 18% austenite stainless steel. The difference is up to 2 orders of magnitude, 25% Cr is a In the nickel-base and iron-nickel-based corrosion-resistant alloys, the stress corrosion-resistance of alloys containing 30 qo Cr increases dramatically, and 300 Cr also becomes a catastrophic point. In short, in austenitic stainless steels and in nickel-base and iron-nickel-based alloys. In corrosion resistant alloys, alloys containing more than 25 010 Cr ensure the stress corrosion resistance of their caustic-resistant media. Whether the medium is ventilated or not only affects the absolute value of stress corrosion resistance, and the effect of Ni and Cr does not change.