The alloy has excellent corrosion resistance in fluorine gas, hydrochloric acid, sulfuric acid, hydrofluoric acid and their derivatives. Acid medium: M400 is corrosion-resistant in sulfuric acid with a concentration of less than 85%. M400 is one of the few important materials that can withstand hydrofluoric acid. Water corrosion: M400 alloy in most water corrosion conditions, not only excellent corrosion resistance, but also pitting corrosion, stress corrosion, etc. are rarely found, corrosion rate is less than 0.025mm/a high-temperature corrosion: M400 in the air continuous work of the highest temperature generally in 600 ℃, in the High-temperature steam, Corrosion rate is less than 0.026mm/a. Ammonia: Because Monel 400 alloy nickel content is high, therefore can resist 585 ℃ below anhydrous ammonia and the amination condition corrosion.
Generally, the corrosion resistance of the Monel K500 is the same as that of the Monel 400 alloy, so the corrosion resistance data of the Monel 400 can be applied to Monel K500 alloy completely. Because of the low corrosion rate of the alloy in the flowing seawater and the high strength of the alloy, the alloy is especially suitable for the manufacture of the centrifugal pump shaft which is resistant to seawater corrosion.