Monel 400 Pipe Monel400 is a corrosion-resistant alloy with the largest dosage, the widest range of uses, and excellent comprehensive properties. This alloy has excellent corrosion resistance in hydrofluoric acid and fluorine gas media, and also has excellent corrosion resistance to hot concentrated lye. At the same time, it is also resistant to corrosion of neutral solutions, water, seawater, atmosphere, organic compounds, etc. An important feature of this alloy is that it generally does not produce stress corrosion cracks and has good cutting performance.