Monel 400 is a nickel-copper alloy (about 67% Ni - 23% Cu) that is resistant to sea water and steam at high temperatures as well as to salt and caustic solutions. Alloy 400 is a solid solution alloy that can only be hardened by cold working. This nickel alloy exhibits characteristics like good corrosion resistance, good weldability and high strength. A low corrosion rate in rapidly flowing brackish or seawater combined with excellent resistance to stress-corrosion cracking in most freshwaters, and its resistance to a variety of corrosive conditions led to its wide use in marine applications and other non-oxidizing chloride solutions. This nickel alloy is particularly resistant to hydrochloric and hydrofluoric acids when they are de-aerated. As would be expected from its high copper content, alloy 400 is rapidly attacked by nitric a cid and ammonia systems. Monel 400 has great mechanical properties at subzero temperatures, can be used in temperatures up to 1000° F, and its melting point is 2370-2460° F. However, alloy 400 is low in strength in the annealed condition so, a variety of tempers may be used to increase the strength.

Features:
* Resistant to seawater and steam at high temperatures
* Excellent resistance to rapidly flowing brackish water or seawater
* Excellent resistance to stress corrosion cracking in most freshwaters
* Particularly resistant to hydrochloric and hydrofluoric acids when they are de-aerated
* Offers some resistance to hydrochloric and sulfuric acids at modest temperatures and concentrations, but is seldom the material of choice for these acids
* Excellent resistance to neutral and alkaline salt
* Resistance to chloride induced stress corrosion cracking
* Good mechanical properties from sub-zero temperatures up to 1020° F
* High resistance to alkalis