Monel 400 material 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 acid and ammonia systems.

Chemical Processing Equipment – in fluorine, hydrofluoric acid, hydrogen fluoride, hydrochloric acid, sulfuric acid, neutral and alkaline salt solutions, caustic alkalies, non-oxidizing halides and dry chlorine service.

Marine Components – shipbuilding, valves, pumps, shafts and in sea and brackish water

Oil and Gas Production – splash-zones for offshore structures and sour gas applications

Ore Processing – uranium refining and separation in the production of nuclear fuels

Petroleum Refining – alkylation units, crude petroleum stills, piping and storage tanks

Power Generation – feed-water heaters and steam generators

Water Treatment – brine heaters and evaporators in seawater desalination plants

Alloy 400 is a very versatile corrosion resistant material. It exhibits resistance to corrosion in many reducing environments, and it is generally more resistant than higher copper alloys to oxidizing media. Alloy 400 is one of the few materials that will withstand contact with fluorine, hydrofluoric acid, hydrogen fluoride or their derivatives. The alloy has been found to offer exceptional resistance to hydrofluoric acid in all concentrations up to the boiling point. Alloy 400 also resists sulfuric and hydrochloric acids under reducing conditions. It has outstanding resistance to neutral and alkaline salts and has been utilized for many years as a material of construction for salt plants.

Alloy 400 is one of the most widely used materials for marine applications, shipbuilding and seawater desalination plants. The alloy exhibits very low rates of corrosion in flowing sea or brackish water. However, under stagnant conditions, the alloy can encounter crevice and pitting corrosion. Alloy 400 resists stress corrosion cracking and pitting in most fresh and industrial water applications.

seamless pipe B165 welded pipe B725 seamless tube B163

Nickel (plus Cobalt) .....................................................63.0 min.

Carbon..........................................................................0.3 max.

Manganese ...................................................................2.0 max.

Iron................................................................................2.5 max.

Sulfur ........................................................................0.024 max.

Silicon ...........................................................................0.5 max.

Copper ......................................................................28.0 - 34.0