Monel is an alloy consisting mostly of nickel, with copper, iron and small amounts of other elements. It is strongest when cold- forged into shapes. Monel is corrosion resistant when exposed to sea water and a variety of acids, and is highly tolerant of chloride and sulfide corrosion in high-velocity waters. These properties make it an ideal material for marine applications such as boat propellers and other hardware. However, Monel can be susceptible to pitting and corrosion in certain environments due to the presence of copper and other metals.
Monel, named after company director Ambrose Monell, was first developed in 1901 by the International Nickel Company. It was the first commercially viable alloy which combined the practicality of nickel-copper, with the strength and durability of copper-nickel deoxidized steel. Monel is one of the most important of high- nickel alloys, and has a wide variety of industrial uses. It is ubiquitous as a component of medical and surgical instruments, plumbing, automotive and marine components.
Monels properties include very high mechanical strength, excellent ductility and strength-to-weight ratio, excellent corrosion resistance in oxidizing and reducing acids, high temperature and heat transfer performance, and excellent magnetic properties. Monel is often combined with other metals, such as chromium or manganese, to create superalloys with enhanced strength and hardness, or combinations of corrosion resistance and heat transfer performance, respectively.
Monel alloys are generally weldable, although they may require special welding procedures to ensure that they don’t suffer corrosion or brittle fractures. They are often sold as ready-to-use, pre-shaped components.
Due to its corrosion and temperature resistance, Monel is often used for high-pressure application such as fuel systems, valves, pumps and other equipment in the oil and petrochemical industries. It is also used as a liner in nuclear reactors, as a container for corrosive liquids and gases, and as cladding for submarine reactor vessels. Monel is widely used in many industrial welding processes due to its excellent weldability and forging characteristics. It is often used in the manufacture of jewelry and coins, where the beauty of the material is an essential factor.
In general, Monel is an excellent and versatile alloy with many desirable properties. It is an excellent choice of material for components exposed to seawater, and its strength and corrosion resistance make it suitable for a variety of industrial and marine applications. The alloy is quite expensive, however, and must be used with care due to its susceptibility to pitting and corrosion in some environments.
