What is Monel 400, and what can it be used for?

Monel is a group of nickel alloys that have better corrosion resistance than pure nickel, including to seawater. Therefore, these alloys are suitable for use in the offshore and maritime industries.

Monel alloys are usually composed of nickel and copper, with small amounts of iron, carbon, manganese, and silicon.

In this article, we will discuss Monel 400, a binary nickel-copper alloy (two main components). The alloy consists of approximately 63-70 percent nickel and 28-34 percent copper.

Applications for Monel 400

Monel 400, also known as Alloy 400, UNS N04400 or Werkstoff 2.4360/2.4361, is a nickel-copper alloy with very high corrosion resistance.

The alloy has particularly good resistance in reducing environments, but can also withstand some oxidizing conditions. Monel 400 is among the few materials that can be used in contact with fluorine, hydrofluoric acid and hydrogen fluoride, under controlled conditions. In addition, it resists sulfuric acid and hydrochloric acid in reducing environments, as well as neutral and alkaline salts.

Because of these properties, Monel 400 is often used in the offshore and marine industries, shipbuilding, desalination plants, and the chemical industry. Monel 400 is also a popular choice for process piping that will transport pure oxygen (both liquid and gas).

The alloy has a low corrosion rate in flowing seawater and brackish water, but can be subject to pitting and crevice corrosion under stagnant conditions.

At the same time, the alloy provides good mechanical properties and resistance to stress corrosion cracking, which makes Monel 400 an attractive choice for both industrial and maritime use.

Equipment and Components Monel 400 is Often Used for

• Valves and pumps
• Shafts for pumps and propellers
• Maritime parties
• Electrical and electronic components
• Process equipment in the chemical industry
• Gasoline and fresh water tanks
• Refinery equipment
• Process vessels and pipelines
• Heat exchangers

Approved according to ASME and included in NACE

Monel 400 is included in NACE MR01-75 (ISO 15156), which is a standard for materials used in oil and gas environments.

The alloy is supplied in pipe, plate, strip, bar, wire and other standard forms. Monel 400 is also approved for pressure vessels under the ASME Boiler and Pressure Vessel Code .

Welding Monel 400

Monel 400 is easily welded, whether to the same alloy or to other metals. Welding can be performed using common methods such as TIG, MIG/MAG , plasma or MMA (manual metal arc welding).

The type of welding method used depends on the material to be welded and the environment in which the welding will be carried out.

Monel 400 can also be hot formed, cold formed and machined.

Please contact us if you have any questions regarding Monel 400.

Sources: Sandmeyer Steel Company, Special Metals Corporation, PubMed Central