What exactly is Monel? Monel Properties, Applications, Grades, and Advantages

ByAshwin Nik
MONEL SHEETS (1)-e4099786

What is Monel?

Monel is a brand name for a class of nickel alloys that are mostly made of nickel and copper, with traces of iron, manganese, carbon, and silicon. Monel alloys, which are stronger than pure nickel, are known for their corrosion resistance in a variety of corrosive environments. In 1901, Robert Crooks Stanley invented the material. The term “Monel” is a registered trademark of “Special Metals Corporation.”

The microstructure of Monel, known as Superalloy, exhibits a face-centered cubic lattice structure. The ASME Boiler and Pressure Vessel Code has approved Monel alloy 400 as a construction material.

What is the purpose of Monel?

Monel is widely used in the marine and chemical processing industries due to its ease of fabrication through hot and cold working, machining, and welding. However, because the material is expensive, it should only be used when cheaper alternatives are unavailable. Monel Sheets piping is typically more than three times the price of carbon steel pipe. Valve and pump shafts; electrical and electronic components; crude petroleum stills, boiler feedwater heaters, marine fixtures and fasteners; gasoline and water tanks; fuel tanks; springs; chemical processing equipment; process vessels and piping; heat exchangers; metal instruments; deaerating heaters; musical instruments; refrigerators; film processing; kitchen sinks; roofing; and eye-glass frames are examples of typical Monel applications. Monel is available in the following forms: pipe, fittings, plate, strip, round bar, strip, tube, sheet, and wire.

Monel Alloy Properties

Monel is a solid-solution, single-phase binary alloy with excellent mechanical properties at subzero temperatures. Monel alloy 400 has a specific gravity of 8.80, a melting temperature range of 1300-1350 °C, and a Poisson ratio of 0.32. The mechanical properties of Monel Alloy 400 at room temperature are shown in the table below.

Grades of Monel

Commercially, there are five types of Monel: ISO 6208 (plate, sheet, and strip), ISO 9725 (forgings), ISO 9723 (bars), ISO 9724 (wire), and DIN 17751 (wire) (pipes and tubes). These are the Monel grades:

  • Monel 400 or alloy 400
  • Monel 401
  • Monel 404
  • Monel 405, and
  • Monel K-500