Monel 400

Monel 400

One of the popular groups of nickel alloys is Monel, mainly developed with nickel (from 52% to 67%), copper, and with little contents of iron, manganese, carbon and silicon. Monel metal alloys are stronger than pure nickel, and they have greater corrosion resistance to many agents, including rapidly flowing seawater.

Monel 400 alloy is a strong combination of a binary alloy. As nickel and copper are commonly dissolvable in all extents, it is a single-phase alloy. It has a face-centered cubic cross-section structure with a lattice boundary of 3.534 A.

Monel metal alloy 400 or UNS N04400 is a solid solution alloy that can be strengthened only by cold working. It has better strength and toughness over a range of temperatures and has excellent resistance to many corrosive conditions.

Some of the Monel alloy 400 properties are better helpful in freezing environments. Its solidarity and hardness increment with just slight impairment with just ductility or impact resistance. The alloy 400 doesn’t go through bendable-to-fragile progress in any event when cooled to the temperature of fluid hydrogen.

Physical properties of Monel metal 400

Grade Density
Elastic Modulus
Co-eff of Thermal Expansion
Thermal Conductivity
Electrical Resistivity
Monel 400 8.83 190 21-93°C at 23°C at 93°C 850
13.9 21.8 24.1

Corrosion Resistance of Monel 400 

Alloy Monel 400 shows resistance to corrosion by many reducing media. It is likewise commonly more resistant to attacks by oxidizing media than greater copper combinations. This adaptability makes nickel alloy 400 appropriate for service in a range of conditions.

Alloy 400 shows resistance to many of the alkalis, salts, waters (including saline or brackish), food products, substances like organic foods, and atmospheric conditions at normal and higher temperatures.

Monel 400 chemical composition

GRADE   c Ni Fe Cu Si Mg S
Monel 400 MIN 63 28
MAX 0.3 70 2.5 34 0.5 2 0.024

This alloy is not suitable for acids like nitric and nitrous which are highly oxidizing.

Monel 400 alloy is by and large used in marine applications as it shows low corrosion rate in a stream of seawater, latent conditions have been seemed to start crevice and pitting corrosion. Alloy Monel 400 shows resistance to stress corrosion breaking and pitting in commonly new and modern waters.

Hot forming of Monel 400 

Monel metal alloy 400 goes through a hot or cold working cycle. The hot working flow lies between 1700°F to 2150°F and the ideal working temperature is about 2000°F. Completed work can be delivered to a somewhat wide scope of mechanical properties by legitimate control of the measure of hot and cold work and by the selection of appropriate thermal processes.

Monel nickel 400 alloy can be manufactured promptly by hot and cold-working, machining, and welding. By accurate control of the measure of hot or cold work and by the choice of fitting thermal processes, completed fabrications can be delivered to a somewhat wide scope of mechanical properties.


MONEL 400 NO4400 BS EN 2.436 NU-30M МНЖМц 28-2,5-1,5 NW 4400 B 165, B 163,B 725,B 730
NA 13 NiCu30Fe

Heat treatment of Monel 400 

Monel 400 can go through heat treatment cycles, for example, stress leveling, stress relieving, and strengthening relying upon the mechanical properties needed. The process of adjusting the stress is performed at a temperature of 575°F for a time of 3 hours followed by a quick quench. This causes an increment in yield strength without any consequences for different properties.

Relieving the stress can be accomplished at a temperature somewhere in the range of 1000°F and 1050°F for a time of 1 to 2 hours followed by gradual cooling. This will lessen stresses without delivering a recrystallized grain structure and is advised to get the least contortion after metal removal.

The annealing process will completely soothe the work of hardened material and is performed by holding at temperatures ranging in 1600°F and 1800°F for 2 to 10 minutes followed by quick cooling.

Weldability of Monel 400 

Alloy Monel 400 is promptly joined by traditional cycles and techniques. The vast majority of the traditional welding cycles can be used to join Monel alloy 400 to itself or different alloys. The choice of welding material depends upon the materials being joined and the climate to which they will be uncovered to.

Applications of Monel 400 

Monel 400 ASTM alloy is frequently found in chemical processing plant equipment because of its solid resistance from substance corrosion. They are likewise utilized in the manufacturing of airplanes and similar products. Items worked with Monel are heat exchangers, screw machine items, wind equipment, channeling frameworks, fuel and water tanks, kitchen sinks, and roofing material.

  • Chlorinated solvents
  • Crude oil distillation towers
  • Ethyl chloride purification
  • HF alkylation
  • HF reboilers
  • Marine components
  • Marine splash zone sheathing
  • MEA reboilers
  • Oil well recovery pumps
  • Salt production
  • Salt residual compounds
  • Shafting
  • Wire netting for insulation

NOTE: Monel 400 is a registered trademark of  Special Metals Corporation.