Monel 400 is a nickel-copper alloy 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.

Application of Monel 400:

• Marine engineering
• Chemical and hydrocarbon processing equipment
• Gasoline and freshwater tanks
• Crude petroleum stills
• De-aerating heaters
• Boiler feed water heaters and other heat exchangers
• Valves, pumps, shafts, fittings, and fasteners
• Industrial heat exchangers
• Chlorinated solvents
• Crude oil distillation towers

Monel 400 Chemical Composition, %:

Ni	Cu	Fe	C	Mn	Si
63.0 min	28.0-34.0	2.5 max	0.3 max	2.00 max	0.5 max

Monel 400 ASTM Specification:

Pipe Smls	Pipe Welded	Tube Smls	Sheet / Plate	Bar	Forging	Fitting
B165	B725	B163	B127	B164	B564	B366

Mechanical Properties of Monel 400:

Product form	Condition	Tensile (ksi)	0.2 % Yield (ksi)	Elongation (%)
Rod & Bar	Annealed	75-90	25-50	60-35
Rod & Bar	Cold Drawn Stress Relieved	84-120	55-100	40-22
Plate	Annealed	70-85	28-50	50-35
Sheet	Annealed	70-85	30-45	45-35
Tube & Pipe Smls	Annealed	70-85	25-45	50-35

Monel K-500 is a precipitation-hardenable nickel-copper alloy that combines the excellent corrosion resistance characteristic of Monel 400 with the added advantage of greater strength and hardness. These amplified properties, strength and hardness, are obtained by adding aluminum and titanium to the nickel-copper base and by a thermal processing used to effect precipitation, typically called age hardening or aging. When in the age-hardened condition, Monel K-500 has a greater tendency toward stress-corrosion cracking in some environments than Monel 400. Alloy K-500 has approximately three times the yield strength and double the tensile strength when compared with alloy 400. Plus, it can be further strengthened by cold working prior to precipitation hardening. The strength of this nickel steel alloy is maintained to 1200° F but stays ductile and tough down to temperatures of 400° F. Its melting range is 2400-2460° F.

Monel K-500 Chemical Composition, %:

Ni	Cu	Al	Ti	Fe	Mn	S	C	Si
63 min	27.0-33.0	2.3-3.15	0.35-0.85	2.0 max	1.5 max	0.01 max	0.25 max	0.5 max

Monel K-500 ASTM Specification:

Rod & Bar

AMS 4676

Mechanical Properties of Monel K-500:
Typical Room Temperature Tensile Properties of Annealed Material

Product form	Condition	Tensile (ksi)	0.2 % Yield (ksi)	Elongation (%)
Rod & Bar	Hot-Finished/Aged	140-190	100-150	30-20
Rod & Bar	Hot Finished/Annealed	90-110	40-60	45-25
Rod & Bar	Hot Finished / Annealed/Aged	130-165	85-120	35-20
Rod & Bar	Cold-Drawn/Aged	135-185	95-160	30-15
Rod & Bar	Cold-Drawn/ Annealed/Aged	130-190	85-120	30-20
Plate	ot-Finished/Aged	140-180	100-135	30-20
Sheet	Cold-Rolled/ Annealed	90-105	40-65	45-25