Monel K500 characteristics

Monel K500 material is a 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.

The Chemical Composition of Monel K500, %

Grade	C≤	Mn≤	Si	S≤	Cu	Fe≤	Ni≥	Al	Ti
Monel K500	0.18	1.5	0.5	0.003	27.0-33.0	2.0	63	2.3-3.15	0.03-0.04

Monel K500 Mechanical Property

Mechanical properties	Tensile, min, ksi[MPa]	Yield, min, ksi[MPa]	Elongation, %(min)
Monel K500	140[965]	100[690]	20

Monel K500 Equivalent Grades

STANDARD	WERKSTOFF NR.	UNS
Monel K500	2.4375	N05500

ASTM Specifications

Form	Metal Type	Bar	Wire	Sheet	Plate	Forging	Weld Wire	Weld Electrode	Din
Standard	UNS N05500	ASTM B865 QQ-N-286	AMS4676	ASTM B865 QQ-N-286	ASTM B865 QQ-N-286	QQ-N-286 Din 17754	FM 60 ERNiCu-7	FM 190 ENiCu-7 Din 17753	2.4375

Hot Forming

Proper temperature during deformation is themost important factor in achievement of hot malleability.Maximum recommended heating temperature for hot-working MONEL alloy K-500 is 2100°F. Metal should becharged into a hot furnace and withdrawn when uniformlyheated. Prolonged soaking at this temperature is harmful. Ifa delay occurs, such that the material should be subjected toprolonged soaking, the temperature should be reduced to orheld at 1900°F until shortly before ready to work, thenbrought to 2100°F. When the piece is uniformly heated, itshould be withdrawn. In the event of long delay, the workshould be removed from the furnace and water-quenched.The hot-working temperature range is 1600° to 2100°F. Heavy work is best done between 1900° and 2100°F; working below 1600°F is not recommended. To producefiner grain in forgings, the final reheat temperature should be2000°F and at least 30% reduction of area should be taken inthe last forging operation

When hot working has been completed, or when it is necessary for MONEL alloy K-500 to cool before furtherhot working, it should not be allowed to cool in air butshould be quenched from a temperature of 1450°F or higher.If the piece is allowed to cool slowly it will self-heat-treat(age-harden) to some extent, and stress will be set up thatmay lead to thermal splitting or tearing during subsequentreheating. In addition, quenched material has better responseto age hardening, since more of the age-hardeningconstituent is retained in solution.The surface of the material will be oxidized to a lesserdegree and will be easier to pickle if it is quenched in watercontaining about 2% by volume of alcohol.

Cold Forming

In the annealed condition, alloy K-500 canbe cold-worked by standard procedures. Although the alloyrequires considerable power to form, it has excellentductility. Its increase in hardness with increasing cold work,in comparison with other materials