Nickel Alloys Monel K-500 N05500

Product Data Sheet – Nickel Alloys

Monel K-500 UNS-N05500

Monel K-500 is a nickel copper alloy combining the excellent corrosion resistance of Monel 400 with greater strength. It is widely used, particularly in marine and chemical processing applications. It has excellent resistance to sea water.

Chemical Composition

ASTM B865 – Bar, rod, wire, forgings & forging stock

Nickel	Copper	Aluminium	Titanium	Manganese	Silicon	Carbon	Iron	Sulphur
63.0 min	27.0-33.0	2.30-3.15	0.35-0.85	1.5 max	0.50 max	0.18 max	2.0 max	0.010 max

Equivalent Specifications

Country	Body	Grade
USA	UNS	N05500
France	AFNOR	–
GB	BS	NA18
Germany	DIN	2.4375

ASTM Product Specifications

Specification	Title
B865	Precipitation Hardening Nickel-Copper-Aluminium Alloy (UNS N05500) Bar, Rod, Wire, Forgings, and Forging Stock

Specified Minimum Mechanical Properties

ASTM B865 – Bar, rod, wire, forgings & forging stock

	0.2% Proof Stress	Tensile Strength	Elongation
Product	MPa	MPa	%
As Hot Rolled	275	515	25
Annealed	195	485	35
Hard	620	690	2

Available Forms Austral Wright Metals can supply Monel K-500 as plate, sheet and strip, rod and bar, tube and pipe, welding fittings, forgings and forging billet, wire.

General Description Monel K-500 is a nickel copper alloy with high strength and good ductility, good weldability and excellent resistance to corrosion. It is tough over a wide range of temperatures. It is a precipitation hardening alloy, and a wide range of properties can be obtained by suitable heat treatments.

It is often used in marine applications, particularly for pumps and propeller shafts. Corrosion resistance is substantially matches the excellent properties of Monel 400, except for greater susceptibility to stress corrosion cracking in some aggressive environments in the aged condition.

Typical applications Pump shafts, propeller shafts, doctor blades and scrapers, springs, valve trim, fasteners.

Physical Properties

Property	Metric Units
Melting Range	1315-1350°C

Density	8,440 kg/m³ @ 20°C

Coefficient of Thermal Expansion	13.7 x 10 ^-6 / °C (20°C)
Curie Temperature	-65°C
Themal Conductivity	17.5 W/m. °C @ 20°C
Thermal Capacity (Specific Heat)	419 J/kg. °C @ 20°C

Electrical Conductivity	2.8 %IACS
Electrical Resistivity	0.615 microhm.m @ 20°C

Modulus of Elasticity (tension)	179 GPa @ 20°C
Modulus of Rigidity (torsion)	65.5 GPa @ 20°C
Poisson’s Ratio	0.32


High temperature tensile properties of annealed Monel K-500		Tensile property ranges of heat treated Monel K-500

Corrosion Resistance

Monel K-500 is generally more corrosion resistant that both of the major constituents nickel and copper. It is highly resistant to chlorinated solvents, glass etching agents, sulphuric, hydrofluoric and many other acids, and practically all alkalies. The alloy gives excellent service in sea water under high velocity conditions, where resistance to cavitation and erosion are important. Corrosion rates in strongly agitated and aerated sea water are extremely low. It is generally free from chloride stress corrosion cracking, but only annealed material resists stress cracking in the presence of mercury or mercury salts. Stress corrosion cracking in hydrofluoric acid vapours has also been encountered. Monel K-500 should not be used for nitric acid service. Please consult Austral Wright Metals for advice on your specific application.

Pressure Vessels

Monel K-500 is not prequalified by AS1210 or the ASME Boiler & Pressure Vessel Code for use in pressure vessels.

Fabrication

Monel K-500 can be readily hot worked, in the range 870°C to no higher than 1150°C. The forging should be water quenched from 790°C or higher. Care is needed in reheating practice. The alloy can be cold formed, with high forces even in the annealed condition, but ductility is good.

Machinability

Monel K-500 is best to machined when annealed, but can be finish machined when age hardened. During age hardening there is a slight, uniform contraction.

Weldability

Monel K-500 is readily welded by GMAW (MIG), GTAW (TIG), SMAW (manual) and SAW processes. Preheat, post heat and post weld heat treatment are not required. The area around the weld must be clean to prevent contamination of the weld pool. Argon shielding gas is used. Welding should be done on annealed material, and the assembly stress relieved before ageing.

Heat Treatment

Adequate softening may be obtained by annealing at 760-870°C, but best response to subsequent ageing is achieved by annealing at 980°C for hot finished material and 1040°C for cold drawn products. Work should be water quenched after annealing. Addition of 2% alcohol to the quench water will minimise oxidation and facilitate pickling. The ageing treatment depends on the properties required, and Austral Wright Metals will be pleased to provide advice.

Filler Metal Selection

	Normal Service	Higher Strength	Best Corrosion Resistance
Welding Electrode	Monel WE 190	Monel WE 190	Monel WE 190
Filler Metal	Monel FM 60	Monel FM 60	Monel FM 60
Flux Cored Wire	–	Inco-Cored 82DH	–

The technical advice and recommendations made in this Product Data Sheet should not be relied or acted upon without conducting your own further investigations, including corrosion exposure tests where needed. Please consult current editions of standards for design properties. Austral Wright Metals assumes no liability in connection with the information in this Product Data Sheet. Austral Wright Metals supplies a comprehensive range of stainless steels, copper alloys, nickel alloys and other high performance metals for challenging service conditions. Our engineers and metallurgists will be pleased to provide further data and applications advice.