Nickel Alloy K-500 | UNS N05500 | 2.4375 | Monel K-500

Shaanxi Shangyou Stainless Steel Co., Ltd. supplies Nickel Alloy K-500, also known as Monel K-500, identified as UNS N05500 and Werkstoff 2.4375, in plate, sheet, round bar, rod, wire, and forging forms. Our Alloy K-500 products can be supplied according to ASTM B865 and AMS 4676.

Nickel Alloy K-500 is a precipitation-hardenable nickel-copper alloy that combines the excellent corrosion resistance of Alloy 400 with the added advantages of significantly greater strength and hardness. These enhanced properties are achieved by adding aluminum (2.30-3.15%) and titanium (0.35-0.85%) to the nickel-copper base, followed by controlled thermal processing (age hardening) to precipitate submicroscopic Ni₃(Al,Ti) particles throughout the matrix. The alloy has approximately three times the yield strength and double the tensile strength of Alloy 400. It remains ductile and tough at cryogenic temperatures down to -101°C while maintaining strength up to approximately 650°C.

Actual properties depend on product form, dimensions, heat-treatment cycle, and the specified standard.

Annealed

Alloy K-500 is normally supplied in the annealed condition for forming and machining. Annealed material typically exhibits tensile strength of 650 – 850 MPa (94 – 123 ksi).

Age Hardened (Precipitation Hardened)

The alloy develops its high strength through precipitation aging. A typical aging cycle includes holding at approximately 580 – 590°C (1,075 – 1,095°F) for 8 – 10 hours, followed by air cooling. Aged properties: tensile strength ~950 – 1,050 MPa (138 – 167 ksi), yield strength ~690 – 965 MPa.

Spring Temper + Aged

Material can be cold worked prior to aging for even higher strength. Spring temper + aged condition achieves tensile strength up to 1,200 – 1,500 MPa (174 – 218 ksi). Cold working before precipitation hardening further enhances mechanical properties.

Alloy K-500 provides corrosion resistance substantially equivalent to Alloy 400, with the addition of significantly higher mechanical strength.

Key Corrosion Characteristics:

• Excellent resistance to seawater, particularly in high-velocity conditions, making it ideal for pump shafts and impellers in marine service
• Resistant to sour-gas environments (hydrogen sulfide) – NACE MR0175/ISO 15156-3 compliant for suitable applications
• Good resistance to non-oxidizing mineral acids, salts, and alkalis
• Excellent resistance to erosion and cavitation
• Resistant to stress-corrosion cracking in most environments
• Virtually non-magnetic down to -101°C

Selection Considerations:

• Greater tendency toward stress-corrosion cracking than Alloy 400 when in the age-hardened condition in certain environments
• Not recommended for strongly oxidizing acid environments such as nitric acid
• May suffer pitting in stagnant or slow-moving seawater – fouling may occur followed by pitting, though this slows after initial attack
• Magnetic surface layer may develop during processing – aluminum and copper may selectively oxidize during heating, leaving a magnetic nickel-rich film; acid pickling can remove this
• Final selection must consider the specific medium, concentration, temperature, and exposure conditions

• Marine Engineering: Pump shafts, propeller shafts, impellers, fasteners, chains, cables, and springs for marine service
• Oil and Gas: Drill collars, oil-well tools and instruments, safety lifts, valves, sour-gas service equipment
• Chemical Processing: Valve components, pump and valve parts
• Pulp and Paper: Doctor blades and scrapers
• Electronic Components: Sensors and other non-magnetic components

Available quality-control services include:

• Heat-number traceability
• Chemical composition verification
• Tensile, yield and elongation testing
• Hardness inspection
• Dimensional and surface inspection
• Positive Material Identification (PMI)
• Ultrasonic testing
• Dye penetrant inspection
• Heat-treatment records
• EN 10204 3.1 material certificate

For an accurate quotation, please provide:

Alloy Grade · Standard · Product Form · Dimensions · Quantity · Heat Treatment · Inspection Requirement · Application · Working Temperature · Destination Port

For corrosive environments, also provide:

Chemical Medium · Concentration · Temperature · Oxidizing or Reducing Conditions

• Request Nickel Alloy K-500 Quote
• Upload Drawing or MTO
• Check Available Stock
• Ask for Alloy Selection Support

Nickel Alloy K-500 (UNS N05500), also known as Monel K-500, is a precipitation-hardenable nickel-copper alloy that combines the corrosion resistance of Alloy 400 with significantly higher strength and hardness achieved through aluminum and titanium additions.

The UNS designation is N05500; the European Werkstoff number is 2.4375; the EN material symbol is NiCu30Al.

ASTM B865 is the primary standard for Alloy K-500 plate, bar, and tubing. AMS 4676 and BS 3076 NA18 are also applicable.

Alloy K-500 has approximately three times the yield strength and double the tensile strength of Alloy 400, achieved through precipitation hardening with aluminum and titanium additions, while maintaining similar corrosion resistance.

Yes. Alloy K-500 requires age hardening (precipitation hardening) to achieve its high strength. A typical cycle is 580-590°C for 8-10 hours, air cooled.

It resists seawater, non-oxidizing mineral acids, salts, alkalis, and sour-gas (H₂S) environments. It is also resistant to erosion and cavitation in high-velocity seawater.

Yes. Its combination of low corrosion rates and high strength makes it particularly suitable for centrifugal pump shafts and impellers in marine service. However, pitting may occur in stagnant seawater.

Alloy K-500 is virtually non-magnetic down to -101°C (-150°F), making it suitable for electronic and sensitive instrumentation applications.

Yes. Welding is best accomplished by gas-tungsten-arc welding (GTAW). It is recommended that the alloy be annealed when welded and that weldments be stress relieved prior to aging. Recommended filler material is MONEL 60.

Please provide the standard, product form, dimensions, quantity, heat-treatment condition, inspection requirements, application, working temperature and destination port. For corrosive environments, also specify the chemical medium and concentration.