Alloy K500, commonly referred to as “K-Monel”, is a precipitation hardenable, nickel-copper alloy with similar corrosion resistance to that of Alloy 400 but with greater strength. Typical industrial applications for Alloy K500 include fasteners, springs and chains for marine service, pump and valve components for chemical processing facilities as well as blades and scrapers used in pulp and paper production. Oil and gas production utilize Alloy K500 for drill collars, instruments, pump shafts, impellers and valves as well as for sensors and electronic components.

Resistance to Corrosion:

The corrosion resistance of Alloy K500 is virtually the same as Alloy 400 with exception when in the age- hardened condition, Alloy K500 is more susceptible to stress-corrosion cracking in certain environments. Resistance to hydrogen sulfide makes Alloy K500 useful in sour-gas environments making it extremely popular in the oil patch. Low corrosion rates in sea water make Alloy K500 suitable for marine service although pitting may occur in stagnant waters but the rate of pitting slows after initial attack.

Fabrication and Heat Treat:

Alloy K500 can be fabricated by using standard commercial procedures. Hot working the alloy should be performed at temperatures between 1600°F and 2100°F avoiding any prolong soaking time at the higher temperatures. Material should be water quenched from a temperature no lower than 1450°F after hot working. Cold forming in

the annealed condition can also be performed using standard methods although may require considerable power to form. Machining of Alloy K500 is easiest in the annealed condition therefore the best practice would be to machine oversize, age-harden, then finish to size. Contraction can occur during aging and 0.0002 in/in should be accounted for in size prior to aging. Welding Alloy K500 is best achieved by gas-tungsten-arc-welding (GTAW). Filler metal AWS A5.14 ERNiCu-7 is typically used for joining. Weldments using this filler metal will not have the strength compared to age hardened base metal. For weldments that require strength, AWS A5.14 ERNiFeCr-2 filler metal can be used.

Solution annealing of the alloy should be performed prior to aging to dissolve phases in the structure that may have formed during previous processing. If the material is hot-finished, then the anneal temperature should be 1800°F. If the material was cold worked, the temperature should be 1900°F. Time at temperature should be kept at a minimum to avoid excessive grain growth. Quenching in water immediately after solution annealing will avoid any partial precipitation of age hardening constituents. Age hardening of annealed (soft) material to obtain maximum properties should be performed as follows. Heat material between 1100°F & 1125°F and hold temperature for 16 hours followed by furnace cooling at a rate of 15°F to 25°F per hour until the material reached a temperature of 900°F. Once the material reached 900°F, cooling can continue via furnace cooling, air cooling or quenching.



 Common Trade Names:

MONEL® alloy K-500

MONEL® is a registered trademark of the Special Metals Corporation group of companies.

Data Sheet

Chemical Composition:

Element Nickel + Cobalt Aluminum Titanium Iron Manganese Carbon Silicon Copper
Avg. Nominal % 63.0 Min 3.0 0.6 2.0 Max 1.5 Max 0.25 Max 0.50 Max Balance

Standard Products

Alloy K500 E, F & G Plate

Alloy K500 E, F & G Fittings

Alloy K500 E, F & G Tube

Alloy K500 E, F & G Pipe

Alloy K500 E, F & G Bar

Alloy K500 E, F & G Sheet

Alloy K500 E, F & G Fasteners

Alloy K500 E, F & G Flanges

Alloy K500 E, F & G Welding Product

Alloy K500 E, F & G Coil