The corrosion resistance of Monel K-500 (UNS N05500) is a nickel-copper alloy which combines the excellent corrosion resistance of Monel alloy 400 with the added advantages of greater strength and hardness. The Alloy is non-magnetic and excellent resistant to high velocity sea water. The increased properties are obtained by adding aluminum and titanium to the nickel-copper base, and by heating (The thermal processing used to effect precipitation is commonly called age hardening or aging) under controlled conditions so that submicroscopic particles of Ni3(Ti, Al) are precipitated throughout the matrix.

Monel K-500 has approximately triple times the yield strength and double the tensile strength when compared with Monel 400. Monel K-500 can be further strengthened by cold working before the precipitation hardening. Excellent mechanical properties from sub-zero temperatures up to about 4800C. Corrosion resistance in an extensive range of marine and chemical environments from pure water to non-oxidising mineral acids, salts and alkalis.
Monel alloy K-500 typical applications are oil well drill collars and instruments, pump shafts and impellers, non-magnetic housings, safety lifts and valves for oil chains and cables, fasteners and springs for marine service; Pump and valve components for chemical processing; Valve components for offshore drilling towers and ships; Valves and pumps used in the manufacturing of chlorinated plastics; Doctor blades and scrapers for pulp processing in paper production; And gas production; Sensors and other electronic components.; Sour-gas service applications etc.

Specification: ASTM B 865, AMS 4676.
Monel K-500 Machinability
The best machinability for the alloy is in the annealed condition. It may also be machined in the aged condition, but the preferred practice is to heavy machine as close to finish as possible in the annealed condition and final machining after aging may be done. A very slight dimensional contraction occurs upon age hardening. Machining includes drilling, turning, tapping, threading, CNC shapes, flanges and more.

Monel K-500 Welding
All of the conventional welding techniques may be used on Monel K-500. However The best way to weld with the alloy is in the annealed condition and the finished weld should then be stress-relief annealed. The espousing temperatures in the age-hardening range (900 F to 1100 F) should be avoided except when the final age-hardening treatment is to be accomplished.