K-500

Alloy K-500 is a nickel-copper alloy, which combines the excellent corrosion resistance of alloy 400 with the added advantages of greater strength and hardness. Alloy K-500 provides roughly three times the yield strength of alloy 400. The increased properties are obtained by adding aluminum and titanium to the nickel-copper base and age hardening. The aging process precipitates submicroscopic particles of Ni3 (Ti, Al) throughout the matrix.

The combination of low magnetic permeability, high strength and good corrosion resistance have been used in a number of applications, notably oil-well surveying equipment and electronic components. A useful characteristic of the alloy is that it is virtually nonmagnetic, even at quite low temperatures. Age hardening causes an initial volume contraction. An annealed rod contracted 2.5 x 10-4 in/in during aging. The following is a typical age-hardening procedure to achieve of optimal properties.

Anneal at 1800°F for 30 minutes followed by a water quench. Hold for 16 hours at 1100-1125°F followed by furnace cooling at a rate of 15 -25°F per hour to 900°F. Cooling from 900°F to room temperature may be carried out by furnace or air cooling, or by quenching, without regard to cooling rate.