MK500 M400 UNS N04400 UNS N05500 Valve Stem

The valve stem which actuates or drives a valve-stem; the rod which is fastened to a valve to move it back and forth.

DescriptionMonel nickel-copper alloy K-500 combines the excellent corrosion resistance characteristic of Monel alloy 400 with the added advantages of greater strength and hardness. The increased properties are obtained by adding aluminum and titanimum to the nickel-copper base, and by heating under controlled conditions so that submicroscopic particles of Ni3 (Ti, Al) are precipitated thoughout the matrix. The thermal processing used to effect precipitation is commonly called age hardening or aging.

Corrosion ResistanceThe corrosion resistance of Monel alloy K-500 is subtantially equivalent to that of alloy 400 except that, when in the age-hardened condition, alloy K-500 has a greater tendency toward stress-corrosion cracking in some environments. Monel alloy K-500 has been found to be resistant to a sour-gas environment. After 6 days of continuous immersion in saturated (3500ppm) hydrogen sulfide solutions at acidic and basic pH's (ranging from 1.0 to 11.0), U-bend specimens of age-hardened sheet show no cracking. There was some tightly adherent black scale. Hardness of the specimens ranged from 28 to 40 Rc.The combination of very low corrosion rates in high-velocity sea water and high strength make alloy K-500 particularly suitable for shafts of centrifugal pumps in marine service. In stagnant or slow-moving sea water, fouling may occur followed by pitting, but this pitting slows down after a fairly rapid initial attack.

 useful characteristic of the alloy is that it is virtually nonmagnetic, even at quite low temperatures (see table). It is possible, however, to develop a magnetic layer on the surface of the material during processing. Aluminum and copper may be selectively oxidized during heating, leaving a magnetic nickel-rich film on the outside of the piece. The effect is particularly noticeable on thin wire or strip where there is a high ratio of surface to weight. The magnetic film can be removed by pickling or bright dipping in acid, and the nonmagnetic properties of the material will be restored.The combination of low magnetic permeability, high strength, and good corrosion resistance has been used to advantage in a number of applications, notably oil-well surveying equipment and electronic components.

Valve Rod pictures:

MK500 M400 UNS N04400 UNS N05500 Valve Stem