ALLOY 500 / NA18 / N05500 / K500

NA18 / N05500 is a high performance nickel copper alloy that is generally supplied in the precipitation hardened condition to offer the optimum mechanical properties. Sometimes referred to as Alloy 500, the NA18 / N05500 gives an excellent combination of corrosion resistance, very low magnetic permeability and high strength levels that are retained up to 650°C

Developed primarily as a marine alloy the enhanced corrosion resistance of Alloy 500 / NA18 means it is often utilised for components in high-velocity, stagnant or slow-moving seawater. During installation some initial fouling may occur followed by pitting, but this slows after a fairly rapid initial attack.

The NA18 / N05500 is resistant to stress corrosion cracking (SSC) in sour-gas environments (although it should be noted that it can be susceptible SSC in some environments when fully age hardened).

Related Standard Specifications

BS3076: NA18

ASTM B865: N05500

ALLOY 500

K500

2.4375

 

Chemical Composition

Nickel

63.0% min

Carbon         

0.25% max

Copper         

27.0-33.0% min

Silicon

0.5% max

Iron

2.0% max

Manganese

1.5% max

Aluminium

2.3-3.2%

Titanium

0.35-0.85%

Sulphur

0.01% max

 

 

 Key Features

  • Excellent Strength and Hardness
  • Very good marine corrosion resistance
  • Good resistance to non-oxidising acids, alkali and salts
  • High retention of properties up to 650°C
  • Very Low magnetic permeability

Minimum Mechanical Properties (cold worked age hardened <25mm)

UTS   

1000 N/mm²  min

0.2% Proof Strength

760 N/mm² min

Elongation

15 % min

Hardness

32 HRC min

Physical Properties (aged condition)

Melting Point  

1350°C                            

Density

8.43 g/cm³

Thermal conductivity

17.5 W/m°C

Thermal expansion coefficient (20-200°C)

13.4 x 10-6

Electrical Conductivity

28 IACS

Youngs Modulus

179 GPa

Magnetic permeability                            

<1.005

Curie Temperature

-90?C 

Fabrication Properties

Hot Working Temperature                      

1030-1150°C

Hot Formability

Good

Cold Formability

Good (annealed condition)

Machinability rating

Okay (annealed condition) 

Joining Methods

Alloy 500 can be satisfactorily joined by all conventional methods including soldering, brazing and welding techniques

Typical Applications

NA18 / K500 nickel copper is mainly utilised in the offshore, marine, shipbuilding and chemical process industries including components in processing organic acids, caustic soda and dry chlorine, the production of chlorinated plastics, rotor blades and scrapers for pulp processing in paper production, propeller and pump shafts, impellers, high strength fasteners, gyroscopes, pump shafts, valve stems, drill collars.

This technical information is given by John Hood & Co.without charge and the user shall employ such information at their own discretion and risk. For more detailed technical advice on temper selection, fabrication, joining, machining, physical and mechanical data please contact us as space does not permit the listing of every feature of the material.