Alloy K-500 (UNS N05500)

Description:

Alloy K-500 is a precipitation-hardenable nickel-copper alloy.  Although Langley Alloys supply Alloy K-500 in all conditions, we predominantly supply material in the Hot Worked and Precipitation Treated condition, which offers the optimum combination of high strength and ductility across the size range. The increased properties are obtained by adding aluminium and titanium to the nickel-copper base, and by heating under controlled conditions so that particles of ‘ϒ’ Ni3 (Ti, Al) are precipitated throughout the matrix. The thermal processing used to effect precipitation is commonly called age hardening or ageing.

This alloy provides excellent corrosion resistance in a range of environments including sea water, hydrofluoric acid, sulphuric acid and alkalis. It has found to be resistant to a sour-gas environment and is listed within NACE MR1075. The combination of very low corrosion rates in high-velocity sea water and high strength make it well-suited for marine shafts in stagnant or slow-moving sea water, fouling may occur followed by pitting but this pitting slows down after a fairly rapid initial attack.

 

Alloy K-500 is refined by Electro Slag Refining (ESR), ensuring the cleanest and highest quality of material is supplied. This increased alloy purity limits the likelihood of hard non-metallic inclusion that can increase machining difficulty, processing times and ultimately part failures. It also has low permeability and is nonmagnetic to temperatures as low as -150°F (-101°C).

Key Features:

  • High strength and hardness from sub-zero to elevated temperatures
  • Excellent corrosion resistance in a wide range of environments
  • Resistant to chloride stress corrosion
  • Good resistance to impingement attack
  • High fatigue strength in seawater
  • Low magnetic permeability to very low temperatures

Applications:

  • Process industry applications such as doctor blades & scrapers involving organic acids, caustic soda, dry chlorine, chlorinated plastics
  • Marine industry and shipbuilding applications such as propellers, shafts, fasteners, gyroscopes, springs
  • Oil & Gas industry pump shafts, valve stems, drill collars, instrumentation
  • Sensors and electronic components
  • Heat exchanger components

Chemical Composition:

Cr Ni Mo Co Nb (+Ta) Ti V W Cu C Mn N Si P S Fe Al
Min 63.00 0.35 27.00 2.30
Max 0.85 33.00 0.25 1.50 0.50 0.010 2.00 3.15

Mechanical Properties:

Cold Worked & Precipitation Treated Cold Worked, Solution Treated & Precipitation Treated Hot Worked & Precipitation Treated Hot Worked, Solution Treated & Precipitation Treated
Bars up to and including 25mm section size or diameter Bars between 25-55mm section size or diameter Bars up to and including 25mm section size or diameter Bars between 25-55mm section size or diameter Bars up to and including 110mm section size or diameter Bars between 110-300mm section size or diameter Bars up to and including 25mm section size or diameter Bars between 25-110mm section size or diameter Bars between 110-300mm section size or diameter
0.2% Proof Stress 760 (110) 690 (100) 620 (89.9) 550 (79.8) 724 (105) 724 (105) 500 (72.5) 585 (84.8) 500 (72.5)
N/mm2 (ksi)
Tensile Strength, N/mm2 (ksi) 1000 (145) 970 (140.6) 900 (130.5) 830 (120) 965 (140) 965 (140) 830 (120.3) 900 (130.5) 830 (120.3)
Elongation, 5.65√S0 and 4D 14% 16% 20% 20% 20% 20% 15% 20% 15%
Hardness (Rockwell C) 27-35 27-35 27-35 27-35 27-35 27-35 27-35 27-35 27-35
Impact Strength (-29oC or lower) 27J av (20J min) 27J av (20J min) 27J av (20J min) 27J av (20J min) 27J av (20J min) 27J av (20J min) 27J av (20J min) 27J av (20J min) 27J av (20J min)

Notes:

  1. Testing shall be carried out in accordance with ASTM A370 or EN ISO 6892-1 (tensile), EN ISO 6506-1 (hardness)
  2. Minimum properties quoted (tested at room temperature in a longitudinal direction)
  3. Testing performed on each melt of material per heat treatment batch

Physical Properties:

Density (Kg/m3) 8430
Magnetic Permeability (20°C) <1.005 (1.002 typical)
Young’s Modulus (kN/mm2) 179
Specific Electrical Resistance, 20°C (µΩ-m) 0.62
Mean coefficient of thermal expansion, 20-100°C (m/m/degC) 13.4 x 10-6
Specific Heat, 20°C (J/kg.K) 418
Thermal conductivity, 20°C (W/m.K) 17.5
Curie Temperature (°C) -90

Downloads

Datasheet - NA-Alloy K-500

Datasheet - NA-Alloy K-500