Haynes 188 (UNS R30188 / W.Nr 2.4683)

Haynes 188 (UNS R30188 / W.Nr. 2.4683) is a cobalt-nickel-chromium-tungsten alloy that com- bines excellent high-temperature strength with very good resistance to oxidizing environ- ments up to 1095℃ for prolonged exposures, and excellent resistance to sulfate deposit hot corrosion. It is readily fabricated and formed by conventional techniques, and has been used for cast component. Other attractive features include excellent resistance to molten chloride salts, and good resistance to gaseous sulfidation.

Equivalent Grades

Haynes 188GH5188Haynes 188R301882.4683KCN22W

Chemical Composition, %

Haynes 1880.05-0.150.2-0.5≤1.25≤0.02≤0.01521.0-23.020.0-24.0Bal13.0-15.00.03-0.15≤3.0

Typical Physical and Mechanical Properties (RT, Solution annealed)

Density, g/cm3Melting Point, ℃Tensile Strength, MPaYield Strength, MPaELongation, %Hardness, HRB

Available Products and Specifications

Rod, Bar, Wire and ForgingsAMS 5772
Plate, Sheet and StripAMS 5608
Pipe and Tube
Welding Product


  • Meets AMS 5608 specifications
  • Meets AMS 5772 specifications
  • Enormously beneficial high temperature strength
  • Provides oxidation resistance up to 2100° F
  • Excellent post-aging ductility
  • Galling resistant
  • Easily strengthened by cold deformation


  • Gas turbine operations
  • Combusters
  • Flame holders
  • Liners
  • Transition ducts
  • Exhaust frames