Haynes 188 Alloy Introduction to Characteristics and Execution Standards

Haynes 188 Alloy Introduction to Characteristics and Execution Standards

Common Trade Names: Haynes 188, Alloy 188, Udimet 188, Conicro 4023,

Haynes 188 Alloy is a Cobalt-Nickel-Chromium-Tungsten Alloy that combines excellent high temperature strength with very good resistance to oxidizing environments up to 2000°F (1095°C). 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.

Haynes 188 Alloy is a solid solution-strengthened material which combines excellent high temperature strength. It is particularly effective for very long-term applications at temperatures of 1200°F (650°C) or more. It is stronger than nickel-base solid-solutionstrengthened alloys, and far stronger than simple nickel-chromium or iron-nickel-chromium heat-resistant alloys.

The high chromium level coupled with small additions of lanthanum produce an extremely tenacious and protective scale. The alloy also has good sulfidation resistance and excellent metallurgical stability as displayed by its good ductility after prolonged exposure to elevated temperatures. Good fabricability and weldability combine to make the alloy useful in gas turbine applications such as combustors, flame holders, liners and transition ducts.

This can allow for significant section thickness reduction when it is substituted for thesematerials.

Available Product Forms: Plate, Sheet, and Bar.

Specifications:Haynes 188 is covered by the following specifications:UNS R30188;

Rod, Bar, Wire and Forging Stock: AMS 5772;

Plate, Sheet and Strip: AMS 5608

Welding Wire: AMS 5801;

Haynes 188 Alloy Chemical Composition

Limiting Chemical Composition, % by Weight

Cobalt.........................................................................Balance;

Carbon........................................................................0.05-0.15; 

Manganese.................................................................1.25 max. 

Silicon.........................................................................0.20-0.50 ;

Chromium...................................................................20.0-24.0 ;

Nickel..........................................................................20.0-24.0; 

Tungsten.....................................................................13.0-16.0 ;

Lanthanum..................................................................0.02-0.12 ;

Boron........................................................................0.015 max. 

Iron...............................................................................3.0 max.