Alloy 188 Cobalt Sheet, Coil & Bar - AMS 5608, 5772

Sheet

Udimet Alloy® 188 is a cobalt-base austenitic alloy with excellent high temperature strength and good oxidation resistance to 2000°F (1093°C). 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 displayed by its good ductility after prolonged exposure to elevated temperatures. 

Inventory Size Ranges for 188

Type Thickness AMS Standards UNS Get a Quote
Coil 0.020" - 0.080" AMS 5608, AMS 5772 UNS R30188 Get a Quote
Sheet 0.020" - 0.080" AMS 5608, AMS 5772 UNS R30188 Get a Quote
Bar 0.375" - 3.000" AMS 5608, AMS 5772 UNS R30188 Get a Quote

Not finding what you are looking for? Connect with our specialty metals sourcing group.


Characteristics of Alloy 188

Alloy 188 is non-magnetic. It has good high temperature strength up to 1800ºF (982°C) and good oxidation resistance up to 2100ºF (1149°C). This alloy performs well in continuous high temperature service and has excellent oxidation, spalling and corrosion resistance, achieved through the addition of chromium in combination with a minute amount of lanthanum. The lanthanum addition produces a tenacious, protective oxide scale at high temperatures. This alloy also maintains its ductility at cryogenic temperatures, but strength levels are increased substantially. 

Other industry standards we comply with:

  • B50TF74
  • PWA-LCS
  • GE Aircraft Engine (GT193)
  • GE Aviation S-SPEC-35 AeDMS S-400
  • RR SABRe Edition 2
  • DFARS Compliant

Common Trade Names

  • Udimet Alloy 188 (® Special Metals )
  • Haynes 188 Alloy (® Haynes International)
  • ATI 188 (™ Allegheny Technologies)

Industry Applications for 188

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

Chemical Composition

Chemical Composition Percentage of Alloy 188
Element Min Max
C Carbon 0.05 0.15
Mn Manganese - 1.25
Si Silicon 0.20 0.50
Cr Chromium 20.0 24.0
Ni Nickel 20.0 24.0
W Tungsten 13.0 16.0
La Lanthanum 0.02 0.12
B Boron - 0.015
Fe Iron - 3.0
Co Cobalt - Balance

Physical Properties

Physical Properties of Alloy 188
PropertyValue
Density 0.330 lb/in³   9.14 g/cm³
 Melting Range 2375-2425 °F   1300-1330 °C
Specific Heat 0.097 at  70 °F, Bru/lb °F   405 at 21 °C, J/kg °C
Permeability 1.0007 at 200 oersted
Coefficient of Expansion 6.6 0-200 °F, 10¯⁶ in/in·°F
Thermal conductivity 84 Btu·in/ft²·h·°F   W/wm·°C
Electrical Resistivity613 ohm·circ mil/ft   102.0 microhm-cm

Mechanical Properties

Mechanical Properties and Yield Strength of Alloy 188
Yield StrengthTensile StrengthElongation %
ksiMPaksiMPa
6544614096355

Datasheet

188-datasheet.pdf (768.16 KB)

Additional Info