Description of HAYNES 188 Tube
Alloy 188 is a cobalt-based superalloy that offers high resistance to elevated temperatures and oxidation while maintaining sufficient ductility after prolonged exposure within the 1400-1600 °F range. Cobalt alloys demonstrate an advantage over nickel-based alloys in high-temperature creep. Alloy 188 is a solid solution with a tungsten addition of 14% and is further reinforced with M6CC and M23C6 carbides.

Specifications of HAYNES 188 Tube
Element
|
Percentage by weight
|
C
|
Carbon
|
0.05 - 0.15%
|
Mn
|
Manganese
|
1.25% max.
|
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% maximum
|
Fe
|
Iron
|
Maximum 3%
|
Co
|
Cobalt
|
Balance
|
Density
|
0.330 lb/in³ 9.14 g/cm³
|
Melting Range
|
2375-2425 °F; 1300-1330 °C
|
Specific Heat
|
0.097 Btu/lb °F at 70 °F; 405 J/kg °C at 21 °C
|
Magnetic Permeability
|
1.0007 at 200 oersted
|
Coefficient of Thermal Expansion
|
6.6 (at 0-200 °F), 10⁻⁶ in/in °F
|
Thermal Conductivity
|
84 Btu·in/ft²·h·°F; W/m·°C
|
Electrical Resistivity
|
613 Ohm-circ mil/ft; 102.0 µΩ-cm
|
Applications of HAYNES 188 Tube
- Operation of gas turbines
- Lining applications
- Combustion systems
- Transition channels
- Flame holders
- Exhaust frames
Specification
Chemical Composition (wt%)
Element
|
C
|
Mn
|
Si
|
Cr
|
Ni
|
W
|
La
|
B
|
Fe
|
Co
|
Wt%
|
0.05-0.15
|
≤1.25
|
0.20-0.50
|
20.0-24.0
|
20.0-24.0
|
13.0-16.0
|
0.02-0.12
|
≤0.015
|
≤3
|
Bal.
|
Properties
Item
|
Metric
|
English
|
Density
|
8.9 g/cm³
|
0.32 lbs/in³
|
Modulus of Elasticity
|
232 GPa
|
33.7 Mpsi
|
Electrical Resistivity
|
101.0 µohm*m
|
39.6 µohm*in
|
Thermal Conductivity
|
10.4 W/m*°K
|
72 BTU*in/hr*ft²*°F
|
Coefficient of thermal expansion
|
12.1 µm/(m*°C)
|
6.7 µin/(in*°F)
|
Melting Point
|
1330°C
|
2425°F
|