Alloy 800 is a widely used material of construction for equipment that must resist corrosion, have high strength or resist oxidation, carburization and other harmful effects of high-temperature exposure. For high temperature applications requiring optimum creep and rupture propertiesAlloy 800HP is used. The Chromium in the alloy imparts resistance to oxidation and corrosion. The high Nickel content maintains an austenitic structure so that the alloy is ductile. The Nickel also contributes resistance to scaling, general corrosion and stress corrosion cracking. The iron content provides resistance to internal oxidation.
Availability – Alloy 800
Seamless Pipe 1/2″ – 8″
Welded Pipe 8″ – 12″
Butt-Weld Fittings 1/2″ – 8″
Flanges 1/2″ – 8″
Bar 1″ – 6″
Specifications – Alloy 800
| ASTM | B407, B514, B366, B408, B564 |
| ASME | SB407, SB514, SB366, SB408, SB564 |
Chemical Composition – Alloy 800
| C | CR | FE | NI | AI | TI | AI/TI |
|---|---|---|---|---|---|---|
| Min | ||||||
| 0.06% – 0.1% | 19%-23% | 39.5% | 30% -35% | 0.15 – .60% | 0.15 – .60% | 0.85% – 1.20% |
Design Features – Alloy 800
- Good creep-rupture properties at temperatures above 600 deg. C (1110 deg.F) without loss of ductility during long term use at temperatures below 700 deg. C (1290 deg.F), due to limitation of (Ti & A) content to max 0.7%. However, by using 800HP with increased (Al & Ti) content to 1.2%, temperatures above 700 deg. C (1290 deg.F) can be achieved.
- Good resistance to reducing oxidizing and nitriding atmospheres and to atmospheres which alternates between reducing and oxidizing conditions.
- Metallurgical stability in long-term applications at high temperatures.
Typical Applications – Alloy 800
- Steam / hydrocarbon reforming for components such as pig tails, headers, collectors, manifolds, transfer piping, catalyst tubes, and quench system piping
- Ethylene pyrolsis tubing in convection and radiant sections – resistance to carburization and good mechanical properties
- Ethylene dichloride cracking tubes – resistance to carburization and to dry hydrogen chloride and chlorine Components, eg. Heat exchangers, piping systems, etc., in coal conversion plants
- Steam generators tubing in helium coolant, high temperature reactor systems – high strength, resistance to helium and steam
Tensile Requirements – Alloy 800
Tensile Strength (KSI): 72.5
Yield Strength (KSI): 25
KSI can be converted to MPA (Megapascals) by multiplying by 6.895.