Alloy 800/800H/800HT
Description
Alloy 800 is an iron-nickel-chromium alloy with moderate strength and good resistance to oxidation and carburization at elevated temperatures. It is particularly useful for high-temperature equipment in the petrochemical industry because the alloy doesn’t form the embrittling sigma phase after long time exposure at 1200°F (649°C). Excellent resistance to chloride stress-corrosion cracking is another important feature of alloy 800.
Alloy 800H is a solution heat treated (2100°F/1150°C), controlled-carbon version of alloy 800 with improved elevated temperature properties. It has improved creep and stress-rupture characteristics in the 1100°F (593°C) to 1800°F (982°C) temperature range.
Applications
Typical applications for alloy 800 and 800H are – Heat exchangers and process piping; carburizing fixtures and retorts; furnace components; electric range heating-element sheathing; extruded tubing for ethylene and steam methane reforming furnaces; ammonia effluent coolers.
Type Analysis
| Incoloy | Incoloy 800 | Incoloy 800H | ||
|---|---|---|---|---|
| Element | Min | Max | Min | Max |
| Nickel + Cobalt | 30.0 | 35.0 | 30.0 | 35.0 |
| Cobalt | — | 2.00 | — | 2.00 |
| Chromium | 19.0 | 23.0 | 19.0 | 23.0 |
| Copper | — | 0.75 | — | 0.75 |
| Iron | Bal | Bal | ||
| Silicon | — | 1.00 | — | 1.00 |
| Manganese | — | 1.50 | — | 1.50 |
| Carbon | — | 0.10 | 0.05 | 0.10 |
| Aluminum | 0.15 | 0.60 | 0.15 | 0.60 |
| Titanium | 0.15 | 0.60 | 0.15 | 0.60 |
| Sulfur | — | 0.015 | — | 0.015 |
Physical Properties
| Physical Properties | °F | British Units | °C | Metric Units |
|---|---|---|---|---|
| Density | Room | 0.287 lb./in.(3) | Room | 7.95 g/cm(3) |
| Electrical Resistivity |
70 200 400 600 800 |
38.9 microhm-in. 40.6 microhm-in. 43.0 microhm-in. 44.7 microhm-in. 46.1 microhm-in. |
21 93 204 316 427 |
0.989 microhm-m 1.03 microhm-m 1.09 microhm-m 1.13 microhm-m 1.17 microhm-m |
| Mean Coefficient of Thermal Expansion |
70-200 70-400 70-600 70-800 |
7.9 microin./in.-°F 8.8 microin./in.-°F 9.0 microin./in.-°F 9.2 microin./in.-°F |
21-93 21-204 21-316 21-427 |
14.2 X 10(-6)m/m-K 15.8 X 10(-6)m/m-K 16.2 X 10(-6)m/m-K 16.6 X 10(-6)m/m-K |
| Thermal Conductivity |
70 200 400 600 800 |
80 Btu-in/ft²-hr-°F 89 Btu-in/ft²-hr-°F 103 Btu-in/ft²-hr-°F 115 Btu-in/ft²-hr-°F 127 Btu-in/ft²-hr-°F |
21 93 204 316 427 |
11.5 W/m-K 12.8 W/m-K 14.8 W/m-K 16.6 W/m-K 18.3 W/m-K |
| Dynamic Modulus of Elasticity |
Room | 28.5 x 10(6) psi | Room | 196 GPa |
These properties apply to both alloys
Mechanical Properties
| Alloy | Form | Condition | Ultimate Tensile Strength, ksi (MPa) |
Yield Strength at 0.2% offset, ksi (MPa) |
Elongation in 2″ or 4D, percent |
|---|---|---|---|---|---|
| 800 | Sheet, Plate | Annealed | 85 (586) | 40 (276) | 43 |
| 800 | Sheet, Plate Strip, Bar |
Annealed | 75 (520)* | 30 (205)* | 30* |
| 800H | Sheet, Plate | SHT | 80 (552) | 35 (241) | 47 |
| 800H | Sheet, Plate Strip, Bar |
SHT | 65 (450)* | 25 (170)* | 30* |
Alloy 800/800H/800 HT Avaliability
- Seamless Pipe 1/4”- 8”
- Seamless Tube 1/8” – 1”
- Plate 1/8” – 3”
- Pressure Fittings 1/4” – 2”
- Welded Pipe 4” – 24”
- Bar 1/8” – 11”
- Flanges 1/2” – 24”
- Butt-Weld Fittings 1/2” – 24”
- Welded Pipe 8” – 24”
Alloy 800/800H/800 HT Specifications
- ASTM B407, B514, B366, B408, B564
- ASME SB407, SB514, SB366, SB408, SB564
Alloy 800/800H/800 HT Tensile Requirements
- Tensile Strength 72.5 KSI
- Yield Strength 25 KSI