Incoloy 800, 800H, and 800HT are nickel-iron-chromium alloys with good strength and excellent resistance to oxidation and carburization in high-temperature exposure. These nickel steel alloys are identical except for the higher level of carbon in alloy 800H, and the addition of up to 1.20 percent aluminum and titanium in alloy 800HT. Incoloy 800 was the first of these alloys and it was slightly modified into Incoloy 800H. This modification was to control carbon (.05-.10%) and grain size to optimize stress rupture properties. Incoloy 800HT has further modifications to the combined titanium and aluminum levels (.85-1.20%) to ensure optimum high temperature properties.The nickel alloy is dual certified (800H/HT) and combines the properties of both forms. Incoloy 800H/HT alloy was intended for high temperature structural applications. The nickel content makes the alloys highly resistant to both chloride stress-corrosion cracking and to embrittlement from precipitation of sigma phase. The general corrosion resistance is excellent. In the solution annealed condition, alloys 800H and 800HT have superior creep and stress rupture properties. Today, most suppliers, including Mega Mex, only carry the dual certified 800H/HT alloy.
Equivalent Grades Of Incoloy 800/800H/800HT
| STANDARD | WERKSTOFF NR. | UNS | JIS | BS | GOST | AFNOR | EN |
| Incoloy 800 | 1.4876 | N08800 | NCF 800 | NA 15 | ЭИ670 | Z8NC32-21 | X10NiCrAlTi32-20 |
| Incoloy 800H | 1.4958 / 1.4876 | N08810 | NCF 800H | NA 15(H) | ЭИ670 | Z8NC33-21 | X5NiCrAlTi31-20 |
| Incoloy 800HT | 1.4859 / 1.4876 | N08811 | NCF 800HT | NA 15(HT) | ЭИ670 | - | X8NiCrAlTi32-21 |
ASTM Specifications
| Alloy | Pipe Smls | Pipe Welded | Tube Smls | Tube Welded | Sheet/Plate | Bar | Forging | Fitting |
| Alloy 800 (UNS N08800) | B407 | B154 | B163 | B515 | B409 | B408 | B564 | B366 |
| Alloy 800H (UNS N08810) | B407 | B154 | B163 | B515 | B409 | B408 | B564 | B366 |
| Alloy 800HT (UNS N08811) | B407 | B154 | B163 | B515 | B409 | B408 | B564 | B366 |
Chemical Composition
| Grade | Ni | Cr | Fe | C | Al | Ti | Al+Ti |
| Alloy 800 (UNS N08800) | 30.0-35.0 | 19.0-23.0 | 39.5 min | 0.10 max | 0.15-0.60 | 0.15-0.60 | 0.30-1.20 |
| Alloy 800H (UNS N08810) | 30.0-35.0 | 19.0-23.0 | 39.5 min | 0.05-0.10 | 0.15-0.60 | 0.15-0.60 | 0.30-1.20 |
| Alloy 800HT (UNS N08811) | 30.0-35.0 | 19.0-23.0 | 39.5 min | 0.06-0.10 | 0.25-0.60 | 0.25-0.60 | 0.85-1.20 |
Typical Mechanical Properties
| Material | Temp | Hardnes BHN | Tensile Strength MPa | Yield Strength (0.2% Offset) | |||
| °F | °C | ksi | MPa | ksi | MPa | ||
| Alloy 800H and Alloy 800HT | 80 | 27 | 126 | 77.8 | 536 | 21.7 | 150 |
| Alloy 800H and Alloy 800HT | 800 | 425 | / | 67.5 | 465 | 18.8 | 130 |
| Alloy 800H and Alloy 800HT | 1000 | 540 | 90 | 62.7 | 432 | 13.0 | 90 |
| Alloy 800H and Alloy 800HT | 1200 | 650 | 84 | 54.8 | 378 | 13.5 | 93 |
| Alloy 800H and Alloy 800HT | 1300 | 705 | 82 | 47.7 | 329 | 15.8 | 109 |
| Alloy 800H and Alloy 800HT | 1400 | 760 | 74 | 34.2 | 236 | 13.1 | 90 |
Note:Alloy 800 is available in Bar (Round), Round Bar, Flat Bar, Rod, Plate, Sheet, Strip, Shapes, Forging Stock, Tube and Welding Wire. View Stock List, Plate Stock List or contact Sales for further availability.
Post time: Jun-26-2023