

| UNS Number | N08811 |
|---|---|
| Werkstoff Number | 1.4959 |
Incoloy 800HT is a nickel-iron-chromium alloy with good strength and excellent resistance to oxidation and carburization in high-temperature exposure. Except for the higher level of carbon in alloy 800H, 800 and 800HT alloys are identical and the addition of up to 1.20 percent titanium and aluminum in 800HT alloy. Incoloy 800HT has additional modifications to the combined titanium and aluminum levels (.85-1.20%) to make sure optimum heat properties. 800H/HT alloy combines the properties of both forms and it is dual certified. Incoloy 800HT was meant for high temperature structural applications. The nickel content makes the alloys extremely proof against each chloride stress-corrosion cracking and to embrittlement from precipitation of sigma phase. Incoloy 800HT have superior creep and stress rupture properties. Incoloy 800HT is used where resistance to creep and rupture is required i.e under temperatures above 1100°F. The nickel steel alloy exhibits excellent resistance to carburization, oxidation and nitriding atmospheres due to the chemical balance. Many stainless steels become brittle after long periods of usage in the 1200-1600°F range.Incoloy 800HT won’t become embrittled even when long periods of usage within the 1200-1600°F range where many stainless steels become brittle. Incoloy 800HT shows excellent cold forming characteristics typically associated with the nickel-chromium alloys.

| Chemical Components | C | Si | Mn | P | S | Cr | Ni | Cu | Ti | Al | Al+Ti | Fe |
| Minimum | 0.06 | – | – | – | – | 19 | 30 | – | 0.15 | 0.15 | 0.85 | 39.5 |
| Maximum | 0.1 | 1 | 1.5 | 0.045 | 0.015 | 23 | 35 | 0.75 | 0.60 | 0.60 | 1.20 | – |
| Tensile Strength σb Mpa |
Yield Point σs Mpa |
Elongation δ % |
Hardness
HBW |
| ≥450 | ≥170 | long. ≥30 |
≤192 |
| Elastic Modulus | Coefficient of Thermal Expansion (CTE) | Coefficient of Thermal Conductivity | Specific Heat Capacity | Resistivity | ||||||||||
| 500°C | 600°C | 700°C | 800°C | 900°C | 1000°C | 500°C | 600°C | 700°C | 800°C | 900°C | 1000°C | 20°C | 20°C | 20°C |
| GPa | 10-6K-1 | W/m.K | J/kg.K | Ω.mm2/m | ||||||||||
| 160 | 155 | 145 | 140 | 135 | 125 | 17.2 | 17.5 | 17.9 | 18.3 | 18.6 | 19 | 12 | 460 | 0.99 |
| Product Form | Size Range From | Size Range To |
| Sheet & Plate | 0.30 mm | 25 mm |
| Round Bar | 4 mm | 380 mm |
| Tube | 6 mm | 260 mm |