General Description
Incoloy 800H is similar to alloy 800 but with improved creep and stress-rupture properties for applications above 650 °C (1200 °F). Resistant to high-temperature oxidation, carburization, and nitridation, it is widely used in petrochemical and thermal processing.
Incoloy 800HT is similar to alloy 800H but with even more precisely controlled composition.
Alloys 800H and 800HT are the standard materials for intermediate temperatures (620–925 °C, or 1150–1700 °F). These alloys combine corrosion resistance with strength and metallurgical stability. Major applications include hydrogen reformer manifolds and pigtail piping, ethylene dichloride furnace tubing, transfer piping, and high-temperature pressure vessels.
Chemical Composition
| Grade | Ni% | Cr% | Fe% | C% | Mn% | S% | Si% | Cu% | Al% | Ti% | Al+Ti% |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Incoloy 800H | 30.5-35.0 | 19.0-23.0 | Bal. | 0.05-0.10 | Max 1.50 | Max 0.015 | Max 1.0 | Max 0.75 | 0.15-0.60 | 0.15-0.60 | 0.30-1.20 |
| Incoloy 800HT | 30.0-35.0 | 19.0-23.0 | Bal. | 0.06-0.10 | Max 1.50 | Max 0.015 | Max 1.0 | Max 0.75 | 0.25-0.60 | 0.25-0.60 | 0.85-1.20 |
Designations
Incoloy 800H
UNS N08810
Werkstoff Nr. 1.4958
Incoloy 800HT
UNS N08811
Werkstoff Nr. 1.4959
Specifications
Incoloy 800H/HT Wire: ISO 9724
Incoloy 800H/HT Bar: ASTM B408
Incoloy 800H/HT Forging: ASTM B564
Incoloy 800H/HT Pipe/Tube: ASTM B163/B407/B755/B751
Incoloy 800H/HT Sheet/Strip: ASTM A240/A480/B409/B609
Physical Properties
Density：8.0 g/cm3
Melting Point: 1370°C-1400 °C
Mechanical Properties
Tensile: Min 450 MPa
Yiled: Min 170 MPa
Elongation: Min 35%
Welding of Incoloy 800H/HT
Alloy 800H and 800HT have the same good weldability as alloy 800. Both are normally used for applications requiring high creep-rupture strength and should be joined with welding products that have suitable strength characteristics for the intended service temperatures.
Filler Metal 82 is used for gas-shielded welding. Filler Metal 82 is also used with Submerged Arc Flux for submerged-arc welding of Incoloy 800H and 800HT.