Incoloy 800H (UNS N08810, ASTM B409) and 800HT (N08811) Foil: Superior Creep-Rupture Performance
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An ethylene cracker in Texas experienced tube ruptures at 950°C due to creep deformation in standard 800 alloy, leading to a fiery shutdown and $5 million losses. Incoloy 800H (UNS N08810) and 800HT (N08811) foils overcome this with controlled chemistry for 4x creep life.
Specifications & Standards
Incoloy 800H/800HT foil aligns with ASTM B409 (sheet/plate Gr. 1.1/1.2), ASME SB409, DIN 1.4958/EN 10028-5 for >ASTM 5 grain size. Dual certifiable N08810/N08811 per UNS.
Cyclic oxidation ASTM G28, tensile E8 validate for power vessels up to 1100°C with EN 10204 3.2.
Product Forms & Availability
Annealed foils 0.01-0.6 mm, widths 300-1200 mm per B409 tolerances. Stabilized 2100°F (1150°C) for coarse grain.
Mumbai supply includes tube sheets, reformer skins.
Chemical Composition
| Element | 800H/800HT % |
|---|---|
| Nickel | 30.0-35.0 |
| Chromium | 19.0-23.0 |
| Iron | 39.5 min |
| Carbon | 0.06-0.12 |
| Al+Ti | 0.85-1.20 |
| Aluminum | 0.30-0.70 |
| Titanium | 0.25-0.60 |
| Silicon | 1.0 max |
C/Al/Ti control precipitates M(C,Nb,Ti) carbides for creep.
Mechanical & Physical Properties
Density 7.94 g/cm³, melt 1357-1385°C, UTS 550-600 MPa, yield 240 MPa, 35% EL post-anneal. Rupture 35 MPa/10000h @900°C.
Oxidation <0.5 mg/cm²/24h @1000°C, CTE 15.9 µm/m°C.
Why this grade
Incoloy 800H shares the chemistry of 800 with two deliberate changes: carbon is controlled to 0.05–0.10% and the solution anneal is carried out at a higher temperature to give a coarser grain. Both raise creep and stress-rupture strength, which is why 800H rather than 800 is the grade for ASME pressure service above 650°C.
Frequently Asked Questions
Certifications & Compliance
AD2000-WO, VdTÜV 479, grain cert E112. PED 2014/68/EU module H.
Global Export Destinations
We ship worldwide from Mumbai. See every destination we export to on our export markets page.
Domestic Supply Network
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
Incoloy 800H and 800HT foils empower long-term reliability in creep-critical heat, certified for global demands. Buyers trust their field-validated strength. What high-temp project requires this edge?