Alloy 800HT (Incoloy 800HT)

UNS N08811EN 1.4959 / X8NiCrAlTi32-21Trade name Incoloy 800HT
Stock statusMill indent
Typical lead time4 - 8 weeks mill indent

The creep-optimised version of Alloy 800. Controlled carbon plus a combined aluminium and titanium window of 0.85 - 1.20% gives far better creep rupture strength above 600 C, so 800HT is the grade for the hottest reformer and pigtail service rather than plain 800.

  • Creep rupture strength qualified for service above 600 C
  • Controlled Al + Ti and grain size for long term stability
  • Direct upgrade from Alloy 800 / 800H in reformer service
  • Available as seamless pipe, BA finish tube and plate

Available forms & sizes

FormSize range
Seamless Pipes & Tubes1/2" - 16" NB, SCH 10S - SCH 160, seamless
Seamless Pipes & Tubes6 - 88.9 mm OD tube, BA / bright annealed finish
Plates3 - 50 mm thk, hot rolled and solution annealed
Round Bars10 - 300 mm dia
Fittings1/2" - 24" butt weld fittings and flanges

Chemical composition (%)

ElementMinMax
Ni30.035.0
Cr19.023.0
Fe39.5-
C0.060.10
Al + Ti0.851.20

Mechanical properties

PropertyValueUnit
Yield Strength (0.2%)170 minMPa
Tensile Strength450 minMPa
Elongation30 min%
ConditionSolution annealed, grain size controlled-

Physical properties

PropertyValueUnit
Density7.94g/cm3
Max Service Temperature1100 (short term)C

Typical applications

Steam reformer outlet pigtails and headers
Ethylene cracking coils
Radiant tubes and furnace hardware
Hydrogen plant transfer lines

Frequently asked

[ 02 ] Other grades in Nickel Alloys

Inconel 625

Inconel 625

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UNS N06625EN 2.4856

Nickel-chromium-molybdenum alloy strengthened by niobium. Exceptional strength and corrosion resistance from cryogenic temperatures to 980 C without heat treatment.

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Inconel 600

Inconel 600

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UNS N06600EN 2.4816

Solid solution nickel-chromium-iron alloy with high resistance to oxidation, carburisation and chloride ion stress corrosion cracking at elevated temperature.

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Monel 400

Monel 400

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UNS N04400EN 2.4360

Nickel-copper alloy with outstanding resistance to flowing seawater, hydrofluoric acid and alkalis, and total immunity to chloride stress corrosion cracking.

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Hastelloy C276

Hastelloy C276

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UNS N10276EN 2.4819

Nickel-molybdenum-chromium alloy with tungsten, regarded as the most universally corrosion resistant alloy available for both oxidising and reducing media.

5 forms available
Alloy 800 (Incoloy 800)

Alloy 800 (Incoloy 800)

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UNS N08800EN 1.4876 / X10NiCrAlTi32-21

Iron-nickel-chromium alloy for high temperature strength with oxidation and carburisation resistance. The 32Ni-21Cr balance resists chloride stress corrosion cracking that austenitic stainless suffers, which is why it is standard for process heater and reformer tubing.

5 forms available
Alloy 825 (Incoloy 825)

Alloy 825 (Incoloy 825)

Mill indent
UNS N08825EN 2.4858 / NiCr21Mo

Nickel-iron-chromium with molybdenum, copper and titanium. The combination handles both reducing and oxidising acids and resists chloride stress corrosion cracking and sour well fluids, making 825 the standard CRA for sour service tubulars, cladding and acid plant.

5 forms available
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