Alloy 800 HT from the 800 series (Incoloy 800, 800H and 800HT) is a nickel-iron-chromium high temperature alloy that has high strength and temperature resistance to oxidation, carburization and other high temperature corrosion.

After the creation of 800HT material, it acquired the status of a trade brand of the Special Metals corporation, along with Incoloy.
Alloy 800HT is used in the petrochemical industry, for the manufacture of elements of industrial furnaces and thermal deformation units.
Corrosion resistance
The high nickel and chromium content of Nicrofer 3220 HP provides excellent oxidation resistance. The alloys are also very resistant to carburization, nitriding, and oxidation in sulfur-containing atmospheres.
The protective oxide layer adheres firmly under static and cyclic temperature stress. It is especially resistant to carburization if a thin oxide film has been formed by pre-oxidation.
The hydrogen resistance of 3220 HP is excellent, so these alloys are used in hydrogen production and steam / hydrocarbon conversions.
Nicrofer 3220 HP can be welded using all conventional welding methods: non-consumable, consumable, hot-electrode, plasma, inert gas and submerged arc welding.
The following welding consumable is recommended:
NicroferS 7020-FM 82
op material. No. 2.4806
Short designation SG / UP-NiCr20Nb
AWSA5.14 ERNiCr-3
Coated rod electrodes
op.material. No. 2.4648
Short designation EL-NiCrl9Nb
AWSA5.il: ENiCrFe-3 mod.
Alternatively, you can use:
NicroferS 5520-FM 617
op material. No. 2.4627
Short designation SG-NiCr22Col2Mo
AWSA5.14 ERNiCrCoMo-1
Coated rod electrodes
op.material. No. 2.4628
Short designation EL-NiCr21Col2Mo
AWSA5.il: ENiCrMo-1
Main features and advantages of the alloy:
Excellent fatigue strength at temperatures above 700 กใ C;
Good resistance in oxidizing, reducing and nitriding atmospheres, as well as under changing oxidizing and carburizing conditions;
Metallurgical stability with long-term use at high temperatures.
Spheres of use of the alloy:
Considering its high long-term strength and resistance to carburization and nitriding, 3220 HP has found many applications such as steam / hydrocarbon conversion: for components such as coils, battery systems, piping, catalyst tubes, refrigeration systems.
ethylene and pyrolysis pipes in the radiation-convection area of ​​the furnaces; resistance to carburization and oxidation, good mechanical properties;
ethylene dichloride pipes resistant to carburization as well as dry hydrogen chloride and chloride gases;
pipes for the production of acetic acid hydride and ketone, high strength, resistance to carburization and sigma phase formation;
components of coal conversion plants such as heat exchangers, pipe systems, etc .;
steam generator tubes in helium cooled high temperature reactors high strength, helium and vapor resistance.
Various products are produced from this alloy according to ASTM standards:
B163 - seamless tubes for condensers and heat exchangers;
B366 - Forged fittings;
B407- seamless pipes
B408 - rods;
B409 - Plates, sheets, strips;
B514, B515 - welded pipes;
B564 - forgings;
B751, B775 - welded pipes;
B924 - Seamless welded tubes for heat exchangers and condensers with integrated fins.
Other materials

Steel 4Si1
Steel C32D2 - 1.1143
Steel DC04 - 1.0338
Steel EN-GJSA-XNiSiCr30-5-5

Steel R260Mn - 1.0624
Steel S355G9 + N - 1.8811 + N
Steel X56QS - 1.8760
Titanium Grade 27 / Ti Grade 27 / R52254


Inconel 625 / N06625 / 2.4856   Inconel 601 / N06601 / 2.4851   Inconel 718 / N07718 / 2.4668    Inconel 690 / N06690 / 2.4642

Inconel 617 / N06617 / 2.4663   Inconel X-750 / N07750 / 2.4669  Inconel 600 / N06600 / 2.4816    1.4876 / 1.4958

​​Incoloy 800HT / ​​N08811 / 1.4959     Incoloy 825 / N08825 / 2.4858   Incoloy 800H / N08810 / 1.4958     Incoloy 20 / N08020 / 2.4660

Incoloy 925 / UNS N09925            Hastelloy B-2 / N10665 / 2.4617   Hastelloy C-276 / N10276 / 2.4819   Hastelloy C-22 / N06022 / 2.4602

Hastelloy B-3 / UNS 10675 / 2.4600       Hastelloy C-4 / N06455 / 2.4610    Hastelloy X / N06002 / 2.4665        Monel 400 / UNS N04400 / 2.4360

 Monel K-500 / N05500 / 2.4375      Monel R-405 / N04405