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Incoloy 800H/Ht

Incoloy 800H/Ht

INCOLOY alloys 800H and 800HT have significantly higher creep and rupture strength than INCOLOY alloy 800. The three alloys have nearly identical chemical composition limits. However, chemical composition limits vary with carbon, aluminum and titanium. The carbon content of INCOLOY alloy 800 (UNS N08800) is 0.10% max with no limit on the lower end. The carbon content for INCOLOY alloy 800H (UNS N08810) is 0.05 to 0.10%, which is the upper end of the 0.10% maximum specified for INCOLOY alloy 800. The chemical limits for INCOLOY alloy 800HT (UNS N08811) are even more restrictive yet still within the limits specified for INCOLOY alloy 800H.Alloys 800H and 800HT are also used in power generation for steam superheating tubing and high temperature heat exchangers in gas-cooled nuclear reactors.

Physical Composition

Density, lb/in3…………………0.287
Density, g/cm3 ………………..7.94
Melting Range, °F ……………2475-2525
Melting Range, °C ……………1357-1385
Specific Heat, (32-212°F), Btu/lb•°F ………………..0.11
Specific Heat, (0-100°C), J/kg•°C ……………………460
Permeability at 70°F (21°C) and 200 oersted (15.9 kA/m)
Annealed………………………………………………1.014
Hot-Rolled ……………………………………………1.009
Curie Temperature, °F…………………………………..-175
Curie Temperature, °C …………………………………..-115

Designation & Standards

Rod, Bar, Wire, Forgings, and Forging Stock:ASTM B 408 & ASME SB 408 (Rod & Bar), ASTM B 564 &
ASME SB 564 (Forgings), ASME Code Case 1325 (All Product Forms), ASME Code Case 1949 (Forgings), ISO
9723 (Rod & Bar), ISO 9724 (Wire), ISO 9725 (Forgings), BS 3076NA15 (Rod & Bar), BS 3075NA15 (Wire), SEW
470 (All Products), VdTÜV 412 & 434 (All Products), DIN 17460 (Rod, Bar, & Forgings), EN 10095 (Rod & Bar)

Plate, Sheet, and Strip: ASTM A 240/A 480 & ASME SA 240/SA 480 (Plate, Sheet, and Strip), ASTM B 409/B
906 & ASME SB 409/SB 906 (Plate, Sheet, and Strip), ASME Code Case 1325 (All Product Forms), ASME Code
Case 2339 (INCOLOY alloy 800H Plate), BS 3072NA15 (Plate & Sheet), BS 3073NA15 (Strip), SEW 470 (All Products), VdTÜV 412 & 434 (All Products), DIN 17460 (Plate, Sheet, & Strip), EN 10028-7 & EN 10095 (Plate, Sheet, & Strip)

Pipe and Tube: BS3074NA13 (Tube), ASTM B 163(Condenser and Heat Exchanger Tube), ASTM B 165
(Seamless Pipe and Tube), ASTM B 725 (Welded Pipe),ASTM B 730 (Welded Tube), ASTM B 751 (Welded
Tube), ASTM B 775 (Welded Pipe), ASTM B 829(Seamless Pipe and Tube), ASME SB 163 (Condenser and
Heat Exchanger Tubes), ASME SB 165 (Seamless Pipe and Tube), ASME SB 725 (Welded Pipe), ASME SB 730
(Welded Tube), ASME SB 751 (Seamless and Welded Tube), ASME SB 775 (Seamless and Welded Pipe), ASME
SB 829 (Seamless Pipe and Tube), SAE AMS 4574(Seamless Tubing), DIN 17751 (Pipe and Tube), VdTÜV
263 (Sheet, Plate, Bar, and Tubing)

Other Product Forms– ASTM B 366 & ASME SB 366 (Fittings), ASME Code Cases N-201 & N-254 (All Products for Nuclear Construction), ISO 4955A (General)

Applications

Alloy 800H and Alloy 800 HT have a wide range of applications in areas of elevated temperatures in furnace construction, in the chemical industry, in environmental protection equipment, in the automotive industry and in power plants. Typical applications include furnace muffles, containers, bins, holders in various heat treatment plants and burner components.

Because of their resistance to carburization and nitriding, the alloys are furthermore used in the areas of

  •  Steam/hydrocarbon reformers
  •  Ethylene pyrolysis
  •  Equipment for acetic anhydride and ketone production