Heat Resistant Alloys

NAS 800H・NAS 800T

  • NAS 800H
  • JISNCF 800H
  • UNSN08810
  • DIN/EN1.4876
  • NAS 800T
  • JIS
  • UNSN08811
  • DIN/EN1.4876
, comparable to Incoloy® 800H Alloy

NAS 800H (NCF 800H, UNS N08810)/NAS 800T (UNS N08811) are nickel-iron-chromium alloys that provide high strength and excellent resistance to oxidation and carburization at high temperatures. High creep strength is attained through control over crystal grains—via high temperature heat treatment, together with fine control over carbon, titanium, and aluminum content. Nippon Yakin provides this product in plate, sheet, and strip forms.

* Incoloy is a registered trademark of Special Metals Corporation.

Products & Materials

NAS 800H・800TProductsPDF(243KB)

Chemical Composition [NAS 800H]32Ni-20Cr-0.2Ti-0.2Al
[NAS 800T]32Ni-20Cr-0.5Ti-0.5Al
Product shape
Workability Whether for hot working or cold working, NAS 800H/800T offer workability similar to austenitic stainless steels. For hot working, temperatures should be between 1000 and 1230℃, although light work may be done at temperatures as low as 850℃. To prevent cracks, we recommend avoiding the temperature range between 650 and 800℃. Although cold workability is similar to austenitic stainless steels, work hardening tends to be slightly lower.
Weldability As with standard austenitic stainless steels, NAS 800H/800T may be welded using techniques such as TIG, MIG, and shield metal arc welding. AWS ERNiCr-3/AWS ENiCrFe-2 welding rods are often used.
Heat Treatment NAS 800H/800T exhibit an austenite structure similar to austenitic stainless steels, and appropriate heat treatment procedures and requirements are similar. Typical heat treatments are as follows:
・Solution treatment: 1100~1170℃; rapid cooling
For applications requiring creep rupture strength in high-temperature environments, the following ASTM B409 heat treatment may be used:
・Solution treatment:
1121℃ minimum (UNS N08810)
1149℃ minimum (UNS N08811)
Properties at High Temperatures Because of its high nickel and chromium content, NAS 800H/800T resist oxidation and carburization at high temperatures. NAS 800H/800T are superior to Type 310S and approach NAS 600 in resistance to oxidation. Offering superior high-temperature strength nearly equal to NAS 600, NAS 800H/800T are widely used in applications requiring heat resistance, as they do not become brittle due to sigma phase precipitation during use. While NAS 800 is generally used at temperatures below 600℃, NAS 800H/800T are recommended for applications requiring superior creep properties at higher temperatures.
Corrosion resistance NAS 800H/800T offer superior corrosion resistance in oxidizing corrosive environments such as nitric acid or nitric acid-sulfuric acid. Likewise, they perform well in sodium salt and other molten salt environments, with stress corrosion cracking resistance surpassing standard austenitic stainless steels.
Applications NAS 800H/800T are widely used in chemical plants, heat treatment furnaces and other high-temperature environments.