Nickel-based super alloy: Incoloy 840 (Alloy 840/UNS S33400)

What is Incoloy 840?

Nickel-based super alloy Incoloy 840 (Alloy 840/UNS S33400): Incoloy 840 nickel-based alloy: The Cr content in Incoloy 840 nickel-based alloy alloy is usually 18-20%, and the nickel content is 19-21%. Incoloy 840 alloy is a kind of austenitic stainless steel containing titanium and aluminum. It contains enough chromium to form and maintain a sufficient scale of chromium oxide to protect it under high temperature conditions and is more resistant to high temperatures than traditional chromium-nickel stainless steels such as 304; The higher nickel content makes it have better oxidation resistance than the standard 18-8 stainless steel, and its oxidation resistance is not inferior to higher-grade alloys whose service temperature is as high as 1900°F (1038°C) . Therefore, Incoloy 840 alloy is an ideal material for manufacturing electric heating pipes, automobile emission control systems and other high temperature resistant products.

Chemical composition % of Nickel-based super alloy: Incoloy 840 (Alloy 840/UNS S33400):

C≤ Si≤ Mn≤ P≤ S≤ Cr≥ Ni≥ Mo≥ Cu≤
0.08 1.00 1.00 0.040 0.030 18.0-20.0 19.0-21.0
Other N≤ Al≤ Ti≤ Fe≤ Co≤ V≤ W≤ Nb≤
0.15-0.60 Margin

Physical properties of Nickel-based super alloy: Incoloy 840 (Alloy 840/UNS S33400):

  • Incoloy 840 nickel-based alloy elastic modulus: 29×106PSI (200 GPA)
  • Incoloy 840 nickel-based alloy density: 0.29 lb/in3 (8.03 g/cm3)

Incoloy Thermal conductivity of 840 nickel-based alloy:

°F °C Btu·in/h·ft2·°F W/m·K
68-132 20-56 90.0 12.9
68-204 20-96 93.6 13.5
68-333 20-167 104.4 15.0
68-465 20-241 114.0 16.3
68-590 20-310 122.4 17.6
68-726 20-385 133.2 19.2
68-848 20-453 145.2 20.9
68-972 20-522 156.0 22.4
68-1101 20-594 168.0 24.1
68-1198 20-648 181.2 26.0

Application areas of nickel-based alloy incoloy 20 (UNS N08020):

  • Heating pipes, containers, baskets and chains used in sulfuric acid pickling plants.
  • Sea water cooling heat exchanger, marine product pipeline system, acid gas environment pipeline.
  • Heat exchanger, evaporator, washing, dip tube, etc. in phosphoric acid production.
  • Air heat exchanger in petroleum refining.
  • Food engineering, chemical process.
  • Flame retardant alloy for high pressure oxygen application.
  • Heat exchange tubes
  • Pipe fittings
  • Flanges
  • Valves

Variety specifications and supply status of Nickel-based super alloy: Incoloy 840 (Alloy 840/UNS S33400):

Variety classification:

Yaang Pipe Industry can produce various specifications of Incoloy840 seamless pipe, Incoloy840 steel plate, Incoloy840 round bar, Incoloy840 forgings, Incoloy840 flangeIncoloy840 pipe fittings, Incoloy840 welded pipe , Incoloy840 steel strip, Incoloy840 wire and supporting welding materials. 

Delivery status:

  • Seamless pipe: solid solution + acid white, length can be set;
  • Plate: solid solution, pickling, trimming;
  • Welded pipe: solid solution acid white + RT% flaw detection;
  • Forging: annealing + car polish; Bars are forged and rolled, surface polished or car polished;
  • Strips are delivered after cold rolling, solid solution soft state, and deoxidized;
  • Wire rods are finely ground in solid solution pickled disk or straight strips, solid solution straight strips Delivery in light state.

Source: China Incoloy 840 Flanges Manufcturer – Yaang Pipe Industry (

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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