Austenitic SS 904L

Austenitic SS 904L

What is Grade 904L Stainless Steel?

904l stainless steel is high purity steel with low sulphur content and also non-stabilized austenitic stainless steel with low carbon content. Alloy 904L (UNS N08904) is super-austenitic stainless steel that is designed for moderate to high corrosion resistance in a wide range of process environments.

SS 904L Material Specification – What Is 904L Steel?

SS 904L N08904 BS EN NO NAME 2562 B 677, B 674, B 673
904S13 1.4539 X1NiCrMoCuN25-20-5

SS 904L chemical composition and 904L material specifications is a combination of high chromium and nickel content in 904L, coupled with additions of molybdenum and copper, assure good to excellent corrosion resistance. ASTM 904L offers good resistance to several other inorganic acids, such as phosphoric acid and most organic acids.

Chemical Composition of SS 904L














SS 904L


















Corrosion Resistance

SS 904L with its high alloying element and alloy 904L composition gives it exceptionally good resistance to uniform corrosion, hence 904L steel cost is more than other stainless steels. 904L steel was originally developed to withstand an environment containing dilute sulphuric acid, and its few stainless steels provide full resistance in such an environment even at low temperatures. Hence, among 904L SS vs 316l SS, 904L is the better choice. 904L stainless steel pipe price is also affordable for various big industries, therefore, you can find 904L steel for sale.

The higher performance austenitic stainless steels such as 904L UNS N08904 have very good resistance to SSC due to the 904L stainless steel chemical composition. This resistance is ideal for equipment like SS 904L pipe and SS 904L plate because of the 904L price.

904L SS tubing and Alloy 904L pipe have proven to be a good alternative to most conventional stainless steels. Conventional stainless steels such as 304L and 316L, when compared to AISI 904L vs 316L, are susceptible to chloride stress corrosion cracking (SSC) under certain conditions. That is why the better steel is 904L vs 316L. 904L steel hardness is due to the 904L chemical composition and 904L steel price. You can also find the 904L material equivalent at various 904L stainless steel plate suppliers.

The 904L material composition and AISI 904L chemical composition make it less resistant to nitric acid than grades 304L and 310L, which are free of molybdenum. This steel grade needs to be solution treated following cold working, to achieve maximum stress corrosion cracking resistance under critical environments.

FABRICATION & Heat Treatment

AISI 904L stainless steel can be easily welded and processed by the standard fabrication process because of the 904L composition. 904L is quite ductile and forms easily, hence it is available at various 904L pipe suppliers and 904L plate suppliers. The addition of molybdenum and nitrogen implies more powerful processing equipment may be necessary when compared with the standard 304/304L grades.

Physical Properties of SS 904L

Grade Density (g/cm3) Elastic Modulus (GPa) Mean Co-eff of Thermal Expansion (μm/m/°C) Thermal Conductivity (W/m.K) Melting Range Specific Heat ( J/Kg.K) Electrical Resistivity (μΩ.m)
SS 904L 8 190 20-100°C at 100°C 1300-1390 0-100°C at 20°C
15.3 12.9 450 1

904L grade stainless steel hot working temperature is recommended from 1562–2102°F (850–1150°C). Due to alloy 904L chemical composition, normally hot working should be followed by a solution anneal and quench, but for 904L, if hot forming is discontinued at a temperature above 2012°F (1100°C) and the material is quenched directly thereafter, the material may be used without subsequent heat treatment because of the 904L stainless steel composition.


Alloy 904L material and SS 904L equivalent can be readily welded by most standard processes. Due to AISI 904L properties, it does not require preheat and post-weld heat treatments. Segregation is less evident in AISI 904L material, and this material is normally welded using a filler metal of the same composition as the base metal and can even be welded without filler metal. Grade 904L electrodes and rods are used for welding grade 904L steels according to AS 1554.6. Various materials made from SS 904 include 904L plate, 904L pipe, 904L round bar, 904L fittings, 904L sheet, 904L seamless pipe, 904L stainless steel tubing, 904L pipe fittings, 904L flanges. You can also get a 904L stainless steel plate, 904L stainless steel round bar, 904L stainless steel sheet, 904L stainless steel pipe from various 904L stainless steel pipe suppliers and other 904L stainless steel suppliers.


The chemical composition of SS 904L makes it ideal for various steel suppliers. 904L steel properties and AISI 904L specification make the SS 904L price a little higher, however, it is worth the money. Below are listed a few application of the SS 904 and 904L stainless steel equivalent:

  • Air Pollution Control — scrubbers for coal-fired power plants because of the SS 904L material properties
  • Chemical processing — 904L material properties are best for process equipment for the production of sulfuric, phosphoric, inorganic, and organic acids and the production of phosphate-based fertilizers 
  • Metallurgical Processing — pickling equipment using sulfuric acid 
  • Oil and Gas Production — 904L stainless steel properties help in offshore process equipment 
  • Pharmaceutical Industry — SS 904L properties help to produce process equipment 
  • Pulp and Paper — processing equipment due to good SS 904L price in the market
  • Seawater and Brackish Water — condensers, heat exchangers, and piping systems

904L stainless steel price also makes it useful for various other applications like:

  • Wiring in electrostatic precipitators because of the SS 904L equivalent casting grade
  • Oil refinery components
  • Seawater cooling devices due to 904L steel composition
  • Gas scrubbing plants
  • Pulp and paper processing industries
  • Acetic, phosphoric, and sulphuric acid processing plants
  • 904L tubing and Alloy 904L tubing