|Material Grade||SS 904L|
|Single Piece Length||6 meter|
Common Applications of 904L
▲ Air Pollution Control — scrubbers for coal-fired power plants
▲ Chemical Processing — 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 — offshore process equipment
▲ Pharmaceutical Industry — process equipment
▲ Pulp and Paper — processing equipment
▲ Seawater and Brackish Water — condensers, heat exchangers and piping systems
|904L Chemical Composition|
Percent by Weight
19.00 - 23.00 maximum
23.00 – 28.00 maximum
1.00 – 2.00 maximum
2372 – 2534 °F
Specific Heat Capacity at 32 - 212°F
Thermal Conductivity at 212°F
Elastic Modulus at 68°F
28 x 106 psi
Alloy 904L can be easily welded and processed by standard shop fabrication practices.
● Cold Forming
904L is quite ductile and forms easily. The addition of molybdenum and nitrogen implies more powerful processing equipment may be necessary when compared with the standard 304/304L grades.
● Hot Forming
Working temperatures of 1562 – 2102°F (850 –1150°C) are recommended for hot working processes. 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. It is important that the entire workpiece be quenched from temperatures above 2012°F (1100°C). In the event of partial heating or cooling below 2012°F (1100°C), or if the cooling has been too slow, hot working should always be followed by a solution anneal and quenching. 904L should be solution annealed at 1940 – 2084°F (1060 –1140°C).
The cold work hardening rate of Alloy 904L makes it less machinable than 410 and 304 stainless steels.
Alloy 904L can be readily welded by most standard processes. Austenitic plate materials have a homogeneous austenitic structure with an even distribution of alloying elements. Solidification after welding causes the redistribution of certain elements such as molybdenum, chromium and nickel. These segregations remain in the cast structure of the weld and can impair the corrosion resistance in certain environments. Segregation is less evident in 904L, 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.