What is 904L stainless steel used for?

What is 904L stainless steel used for?

 

General Properties
Alloy 904L (UNS N08904) is a superaustenitic stainless steel designed to provide moderate to high corrosion resistance in a wide range of process environments. The combination of high chromium and nickel contents, plus the additions of molybdenum and copper, ensure good to excellent corrosion resistance. 904L has a highly alloyed chemistry - 25% nickel and 4.5% molybdenum, which provides good resistance to chloride stress corrosion cracking, pitting, and general corrosion resistance, superior to the 316L and 317L molybdenum reinforced stainless steels. Alloy 904L was originally developed to withstand environments containing dilute sulfuric acid. It also has good resistance to other inorganic acids, such as hot phosphoric acid, as well as most organic acids. Alloy 904L is easily welded and fabricated by standard shop fabrication practices. Applications
Air pollution control — Coal-fired power plant scrubbers
Chemical processing — Process equipment for the production of sulfuric acid, phosphoric acid, inorganic and organic acids, and for 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 — Process equipment
Seawater and brackish water — Condensers, heat exchangers, and piping systems

Chemical Analysis

Weight % (all values are maximum unless a range is otherwise indicated)

Nickel	23.0 min.-28.0 max.	Silicon	1.00
Chromium	19.0 min.-23.0 max.	Phosphorus	0.045
Molybdenum	4.0 min.-5.0 max.	Sulfur	0.035
Copper	1.0-2.0 max.	Iron	Balance
Manganese	2.00

 

ALLOY	Corrosion Rate, mm/year
316L	0.88
317LMN	0.29
904L	0.056
254 SMO®	0.01

 

ALLOY	Corrosion Rate, mm/year
316L	>5
904L	1.2
254 SMO®	0.05

 

Uniform Corrosion in pickling acid* at 25°C

ALLOY	Corrosion Rate, mm/year
316L	>6
904L	0.47
254 SMO®	0.27
654 SMO®	0.06