|   904L Super Austenstic 
Stainless Steel(1.4539,UNS N08904)    
904L is a high-alloy austenitic stainless steel with low carbon content. The grade 
is intended for use under severe corrosive conditions. It has been application 
proved over many years and was originally developed to resist corrosion in dilute 
sulfuric acid. It is standardized and approved for pressure vessel use in several 
countries. Structurally, 904L is fully austenitic and is less sensitive to precipitation 
ferrite and sigma phases than conventional austenitic grades with high molybdenum 
content. Characteristically, due to the combination of relatively high contents 
of chromium, nickel, molybdenum and copper 904L has good resistance to general 
corrosion, particularly in sulfuric and phosphoric conditions. Chemical 
Composition %  C Cr Cu Mn Mo Ni P S Si   0.02 19.0-23.0 1.0-2.0 2.0 
4.0-5.0 23.0-28.0 0.045 0.035 1.0 
  TYPICAL 
APPLICATIONS  Production and transport 
of sulfuric acid  Metal pickling in sulfuric acid  Production and concentration 
of phosphoric acid  Use in seawater, brackish water, condensers, heat exchangers 
and pipe work in general  Paper and allied industries  Gas washing  Chemical 
and pharmaceutical industries
  TENSILE 
REQUIREMENTS  Tensile Strength (KSI) 70   Yield Strength (KSI) 25  
KSI can be converted to MPA (Megapascals) by multiplying by 6.895.  |