904L Stainless Steel Seamless Pipe Non-stabilised Low Carbon For Pressure Vessels

 
904L is a non - stabilised low carbon high alloy austenitic stainless steel. The addition of
copper to this grade gives it greatly improved resistance to strong reducing acids,
particularly sulphuric acid. It is also highly resistant to chloride attack - both pitting /
crevice corrosion and stress corrosion cracking. This grade is non - magnetic in all
conditions and has excellent weldability and formability. The austenitic structure also gives
this grade excellent toughness, even down to cryogenic temperatures. 904L does have very
substantial contents of the high cost ingredients nickel and molybdenum. Many of the
applications in which this grade has previously performed well can now be fulfilled at lower
cost by duplex stainless steel 2205 (S31803 or S32205), so it is used less commonly than in
the past.
 

904L Stainless Steel Pipes and Tubes Product Range
904L Stainless Steel Pipes and Tubes Specifications: ASTM A/ASME SA 269/677 904L Stainless Steel Pipes and Tubes Sizes
(Seamless): 1/2" NB - 8" NB
904L Stainless Steel Pipes and Tubes Sizes (ERW): 1/2" NB - 24" NB
904L Stainless Steel Pipes and Tubes Sizes (EFW): 6" NB - 100" NB

904L Stainless Steel Pipes and Tubes Wall Thickness available:
Schedule 5S - Schedule XXS (heavier on request)
904L Stainless Steel Pipes and Tubes Other Materials Testing:
NACE MR0175, H2 SERVICE, OXYGEN SERVICE, CRYO SERVICE, etc

These properties are specified for flat rolled product (plate, sheet and coil) in ASTM B625. Similar but not necessarily identical properties are specified for other products such as pipe, tube and bar in their respective specifications

Corrosion Resistance
Although originally developed for its resistance to sulphuric acid it also has a very high resistance to a wide range of
environments. A PRE of 35 indicates that the material has good resistance to warm sea water and other high chloride
environments. High nickel content results in a much better resistance to stress corrosion cracking than the standard austenitic grades. Copper adds resistance to sulphuric and other reducing acids, particularly in the very aggressive "mid concentration" range.
In most environments 904L has a corrosion performance intermediate between the standard austenitic grade 316L and the very highly alloyed 6% molybdenum and similar "super austenitic" grades.
In aggressive nitric acid 904L has less resistance than molybdenum - free grades such as 904L and 310L.
For maximum stress corrosion cracking resistance in critical environments the steel should be solution treated after cold work.
Heat Resistance
Good resistance to oxidation, but like other highly alloyed grades suffers from structural instability (precipitation of brittle
phases such as sigma) at elevated temperatures. 904L should not be used above about 400C.
Heat Treatment

Solution Treatment (Annealing) - heat to 1090 - 1175C and cool rapidly. This grade cannot be hardened by thermal treatment. 

Welding

APPLICATIONS FIELD :