1.4539 904L N08904 Stainless Steel Seamless Round Pipe Tube
- Model
- 1.4539 904L N08904
Item specifics
- Delivery condition
- +AT
- Surface condition
- Acid pickled
- Length range
- 50-12000mm
Review
Description
* Seawater cooling equipment
* Chemical processing for sulphuric, phosphoric and acetic acids
* Gas washing
* Condenser tubes
* Control and instrumentation
* Heat exchangers
Industries predominantly using this Grade
* Chemical processing
* Oil and gas
* Pharmaceutical
Typical Manufacturing Specifications
* ASTM A213
* ASTM A269
* ASTM A312
* BS EN 10216 pt.5
* Also individual customer specifications.
UNS NO8904, commonly known as 904L, is a low carbon high alloy austenitic stainless steel which is widely used in applications where the corrosion properties of AISI 316L and AISI 317L are not adequate.
The addition of copper to this grade gives it corrosion resistant properties superior to the conventional chrome nickel stainless steels, in particular to sulphuric, phosphoric and acetic acids. However, there is limited use with hydrochloric acids. It also has a high resistance to pitting in chloride solutions, a high resistance to both crevice and stress corrosion cracking. Alloy 904L performs better than other austenitic stainless steels due to the higher alloying of nickel and molybdenum.
The grade is non-magnetic in all conditions and has excellent formability and weldability. The austenitic structure also gives this grade excellent toughness, even down to cryogenic temperatures.
The high chromium content promotes and maintains a passive film which protects the material in many corrosive environments.904L has a greater resistance to precipitation of ferrite and sigma phases on cooling and welding than other stainless steels containing molybdenum such as 316L and 317L. There is no risk of intercrystalline corrosion on cooling or welding due to the low carbon content. Its maximum service temperature is at 450°C.
The corrosion resistance of grade 904L is intermediate between super austenitic grades, with 6% molybdenum content, and standard 316L austenitic grades. Grade 904L is 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.
Heat Resistance
Grade 904L stainless steels offer good oxidation resistance. However, the structural stability of this grade collapses at high temperatures, particularly above 400°C.
Heat Treatment
Grade 904L stainless steels can be solution heat-treated at 1090 to 1175°C, following by rapid cooling. Thermal treatment is suitable for hardening these grades.
Welding
Welding of grade 904L stainless steels can be performed using all conventional methods. This grade does not require pre-heat and post-weld heat treatments. Grade 904L can be subjected to hot cracking in constrained weldment. Grade 904L electrodes and rods are used for welding grade 904L steels according to AS 1554.6.
Fabrication
Grade 904L stainless steels are high purity steels with low sulphur content. They can be machined using any standard methods. These grades can be readily bent to a small radius under cold conditions. Although subsequent annealing is not required in most cases, it should be carried out when the fabrication is performed under severe stress corrosion cracking conditions.
