1.4539 Stainless Steel | AISI 904L/UNS N08904 | BS EN 10088

1.4539 Stainless Steel | AISI 904L/UNS N08904 | BS EN 10088

904L grade stainless steel is a stainless steel grade containing very high amounts of chromium, nickel and molybdenum. This grade, also called super austenitic stainless steel, has very good corrosion resistance. This stainless steel grade is particularly resistant to sulfuric acid and heavily chlorinated environments. This stainless steel quality, which has a much better corrosion resistance than 1.4462 duplex quality stainless steel material, has a very good antimagnetic structure.

Chemical Properties

Mechanical Properties

Corrosion resistance

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.

Application

904L quality stainless steel is a stainless steel quality that is frequently used in highly corrosive environments where there are very difficult conditions. 904L (1.4539) quality stainless steel material is preferred in acidic environments that normal stainless steel cannot withstand, in the petro-chemical industry where excessive rusting and corrosion occur, in paper mills, purification facilities, gas production and filling facilities, medical applications, in short, wherever corrosion resistance must be at a high level. is being done.