Technical center

904L /1.4539/N08904

904L is a Molybdenum and Copper Alloyed Cr-Ni austenitic stainless steel with low Carbon content.

Its specific characteristics are:

Austenitic micro structure.

High resistance to:

Pitting and crevice corrosion.

Stress corrosion and corrosion fatigue.

Uniform corrosion.

Good ductility and weldability.


INSPECTION STANDARDS
Europe

EN 10217-7 Welded SS tubes for pressure purposes

EN 10296-2 Welded SS tubes for general purposes.


USA

ASTM A 249 Welded Austenitic SS Heat Exchanger Tubes

ASTM A 269 Welded and seamless Austenitic SS Tubing

ASTM A 312 Welded and seamless Austenitic SS Pipes

ASTM A 358 EF Welded Austenitic Pipe with filler metal

ASTM B 673 Welded Pipe

ASTM B 674 Welded Tube


CHEMICAL COMPOSITION, %

Grade
Cmax
Cr
Ni
Mo
Cu
PRENmin
904L 
0.020
19.5-20.5
19.5-20.5
24.0-26.0
1.2-2.0
35.0
EN 1.4539
0.020
19.0-21.0
19.0-21.0
24.0-26.0
1.2-2.0
35.0
UNS N08904
0.020
19.0-23.0
19.0-23.0
24.0-28.0
1.2-2.0
35.0


Cold forming

Excellent cold forming properties. The same properties as for other standard

austenitic stainless steels.


Hot forming

904L is slightly harder at higher temperatures than austenitic standard

grades. Forming at temperatures in the range 1000-1200 C does not require

any post heat treatment, if the operation is followed by a reasonable

fast cooling, (>600C/min).


Heat treatment

1120-1180 C followed by rapid cooling to at least 700 C. At

temperatures between 900-800 C, intermetallic phases that impair the

properties will form within a few minutes.


APPLICATIONS

Chloride containing environments

Heat exchanger tubes

Pipe systems within

Chemical and Petrochemical

Hydrometallurgy