Stainless Steel 904L Seamless Pipes & Tubes Manufacturer & Supplier

SS 904L (UNS N08904) is a high-alloy austenitic stainless steel with elevated nickel (25%), molybdenum (4.5%), and copper content. It provides exceptional corrosion resistance in sulfuric acid, phosphoric acid, and chloride-containing environments, bridging the gap between standard stainless steels and nickel alloys.

UNS: N08904 | Category: Austenitic Stainless Steel | Werkstoff Nr: 1.4539 | EN Name: X1NiCrMoCu25-20-5

Size Range

Outer Diameter: 1/4" NPS to 10" NPS (6.35mm to 273.1mm OD)

Wall Thickness: SCH 5S to SCH 80S

Chemical Composition (%)

C	Mn	Si	Cr	Ni	Mo	Cu	P	S
0.020 max	2.00 max	1.00 max	19.0-23.0	23.0-28.0	4.0-5.0	1.0-2.0	0.045 max	0.035 max

Mechanical Properties

Tensile Strength: 490 MPa min
Yield Strength: 220 MPa min
Elongation: 35% min
Hardness: 90 HRB max

Physical Properties

Density: 7.95 g/cm3
Melting Range: 1350-1400 C
Thermal Conductivity: 12.2 W/m-K
Electrical Resistivity: 950 nOhm-m
Specific Heat: 460 J/kg-K
Coeff. of Thermal Expansion: 15.8 um/m-C

Corrosion Resistance

Pitting Resistance (PREN): ~36
Max Service Temp (Oxidizing): 450 C
Intergranular Corrosion: Highly resistant
Stress Corrosion Cracking: Excellent resistance
General Corrosion Rate: <0.01 mm/yr in dilute sulfuric acid
Seawater Resistance: Excellent

Applicable Standards

ASTM A312 / ASME SA312
ASTM B673 / ASME SB673
ASTM B674 / ASME SB674
DIN EN 10216-5

Applications

Sulfuric acid handling and storage
Phosphoric acid production
Seawater cooling systems
Bleaching equipment in pulp mills
Organic acid processing
Gas scrubbing systems

Industries Served

Chemical Processing
Fertilizer
Pulp & Paper
Marine
Mining

Key Advantages

Exceptional sulfuric acid corrosion resistance
Outstanding pitting resistance (PREN ~36)
Copper addition improves resistance to reducing acids
Excellent SCC resistance due to high nickel content
More economical than nickel alloys for many acid applications

Equivalent Grades

ASTM: N08904
JIS: SUS 890L
Trade: Uranus B6