904L, 1.4539, N08904

904L is an austenitic stainless steel. Compared to 316L, its increased molybdenum (Mo) content enhances resistance to localized attack such as pitting and crevice corrosion, particularly in chloride-rich environments. Additionally, the presence of copper (Cu) provides excellent corrosion resistance across all concentrations of sulfuric acid. The high alloy content of 904L improves its resistance to chloride stress corrosion cracking, though it remains susceptible under extreme conditions. Furthermore, its low carbon content prevents sensitization during welding, effectively reducing the risk of intergranular corrosion. Applications include piping systems, pollution control equipment, heat exchangers, and bleaching systems.

Chemical Composition

• Nickel (Ni):23-28%
• Chromium (Cr):19-23%
• Carbon (C):≤0.02%
• Copper (Cu):1-2%
• Molybdenum (Mo):4-5%
• Manganese (Mn):≤2%
• Silicon (Si):≤1.0%
• Iron (Fe):Balance

904L （1.4539）
Summary	1.4539 (alloy 904L) is an austenitic special steel with high molybdenum content as well as addition of copper and extremely low carbon content.
Standard Product Forms
Chemical Composition Wt,%		Min	Max.		Min.	Max.	Min.	Max.
Ni	23	28	Cu	1.0	2.0	C	0.02
Cr	19	23	Co			Si	1.0
Fe			Al			P	0.04
Mo	4	5	Ti			S	0.03
W			Mn		2.0	N
Physical Constants	Density,g/cm³ 8.24
Melting Range,℃
Typical Mechanical Properties	Elastic Modulus (Gpa)	200
Mean Co-eff of Thermal Expansion (μm/m/℃)	0-100℃	15
0-315℃
0-538℃
Thermal Conductivity (W/m.k)	At 20℃	13
At 500℃
Specific Heat 0-100 ℃ (J/Kg.K)	500
Elec Resistivity (nΩ.m)	850
Tensile Strength (Mpa) min	490
Yield Stregth 0.2% Proof (Mpa) min	220
Elongation (% in 50 MM) min	35

We have products:

904L seamless tube steel tube; 1 / 4 Inch Sch10s TP347 / 347H Stainless Steel Welded Multi-core Coiled Tubing; 3 / 4 Inch Sch40s Precision Stainless Steel Tube, TP347 / 347H Seamless Tube; ASTM A182 F904L Flange, Stainless Steel 904L Flanges;