High-Strength Austenitic Steels
X1NiCrMoCu25-20-5 – 1.4539 / 904L / N08904 / Z2NCDU25-20 / 904S13 / 2562 / 00H22N24M4TCu
X1NiCrMoCu25-20-5 – 1.4539 stainless steel is a super austenitic stainless steel designed for applications requiring extremely high corrosion resistance. Commonly known as 904L, this grade delivers superior performance in highly aggressive chemical environments, significantly exceeding the corrosion resistance of standard 304 and 316L stainless steels. For this reason, it is widely used in demanding industries such as chemical processing, petrochemical plants, and marine applications.
The chemical composition of this steel is highly alloyed, typically containing approximately 19–23% chromium, 23–28% nickel, 4–5% molybdenum, and 1–2% copper (Cu). The high nickel content enhances overall corrosion resistance and structural stability, while molybdenum provides strong resistance to pitting and crevice corrosion, especially in chloride-rich environments. The addition of copper significantly improves resistance to acidic environments, particularly against sulfuric acid. This unique combination makes 904L highly resistant to severe chemical exposure.
Due to its low carbon content (L grade), the risk of intergranular corrosion after welding is minimal, ensuring safe use in welded constructions. The material is suitable for both hot and cold forming processes. Mechanically, it offers moderate strength combined with high ductility, allowing it to withstand impact and deformation without failure.
Another advantage of 904L stainless steel is its hygienic and aesthetic surface properties. Its smooth and bright surface finish facilitates easy cleaning and provides an attractive appearance, making it suitable not only for industrial use but also for architectural and high-end decorative applications.
Overall, X1NiCrMoCu25-20-5 – 1.4539 (904L) is a premium-grade stainless steel that delivers reliable, long-lasting performance even under extremely harsh conditions. It is a preferred solution for applications requiring maximum corrosion resistance and durability.
Main Application Areas
- Chemical and petrochemical processing plants
- Systems exposed to sulfuric acid and aggressive chemicals
- Marine equipment and seawater-exposed components
- Heat exchangers and process equipment
- Tanks, pipes, and pressure vessel systems
- Specialized applications in the food and pharmaceutical industries
- Architectural and decorative stainless steel projects
- Oil and gas industry equipment
- All industrial applications requiring extreme corrosion resistance
Thanks to these properties, 904L stainless steel stands out as a high-performance engineering material capable of maintaining durability and reliability even in the most demanding environments.
General Identity
X1NiCrMoCu25-20-5 – 1.4539
| Grade |
X1NiCrMoCu25-20-5 |
| Number |
1.4539 |
| Classification |
Austenitic Stainless Steel |
Equivalent Grades
>X1NiCrMoCu25-20-5 – 1.4539
| USA |
904L N08904 |
| France, AFNOR |
Z2NCDU25-20 |
| England, BS |
904S13 |
| Sweden, SS |
2562 |
| Poland, PN |
00H22N24M4TCu |
Standards
X1NiCrMoCu25-20-5 – 1.4539
| Standard 1 |
EN 10088-2: 2005 |
| Standard 2 |
EN 10088-3: 2005 |
| Standard 3 |
EN 10028-7: 2007 |
| Standard 4 |
EN 10217-7: 2005 |
| Standard 5 |
EN 10296-2: 2005 |
| Standard 6 |
EN 10253-3: 2008 |
| Standard 7 |
EN 10253-4: 2008 |
| Standard 8 |
EN 10272: 2007 |
| Standard 9 |
EN 10250-4: 2000 |
| Standard 10 |
EN 10297-2: 2005 |
| Standard 11 |
EN 10088-1: 2005 |
| Standard 12 |
EN 10088-4: 2009 |
| Standard 13 |
EN 10088-5: 2009 |
Chemical Composition
X1NiCrMoCu25-20-5 – 1.4539
| C |
max 0.02 |
| Si |
max 0.70 |
| Mn |
2.00 |
| Ni |
24 – 26 |
| P |
max 0.03 |
| S |
max 0.01 |
| Cr |
19 – 21 |
| Mo |
4 – 5 |
| N |
max 0.15 |
| Cu |
1.2 – 2 |
Mechanical Properties
X1NiCrMoCu25-20-5 – 1.4539
| Rm – Tensile strength (MPa) (+A) |
520 – 730 |
|
| Rm – Tensile strength (MPa) (+AT) |
520 – 720 |
|
| Rp0.2 0.2% proof strength (MPa) (+AT) |
220 – 230 |
|
| Rp0.2 0.2% proof strength (MPa) (+A) |
220 – 260 |
|
| KV – Impact energy (J) transverse (+A) |
+20° – 60 |
-196° – 60 |
| KV – Impact energy (J) longitud (+A) |
+20° – 100 |
|
| KV – Impact energy (J) transverse (+A) |
+20° – 90 |
-196° – 60 |
| KV – Impact energy (J) longitud (+A) |
+20° – 120 |
|
| A – Min. elongation at fracture (%) (+A) |
30 – 35 |
|
| A – Min. elongation at fracture (%) transverse., (+AT) |
30 |
|
| A – Min. elongation at fracture (%) longitud., (+AT) |
35 |
|
| Birinel hardness (HB) (+A): |
230 |
|
| Birinel hardness (HB) (+AT): |
220 |
|
