Z2NCDU25-20
Z2NCDU25-20 Stainless Steel Supplier in Tunisia
Z2NCDU25-20 is a French AFNOR designation associated with 904L stainless steel, a high-alloy austenitic stainless steel known for its excellent corrosion resistance in many aggressive industrial environments. It is commonly associated with UNS N08904, EN 1.4539, and X1NiCrMoCu25-20-5.
With high levels of nickel, chromium, molybdenum and copper, 904L stainless steel is designed to provide improved resistance to several corrosive media, particularly sulfuric acid solutions under suitable operating conditions. It is used in chemical processing, fertilizer production, phosphoric acid plants, oil and gas facilities, marine equipment and other demanding industrial applications.
Emirerri Steel supplies stainless steel products according to project requirements, applicable standards, dimensions and material specifications. Availability and certification are confirmed against each enquiry.
Key Characteristics
- Material grade: Z2NCDU25-20
- Common equivalent grade: 904L stainless steel
- UNS designation: N08904
- EN material number: 1.4539
- EN designation: X1NiCrMoCu25-20-5
- Material type: Austenitic stainless steel
- Corrosion resistance: Excellent in many specified acidic and chloride-containing environments, depending on conditions
- Weldability: Generally good with appropriate procedures and consumables
- Fabrication: Suitable for forming and machining with suitable controls
- Typical applications: Chemical processing, fertilizer plants, phosphoric acid production, marine systems and industrial piping
Z2NCDU25-20 Chemical Composition
The following values are typical indicative composition ranges for 904L. The exact limits must be verified against the governing material standard and product form.
| Element | Typical composition (% by weight) |
|---|---|
| Carbon (C) | ≤ 0.020 |
| Silicon (Si) | ≤ 0.70 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.010 |
| Chromium (Cr) | 19.0–21.0 |
| Nickel (Ni) | 24.0–26.0 |
| Molybdenum (Mo) | 4.0–5.0 |
| Copper (Cu) | 1.2–2.0 |
| Nitrogen (N) | ≤ 0.15 |
| Iron (Fe) | Balance |
The combination of chromium, nickel, molybdenum and copper contributes to the alloy’s corrosion resistance. Low carbon content helps reduce the risk of sensitization during welding when appropriate fabrication practices are followed.
Z2NCDU25-20 Mechanical Properties
Mechanical properties vary according to product form, thickness, heat treatment and the applicable specification. The values below are indicative and should not replace certified product data.
| Property | Indicative value |
|---|---|
| Tensile strength | Approximately 580–800 MPa |
| 0.2% proof strength | Typically 220 MPa minimum for certain product forms |
| Elongation | Depends on product form and governing standard |
| Hardness | Commonly limited to approximately 250 HBW maximum under applicable specifications |
| Material condition | Usually supplied in a solution-annealed condition, as specified |
For design, procurement and inspection, the material test certificate (MTC) and the exact product standard should be used to confirm compliance.
Z2NCDU25-20 Physical Properties
| Physical property | Approximate value |
|---|---|
| Density | 8.0 g/cm³ |
| Thermal conductivity | 14 W/m·K |
| Electrical resistivity | 0.85 µΩ·m |
| Mean thermal expansion, 20–100°C | 17.5 × 10⁻⁶/K |
| Material structure | Austenitic |
These are reference values. Actual values may vary with temperature, product condition and source specification.
Corrosion Resistance
One of the principal reasons for selecting 904L stainless steel is its resistance to a range of corrosive environments.
Resistance to Acidic Environments
The alloy is used in selected sulfuric acid and phosphoric acid services, subject to acid concentration, temperature, impurities, flow conditions and other process variables. These factors should be evaluated before selecting the grade for a specific plant.
Resistance to Pitting and Crevice Corrosion
Its chromium and molybdenum content improves resistance to localized corrosion compared with many conventional stainless steel grades. However, performance depends on chloride concentration, temperature, surface condition and the geometry of the equipment.
Resistance to Chloride-Containing Environments
904L can be suitable for certain marine and chloride-containing applications. It is not immune to all chloride-related corrosion, and it should not automatically be considered a replacement for duplex or super duplex stainless steels in every service.
Intergranular Corrosion Resistance
The low carbon content helps reduce the risk of intergranular corrosion associated with carbide precipitation during welding or heating. Correct welding procedures and post-fabrication practices remain important.
Common Standards and Product Forms
The applicable standard depends on whether the material is supplied as plate, sheet, bar, pipe, tube, fittings or forgings.
| Product form | Commonly referenced standards |
|---|---|
| Stainless steel sheets and plates | EN 10088-2; ASTM A240, where the grade and product scope are covered |
| Stainless steel bars | EN 10088-3, subject to product specification |
| Seamless stainless steel tubes and pipes | EN 10216-5; ASTM A312 or ASTM A269 where applicable |
| Welded stainless steel tubes and pipes | EN 10217-7; applicable ASTM pipe or tube specifications |
| Pipe fittings and flanges | Applicable product standards and material specifications must be confirmed individually |
Important: Not every standard listed covers every product form or grade in every size. Confirm the exact standard, dimensions, manufacturing route, inspection requirements and certification before placing an order.
Equivalent Designations
| Standard or system | Designation |
|---|---|
| AFNOR | Z2NCDU25-20 |
| AISI / common industry name | 904L |
| UNS | N08904 |
| EN material number | 1.4539 |
| EN designation | X1NiCrMoCu25-20-5 |
These designations are commonly associated with the same alloy family. Formal equivalence should be checked against the purchasing specification and applicable standard; similar designations alone do not guarantee that products are interchangeable.
Welding and Fabrication
904L stainless steel generally offers good weldability when suitable procedures and filler materials are selected.
Recommended considerations include:
Use welding procedures qualified for the material thickness, joint design and service conditions.
Select filler metal compatible with 904L and the required corrosion performance.
Maintain appropriate cleanliness and avoid contamination from carbon steel tools or work surfaces.
Control heat input and interpass temperature in accordance with the qualified welding procedure.
Use suitable pickling, passivation and cleaning procedures where required to restore corrosion performance.
Confirm whether any post-weld treatment is necessary for the application and governing specification.
Machining and forming should be performed using suitable tooling, feeds and work-hardening controls.
Applications
Chemical Processing
Used for selected tanks, piping systems, heat exchangers and process equipment exposed to corrosive chemicals.
Phosphate and Fertilizer Industries
Suitable for evaluating in certain phosphoric acid production and fertilizer-processing equipment. Material selection must account for acid chemistry, impurities, operating temperature and erosion conditions.
Oil and Gas
Used in selected process equipment and piping applications where its corrosion resistance meets the operating requirements.
Marine and Offshore
Considered for selected components exposed to marine atmospheres and certain chloride-containing environments, with service-specific corrosion assessment.
Industrial Piping and Equipment
May be specified for tanks, vessels, valves, heat exchangers, tubing and other components when the design conditions and product standards permit its use.
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