FORTSCHRITT
UNS N08904 / IN 1.4539 Stainless Steel Plate for Corrosive Service
904L stainless steel plate is a low-carbon, high-alloy austenitic stainless steel used in chemical processing and other demanding corrosion environments. Its combination of chromium, Nickel, molybdenum and copper provides improved resistance to many acidic and chloride-containing conditions compared with conventional stainless steels such as 316L.
For purchasing enquiries, specify 904L / UNS N08904, the required material standard, plate dimensions, quantity and operating environment. QIDAMT can review your requirements for a quotation, with material availability, inspection documents and delivery conditions confirmed before ordering.
What Is 904L Stainless Steel?
904L is commonly identified by the following designations:
| Identification system | Designation |
|---|---|
| Common grade name | 904L |
| UNS designation | N08904 |
| European material number | IN 1.4539 |
| European steel name | X1NiCrMoCu25-20-5 |
| Microstructure | Austenitic |
These designations identify the material family. The purchase order should also specify the applicable product standard and edition, because chemical limits, mechanical requirements and inspection conditions must follow the agreed specification.
904L is selected primarily for corrosion performance. It should not be chosen solely because it contains more alloying elements than 304L or 316L; suitability depends on the actual service conditions.
Product Specifications and Ordering Options
| Artikel | Information to specify |
|---|---|
| Produkt | 904L stainless steel plate or sheet |
| Material identification | UNS N08904 / IN 1.4539 |
| Product standard | ASTM A240/A240M, or the applicable EN product standard |
| Pressure-equipment requirements | State the required ASME specification, design code and certification |
| Dicke | Required nominal thickness and permitted tolerance |
| Width and length | Finished dimensions in millimetres |
| Oberflächenbeschaffenheit | Warmgewalzt, geglüht und gebeizt; cold rolled or polished finish where applicable |
| Delivery condition | State the required heat-treatment and surface condition |
| Edges | Mill edges or cut edges, as agreed |
| Menge | Number of plates, total weight or both |
| Inspection documents | Required certificate type, test results and traceability |
| Packing and delivery | Destination, packing requirements and delivery terms |
| MOQ and lead time | Confirmed against the requested specification and quantity |
Reference enquiry formats include 1500 × 3000 mm Und 2000 × 6000 mm, with thickness stated separately. These are examples for preparing an enquiry, not a stock list. Custom dimensions and processing requirements should be submitted for review.
Chemische Zusammensetzung
The following table shows published composition limits for UNS N08904. Use the agreed product standard and the supplied material certificate for order acceptance.
| Element | Content by weight |
|---|---|
| Kohlenstoff, C | ≤ 0.020% |
| Chrom, Cr | 19.0–23.0% |
| Nickel, In | 23.0–28.0% |
| Molybdän, MO | 4.0–5.0% |
| Kupfer, Cu | 1.0–2.0% |
| Mangan, Mn | ≤ 2.00% |
| Silizium, Und | ≤ 1.00% |
| Phosphor, P | ≤ 0.045% |
| Schwefel, S | ≤ 0.035% |
| Stickstoff, N | ≤ 0.10% |
| Eisen, Fe | Gleichgewicht |
Published producer specifications support these limits. They describe the grade requirements and do not represent the actual analysis of a particular QIDAMT shipment.
Mechanische Eigenschaften
The following values provide a reference for annealed 904L plate, sheet and strip under ASTM A240 requirements:
| Eigentum | Reference requirement |
|---|---|
| Zugfestigkeit | ≥ 490 MPa |
| 0.2% proof strength | ≥ 220 MPa |
| Verlängerung, A50 | ≥ 35% |
These figures are material acceptance references, not allowable design stresses. Requirements under EN specifications can differ by product form. Confirm the applicable standard, Dicke, test method and delivery condition when ordering.
Korrosionsbeständigkeit
Acid-Handling Applications
904L was developed for sulfuric-acid service and is also considered for certain phosphoric-acid and organic-acid environments. Its copper addition contributes to performance in selected reducing-acid conditions.
Acid resistance depends on concentration, Temperatur, aeration and contaminants. A statement such as “suitable for sulfuric acid” should therefore be supported by the actual process conditions.
Chloride-Containing Environments
904L generally provides better resistance to pitting, crevice corrosion and chloride-induced stress corrosion cracking than standard 304 Und 316 Noten.
It is nevertheless susceptible to corrosion under sufficiently severe conditions. Stagnant liquid, deposits, tight crevices and elevated temperatures can substantially change its performance. Seawater service requires particular attention to equipment geometry and operating conditions.
For material selection, provide the process medium, chemical concentrations, operating temperature and expected cleaning conditions.
Typische Anwendungen
904L plate may be considered for equipment and fabricated components in:
- Chemical processing and acid handling.
- Phosphoric-acid and fertilizer production.
- Selected flue-gas cleaning and scrubbing systems.
- Pulp and paper processing.
- Heat exchangers, condensers and process vessels.
- Selected seawater and brackish-water equipment.
These are application examples rather than universal approvals. Pressure equipment, regulated installations and corrosive processes require material selection against the relevant design and service requirements.
Schweißen, Forming and Machining
904L plate can be fabricated using established stainless-steel welding and forming practices. Welding procedures and consumables should be selected for the required joint properties and corrosion environment.
The material is ductile, but work hardening affects forming loads and machining behaviour. Werkzeuge, equipment capacity and processing parameters should suit the plate thickness and component geometry. Hot forming may require subsequent solution treatment and rapid cooling to restore the required material condition.
For fabricated parts, submit drawings showing bend radii, hole locations, weld details and dimensional tolerances. Also identify any restrictions on thermal cutting, surface contamination or post-fabrication cleaning.
Surface Finish and Inspection
Choose the surface finish according to the component’s function. A decorative finish and a process-contact surface can have different acceptance requirements.
For enquiries involving polished material, specify the finish designation or target surface roughness rather than requesting only a “smooth surface.” Identify whether protective film, weld-area cleaning or additional surface treatment is required.
Inspection requirements should be agreed before supply. Depending on the order, these may include:
- Mühlenprüfzertifikat, such as EN 10204 3.1 where specified and available.
- Heat-number identification and traceability.
- Chemical and mechanical test results.
- Positive material identification.
- Dimensional and visual inspection.
- Additional testing required by the project specification.
Request the scope of each inspection explicitly. Additional testing and third-party inspection can affect cost and delivery.
Frequently Asked Questions
Is 904L Better Than 316L?
904L can offer better corrosion performance in selected acids and chloride-containing environments. Whether the additional alloy cost is justified depends on the service conditions and expected equipment life. It is not automatically the best choice for every stainless-steel application.
Is 904L the Same as Duplex 2205?
NEIN. 904L is austenitic, während 2205 is duplex stainless steel. Their strength, fabrication requirements and corrosion behaviour differ. Substitution requires a technical review against the application.
Can 904L Plate Be Used for Pressure Vessels?
It may be specified for pressure equipment when the material, product form, certification and design comply with the applicable code. A grade name alone does not establish pressure-vessel compliance.
What Determines the Price of 904L Plate?
Price depends on thickness, Abmessungen, quantity, finish, inspection requirements, processing and delivery terms. Provide a complete specification to obtain a quotation that can be compared meaningfully with other offers.
Can I Request Cut-to-Size Plates?
Include finished dimensions, quantities, tolerances and cutting requirements in your enquiry. Availability and processing options will be confirmed in the quotation.
Request a 904L Stainless Steel Plate Quotation
Send the following details to obtain a quotation:
- Material grade and required standard.
- Dicke × Breite × Länge.
- Quantity in plates or tonnes.
- Surface finish and delivery condition.
- Intended application and operating environment.
- Required certificates, testing and processing.
- Destination country, port and delivery terms.
Enquiry example:
904L / UNS N08904 plate, ASTM A240/A240M, 10 × 1500 × 3000 mm, 20 Teller, geglüht und gebeizt, IN 10204 3.1 certificate requested, delivery to Genoa, Italien.
Contact QIDAMT to discuss your specifications and request current pricing.
