AISI 904L Stainless Steel Plate | 904L China steel mill-Direct Supply
What is AISI 904L Stainless Steel?
As a professional China steel mill-Direct Supply and stainless steel plate supplier, SHH STEEL is pleased to present AISI 904L Stainless Steel Plate.
AISI 904L is widely known and searched under many different names and designations, including 904L, AISI 904L, UNS N08904, 1.4539, X1NiCrMoCu25-20-5, Alloy 904L, SS 904L, 904L stainless steel, and the historical commercial name Uranus B6. All these refer to the same high-alloy super austenitic stainless steel grade.
904L contains high levels of chromium (19–23%), nickel (23–28%), molybdenum (4–5%) and copper (1–2%). This composition provides outstanding resistance to pitting, crevice corrosion and stress corrosion cracking in chloride environments, as well as excellent resistance to a wide range of acids, including sulfuric, phosphoric and acetic acids. The low carbon content (≤ 0.02%) ensures excellent resistance to intergranular corrosion after welding.
AISI 904L is non-magnetic in the annealed condition and is widely used in chemical processing, pollution control, seawater handling, pulp and paper, and pharmaceutical industries where the corrosion resistance of 316L or 317L is insufficient.
SHH STEEL supplies AISI 904L as true China steel mill-Direct Supply, sourcing directly from major Chinese stainless steel mills. This model delivers competitive mill pricing, consistent quality, complete heat traceability and reliable delivery. SHH STEEL offers AISI 904L in plate and sheet form across a practical range of thicknesses and surface finishes.
904L is frequently compared with a240 316l, a240 317l, a240 2205, a240 2507 and a240 310s when selecting materials for highly corrosive service. SHH STEEL provides technical support to help customers choose the most appropriate grade.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | AISI 904L / UNS N08904 / 1.4539 | Confirmed |
| Related Standards | ASTM A240, ASME SA240, EN 10088, related | Available |
| Product Form | Plate, Sheet | Available |
| Delivery Condition | Solution Annealed | Standard |
| Thickness Range | 0.5 mm – 80 mm (thicker available on request) | Custom sizes supported |
| Width | Up to 2000–3000 mm | Available |
| Length | Up to 12000 mm or cut-to-length | Available |
| Surface Finish | 2B, No.1, BA, No.4 | Available |
| Certification | EN 10204 3.1 / Mill Test Certificate | Available |
SHH STEEL can supply AISI 904L dual-certified to ASTM A240 / ASME SA240 when required by the project.
Chemical Composition
Typical Chemical Composition of AISI 904L (UNS N08904):
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.020 |
| Silicon (Si) | ≤ 1.00 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.035 |
| Chromium (Cr) | 19.00 – 23.00 |
| Nickel (Ni) | 23.00 – 28.00 |
| Molybdenum (Mo) | 4.00 – 5.00 |
| Copper (Cu) | 1.00 – 2.00 |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
The high nickel, molybdenum and copper contents are the key features that give 904L its outstanding corrosion resistance in aggressive chloride and acid environments. The extra-low carbon content ensures excellent weldability and resistance to intergranular corrosion. SHH STEEL carefully controls composition to ensure consistent high-performance results.
Mechanical Properties
Annealed Condition (typical values)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 490 MPa |
| Yield Strength (0.2%) | ≥ 220 MPa |
| Elongation (in 50 mm) | ≥ 35% |
| Hardness | ≤ 220 HB |
AISI 904L offers good strength combined with excellent ductility and toughness. SHH STEEL supplies material with consistent mechanical properties suitable for fabrication and welding in highly corrosive service.
Physical Properties Density is approximately 8.00–8.05 g/cm³. The grade is non-magnetic in the annealed condition. Melting range is approximately 1300–1390°C.
Material Comparison
| Grade | Mo (%) | Ni (%) | Cu (%) | Pitting Resistance | Strength Level | Typical Preference |
|---|---|---|---|---|---|---|
| AISI 316L | 2.0–3.0 | 10–14 | — | Better | Standard | Standard welded chloride service |
| AISI 317L | 3.0–4.0 | 11–15 | — | Superior | Standard | Aggressive chloride service |
| AISI 904L | 4.0–5.0 | 23–28 | 1.0–2.0 | Excellent | Standard | Highly aggressive chloride & acid |
| AISI 2205 | 3.0–3.5 | 4.5–6.5 | — | Excellent | High | High strength + high chloride resistance |
| AISI 2507 | 3.0–5.0 | 6–8 | — | Outstanding | Very High | Super duplex severe service |
| AISI 310S | — | 19–22 | — | Good | Standard | High-temperature oxidation |
AISI 904L (also known as UNS N08904 / 1.4539 / Alloy 904L) provides a significant upgrade in corrosion resistance over a240 316l and a240 317l, especially in sulfuric acid and high-chloride environments. When both high strength and high corrosion resistance are required, SHH STEEL also recommends evaluating duplex and super duplex grades such as a240 2205 and a240 2507.
Corrosion Resistance
AISI 904L offers outstanding resistance to pitting and crevice corrosion in chloride environments and excellent resistance to a wide range of acids, including dilute sulfuric acid, phosphoric acid and acetic acid. The high nickel content also provides good resistance to stress corrosion cracking.
It is widely used in environments where 316L and 317L suffer from pitting or general corrosion. In extremely aggressive conditions (very high temperatures + high chlorides or strong reducing acids), more specialized alloys or super duplex grades may still be required. SHH STEEL can assist in material selection based on the specific service environment.
Weldability
AISI 904L has good weldability. Matching or higher-alloy filler metals (such as 904L or nickel-based fillers) are recommended. The extra-low carbon content provides excellent resistance to intergranular corrosion in the as-welded condition, and post-weld annealing is generally not required.
SHH STEEL recommends controlled heat input and proper post-weld cleaning to achieve optimum corrosion performance in aggressive service.
Heat Treatment
AISI 904L is normally supplied in the solution-annealed condition by SHH STEEL.
Recommended solution annealing temperature range is 1090–1175°C, followed by rapid cooling. Proper annealing optimizes corrosion resistance and ductility. SHH STEEL controls heat treatment to ensure consistent high-performance results.
Surface Finishes
| Finish | Description | Typical Use / Keywords |
|---|---|---|
| 2B | Cold-rolled, annealed, pickled, skin-passed | AISI 904L 2B – most common for general fabrication |
| No.1 | Hot-rolled, annealed and pickled | AISI 904L No.1 – industrial plate |
| BA | Bright Annealed | AISI 904L BA – cleaner surface applications |
| No.4 | Brushed finish | AISI 904L No.4 – architectural / specialized surfaces |
SHH STEEL regularly supplies AISI 904L in 2B and No.1 finishes, and can provide other finishes according to project requirements.
Tolerances
Dimensional tolerances for AISI 904L Stainless Steel Plate supplied by SHH STEEL generally conform to ASTM A480 practices.
Typical available size range is thickness 0.5 mm – 80 mm, width up to 2000–3000 mm, and length up to 12000 mm or cut-to-length. SHH STEEL provides precise dimensional control and can support tighter tolerances when required.
Equivalent Material Grades
| Grade / Designation | Standard / Region | Notes |
|---|---|---|
| AISI 904L | — | — |
| UNS N08904 | Unified Numbering System | Most common UNS designation |
| 1.4539 / X1NiCrMoCu25-20-5 | EN (Europe) | European equivalent |
| Alloy 904L / SS 904L | Commercial | Common trade names |
| Related high-alloy grades | JIS / GB | Approximate national equivalents |
| Related 317L / 2205 / 2507 | Multiple | Lower / alternative high-performance grades |
Related grades for comparison include a240 316l, a240 317l, a240 2205, a240 2507 and a240 310s.
Applications
AISI 904L (also searched as UNS N08904, 1.4539, Alloy 904L and SS 904L) is selected for highly corrosive environments where standard 316L or 317L is insufficient. Typical applications of AISI 904L include:
| Industry / Sector | Typical Components / Equipment (with keywords) |
|---|---|
| Chemical & Process Industry | AISI 904L tanks, vessels, reactors, piping and process equipment |
| Pollution Control & FGD | AISI 904L scrubbers, ducts and components in flue gas systems |
| Seawater & Marine | AISI 904L seawater handling equipment and offshore components |
| Pulp & Paper | AISI 904L process equipment in aggressive chemical environments |
| Pharmaceutical & Food | AISI 904L high-purity equipment and storage systems |
| Sulfuric & Phosphoric Acid | AISI 904L equipment handling dilute sulfuric and phosphoric acids |
| General Corrosive Service | AISI 904L tanks, heat exchangers and welded structures |
SHH STEEL supplies AISI 904L for these highly demanding corrosive applications with consistent quality. For related industry solutions, see our petrochemical industry, marine industry and equipment manufacturing pages. Supporting services include steel cutting services and steel welding services.
Why Choose SHH STEEL
SHH STEEL is a China steel mill-Direct Supply specializing in stainless steel plate and sheet. By working directly with major Chinese stainless steel mills, SHH STEEL supplies AISI 904L with the following advantages:
- Genuine China steel mill-Direct Supply pricing
- Consistent quality and complete heat traceability
- Full Mill Test Certificates (EN 10204 3.1)
- High-alloy super austenitic material optimized for aggressive chloride and acid service
- Flexible dimensions and surface finishes (including AISI 904L 2B and AISI 904L No.1)
- Technical support for selection among 316L, 317L, 904L, 2205 and 2507
- Value-added services including steel cutting services, steel welding services and worldwide shipping service
For more information about our company and full product range, please visit China steel Mill Agent-SHH STEEL.
FAQ
- What are the other common names for AISI 904L?904L is also widely known as UNS N08904, 1.4539, X1NiCrMoCu25-20-5, Alloy 904L, SS 904L and historically as Uranus B6. SHH STEEL can supply material certified to the required designation.
- What is the main advantage of AISI 904L over AISI 316L or 317L?904L has much higher nickel, molybdenum and copper contents, giving it outstanding resistance to pitting, crevice corrosion and many acids (especially sulfuric acid). SHH STEEL recommends 904L when 316L or 317L is not sufficient.
- Is AISI 904L better than duplex stainless steels?904L offers excellent corrosion resistance in many acid and chloride environments. Duplex grades such as 2205 or 2507 provide higher strength. SHH STEEL can help evaluate the best balance of corrosion resistance, strength and cost for your project.
- Is AISI 904L magnetic?Non-magnetic in the annealed condition. SHH STEEL supplies fully annealed material as standard.
- What is the density of AISI 904L?Approximately 8.00–8.05 g/cm³. SHH STEEL provides material certificates confirming physical and mechanical properties.
- Can AISI 904L be welded easily?Yes. It has good weldability and the extra-low carbon content provides excellent resistance to intergranular corros
- Does SHH STEEL supply dual-certified ASTM A240 / AISI 904L material?Yes, SHH STEEL commonly supplies dual-certified material upon request.
Conclusion
AISI 904L Stainless Steel Plate (also known as UNS N08904, 1.4539, Alloy 904L and SS 904L) is a high-alloy super austenitic grade that offers outstanding resistance to pitting, crevice corrosion and a wide range of acids. It is the preferred material for chemical processing, pollution control, seawater handling, pulp and paper and pharmaceutical applications where the corrosion resistance of 316L or 317L is insufficient.
As a professional China steel mill-Direct Supply, SHH STEEL provides high-quality AISI 904L Stainless Steel Plate with competitive pricing, full certification and complete technical support.
Contact SHH STEEL today for stock availability, surface finish options (including AISI 904L 2B and AISI 904L No.1), or a competitive quotation.
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