2304 Duplex Stainless Steel Coil
Material Identity & Key Composition
| Parameter | Value |
|---|---|
| UNS Designation | S32304 |
| EN Designation | 1.4362 |
| Microstructure | Balanced duplex: approximately 45% ferrite + 55% austenite |
| Cr (Chromium) | 22.0–24.0% |
| Ni (Nickel) | 3.0–5.5% - significantly lower than 304/316L, offering cost stability against nickel price volatility |
| Mo (Molybdenum) | 0.10–0.60% - modest addition for localized corrosion resistance |
| N (Nitrogen) | 0.05–0.20% - strength enhancement and austenite stabilization |
| C (Carbon) | ≤ 0.030% - low carbon ensures as-welded corrosion resistance |
Compared to 316L, 2304 uses approximately half the nickel content, making it less susceptible to raw material price surges while delivering superior mechanical performance.
Mechanical Properties: The Strength Advantage
| Property | 2304 Duplex | 304L | 316L |
|---|---|---|---|
| Yield Strength (Rp0.2) | ≥ 400 MPa | ≥ 170 MPa | ≥ 170 MPa |
| Tensile Strength (Rm) | ≥ 600 MPa | ≥ 485 MPa | ≥ 485 MPa |
| Elongation (A50) | ≥ 25% | ≥ 40% | ≥ 40% |
| Hardness (HRB max) | ≤ 290 HB | ≤ 201 HB | ≤ 217 HB |
Design Implications:
2304's yield strength is more than double that of 304L/316L, allowing designers to reduce material thickness by 30–50% while maintaining equivalent load-bearing capacity.
The resulting weight reduction directly lowers fabrication, transportation, and erection costs in large-scale structural and vessel applications.
Ductility at ≥ 25% elongation remains ample for most cold-forming operations, including bending, drawing, and flanging.
Corrosion Resistance Portfolio
2304 bridges the gap between standard austenitic grades and higher-alloy duplexes like 2205:
| Corrosion Mode | 2304 Performance | Comparison Reference |
|---|---|---|
| Pitting Resistance (PREN) | ~24–26 | Equivalent to 316L; superior to 304L (~18) |
| Stress Corrosion Cracking (SCC) | Excellent resistance in chloride environments up to ~150°C | Dramatically outperforms 304L/316L, which can fail rapidly above 60°C in hot chlorides |
| Intergranular Corrosion | Passes ASTM A262 Practice E in as-welded condition | Comparable to low-carbon 304L/316L |
| General Atmospheric Corrosion | Excellent in rural, urban, and mild industrial environments | Equivalent to 316L |
| Seawater Resistance | Moderate - suitable for splash zone and intermittent immersion | Better than 304L; for continuous seawater immersion, 2205 is recommended |
The SCC Differentiator: The duplex microstructure inherently resists chloride stress corrosion cracking propagation. In applications such as industrial water heaters, evaporators, and outdoor structural supports exposed to coastal atmospheres, 2304 eliminates the sudden brittle failure risk associated with standard 304/316L.
Dimensional & Surface Specifications in Coil Form
| Parameter | Capability |
|---|---|
| Thickness | 0.40 – 6.00 mm (cold-rolled); 3.00 – 13.00 mm (hot-rolled, annealed & pickled) |
| Width | 50 – 2000 mm (slit to exact width) |
| Coil Inner Diameter | 508 mm (standard); 610 mm (heavy-gauge hot-rolled) |
| Max Coil Weight | Up to 20 metric tons |
Available Surface Finishes:
| Finish | Code | Description | Typical Application |
|---|---|---|---|
| No.1 | HRAP | Hot-rolled, annealed & pickled; matte, non-reflective | Storage tanks, structural sections, pressure vessel shells |
| 2B | CR 2B | Cold-rolled, annealed, pickled, skin-passed; smooth uniform matte | Process equipment cladding, building panels |
| 2D | CR 2D | Cold-rolled, annealed, pickled; dull finish | Welded tube feedstock, gaskets, deep-drawn components |
| BA | Bright Annealed | Reflective bright finish | Sanitary process piping, food contact surfaces |
| No.4 / Brushed | Polished | Short directional grain | Architectural interior panels, visible structural members |
Key Applications
Water & Desalination
1
>>
Chemical Processing
2
>>
Pulp & Paper
3
>>
Food & Beverage
4
>>
Architectural & Structural
5
>>
Oil & Gas (Non-Sour)
6
Fabrication & Processing Guidelines
Delivery, Certification & Quality Assurance
Mill Test Certificate: EN 10204 3.1 provided as standard with each coil, documenting heat analysis, full mechanical properties (tensile, yield, elongation, hardness), ferrite content verification (typically 30–55%), and intergranular corrosion test per ASTM A262 Practice E.
Optional Supplementary Testing: Positive Material Identification (PMI), pitting corrosion test (ASTM G48 Method A), Charpy impact testing, ultrasonic testing of hot-rolled coils, and full-coil ferrite mapping.
Packaging: VCI anti-corrosion paper wrap, metal edge protectors, export-grade wooden pallets/skids, and weatherproof polyethylene shroud for containerized ocean freight. Custom coil splitting and multi-coil consolidation available for just-in-time delivery programs.
If you have a specific gauge, width, or service environment in mind, I can provide detailed weight calculations, optimize coil dimensions for your slitting or forming line, or prepare a direct cost-performance comparison against your current 316L or 304L specifications.
Hot Tags: 2304 duplex stainless steel coil, China 2304 duplex stainless steel coil manufacturers, suppliers, factory
You Might Also Like
Send Inquiry