AISI 304H Stainless Steel Plate | 304H China steel mill-Direct Supply
What is AISI 304H Stainless Steel Plate?
As a professional China steel mill-Direct Supply and stainless steel plate supplier, SHH STEEL is pleased to present AISI 304H Stainless Steel Plate.
AISI 304H (UNS S30409) is the high-carbon variant of the classic AISI 304 austenitic stainless steel. The carbon content is deliberately controlled in the range of 0.04–0.10% to enhance high-temperature strength and creep resistance. This makes AISI 304H particularly suitable for continuous or intermittent service at elevated temperatures where standard 304 or 304L would lose strength more rapidly.
The grade retains the fundamental 18% chromium and 8–10.5% nickel composition, providing good oxidation resistance, formability and toughness. It is non-magnetic in the annealed condition. AISI 304H is widely used in heat exchangers, boilers, furnace components, superheater tubing and other high-temperature process equipment.
SHH STEEL supplies AISI 304H 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 304H in plate and sheet form across a practical range of thicknesses and surface finishes.
AISI 304H is frequently compared with a240 304, a240 304l, a240 321, a240 310s and a240 309s when selecting materials for elevated-temperature service. SHH STEEL provides technical support to help customers choose the most appropriate grade.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | AISI 304H / UNS S30409 | Confirmed |
| Related Standards | ASTM A240, ASME SA240, JIS, EN related | Available |
| Product Form | Plate, Sheet | Available |
| Delivery Condition | Solution Annealed | Standard |
| Thickness Range | 1 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 | No.1, 2B, and others on request | Available |
| Certification | EN 10204 3.1 / Mill Test Certificate | Available |
SHH STEEL can supply AISI 304H dual-certified to ASTM A240 / ASME SA240 when required by the project.
Chemical Composition
Typical Chemical Composition of AISI 304H (UNS S30409):
| Element | Content (%) |
|---|---|
| Carbon (C) | 0.04 – 0.10 |
| Silicon (Si) | ≤ 0.75 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 18.00 – 20.00 |
| Nickel (Ni) | 8.00 – 10.50 |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
The controlled higher carbon content (0.04–0.10%) is the defining feature of AISI 304H. This higher carbon level increases high-temperature strength and improves creep resistance compared with standard 304 and especially 304L. SHH STEEL ensures precise carbon control to meet the requirements of high-temperature service.
Mechanical Properties
Annealed Condition (typical values)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 515 MPa (75 ksi) |
| Yield Strength (0.2%) | ≥ 205 MPa (30 ksi) |
| Elongation (in 50 mm) | ≥ 40% |
| Hardness | ≤ 201 HB |
At elevated temperatures, AISI 304H retains higher strength than standard 304 or 304L due to the controlled carbon content. This makes it suitable for long-term service in the temperature range of approximately 500–800°C, depending on the specific design stresses and environment. SHH STEEL supplies material with consistent high-temperature performance.
Physical Properties
- Density: 7.93 g/cm³
- Magnetic Response: Non-magnetic in the annealed condition
- Melting Range: approximately 1400–1450°C
Material Comparison
| Grade | Carbon | Key Feature | High-Temp Strength | Weldability | Typical Preference |
|---|---|---|---|---|---|
| AISI 304 | ≤ 0.08 | Standard 18-8 | Good | Good | General purpose |
| AISI 304L | ≤ 0.03 | Extra-low carbon | Lower | Excellent | Heavy welded constructions |
| AISI 304H | 0.04–0.10 | Controlled high carbon | Higher | Moderate | High-temperature strength |
| AISI 321 | ≤ 0.08 | Titanium stabilized | Good | Good | High-temp welded service |
| AISI 309S | ≤ 0.08 | 23Cr-13Ni | Very Good | Good | Higher oxidation resistance |
| AISI 310S | ≤ 0.08 | 25Cr-20Ni | Excellent | Good | Severe high-temperature service |
AISI 304H is selected when improved high-temperature strength and creep resistance are required compared with standard 304 or 304L. For better resistance to intergranular corrosion after welding at elevated temperature, SHH STEEL often recommends a240 321. For more severe oxidizing or higher-temperature service, a240 309s or a240 310s is preferred.
Corrosion Resistance
AISI 304H offers good resistance to atmospheric corrosion, fresh water and many mild chemical environments, similar to standard 304. At elevated temperatures it provides good oxidation resistance in air up to approximately 870–900°C in continuous service (depending on conditions).
Because of its higher carbon content, AISI 304H is more susceptible to intergranular corrosion after welding or prolonged exposure in the sensitization range than 304L or stabilized grades. For welded high-temperature service where intergranular corrosion is a concern, SHH STEEL recommends a240 321 or a240 347.
Weldability
AISI 304H can be welded by standard fusion welding methods. Matching or 308H-type filler metals are preferred to maintain high-temperature strength in the weld metal. Due to the higher carbon content, the risk of sensitization is greater than with 304L.
Post-weld solution annealing is recommended for critical corrosive or high-temperature service. When maximum as-welded corrosion resistance is required, SHH STEEL recommends a240 304l or stabilized grades such as a240 321.
Heat Treatment
AISI 304H is normally supplied in the solution-annealed condition by SHH STEEL.
Recommended Solution Annealing Parameters
- Temperature range: 1040 – 1150°C (typically higher end for 304H)
- Cooling: Rapid cooling (water quench preferred)
Proper solution annealing is important to dissolve carbides and optimize both room-temperature and elevated-temperature properties. SHH STEEL controls heat treatment to ensure consistent performance for high-temperature applications.
Surface Finishes
| Finish | Description | Typical Use / Keywords |
|---|---|---|
| No.1 | Hot-rolled, annealed and pickled | AISI 304H No.1 – most common for industrial plate |
| 2B | Cold-rolled, annealed, pickled, skin-passed | AISI 304H 2B – thinner plates |
| Special | Ground or custom finishes | AISI 304H Special – on request |
SHH STEEL regularly supplies AISI 304H in No.1 finish, which is the most common condition for high-temperature plate applications.
Tolerances
Dimensional tolerances for AISI 304H Stainless Steel Plate supplied by SHH STEEL generally conform to ASTM A480 practices.
Typical available size range:
- Thickness: 1 mm – 80 mm
- Width: up to 2000–3000 mm
- 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
Applications
AISI 304H is selected for applications requiring improved high-temperature strength and creep resistance. Typical applications of AISI 304H include:
| Industry / Sector | Typical Components / Equipment (with keywords) |
|---|---|
| Heat Exchangers & Boilers | AISI 304H heat exchanger plates, tubesheets, shells |
| Power Generation | AISI 304H superheater and reheater components |
| Petrochemical & Refining | AISI 304H furnace components, process piping |
| Industrial Furnaces | AISI 304H fixtures, supports and radiant parts |
| Chemical Processing | AISI 304H high-temperature vessels and equipment |
| General High-Temperature Service | AISI 304H structural parts operating at elevated temperature |
SHH STEEL supplies AISI 304H for these elevated-temperature applications with consistent quality. For related industry solutions, see our energy industry, petrochemical 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 304H 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)
- Material optimized for high-temperature strength
- Flexible dimensions and surface finishes (including AISI 304H No.1 and AISI 304H 2B)
- Technical support for selection among 304, 304L, 304H, 321 and higher-alloy grades
- 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 is the main advantage of AISI 304H over AISI 304 or 304L?The controlled higher carbon content (0.04–0.10%) provides improved high-temperature strength and better creep resistance. SHH STEEL recommends 304H for elevated-temperature service where long-term strength is important.
- How does AISI 304H compare with AISI 321?AISI 321 is titanium-stabilized and offers better resistance to intergranular corrosion after welding, while 304H focuses on higher carbon for strength. SHH STEEL can help select the better grade based on the specific temperature and welding requirements.
- s AISI 304H magnetic?Non-magnetic in the annealed condition. SHH STEEL supplies fully annealed material as standard.
- What is the density of AISI 304H?7.93 g/cm³. SHH STEEL provides material certificates confirming physical and mechanical properties.
- Does SHH STEEL supply dual-certified ASTM A240 / AISI 304H material?Yes, SHH STEEL commonly supplies dual-certified material upon request.
Conclusion
AISI 304H Stainless Steel Plate is the high-carbon version of the classic 304 austenitic stainless steel, specifically designed for improved high-temperature strength and creep resistance. It is an excellent choice for heat exchangers, boilers, furnace components and other elevated-temperature process equipment.
As a professional China steel mill-Direct Supply, SHH STEEL provides high-quality AISI 304H Stainless Steel Plate with competitive pricing, full certification and complete technical support.
Contact SHH STEEL today for stock availability, surface finish options (including AISI 304H No.1 and AISI 304H 2B), or a competitive quotation.
AISI 304H Stainless Steel Plate, 304H China steel mill-Direct Supply, AISI 304H, 304H Stainless Steel Plate, UNS S30409, AISI 304H supplier
Quality Steel Needed? Inquire for Offers
Related Products
