1.4833, 309, 309S, 309H, Heat Resisting Austenitic Steel
Product Description
309, 309S, and 309H are high-performance austenitic heat-resistant stainless steels specifically engineered for applications requiring exceptional oxidation resistance at elevated temperatures. With a high chromium content (22-24%) and moderate nickel content (12-15%), these versatile alloys provide outstanding resistance to oxidation up to 1900°F (1038°C) under non-cyclic conditions and approximately 1850°F (1010°C) under frequent thermal cycling.
The 309 family of stainless steels offers superior resistance to high-temperature oxidizing environments and sulfur-containing atmospheres, making them ideal materials for thermal processing equipment, industrial furnaces, waste treatment facilities, and other applications where component integrity must be maintained under extreme thermal conditions.
Each grade within the 309 family serves specific purposes:
- 309: The standard grade with carbon content up to 0.20%, providing good high-temperature strength and oxidation resistance.
- 309S: A low-carbon variant (≤0.08% C) that improves weldability and reduces susceptibility to carbide precipitation during welding or extended exposure to elevated temperatures.
- 309H: Features a controlled carbon range (0.04-0.10% C) for enhanced creep resistance and high-temperature strength, making it ideal for load-bearing components in high-temperature environments.
Due to their high chromium and low nickel content, 309-series stainless steels are particularly effective in sulfur-containing atmospheres up to 1832°F (1000°C). While they offer moderate resistance to carbon absorption, they are not recommended for highly carburizing environments. These alloys can be used in slightly oxidizing, nitriding, cementing, and thermal cycling applications, though maximum service temperatures should be adjusted accordingly.
FUSHUN METAL supplies premium 309, 309S, and 309H stainless steel in various forms to meet the demanding requirements of high-temperature applications across multiple industries. Our materials provide reliable performance in the most challenging thermal environments while maintaining good fabricability and weldability.
Applications
309, 309S, and 309H stainless steels are widely utilized in high-temperature applications where exceptional oxidation resistance, thermal stability, and resistance to sulfur-containing atmospheres are critical requirements. Their unique combination of properties makes them ideal for components exposed to extreme thermal conditions across various industries.
Primary applications for 309, 309S, and 309H stainless steels include:
- Thermal Processing Equipment:
- Annealing covers and boxes
- Muffles and retorts
- Burners and burner grids
- Lead pans and neutral salt pots
- Furnace fans, doors, and shafts
- Walking beams
- Radiant tubes for aluminum and steel annealing
- Brazing fixtures and carbon saggers
- Recuperators and heat exchangers
- Waste Treatment:
- Waste incinerators
- Rotary kilns and calciners
- Combustion chambers
- Power Generation:
- Pulverized coal burners
- Power boiler tube hangers
- Heat recovery systems
- Petroleum Refining:
- Catalytic recovery systems
- Recuperators
- High-temperature piping components
- Fluidized Bed Systems:
- Grids
- Piping
- Wind boxes
- Glass Manufacturing:
- Glass forming equipment
- Melting tank components
- Paper Mill Equipment:
- Recovery boiler components
- High-temperature conveying systems
- Measurement and Control:
- Thermowells
- Temperature sensors housing
- Structural Components:
- Refractory anchor bolts
- High-temperature structural supports
309S is typically selected when fabrication requirements, particularly welding, are critical to application success, while 309H is preferred for structural components requiring maximum creep resistance at elevated temperatures. Standard 309 provides a balance of properties suitable for many general high-temperature applications.
These alloys are particularly valuable in environments where resistance to both high-temperature oxidation and sulfidation is required, providing reliable performance in some of the most demanding thermal conditions encountered in industrial applications.
Standards
309, 309S, and 309H stainless steels conform to numerous international standards and specifications, ensuring consistent quality and performance in demanding high-temperature applications:
American Standards:
- ASTM A240/ASME SA240: Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications
- ASTM A276/ASME SA276: Standard Specification for Stainless Steel Bars and Shapes
- ASTM A312/ASME SA312: Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
- ASTM A479/ASME SA479: Standard Specification for Stainless Steel Bars and Shapes for Use in Boilers and Other Pressure Vessels
- AMS 5523: Sheet, Strip, and Plate
European Standards:
- EN 10088-2: Stainless steels – Part 2: Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for general purposes
- EN 10088-3: Stainless steels – Part 3: Technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products of corrosion resisting steels for general purposes
- EN 10095: Heat resisting steels and nickel alloys
- EN 1.4833: European designation for X12CrNi23-13 (similar to 309/309S)
Japanese Standards:
- JIS G4304: Hot-rolled stainless steel plate, sheet and strip
- JIS G4305: Cold-rolled stainless steel plate, sheet and strip
- SUS 309S: Japanese designation for 309S stainless steel
Other International Standards:
- UNS S30900: Unified Numbering System designation for 309
- UNS S30908: Unified Numbering System designation for 309S
- UNS S30909: Unified Numbering System designation for 309H
- DIN X12CrNi23-13: German standard designation
- AFNOR Z12CN24-13: French standard designation
These comprehensive standards ensure that 309, 309S, and 309H stainless steels from FUSHUN METAL meet the rigorous requirements for high-temperature applications across various industries worldwide.
Material Designation and Chemical Composition
309, 309S, and 309H stainless steels are known by various designations in different standards and specification systems:
| Grade | UNS | EN/W.Nr. | EN Designation | AISI/SAE | Japanese JIS |
|---|---|---|---|---|---|
| 309 | S30900 | 1.4833 | X12CrNi23-13 | 309 | SUS 309 |
| 309S | S30908 | 1.4833 | X12CrNi23-13 | 309S | SUS 309S |
| 309H | S30909 | – | – | 309H | – |
The chemical composition of 309, 309S, and 309H stainless steels is carefully controlled to ensure optimal performance in high-temperature applications:
| Element | 309 (%) | 309S (%) | 309H (%) |
|---|---|---|---|
| Carbon (C) | 0.20 max | 0.08 max | 0.04-0.10 |
| Chromium (Cr) | 22.0-24.0 | 22.0-24.0 | 22.0-24.0 |
| Nickel (Ni) | 12.0-15.0 | 12.0-15.0 | 12.0-15.0 |
| Manganese (Mn) | 2.0 max | 2.0 max | 2.0 max |
| Silicon (Si) | 0.75 max | 0.75 max | 0.75 max |
| Phosphorus (P) | 0.045 max | 0.045 max | 0.045 max |
| Sulfur (S) | 0.030 max | 0.030 max | 0.030 max |
| Nitrogen (N) | 0.11 max | 0.11 max | – |
| Iron (Fe) | Balance | Balance | Balance |
The primary difference between these grades lies in their carbon content. 309S features a maximum carbon content of 0.08%, which enhances weldability and reduces susceptibility to carbide precipitation. 309H has a controlled carbon range of 0.04-0.10% to provide enhanced creep resistance and high-temperature strength. Standard 309 may contain up to 0.20% carbon, offering a good balance of high-temperature properties for general applications.
It’s worth noting that many products are manufactured to meet both 309S and 309H specifications simultaneously (dual certification), particularly in plate and pipe forms. This provides greater versatility in high-temperature applications while ensuring compliance with multiple specification requirements.
Physical and Mechanical Properties
309, 309S, and 309H stainless steels offer exceptional high-temperature performance, maintaining good strength, ductility, and oxidation resistance under extreme thermal conditions. These properties make them ideal for demanding high-temperature applications.
Physical Properties
| Property | Value |
|---|---|
| Density | 7.9 g/cm³ (0.285 lb/in³) |
| Melting Range | 1480-1530°C (2500-2590°F) |
| Modulus of Elasticity at 20°C | 196 GPa (28.5 × 10⁶ psi) |
| Electrical Resistivity at 20°C | 0.78 Ω·mm²/m (78 microhm-cm) |
| Thermal Conductivity at 100°C | 15 W/m·K (9.0 BTU·hr/ft²/ft/°F) |
| Coefficient of Thermal Expansion (20-100°C) | Approximately 9.7 × 10⁻⁶ /°F |
| Specific Heat Capacity | 500 J/kg·K (0.12 BTU/lb·°F) |
Mechanical Properties
The mechanical properties of 309, 309S, and 309H stainless steels at room temperature according to ASTM A240 and other specifications:
| Property | Typical Value |
|---|---|
| Tensile Strength (min) | 515 MPa (75,000 psi) |
| Yield Strength (0.2% Offset, min) | 205 MPa (30,000 psi) |
| Elongation in 50mm (min) | 40% |
| Hardness (max) | 217 HB (95 HRB) |
Representative elevated temperature tensile properties for 309 stainless steel:
| Temperature | Ultimate Tensile Strength | 0.2% Yield Strength | Elongation |
|---|---|---|---|
| 70°F (21°C) | 90 ksi (620 MPa) | 45 ksi (310 MPa) | 50% |
| 1200°F (649°C) | 52 ksi (359 MPa) | 22 ksi (152 MPa) | 26% |
| 1600°F (871°C) | 18 ksi (124 MPa) | – | 32% |
Typical creep properties for 309 stainless steel:
| Temperature | Creep Rupture Strength (MPa) | ||
|---|---|---|---|
| 1,000 Hours | 10,000 Hours | 100,000 Hours | |
| 600°C (1112°F) | 190 | 120 | 65 |
| 700°C (1292°F) | 75 | 36 | 16 |
| 800°C (1472°F) | 35 | 18 | 7.5 |
| 900°C (1652°F) | 15 | 8.5 | 3 |
| 1000°C (1832°F) | 8 | 4 | 1.5 |
Heat Treatment
The following heat treatment processes are recommended for 309, 309S, and 309H stainless steels:
- Solution Annealing: Heat to 1832-2101°F (1000-1150°C) followed by rapid quenching to ensure that all carbides are in solution and to maximize corrosion resistance.
- Sigma Phase Removal: After prolonged exposure to temperatures between 1202-1742°F (650-950°C), 309 grades may become embrittled due to sigma phase formation. A solution annealing treatment at 2012-2102°F (1100-1150°C) will restore a degree of toughness.
- Hot Forming: Heat uniformly to 1742-2192°F (950-1200°C). After hot forming, a final anneal at 1832-2101°F (1000-1150°C) followed by rapid quenching is recommended.
It’s important to note that these grades cannot be hardened by thermal treatment. The carbon content in standard 309 and 309H contributes to creep resistance but may make these grades more susceptible to sensitization (carbide precipitation) during welding or prolonged exposure to moderate temperatures. For applications requiring extensive welding, 309S with its lower carbon content is typically preferred.
Available Dimensions
FUSHUN METAL supplies 309, 309S, and 309H stainless steel in a wide range of product forms and dimensions to meet diverse application requirements in high-temperature industries:
Plate and Sheet
| Product Form | Thickness | Width | Length |
|---|---|---|---|
| Plate | 4.0 mm – 100 mm (0.156″ – 4.0″) | Up to 3,000 mm (118″) | Up to 12,000 mm (472″) |
| Sheet | 0.5 mm – 3.9 mm (0.020″ – 0.154″) | Up to 1,500 mm (60″) | Up to 6,000 mm (236″) or coil form |
| Strip | 0.1 mm – 3.0 mm (0.004″ – 0.118″) | Up to 600 mm (24″) | Coil form |
Bar
| Product Form | Diameter/Dimension | Length |
|---|---|---|
| Round Bar | 6 mm – 300 mm (0.236″ – 12″) | Up to 6,000 mm (236″) |
| Square Bar | 10 mm – 150 mm (0.394″ – 6″) | Up to 6,000 mm (236″) |
| Hexagonal Bar | 10 mm – 100 mm (0.394″ – 4″) | Up to 6,000 mm (236″) |
| Flat Bar | Thickness: 5 mm – 100 mm (0.197″ – 4″) Width: 10 mm – 200 mm (0.394″ – 8″) |
Up to 6,000 mm (236″) |
Pipe and Tube
| Product Form | Outside Diameter | Wall Thickness | Length |
|---|---|---|---|
| Seamless Pipe | 6 mm – 350 mm (0.236″ – 14″) | 1.0 mm – 30 mm (0.039″ – 1.181″) | Up to 12,000 mm (472″) |
| Welded Pipe | 6 mm – 600 mm (0.236″ – 24″) | 1.0 mm – 30 mm (0.039″ – 1.181″) | Up to 12,000 mm (472″) |
| Tube | 6 mm – 150 mm (0.236″ – 6″) | 0.5 mm – 10 mm (0.020″ – 0.394″) | Up to 12,000 mm (472″) |
Fittings and Flanges
| Product Form | Size Range | Standard |
|---|---|---|
| Buttweld Fittings | 1/2″ – 24″ (DN15 – DN600) | ASTM/ASME standards |
| Forged Fittings | 1/8″ – 4″ (DN6 – DN100) | ASTM/ASME standards |
| Flanges | 1/2″ – 24″ (DN15 – DN600) | ASTM/ASME standards |
Wire
| Product Form | Diameter | Form |
|---|---|---|
| Wire | 0.5 mm – 12 mm (0.020″ – 0.472″) | Coil or straightened lengths |
Custom dimensions, tolerances, and surface finishes are available upon request to meet specific application requirements. FUSHUN METAL can provide dual-certified 309S/309H material for applications requiring compliance with both specifications, offering greater versatility in high-temperature service.
High-Temperature Performance and Corrosion Resistance
309, 309S, and 309H stainless steels provide exceptional performance in high-temperature environments, making them the materials of choice for thermal processing applications. Understanding their behavior under different conditions is essential for proper material selection and application.
Oxidation Resistance
The high chromium (22-24%) content of 309-series stainless steels provides exceptional resistance to oxidation:
- Resistant to oxidation up to 1900°F (1038°C) under non-cyclic conditions
- Approximately 1850°F (1010°C) resistance under frequent thermal cycling
- Resistant to scaling up to 1000°C (1832°F)
The maximum recommended service temperatures vary depending on the specific environment:
- Oxidizing conditions (max sulfur content–2 g/m³): 1050°C (1922°F) continuous service, 1100°C (2012°F) peak temperature
- Oxidizing conditions (sulfur content > 2 g/m³): 950°C (1742°F) maximum temperature
- Low oxygen atmosphere (max sulfur content–2 g/m³): 1000°C (1832°F) maximum temperature
- Nitriding or carburizing atmospheres: 850-950°C (1562-1742°F) maximum
Sulfidation Resistance
309-series stainless steels offer excellent resistance to sulfur-containing atmospheres:
- Because of the high chromium and low nickel content, these alloys can be utilized in sulfur-containing atmospheres up to 1832°F (1000°C)
- Particularly valuable in environments where both oxidation and sulfidation resistance are required
- Performance superior to most other heat-resistant stainless steels in sulfur-bearing atmospheres
Carbon Absorption Resistance
309-series stainless steels exhibit moderate resistance to carbon absorption:
- Not recommended for use in highly carburizing atmospheres
- Can be used in slightly carburizing environments with appropriate temperature reductions
- Outperform most heat-resistant stainless steels in mildly carburizing conditions, though not as effective as nickel-based alloys
Sigma Phase Formation
A notable limitation of 309-series stainless steels is their susceptibility to sigma phase formation:
- When heated between 1202-1742°F (650-950°C), these alloys are subject to sigma phase precipitation
- Sigma phase can cause significant reduction in room temperature ductility and impact resistance
- A solution annealing treatment at 2012-2102°F (1100-1150°C) will restore a degree of toughness
- Should sigma formation be anticipated, care should be taken to avoid heavy mechanical impact at room temperature
Creep Resistance
309-series stainless steels offer good creep resistance at elevated temperatures:
- 309H, with its controlled carbon range, provides enhanced creep resistance for load-bearing applications
- Suitable for long-term service under stress at elevated temperatures
- Maintains structural integrity under prolonged exposure to high temperatures
Aqueous Corrosion Resistance
Although primarily designed for high-temperature applications, 309-series stainless steels also offer some corrosion resistance in aqueous environments:
- Not designed for service in wet corrosive environments
- High carbon content, which enhances creep properties, can have a detrimental effect on aqueous corrosion resistance
- Prone to intergranular corrosion after long-term exposure at high temperatures
- Due to high chromium content (23%), these alloys are more corrosion resistant than many other heat-resistant alloys
These performance characteristics make 309, 309S, and 309H stainless steels versatile materials for a wide range of high-temperature applications, providing reliable service in some of the most demanding thermal environments encountered in industrial processes.
Fabrication and Welding Properties
309, 309S, and 309H stainless steels offer good fabricability and can be processed using standard shop fabrication methods. Understanding their specific fabrication characteristics ensures optimal performance in high-temperature applications.
Cold Forming
309-series stainless steels exhibit good formability at room temperature:
- These alloys are quite ductile and form in a manner similar to Type 316 stainless steel
- Room temperature forming is generally recommended
- Cold forming of components intended for long-term exposure to high temperatures is not recommended, as these alloys are susceptible to carbide precipitation and sigma phase formation
Hot Forming
Hot forming of 309-series stainless steels should be performed under carefully controlled conditions:
- Uniform heating to 1742-2192°F (950-1200°C) is recommended
- After hot forming, a final anneal at 1832-2101°F (1000-1150°C) followed by rapid quenching should be performed to restore optimal properties
- This annealing treatment ensures maximum corrosion resistance and mechanical properties
Welding
309-series stainless steels can be readily welded using standard processes:
- Suitable welding processes include TIG (GTAW), PLASMA, MIG (GMAW), SMAW, SAW, and FCAW
- 309S is preferred for welding applications due to its lower carbon content, which reduces susceptibility to carbide precipitation
- For 309 and 309S, AWS E309-16 covered electrodes or ER309 bare wire are recommended
- Welding procedures for 309S should be selected with care to minimize hot cracking due to the fully austenitic weld microstructure obtained when using matching filler metals
- Post-weld heat treatment is generally not required, but for maximum corrosion resistance, a full solution anneal may be beneficial
Machining
309-series stainless steels have moderate machinability:
- 309 has a machinability rating of approximately 43% relative to AISI B1112 steel
- Standard machining practices for austenitic stainless steels apply
- Work hardening during machining can occur, so sharp tools and appropriate cutting speeds are recommended
- Adequate cooling is essential to prevent excessive work hardening during machining operations
Heat Treatment Considerations
Proper heat treatment is essential for maintaining optimal properties:
- Solution annealing at 1832-2101°F (1000-1150°C) followed by rapid cooling ensures maximum corrosion resistance and mechanical properties
- These grades cannot be hardened by thermal treatment
- After prolonged service at temperatures that may cause sigma phase formation (1202-1742°F/650-950°C), a solution annealing treatment may be necessary to restore ductility
- Care should be taken to minimize time in the sensitization temperature range (800-1500°F/427-816°C) to prevent carbide precipitation, particularly for the standard 309 grade
These fabrication characteristics highlight the versatility of 309, 309S, and 309H stainless steels in manufacturing high-temperature components. By following appropriate fabrication practices, optimal performance can be achieved in demanding thermal applications.
Why Choose FUSHUN METAL for 309, 309S, and 309H Stainless Steel
When selecting a supplier for premium 309, 309S, and 309H heat-resistant stainless steel, FUSHUN METAL stands as your preferred partner for several compelling reasons:
Exceptional High-Temperature Material Expertise
At FUSHUN METAL, we specialize in heat-resistant alloys with a particular focus on the 309 family of stainless steels. Our metallurgical team possesses extensive knowledge of the complex behavior of these materials under extreme thermal conditions, including oxidation resistance, sulfidation performance, and microstructural stability at elevated temperatures. This deep technical expertise allows us to provide valuable guidance in material selection, ensuring you receive the optimal grade—whether 309, 309S, or 309H—for your specific operating environment and temperature requirements.
Superior Quality Control and Material Consistency
We implement rigorous quality control processes throughout our production chain to ensure consistent material properties in our 309-series stainless steels. Each production lot undergoes comprehensive testing for chemical composition, mechanical properties, and microstructure to verify compliance with international standards and specifications. This meticulous attention to quality guarantees that our products will perform reliably in your most demanding thermal applications, providing dependable service even under extreme temperature conditions.
Comprehensive Product Range with Dual Certification
FUSHUN METAL offers one of the most extensive ranges of 309-series stainless steel products available, including plate, sheet, strip, bar, pipe, tube, and fittings in various dimensions. We specialize in providing dual-certified 309S/309H material that meets the requirements of both specifications simultaneously, offering you greater versatility and simplified inventory management. This comprehensive product portfolio allows you to source all your heat-resistant stainless steel requirements from a single, reliable supplier, streamlining your procurement process and ensuring consistency across your projects.
Specialized Processing and Fabrication Expertise
We understand that high-temperature applications often require specialized processing to ensure optimal performance. Our capabilities include custom cutting, edge preparation, solution annealing, and specialized surface finishes tailored to your specific requirements. Our familiarity with the fabrication challenges of heat-resistant alloys allows us to provide materials that facilitate efficient manufacturing of your high-temperature components while maintaining their exceptional thermal performance in service.
Responsive Technical Support and Application Guidance
Our team of technical specialists is available to provide comprehensive support throughout your project lifecycle, from material selection to in-service performance optimization. We can assist with specifying the correct grade and condition for your application, recommend appropriate fabrication practices, and troubleshoot any challenges you may encounter during manufacturing or service. This collaborative approach ensures that you achieve maximum value and performance from your investment in 309-series stainless steel.
For your next project requiring the exceptional high-temperature performance of 309, 309S, or 309H stainless steel, we invite you to contact our technical team to discuss your specific requirements. Our experts are ready to help you select the optimal material grade and form to ensure reliable, long-term performance in your most demanding thermal environments.
