AISI 302B Stainless Steel Plate | 302B China steel mill-Direct Supply
What is AISI 302B Stainless Steel Plate?
As a professional China steel mill-Direct Supply and stainless steel plate supplier, SHH STEEL is pleased to present AISI 302B Stainless Steel Plate.
AISI 302B (UNS S30215) is a specialized variant of the classic AISI 302 austenitic stainless steel. It retains the fundamental 18% chromium and 8–10% nickel composition of the 302/304 family, but features a higher intentional silicon addition. The elevated silicon content significantly improves resistance to oxidation and scaling at elevated temperatures, making AISI 302B more suitable for continuous or intermittent high-temperature service than standard 302 or 304 grades.
The grade remains fully austenitic in the annealed condition, non-magnetic, and offers good formability and toughness at room temperature. The higher silicon level enhances the stability of the protective oxide film that forms on the surface when the material is exposed to hot air or oxidizing atmospheres. This characteristic is particularly valuable in furnace components, heat-treatment fixtures, and certain industrial heating applications.
Although modern designs often prefer Type 309S, 310S or other higher-alloy grades for severe high-temperature service, AISI 302B continues to serve as a cost-effective intermediate solution when moderate improvement in oxidation resistance is required without the full expense of higher-chromium or higher-nickel alloys.
SHH STEEL supplies AISI 302B 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. We offer AISI 302B in plate and sheet form across a practical range of thicknesses and surface finishes.
AISI 302B is frequently evaluated alongside a240 304, a240 304l, a240 309s and a240 310s when selecting materials for elevated-temperature service.
Material Specification
| Specification Element | Requirement | SHH STEEL Compliance |
|---|---|---|
| Grade | AISI 302B / UNS S30215 | Confirmed |
| Related Standards | ASTM A240, ASME SA240, related national standards | Available |
| Product Form | Plate, Sheet | Available |
| Delivery Condition | Solution Annealed | Standard |
| Thickness Range | 0.5 mm – 40 mm (thicker available on request) | Custom sizes supported |
| Width | Up to 1500–2000 mm | Available |
| Length | Up to 6000 mm or cut-to-length | Available |
| Surface Finish | 2B, No.1, BA, No.4 | Available |
| Certification | EN 10204 3.1 / Mill Test Certificate | Available |
Chemical Composition
Typical Chemical Composition of AISI 302B (UNS S30215):
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.15 |
| Silicon (Si) | 2.00 – 3.00 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 17.00 – 19.00 |
| Nickel (Ni) | 8.00 – 10.00 |
| Nitrogen (N) | ≤ 0.10 |
| Iron (Fe) | Balance |
The defining feature of AISI 302B is the elevated silicon content (typically 2.0–3.0%). Silicon improves the adherence and protective quality of the oxide scale that forms at high temperature, thereby enhancing resistance to oxidation and scaling. The carbon content remains similar to standard AISI 302, so the grade still requires care during welding to avoid sensitization.
For higher-temperature or more severe oxidizing service, customers often upgrade to a240 309s or a240 310s.
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 |
The room-temperature mechanical properties of AISI 302B are comparable to those of standard AISI 302 and Type 304. The higher silicon content has only a modest effect on strength at ambient temperature, but it contributes to better retention of strength and scale resistance at elevated temperatures.
Physical Properties
- Density: approximately 7.90–7.93 g/cm³
- Magnetic Response: Non-magnetic in the annealed condition
- Melting Range: approximately 1400–1420°C
When higher elevated-temperature strength is required, grades such as a240 310h or A240 800H are typically considered.
Material Comparison
| Grade | Key Feature | Oxidation Resistance | Strength at RT | Typical Preference |
|---|---|---|---|---|
| AISI 302 | Standard 18-8, higher C | Good | Higher | General strength applications |
| AISI 302B | Higher Silicon | Improved | Similar | Moderate high-temperature service |
| AISI 304 | Lower C, standard 18-8 | Good | Standard | General purpose |
| AISI 304L | Extra-low carbon | Good | Standard | Welded constructions |
| AISI 309S | 23Cr-13Ni | Very Good | Standard | Higher-temperature oxidizing service |
| AISI 310S | 25Cr-20Ni | Excellent | Standard | Severe high-temperature service |
AISI 302B is selected when a moderate improvement in oxidation resistance over standard 302/304 is required at a still economical cost. For more demanding continuous high-temperature exposure, a240 309s or a240 310s is preferred. For maximum high-temperature strength and carburization resistance, A240 800 or A240 800H may be evaluated.
Corrosion Resistance
At room temperature and in mild environments, AISI 302B offers corrosion resistance similar to standard AISI 302 and Type 304. It performs well in atmospheric conditions, fresh water and many food-related applications.
The principal advantage of AISI 302B appears at elevated temperatures. The higher silicon content promotes the formation of a more stable and adherent silicon-rich oxide scale, which improves resistance to oxidation and scaling in hot air and oxidizing atmospheres up to approximately 900–950°C (depending on the specific conditions and cycle frequency).
It is not intended for severe carburizing, sulfidizing or highly reducing atmospheres, nor for continuous service in strong chloride environments. For more aggressive high-temperature or corrosive service, higher-alloy grades such as a240 310s, a240 310h or A240 800H should be considered.
Weldability
AISI 302B can be welded by standard fusion welding methods. Because of its higher carbon content (similar to standard 302), it is susceptible to sensitization if held in the temperature range of approximately 450–850°C. Matching or 308-type filler metals are commonly used.
Post-weld annealing is recommended when the welded component will operate in corrosive service or when maximum corrosion resistance is required. For applications involving extensive welding, low-carbon grades such as a240 304l are generally preferred.
Heat Treatment
AISI 302B is normally supplied in the solution-annealed condition.
Recommended Solution Annealing Parameters
- Temperature range: 1010 – 1120°C
- Holding time: Sufficient to dissolve carbides and ensure uniformity
- Cooling: Rapid cooling (water quench preferred for thicker sections)
Proper annealing restores ductility after cold working and optimizes both room-temperature corrosion resistance and high-temperature oxidation performance. Slow cooling through the sensitization range should be avoided.
Surface Finishes
| Finish | Description | Typical Use / Keywords |
|---|---|---|
| 2B | Cold-rolled, annealed, pickled, skin-passed | AISI 302B 2B – general fabrication |
| No.1 | Hot-rolled, annealed and pickled | AISI 302B No.1 – industrial plate |
| BA | Bright Annealed | AISI 302B BA – cleaner surface applications |
| No.4 | Brushed finish | AISI 302B No.4 – architectural surfaces |
SHH STEEL regularly supplies AISI 302B in 2B and No.1 finishes. Other finishes can be arranged according to project requirements. Related decorative options include A240 430.
Tolerances
Dimensional tolerances for AISI 302B Stainless Steel Plate generally conform to ASTM A480 practices.
Typical available size range:
- Thickness: 0.5 mm – 40 mm
- Width: up to 1500–2000 mm
- Length: up to 6000 mm or cut-to-length
SHH STEEL provides precise dimensional control and can support tighter tolerances when required by the project.
Equivalent Material Grades
Applications
AISI 302B is primarily selected for applications that benefit from improved high-temperature oxidation resistance at a moderate cost. Typical applications of AISI 302B include:
| Industry / Sector | Typical Components / Equipment |
|---|---|
| Heat Treatment & Furnaces | Fixtures, trays, baskets, radiant components |
| Industrial Heating | Furnace parts, muffles, supports |
| Power & Energy | Moderate-temperature components |
| General High-Temperature Service | Oxidizing atmosphere parts requiring better scale resistance |
| Fabrication | Formed and welded components for elevated-temperature use |
For more demanding high-temperature service, higher-alloy options such as a240 309s, a240 310s or A240 800H are commonly specified. Related industry solutions can be found on our energy industry and equipment manufacturing pages. Fabrication support is available through 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, we supply AISI 302B 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)
- Flexible dimensions and surface finishes (including AISI 302B 2B and AISI 302B No.1)
- Technical support for material selection among 302, 302B, 304, 309S and 310S families
- Value-added services including steel cutting services, stainless surface finishing 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 302B over standard AISI 302 or 304?The higher silicon content of AISI 302B improves resistance to oxidation and scaling at elevated temperatures. SHH STEEL recommends 302B when moderate high-temperature oxidation resistance is required at a still economical cost.
- How does AISI 302B compare with Type 309S or 310S?Type 309S and 310S offer significantly better high-temperature oxidation resistance and are preferred for more severe or continuous high-temperature service. AISI 302B is a lower-cost intermediate option. SHH STEEL can help evaluate the most suitable grade.
- Is AISI 302B magnetic?Non-magnetic in the annealed condition. It may become slightly magnetic after heavy cold working.
- What is the density of AISI 302B?Approximately 7.90–7.93 g/cm³. SHH STEEL provides material certificates confirming physical and mechanical properties.
- Does SHH STEEL supply dual-certified ASTM A240 / AISI 302B material?Yes, SHH STEEL commonly supplies dual-certified material upon request.
Conclusion
AISI 302B Stainless Steel Plate is a silicon-modified austenitic grade based on the classic 302 composition. The elevated silicon content provides improved resistance to oxidation and scaling at elevated temperatures, making it a practical and economical choice for moderate high-temperature service where standard 302 or 304 is no longer sufficient, yet the full performance of 309S or 310S is not required.
As a professional China steel mill-Direct Supply, SHH STEEL provides high-quality AISI 302B Stainless Steel Plate with competitive pricing, full certification and complete technical support.
Contact SHH STEEL today for stock availability, surface finish options (including AISI 302B 2B and AISI 302B No.1), or a competitive quotation.
AISI 302B Stainless Steel Plate, 302B China steel mill-Direct Supply, AISI 302B, 302B Stainless Steel Plate, UNS S30215, AISI 302B supplier
Quality Steel Needed? Inquire for Offers
Related Products
