S30215 is a special stainless steel with a duplex structure, meaning it contains both austenitic and ferritic crystal structures. The austenitic portion provides excellent corrosion resistance, toughness, and ductility, while the ferritic part offers higher strength and hardness. This unique structure allows it to combine the benefits of both.

1. Basic Overview
S30215 (UNS number), corresponding to the European standard 1.4845, is also known as 302HQ (high-carbon version).
Type: Austenitic stainless steel (chromium-nickel alloy).

2. Main components

• Chromium (Cr): 17-19%

• Nickel (Ni): 8-10%

• Carbon (C): ≤0.15% (higher carbon content enhances strength)

• Manganese (Mn): ≤2%

• Silicon (Si): ≤1%

• Other trace elements may be added (such as nitrogen, phosphorus, sulfur, etc.)

3. Characteristics and Advantages

（1）Corrosion Resistance: Performs well in oxidative environments (such as air, freshwater, nitric acid), though not as resistant as 316 stainless steel (due to the lack of molybdenum).

（2）High-Temperature Performance: Suitable for long-term use below 800°C, with better oxidation resistance than standard 302 stainless steel.

（3）Mechanical Properties:

• High strength and hardness.

• Excellent cold working hardening capability, ideal for cold forming (such as springs and fasteners).

（4）Non-magnetic: The austenitic structure ensures it is non-magnetic in the annealed state.

4. Common Applications

• High-Temperature Environments: Furnace components, heat exchangers, burner nozzles.

• Industrial Parts: Springs, bolts, valves, bearings.

• Medical and Food: Surgical instruments, food processing equipment.

• Others: Chemical containers, nuclear industry auxiliary equipment.

5. Processing and Heat Treatment

（1）Cold Processing: Suitable for strengthening through cold rolling and drawing.

（2）Heat Treatment:

• Solution treatment: 1050-1100°C followed by rapid cooling.

• Avoid prolonged exposure in the range of 450-850°C to prevent chromium carbide precipitation.

（3）Welding:
S30215 stainless steel can typically be processed by welding, but attention must be paid to the following:

• Heat Affected Zone Control: Due to its duplex structure, control of the heat-affected zone is necessary during welding to prevent intergranular corrosion.

• Post-Weld Heat Treatment: Proper heat treatment after welding is needed to restore optimal physical properties and prevent brittleness.

6. Performance Testing
S30215 stainless steel's performance can be verified through the following standard tests:

• Tensile Strength: Typically around 700 MPa, indicating high strength.

• Yield Strength: Approximately 450 MPa, suitable for applications that bear heavy loads.

• Elongation: Exhibits good elongation, generally reaching over 25%, making it suitable for various bending and forming processes.

• Hardness: Surface hardness is typically high, suitable for high wear environments.

7. Precautions

• Corrosive Environments: Not recommended for use in high chloride ion environments.

• Magnetism: To ensure complete non-magnetism, avoid cold processing.

• Alternative Options: If higher corrosion resistance is required, consider 316 stainless steel; for a more economical, general-purpose material, 304 may be a better choice.

8. Standards and Specifications

ASTM: A493 (wires), A580 (cold-processed parts).

EN: 1.4845 (European material number).

JIS: SUS30215 (Japanese standard).

9. Conclusion
S30215 optimizes strength and high-temperature performance by adjusting carbon content, making it suitable for applications that require both heat resistance and mechanical strength. However, it should be carefully selected for use in harsh corrosive environments. Its balanced properties make it an ideal material in industrial and specialized fields.

Our company can process metals into round bars, steel plates, round pipes/square pipes, and coils according to your requirements.If you have any needs, feel free to contact us. Our email address is: sale@bolaibao1.com. We look forward to your inquiries.