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JIS SUS310S Stainless Steel: High-Temperature Austenitic Alloy for Oxidation Resistance & Corrosive Environments
JIS SUS310S (UNS S31008) is a low-carbon, high-chromium-nickel austenitic stainless steel designed for extreme high-temperature applications up to 1150°C (2100°F). Its 25% chromium and 20% nickel composition provides exceptional oxidation resistance, creep strength, and resistance to sulfidation, making it ideal for furnace components, heat exchangers, and chemical processing equipment. This article explores its chemical properties, mechanical performance, manufacturing process, and industrial applications compared to similar high-temperature alloys.
1. Chemical Composition (JIS G4305 Standard)
| Element | Content Range | Function |
|---|---|---|
| Carbon (C) | ≤ 0.08% | Minimized to prevent carbide precipitation and maintain weldability |
| Chromium (Cr) | 24.00 – 26.00% | Forms protective Cr₂O₃ oxide layer for high-temperature oxidation resistance |
| Nickel (Ni) | 19.00 – 22.00% | Stabilizes austenitic structure; enhances high-temperature strength and ductility |
| Manganese (Mn) | ≤ 2.00% | Improves hot workability and sulfur resistance |
| Silicon (Si) | ≤ 1.50% | Enhances oxidation resistance at elevated temperatures |
| Phosphorus (P) | ≤ 0.045% | Controlled impurity to maintain high-temperature performance |
| Sulfur (S) | ≤ 0.030% | Minimized to prevent hot cracking during fabrication |
| Iron (Fe) | Balance | Base metal providing structural integrity |
2. Mechanical Properties at Elevated Temperatures
| Property | Room Temp | 500°C (932°F) | 800°C (1472°F) | 1000°C (1832°F) |
|---|---|---|---|---|
| Tensile Strength (MPa) | ≥ 515 | ≥ 350 | ≥ 150 | ≥ 80 |
| Yield Strength (MPa) | ≥ 205 | ≥ 170 | ≥ 80 | ≥ 40 |
| Elongation (%) | ≥ 40 | ≥ 30 | ≥ 25 | ≥ 20 |
| Creep Rupture Strength (100,000h, MPa) | – | 120 | 50 | 20 |
3. Manufacturing & Heat Treatment Process
- Melting: Electric arc furnace (EAF) followed by argon oxygen decarburization (AOD) to achieve precise low-carbon composition and remove impurities.
- Hot Working: Hot rolled at 1150-1250°C with controlled cooling to prevent sigma phase formation, followed by solution annealing.
- Cold Working: Limited to light forming due to high work hardening rate; intermediate annealing required for complex shapes.
- Solution Annealing: Heated to 1040-1150°C followed by rapid water quenching to dissolve chromium carbides and restore corrosion resistance.
- Surface Finishing: Pickling with nitric-hydrofluoric acid mixture to remove scale, followed by passivation for enhanced corrosion protection.
4. Key Application Scenarios
Furnace & Kiln Components
Radiant tubes, muffles, retorts, and burner parts in heat treatment furnaces operating up to 1150°C. Resists scaling and maintains dimensional stability.
Chemical Processing Equipment
Reaction vessels, distillation columns, and piping systems for sulfuric acid, nitric acid, and organic chemical production where corrosion resistance at high temperatures is critical.
Petrochemical Industry
Catalytic recovery systems, flare stacks, and reformer tubes in refineries where resistance to sulfidation and carburization is required.
Power Generation
Boiler components, superheater tubes, and exhaust systems in coal-fired and waste-to-energy plants exposed to corrosive flue gases.
Heat Exchangers
High-temperature heat exchangers in aerospace, automotive, and industrial applications where thermal cycling resistance is essential.
Food Processing (Specialized)
High-temperature food processing equipment like continuous ovens and sterilization systems where both heat and corrosion resistance are required.
5. Comparison with Related High-Temperature Alloys
| Alloy | Cr-Ni Content | Max Temp (°C) | Key Advantage | Typical Application |
|---|---|---|---|---|
| SUS310S | 25Cr-20Ni | 1150 | Best oxidation resistance in air | Furnace parts, chemical equipment |
| SUS309S | 23Cr-14Ni | 1050 | Lower cost alternative | Less demanding high-temp applications |
| SUS316 | 17Cr-12Ni-2.5Mo | 900 | Better chloride resistance | Marine, pharmaceutical equipment |
| Inconel 600 | 15Cr-76Ni | 1150 | Superior strength at high temp | Aerospace, nuclear components |
| RA330 | 19Cr-35Ni | 1200 | Higher nickel for extreme temps | Thermal processing equipment |
6. Selection Guidelines & Fabrication Notes
- Welding: Use ER310 or ER310S filler metal; preheat not required but interpass temperature should not exceed 150°C. Post-weld annealing recommended for critical applications.
- Machining: Difficult due to work hardening; use carbide tools with slow speeds and heavy feeds. Annealed condition (HB ≤ 200) is most machinable.
- Thermal Cycling: Avoid repeated heating/cooling cycles above 800°C to prevent sigma phase embrittlement. Use stabilized grades if cycling is unavoidable.
- Surface Protection: For sulfur-containing environments, apply aluminum diffusion coating to enhance sulfidation resistance.
- Inspection: Verify material certification to JIS G4305 or equivalent ASTM A240 standards, with particular attention to carbon content for weldability.
7. Request a Quote for JIS SUS310S Stainless Steel
Need customized JIS SUS310S stainless steel products in sheet, plate, coil, or bar form? Our metallurgical experts provide technical support and competitive pricing for high-temperature alloy requirements. Contact us with your specifications including dimensions, quantities, and surface finish requirements for a prompt quotation.
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