309S Stainless Steel Sheet Coil Thickness 0.6 - 3.0mm Cold Rolled 4ft*8ft SS Sheet Heat Resistant for Boiler

309S Stainless Steel Sheet Coil Thickness 0.6 - 3.0mm Cold Rolled 4ft*8ft SS Sheet Heat Resistant for Boiler

Product Overview

309S stainless steel sheet coil is a high-alloy austenitic stainless steel engineered for exceptional performance in elevated-temperature environments. With a thickness range of 0.6 mm to 3.0 mm, cold-rolled finish, and standard sheet dimensions of 4 feet by 8 feet (1219 mm × 2438 mm), this material is ideal for demanding applications such as boilers, heat exchangers, furnace components, exhaust systems, and thermal processing equipment.

The “S” in 309S denotes a low carbon content (≤0.08%), which significantly reduces the risk of carbide precipitation during welding—making it highly suitable for welded fabrications without requiring post-weld annealing. This feature, combined with its outstanding oxidation resistance up to 980°C (1796°F), positions 309S as a preferred choice in industries where reliability under thermal stress is critical.

Manufactured to meet international standards including ASTM A240/A240M, ASME SA-240, and UNS S30908, our 309S stainless steel sheets offer consistent mechanical properties, excellent formability, and long-term durability in harsh operating conditions.

Key Features & Benefits

• ✅ High-Temperature Resistance: Stable performance up to 980°C; short-term exposure possible up to 1095°C
• ✅ Superior Oxidation Resistance: Forms a protective chromium-rich oxide layer at high temperatures
• ✅ Low Carbon Content (309S variant): Minimizes sensitization and intergranular corrosion in welded zones
• ✅ Cold-Rolled Precision: Tight thickness tolerances, smooth surface finish, and enhanced strength
• ✅ Versatile Dimensions: Standard 4ft × 8ft sheets (custom cutting available)
• ✅ Widely Compatible: Meets global material standards (AISI, UNS, EN, JIS, GB)
• ✅ Corrosion Resistance: Effective against sulfidation, carburization, and moderate acid environments

Typical Chemical Composition (ASTM A240 / UNS S30908)

Note: Exact composition may vary slightly based on production batch and customer specifications.

Mechanical Properties (Typical Values, Annealed Condition)

These properties ensure structural integrity even under cyclic thermal loading—essential for boiler shells, burner nozzles, and radiant tubes.

Physical & Thermal Characteristics

The relatively low thermal conductivity and high expansion coefficient must be considered during design to accommodate thermal stresses.

Available Specifications

Why Choose 309S Over Other Grades?

While 304 and 316 stainless steels are common for general corrosion resistance, they lack the high-temperature stability required for boiler systems. In contrast:

• 309S vs. 304: 309S contains nearly double the chromium and ~3× more nickel, drastically improving oxidation resistance above 600°C.
• 309S vs. 310S: Though 310S offers higher temperature capability (up to 1150°C), 309S provides a cost-effective balance for applications below 1000°C with excellent weldability.
• 309S vs. 309: The “S” version’s lower carbon prevents weld decay—critical for pressure vessels like boilers governed by ASME codes.

Common Industrial Applications

Note: Not recommended for chloride-rich environments due to potential stress corrosion cracking.

Quality Assurance & Certification

All 309S stainless steel sheets are produced under strict ISO 9001:2015 quality management systems. Each batch undergoes:

• Spectrometric chemical analysis
• Tensile and hardness testing
• Ultrasonic or eddy current inspection (optional)
• Surface quality verification (per ASTM A480)
• Mill Test Report (MTR) provided with EN 10204 3.1 certification

We also support third-party inspections (e.g., SGS, BV, TÜV) for critical projects.

Ordering Information

To place an order or request a quote, please provide the following details:

1. Grade: 309S (UNS S30908)
2. Dimensions: Thickness (e.g., 1.5 mm), Width (e.g., 1219 mm), Length (e.g., 2438 mm)
3. Quantity: In kg, tons, or number of sheets
4. Surface Finish: 2B (default), BA, No.4, etc.
5. Certification Requirements: MTR, 3.1 certificate, PMI test, etc.
6. Delivery Terms: FOB, CIF, or EXW; destination port/city

Lead time: Typically 7–15 days for stock items; 25–35 days for mill production.

Frequently Asked Questions (FAQ)

Q: Can 309S stainless steel be used in wet, acidic environments?
A: It performs well in nitric and organic acids at elevated temperatures but is not suitable for hydrochloric or sulfuric acid service. Avoid chloride concentrations >200 ppm.

Q: Is 309S magnetic?
A: Generally non-magnetic in annealed condition. Slight magnetism may develop after cold working.

Q: What’s the difference between hot-rolled and cold-rolled 309S?
A: Cold-rolled sheets offer better surface finish, tighter tolerances, and higher strength—ideal for precision parts. Hot-rolled is used for thicker plates (>3 mm).

Q: Can you laser-cut or CNC-machine 309S sheets?
A: Yes. We offer value-added services including laser cutting, waterjet cutting, bending, punching, and welding.

Conclusion

For engineers and procurement professionals seeking a reliable, high-performance stainless steel for boiler and high-temperature industrial applications, 309S cold-rolled sheet (0.6–3.0 mm, 4ft×8ft) delivers the perfect blend of heat resistance, weldability, and corrosion protection. Backed by rigorous quality control and global material standards, this grade ensures safety, efficiency, and longevity in the most thermally aggressive environments.

Contact us today for competitive pricing, technical data sheets, or sample requests. We serve clients worldwide with fast logistics and customized solutions.

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