STS309S – High-Chromium-Nickel Austenitic Alloy For High-Temperature Oxidation Resistance

Overview

STS309S is a high-chromium-nickel austenitic stainless steel, designed for extreme high-temperature applications requiring excellent oxidation and carburization resistance. With 22.00-24.00% chromium and 12.00-15.00% nickel, it forms a dense protective oxide film that can withstand continuous service at temperatures up to 1038°C and short-term peaks up to 1100°C, even in sulfur-containing atmospheres. It is a low-carbon grade (C ≤ 0.08) that offers good weldability and ductility, and is non-magnetic in the annealed state. Its high alloy content makes it suitable for high-temperature industrial equipment exposed to severe oxidation and thermal cycling.

Chemical Composition (wt%)

C ≤ 0.08, Cr: 22.00-24.00, Ni: 12.00-15.00, Mn ≤ 2.00, Si ≤ 1.00, P ≤ 0.045, S ≤ 0.030

Typical Mechanical Properties (Annealed Condition)

Tensile Strength (Rm): ≥ 515 MPa; Yield Strength (Rp0.2): ≥ 205 MPa; Elongation (A): ≥ 40%; Brinell Hardness (HB): ≤ 201

Core Advantages

High chromium-nickel content provides excellent high-temperature oxidation and carburization resistance; stable performance under thermal cycling; low carbon content improves weldability and prevents intergranular corrosion; non-magnetic; good ductility and formability; suitable for extreme high-temperature environments up to 1038°Ccontinuous service.

Applications

Industrial furnace components (burners, doors, fans), heat treatment fixtures, boiler tubes, petrochemical cracking equipment, and high-temperature kiln linings requiring superior oxidation resistance.

Equivalent Grades

EN 1.4833, UNS S30908, GB 06Cr23Ni13, AISI 309S, SUS309S

Stainless Steel Suppliers

If you have project requirements for stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.