309S Austenitic Heat-Resistant Stainless Steel‌

309S Stainless Steel Sheet: Performance Characteristics and Core Applications

1. Performance Characteristics

1.1 High Temperature Resistance

It can be repeatedly heated below 980℃ and maintains continuous oxidation resistance in environments below 900℃. It exhibits excellent high-temperature strength and outstanding creep resistance.

Short-term temperature resistance can reach 1100℃, suitable for long-term high-temperature load scenarios.

1.2 Corrosion Resistance

The high chromium (23%) and nickel (13%) composition gives it the ability to quickly form an anti-oxidation layer, effectively resisting surface oxidation and corrosion, and adapting to various complex environments.

The low-carbon design reduces carbide precipitation, lowers the risk of intergranular corrosion, and improves weld stability.

1.3 Machining Characteristics

In the solution-treated state, it is non-magnetic; the sulfur content makes it easy to cut, suitable for high surface finish machining.

It has excellent weldability and can be welded using conventional methods, but its machinability is slightly inferior to grades such as 304 and 316.

2. Main Applications

2.1 High-Temperature Industrial Equipment

Boiler Manufacturing: Used for furnace linings, furnace tubes, and burner components to ensure structural stability under high-temperature environments.

Heat Treatment Equipment: Such as the feed inlet of drying furnaces and hot blast furnace tubes, meeting the requirements of repeated heating.

2.2 Chemical and Energy Sectors

Petrochemical Plants: Used for reactor linings and catalyst recovery systems, resisting acid and alkali corrosion.

Nuclear and Thermal Power: Manufactures steam turbine components, ensuring reliability in high-temperature and high-pressure environments.

2.3 Environmental and Public Welfare Applications

Waste Gas Treatment Equipment: Resists corrosion in sulfide environments, extending the lifespan of environmental protection equipment.

Food Processing Equipment: Such as cooking pots and storage tanks, meeting high-temperature disinfection and hygiene requirements.

3. Summary

309S stainless steel, with its excellent high-temperature corrosion resistance, stable mechanical properties, and easy processing characteristics, has become a core material in high-temperature industries, chemical and energy fields, and is widely used in boilers, petrochemical equipment, and environmental engineering, providing reliable solutions for extreme working conditions.