AISI 309 (UNS S30900) is a highly alloyed austenitic stainless steel primarily used in the production of high temperature resistant and corrosion resistant components. The alloy is often referred to as AISI 309, SUS 309 or 1.4828.
AISI 309 is a stainless steel grade with a higher chromium, nickel and carbon content than the more common AISI 304 stainless steel. It is a non hardenable, non magnetic and corrosion resistant grade suited for a range of applications including heat exchangers, high temperature components and automotive exhaust systems.
AISI 309 is composed of 20 - 25% chromium, 11 - 15% nickel and up to 0.2% carbon. The chromium content creates a passive protective oxidation layer and provides resistance to secondary corrosion. The nickel content imparts extra strength and hardness to the grade and the addition of carbon enables the material to be hardened further through a process of heat treating.
AISI 309 has a range of beneficial properties which make it well suited to many applications. It displays excellent strength and hardness, in addition to superior corrosion and oxidation resistance. The alloy is also very ductile and can be easily welded, machined and cold worked.
Some of the most common applications of AISI 309 include:
• Heat Exchangers: AISI 309 provides an excellent resistance to corrosion and oxidation, making it suitable for use in the production of heat exchangers.
• Boiler Components: AISI 309 has superior corrosion and oxidation properties, making it suitable for use in boiler components.
• Automotive Exhaust Systems: AISI 309 is often specified for use in the production of automotive exhaust systems due to its corrosion, oxidation and heat resistance.
• Furnace Equipment: AISI 309 provides superior corrosion resistance, making it well suited for use in furnace equipment, such as trays and baskets.
The material is widely available off the shelf from a variety of suppliers in a range of forms, including plate, sheet, bar, pipe and tube.
AISI 309 is a highly alloyed stainless steel, offering superior corrosion and oxidation resistance, making it an excellent choice for a variety of applications, including heat exchangers, automotive exhaust systems, furnace equipment and boiler components. The material features excellent strength and hardness, while being highly ductile and easy to machine and weld. AISI 309 is widely available in a range of forms and sizes, making it suitable for a variety of applications.
