347 stainless steel is a type of austenitic stainless steel alloy with a high resistance to intergranular corrosion. It contains a minimum of 17% chromium, 10% nickel, and 0.08% carbon, which makes it resistant to sensitization during welding and high-temperature applications.

The addition of niobium to 347 stainless steel enhances its resistance to intergranular corrosion, making it suitable for use in applications involving exposure to corrosive environments, such as chemical processing, pharmaceuticals, and food processing.

347 stainless steel also has good mechanical properties, including high strength and excellent toughness, and is often used in applications that require high performance under extreme conditions. It is commonly used in the manufacturing of aircraft exhaust components, furnace parts, and jet engine components.