JIS G4304 / G4312 SUS 347 Stainless Steel Composition & Niobium‑Stabilized Austenitic Properties
SUS 347 is a niobium‑stabilized austenitic stainless steel defined in JIS G4304 / G4312. With 17–19% chromium, 9–13% nickel, and niobium added to prevent carbide precipitation, it offers improved intergranular corrosion resistance compared with SUS 304.
347 provides excellent stability at 600–850°C, making it suitable for heat exchangers, exhaust systems, boiler components, furnace structures, and high‑temperature pressure equipment. SUS 347 is supplied as sheets, plates, tubes, bars, and strips. It is widely used in petrochemical plants, thermal‑processing equipment, and aerospace exhaust systems.
347 provides excellent stability at 600–850°C, making it suitable for heat exchangers, exhaust systems, boiler components, furnace structures, and high‑temperature pressure equipment. SUS 347 is supplied as sheets, plates, tubes, bars, and strips. It is widely used in petrochemical plants, thermal‑processing equipment, and aerospace exhaust systems.