JIS G4304 / G4312 SUS 321 Stainless Steel Composition & Titanium‑Stabilized Austenitic Properties
SUS 321 is a titanium‑stabilized austenitic stainless steel defined in JIS G4304 / G4312. With 17–19% chromium, 9–12% nickel, and titanium added to prevent carbide precipitation, it offers improved resistance to intergranular corrosion during welding or elevated‑temperature service.
321 performs reliably around 600°C, making it suitable for heat exchangers, exhaust systems, boiler components, furnace structures, and high‑temperature pressure equipment. SUS 321 is supplied as sheets, plates, tubes, bars, and strips. As a heat‑resistant upgrade to 304, it provides reliable performance in high‑temperature and welded applications across petrochemical, thermal‑processing, and aerospace industries.
321 performs reliably around 600°C, making it suitable for heat exchangers, exhaust systems, boiler components, furnace structures, and high‑temperature pressure equipment. SUS 321 is supplied as sheets, plates, tubes, bars, and strips. As a heat‑resistant upgrade to 304, it provides reliable performance in high‑temperature and welded applications across petrochemical, thermal‑processing, and aerospace industries.