Stainless Steel 321 is an austenitic chromium-nickel stainless steel containing titanium and niobium. It is designed to provide good resistance to intergranular corrosion in high-temperature environments up to 870°C (1600°F). Its composition comprises 18% Chromium, 9% Nickel, 3% Molybdenum, 5 % Titanium and 45% Niobium, giving it excellent corrosion resistance properties. Additionally, its lower carbon content compared to other grades of stainless steel can help prevent carbide precipitation during welding for greater protection against intergranular attack.

Stainless Steel 321 is a titanium-stabilized austenitic stainless steel known for its excellent resistance to intergranular corrosion and oxidation. It offers superior high-temperature creep strength and stress rupture properties compared to other alloys. This alloy also features enhanced machinability, toughness, fabricability and weldability, and exceptional mechanical properties, making it suitable for many aerospace, petrochemical, automotive, and more applications. It should be noted that this alloy may be subject to segregation of constituents with long heating times due to its lower thermal stability rating.