Chinese QN1803 stainless steel (4.5–5.5% nickel) is a high-strength, high-nitrogen austenitic alloy developed to offer excellent mechanical performance and corrosion resistance at a lower cost than traditional high-nickel grades. Its composition includes 16.0–19.5% chromium, 0.20–0.30% nitrogen, 4.5–5.5% nickel, and small amounts of manganese and molybdenum, which improve oxidation and wear resistance.

The nitrogen present in the alloy significantly increases mechanical strength, hardness, and structural stability, while also enhancing resistance to pitting corrosion and oxidation. For this reason, QN1803 delivers performance comparable to stainless steel 304 and is recommended for metal structures, architectural panels, tanks, ducts, and industrial equipment that require durability and good weldability.