Comparison of Corrosion Resistance
Q355NHB is a standard high‑strength weathering steel designed for atmospheric service, and its corrosion resistance can be directly compared with other common weathering steel grades.
Compared with ordinary weathering steel (such as Q235NH, Q295NH)
Q355NHB provides similar or slightly better corrosion resistance in industrial and rural atmospheres.The main difference is that Q355NHB has higher strength (yield strength ≥ 355 MPa), while corrosion performance is at the same level.
Compared with ASTM A588 Grade A / B
Q355NHB and ASTM A588 have very similar corrosion resistance.Both rely on the alloy system of Cu, Cr, Ni, P to form a stable protective patina.In typical inland and industrial atmospheres, their long‑term durability and corrosion rates are almost equivalent.
Compared with ASTM A606‑2
Q355NHB and A606‑2 show comparable atmospheric corrosion resistance.The difference lies more in product form, strength specification, and application standards, not in corrosion performance.
Compared with SPA‑H / SPA‑C (Japanese weathering steels)
Q355NHB has similar corrosion resistance to SPA‑H.SPA‑H is generally lower strength, while Q355NHB combines equivalent weathering performance with higher structural strength.
Compared with high‑alloy weathering steels (for severe environments)
Specialized high‑weathering grades with higher Cr, Ni, Cu content have better corrosion resistance than Q355NHB in heavily polluted or coastal environments.Q355NHB is a general‑purpose weathering steel, not a super‑corrosion‑resistant grade.
