Stainless steel is not “rust-proof”. Poor storage and shipping cause rust spots and scratches. Common causes and countermeasures:

1) Moisture and condensation: keep warehouses dry and ventilated; avoid open storage; dehumidify in rainy seasons. 2) Chloride contamination: keep away from salt spray, chloride cleaners and chemicals, especially in coastal areas. 3) Carbon steel contact: direct contact introduces iron contamination and rust spots. Use wooden or plastic dunnage, isolation paper and dedicated lifting gear. 4) Scratches: interleave paper/protective film between sheets; use proper slings and protectors rather than wire rope directly on the surface. 5) Packaging: export/sea shipments need moisture protection (VCI film, desiccant) and low-moisture wooden crates.

Inspection and treatment: when rust appears, determine whether it is contamination, pitting or crevice corrosion; the blue-dot test detects free iron. Light rust can be pickled and passivated; severe cases are downgraded.

Storage management: zone by grade/heat, first-in-first-out, avoid mixing, and keep goods-in/out records with surface inspection.