The corrosion resistance of stainless steel sinks primarily relies on a chromium-rich oxide film (also known as a "passivation film") that forms on the material's surface.
Core Mechanism: Stainless steel contains chromium. When exposed to air or water, chromium reacts with oxygen, forming a dense, stable, and invisible chromium oxide protective film on the metal surface. This film effectively isolates moisture, oxygen, and corrosive substances from contact with the internal iron matrix, thus preventing further oxidation.
Self-Healing Ability: Even with minor scratches, exposure to an oxygen-containing environment allows chromium to quickly recombine with oxygen, repairing the passivation film and restoring corrosion resistance.
Advantages of 304 Stainless Steel: High-quality sinks on the market often use 304 food-grade stainless steel, containing 18% chromium and 8% nickel. The addition of nickel not only improves the material's ductility and processing performance but also enhances the stability of the passivation film in complex environments, making it more corrosion-resistant than 201 or 430 stainless steel.
