科学素养与生活应用·英语30篇（5）

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为何近海钢桥更易遭受盐水腐蚀

Saltwater corrosion accelerates on coastal steel bridges because chloride ions penetrate protective oxide layers.
These ions disrupt electron transfer and promote electrochemical reactions that dissolve iron atoms.
Wind-driven sea spray deposits salt crystals that absorb moisture and form conductive electrolyte films.
Corrosion rates increase exponentially when relative humidity exceeds 70% and temperatures stay above 10°C.
Engineers apply zinc-rich primers and cathodic protection systems to slow degradation.
Accelerated lab tests simulate decades of exposure using salt-fog chambers and cyclic humidity changes.
Inspection drones now detect early-stage pitting using high-resolution thermal and spectral imaging.
Coastal bridges may require maintenance every 5–7 years instead of 15–20 inland.
New alloys with added chromium and molybdenum resist chloride-induced pitting more effectively.
This understanding drives material selection standards for infrastructure in marine environments.