Hidden Function Of Passivation & Sealing: Zinc Coating Loss Doubles Without This Layer

Release time:

2026-07-17

Most buyers only focus on zinc weight, salt spray test and annealing performance, ignoring the final passivation sealing procedure.

Most buyers only focus on zinc weight, salt spray test and annealing performance, ignoring the final passivation sealing procedure. Actual field test data proves that under the same zinc coating thickness, wire without passivation suffers twice faster corrosion loss outdoors, accompanied by rampant white rust, coating pulverization and premature rust penetration, especially in high-salt, large temperature difference, landscape, PV and de-icing road projects.

Core Functions Of Passivation Film

Seal micro pinholes on zinc surface to block penetration of chloride and moisture;
Suppress white rust growth and slow zinc pulverization;
Buffer thermal stress under drastic temperature swing to avoid coating microcracks;
Improve surface wear resistance and reduce zinc peeling during bending & weaving.

Service Life Contrast

For coastal, highway and PV scenarios, passivated high-zinc wire delivers nearly double service life compared with bare zinc wire without sealing treatment.