Marine environments are among the most aggressive conditions for steel corrosion. Chloride ions, high humidity, and continuous salt spray accelerate electrochemical reactions on steel surfaces.

As a result, thermal spray zinc coatings are widely used in offshore platforms, port infrastructure, offshore wind structures, and marine pipeline systems.

Before thermal spraying, steel surfaces typically require abrasive blasting to SA 2.5 standard. Inadequate surface roughness reduces mechanical bonding strength.

Spraying distance, current, voltage, and air pressure all influence zinc particle deposition. Parameter instability may cause uneven coating thickness.

If ambient humidity is too high, micro-oxidation may form on the steel surface before spraying, affecting adhesion stability.

Marine corrosion protection generally requires 99.9%–99.995% high-purity zinc wire. Iron, lead, or oxide impurities in lower-purity materials may affect sacrificial anode performance.

Diameter variation may destabilize the arc and affect particle distribution. Uneven coating structure can increase localized corrosion risk.

Excessive oxidation on the wire surface may result in uneven melting behavior, affecting coating density.

In offshore projects, early coating failure is rarely caused by a single factor. Application process and material quality usually interact with each other.

For example, even when using high-purity zinc wire, insufficient blasting preparation may still reduce adhesion. Likewise, stable spraying parameters cannot fully compensate for low-purity materials.

Offshore projects typically recommend evaluating zinc purity, ±0.01mm diameter tolerance, EN ISO 14919 compliance, stable wire feeding performance, and SA 2.5 surface preparation standards.

Early failure of marine zinc coatings is not caused solely by process conditions or material quality, but by the overall stability of the corrosion protection system.

For offshore structures, high-purity zinc wire, stable feeding performance, and standardized application processes must work together to achieve reliable long-term corrosion protection.