How to Improve the Salt Spray Test Performance of Polished Hardware Parts?

Improving the salt spray test performance of polished hardware parts hinges on optimizing surface treatment processes, selecting corrosion-resistant materials, strengthening pre- and post-treatment processes, and strictly controlling testing environmental conditions. This can significantly extend the corrosion resistance time and improve product reliability.

Improve Surface Finish (Reduce Roughness)

A smoother surface makes it harder for salt spray droplets to accumulate, resulting in fewer corrosion initiation points.

The surface roughness after polishing should ideally be controlled at Ra ≤ 0.2μm. Especially for materials like stainless steel and copper alloys, ultra-fine polishing can extend the salt spray test time from 24 hours to over 120 hours.

Using precision processes such as magnetic polishing can effectively address deep holes and blind areas, eliminate micro-cracks and burrs, and prevent localized corrosion.

Select High Corrosion-Resistant Materials and Coatings

Substrate Selection: Prioritize materials with inherently strong corrosion resistance, such as 304 and 316 stainless steel, zinc-nickel alloys, and aluminum alloys.

Coating Upgrade: From ordinary zinc plating to zinc-nickel alloy plating, corrosion resistance can be improved by 3-5 times.

Using double-layer electroplating (such as copper + nickel + chromium) further enhances the protective barrier.