In-House Salt Spray Testing for Corrosion Resistance:

What Is Salt Spray Testing and Why Does It Matter?

William Hughes has expanded its in-house quality control offering by introducing salt spray testing, a method designed to simulate long-term environmental exposure and evaluate the corrosion resistance of components, particularly in harsh or demanding applications.

Salt spray testing (also known as salt fog testing) is essential for industries like aerospace and automotive, where even minor corrosion could compromise component integrity. It helps validate the longevity and reliability of metal parts and surface treatments before they are approved for operational use.

How Does the Salt Spray Test Work?

Salt spray or salt fog testing exposes springs and other components to a saline fog environment in order to ascertain the corrosion resistance of the material of which they’re made or the surface coating thereof. A controlled saline situation will show how long it takes for a component to accede to rust or other oxides, if indeed it succumbs at all.

What Are the Requirements for Salt Spray Testing?

Salt spray test requirements vary depending on the coating and the end-use sector. For instance, components coated in Delta-Tone® common in aerospace and automotive manufacturing, are often subject to strict anti-corrosion performance standards. Manufacturers must demonstrate that such coatings can withstand extended salt spray exposure without surface failure.

At William Hughes, salt spray testing durations are aligned to customer specifications and industry norms, with test times ranging from 48 to 600+ hours depending on the application.

Equipment required for the salt spray chamber comprises the holding tank with its salt solution of between 4-6% pH and the salt spray cabinet itself where the salt water solution is atomised using pressurised air. The samples to be tested are then exposed to this extremely corrosive saline fog for the requisite amount of time, which can be days or weeks depending on the standard to be achieved. Regular daily tests ensure that temperature and the specific gravity of the salt solution are maintained at a level consistent with ASTM B117, an internationally recognised salt spray standard.

Why Add Salt Spray Testing to In-House Capability?

The addition of this facility complements William Hughes’ wider testing infrastructure, which already includes fatigue testing and ultrasonic inspection. By integrating salt spray testing on-site, the company reduces lead times, ensures tighter quality control and provides faster feedback loops during R&D and production runs.

Common Questions About Salt Spray Testing

What does a salt spray test show?

It reveals how resistant a component or coating is to corrosion in a highly saline environment.

Why is salt spray testing used in the automotive and aerospace sectors?

Because these industries demand high-performance, long-life components that must endure extreme environmental conditions.

Is salt spray testing required for coated springs?

Yes, especially where the springs are treated with anti-corrosion coatings and used in exposed or safety-critical applications.