Salt spray testing is a standardised method of checking the corrosion resistance of components and coated samples.

Coatings are used to protect components, made from materials such as steel and zinc, from corrosion. Coatings can be inorganic, such as plating, anodising and galvanising or organic such as powder or paint coatings. The salt spray test is used to predict the suitability of these coatings as protective finishes, but it can also be used to ascertain the service life of the component in question.

Specimens are exposed to either a continuous or intermittent fine mist of five percent salt solution to determine at which point they start to corrode.

This method of testing has been used for more than ninety years to determine the degree of protection afforded by either inorganic or organic coatings on a metallic substrate.

The neutral salt spray test is the most common form of this method, with testing lasting for anything from just 8 hours up to 2500 hours, depending on the product and the specification. This test consists of atomising a salt solution into uniform droplets on specimens supported or suspended between 15 – 30 degrees from the vertical.

The salt spray test offers numerous different advantages, one of the most interesting being that it is a multi-material test – it can be used to test the bare material as well as painted or coated materials.

Apart from being able to test large samples, this method is also beneficial in that a standardised material is required, the costs are relatively limited and compared to the natural environment the test duration is short.

Whilst being simple to perform, salt spray testing requires careful control to ensure that the results can be understandable to everyone. This also means it is a useful tool for marketing purposes, although the constraints of the testing method should be explained in any marketing materials in order to avoid misinterpretation or misunderstanding.

Learn more about salt spray testing. Stop by the Rotech Labs site where you can find out all about the salt spray test and how it can help your business.

categories: salt spray testing, testing metals, metallurgy, lab tests