Salt spray testing provides a controlled environment used to test the relative corrosion resistance of rust-preventative films, inorganic coatings, and organic coatings such as paints and primers. It is commonly used to evaluate the performance of metal-finishing products and practices.

Test Procedure

ASTM B117 outlines the standard practice for operating the salt spray chamber. The test chamber maintains an internal temperature of approximately 95°F and produces a saturated environment with 100% relative humidity using a 5% salt solution to create the fog. Test specimens are placed inside the chamber for a period determined by the performance requirements of the customer or application.

ASTM D1654 details the method for evaluating the corrosion performance of painted or coated specimens subjected to the salt spray environment specified in ASTM B117. Painted specimens are typically scribed through the paint film to expose the base metal. After a period of exposure to the salt fog, paint delamination, referred to as creep, is rated according to the following table. Results for scribed specimens are reported as a rating number at a specified exposure time. Required ratings and exposure periods vary based on the final use of the product.