Artificial atmosphere-salt spray test, also known as the salt spray test or ASTM B117 test, is a widely used accelerated corrosion test for evaluating the resistance of metallic materials to corrosion.
The test involves exposing metal samples to a highly corrosive artificial environment, the composition of which is a solution containing salt (usually sodium chloride) in water, typically at a temperature controlled environment range of 35°C to 50°C. The samples are either placed in a closed chamber or spray booth for a specified period and are subject to a corrosion cycle exposure (spray & dry cycles) simulating the type of corrosion that may occur in coastal and other aggressive environments.
The test follows different standards from ASTM, ISO, DIN, or JIS, but all follow similar procedures, which include preparing the test sample, exposure to the salt spray, evaluation of the results, and reporting.
The test duration depends on the material being tested, and the standard which the test will follow, but typically ranges from a few hours to several weeks. Corrosion is assessed visually or through advanced measurement techniques such as weight loss, pit depth, salt deposition, or salt spray.
The salt spray test is commonly used as a quick, low-cost method for evaluating the corrosion resistance of materials and coatings applied to metals, such as coatings, anodized surfaces, and painted or powder-coated surfaces. This test method can help determine the suitability of metal materials and coatings for use in aggressive environments, such as marine environments and road salt applications, and help qualify new suppliers or production runs of the same material.