ASTM B117 Salt Spray (Fog) Corrosion
Metals used in or around the ocean, such as on cargo or Navy ships, are exposed to the spray or fog of salt water. Both water and salt (sodium chloride) catalyze the formation of rust, so rust in nautical atmospheres is a serious problem. This test is intended to predict how well an oil will protect metals from rust.
Steel panels are sand blasted, dipped in test oil, allowed to drain and placed in a salt fog chamber for the specified test time. Panels are evaluated daily for the development of rust. The number and size of rust spots is reported. If the rusted area is large, the percent of the panel rusted is reported. This test can be run for a specified period of time or until failure.