SalznebelTest

Salznebeltest, known in English as the salt spray test, is a standardized corrosion test used to evaluate the resistance of metals and coatings to saline environments. The test subjects coated or bare metal specimens to a fine saline mist to simulate exposure to sea air, road salt, and similar corrosive conditions. It is widely used in industries such as automotive, aerospace, marine, and infrastructure to compare protective coatings and materials.

In typical practice, a salt solution of about 5% sodium chloride in water is atomized inside a controlled chamber and maintained at an elevated temperature, commonly around 35°C. The solution pH is kept near neutral, approximately 6.5 to 7.2. There are variations, including continuous spray and cyclic modes that alternate spray periods with dry or humid intervals. Tests run for defined durations measured in hours, and evaluations focus on the onset and extent of corrosion, blistering, coating delamination, or other deterioration. Results are usually expressed as time to first damage or as hours without visible corrosion, and are interpreted comparatively rather than as absolute service life.

Standards such as ISO 9227 and ASTM B117 govern test conditions, specimen preparation, and evaluation criteria. While useful for screening and quality control, Salznebeltests have limitations: they may not replicate all real-world factors and are often complemented by cyclic or environmental aging tests for a more complete assessment.

Historically developed in the mid-20th century, the test remains a common and practical method for assessing corrosion resistance across materials and coatings.