zoutspraytests

Zoutspraytests are a family of standardized corrosion tests that evaluate the resistance of coatings and metallic substrates to saline exposure by exposing samples to a saline mist in a controlled chamber. The term reflects the use of salt spray, with “zout” meaning salt in Dutch, and is used in some contexts to describe these procedures, which align with established salt spray testing protocols used worldwide.

In typical zoutspraytests, samples are placed in a chamber where a salt solution, usually sodium chloride, is atomized to create a fine spray. Variants include neutral salt spray (NSS), acetic acid salt spray (AASS), and copper-accelerated salt spray (CASS). The spray solution concentration commonly ranges around 3-5% NaCl, with temperatures near 35°C, and exposure durations that can span from 24 hours to several thousand hours, depending on the test standard and coating performance expectations. Some protocols adjust pH or apply acceleration additives for specific material systems.

Evaluation focuses on both qualitative and quantitative measures. Visual inspection records rusting, blistering, or coating delamination. Quantitative metrics may include corrosion rating, delaminated area, rust coverage, and weight loss. Results are used to compare coating formulations, assess batch consistency, and support material selection for corrosive environments.

Standards commonly referenced with zoutspraytests include ISO 9227 and ASTM B117, along with related variants such as NSS, AASS, and CASS. Limitations include differences between lab conditions and real-world environments, as well as dependence on specimen geometry, coating thickness, and surface preparation. See also corrosion testing and salt spray testing.