Neutral Salt Spray Test (NSS):

Uses a 5% sodium chloride aqueous solution, with the pH adjusted to a neutral range of 6.5-7.2. The test temperature is generally set at 35°C.

It mainly simulates salt spray corrosion in natural environments and is used to test the corrosion resistance of metals and their alloys, metal coatings, organic coatings, anodized films, and other products, such as steel products, aluminum alloy products, galvanizing layers, chromium plating, etc. It is also commonly used for quality testing of automotive parts, hardware tools, construction materials, and other products.

Acetic Acid Salt Spray Test (AASS):

Some glacial acetic acid is added to a 5% sodium chloride solution, lowering the pH to around 3, making it acidic. The test temperature is also generally 35°C.

Due to the stronger corrosiveness of the salt spray under acidic conditions, this test is used to assess the corrosion resistance of products under harsher environments.

It is suitable for copper-nickel-chromium or nickel-chromium decorative coatings and anodized aluminum films, and is widely applied in aerospace, marine engineering, and other fields requiring high corrosion resistance.
 

Copper Accelerated Acetic Acid Salt Spray Test (CASS):

Based on the acetic acid salt spray test, a small amount of copper chloride is added to further increase the corrosiveness of the salt spray.

The copper chloride in the solution can accelerate the corrosion process, especially against copper and copper alloys. The test temperature and other conditions are basically the same as the acetic acid salt spray test.

It is mainly used to test the corrosion resistance of copper-nickel-chromium decorative coatings and copper alloy products, and is common in testing high-end sanitary products, hardware decorations, and other products that have high appearance requirements and are used in harsh environments.
 

Alternating Salt Spray Test:

This is a comprehensive salt spray test, essentially a combination of the neutral salt spray test and constant humidity-heat test.

It is primarily used for cavity-type complete products. The penetration of the humid environment allows salt spray corrosion to occur not only on the product surface but also inside the product.

The product is alternately subjected to salt spray and humidity-heat conditions, and finally, the electrical and mechanical performance of the complete product is evaluated for any changes.