Salt Spray Testing

Salt spray corrosion is a common and most destructive atmospheric corrosion. Chloride ions in salt spray will penetrate the oxide layer and protective layer on the surface of metal materials. The electrochemical reaction between chloride ions and metal materials can destroy the surface and properties of metal materials and further affect and damage the products through the pores and cracks on the metal surface.

Salt spray testing simulate the environment conditions of salt spray to determine the corrosion resistance of metal materials or coatings.

Test Solutions

• Neutral salt spray testing (NSS): Spray 5% NaCl salt water with pH value of 6.5-7.2 on the tested sample which is placed in a specific test chamber for a certain period of time and observe the surface corrosion state. The temperature of the test chamber is (35±2) °C, the humidity is more than 95%, the amount of fog reduction is 1~2mL/ (h·cm²), and the nozzle pressure is 78.5~137.3kPa (0.8~1.4kgf/cm²). This test method is suitable for metal coating anodizing film and organic coating on metal substrate.
• Acetate salt spray testing (ASS): Spray 5% NaCl salt water added with glacial acetic acid to reduce the pH value to 3 on the tested sample which is placed in a specific test chamber for a certain period of time and observe the surface corrosion state. This test method is suitable for copper-nickel-chromium or copper-chromium decorative coating and anodic oxide film of aluminum.
• Copper accelerated acetic acid salt spray testing (CASS): Based on the ASS testing, CuCl₂ (0.26±0.02) g/L is added to the spray liquid to accelerate the corrosion of the battery, thereby simulating more severe working environment. This test method is suitable for copper-nickel-chromium or nickel-chromium decorative coating and anodic oxide film of aluminum.
• Alternating salt spray testing: Through the penetration of the tidal environment, evaluate the corrosion occurring not only on the surface of the material, but also in the interior of the product under the conditions of salt fog and hot and humid environment. This method is suitable for metal coating anodizing film, organic coating on metal substrate.

Test Material Types

• Metals
• Alloy coated components
• Electroplated components
• Organic coatings
• Painted, primed or lacquered surfaces
• Polymers
• Composites

STEMart's expert team can advise on which test is best for your specific requirements depending on the project goal. For more information about our salt spray testing services, please contact us.