We offer a variety of test techniques, including but not restricted to:
- Neutral Salt Spray Test (NSS)
Applicable Scope: Metal coatings, anodizing films, organic coatings on metal substrates.
This is the most commonly used method for accelerated corrosion testing. The test involves spraying a 5% sodium chloride (NaCl) solution with a pH of 6.5–7.2 into a chamber. The solution settles on the test samples, and after a specified period, the corrosion on the surface is assessed. The chamber conditions are controlled, maintaining a temperature of 35°C, humidity above 95%, and nozzle pressure between 78.5–137.3 kPa (0.8–1.4 kgf/cm²). This test is particularly suitable for evaluating coatings on metal surfaces.
2. Acetate Salt Spray Test (ASS)
Applicable Scope: Aluminum anodic oxide films, decorative copper-nickel-chrome, or copper-chrome coatings.
This test builds on the NSS test by adding glacial acetic acid to the NaCl solution, making it acidic with a pH around 3.0. The corrosion rate for this test is nearly three times faster than the NSS, making it ideal for assessing coatings in harsher conditions.
3. Copper Accelerated Acetic Acid Salt Spray Test (CASS)
Applicable Scope: Decorative copper-nickel-chrome or multilayer nickel-chrome coatings on aluminum.
The CASS test is specifically designed to evaluate multilayered metal coatings, such as copper-nickel-chrome. It accelerates corrosion by adding copper chloride (CuCl₂) to the acetic acid solution, simulating harsher environments. The corrosion rate is about eight times faster than the NSS test, making it an effective method for testing coatings that require high resistance in extreme environments.
4. Alternating Salt Spray Test
Applicable Scope: Metal substrates with organic coatings or anodizing layers.
The alternating salt spray test combines the Neutral Salt Spray Test with a continuous damp-heat test, which is useful for evaluating complex, cavity-type machine parts. This test simulates tidal environments, causing corrosion both on the surface and inside cavities. The alternating cycles of salt fog and humid heat are used to determine if the mechanical or electrical properties of the product have changed over time.
Why Salt Spray Testing Matters
Salt spray testing provides crucial insights into the durability of materials and coatings. Understanding the corrosion resistance of your products allows you to make informed decisions, ensuring that the materials can withstand harsh environmental conditions, leading to improved performance and longer product life.
Trust Om Metalab to deliver reliable, accurate salt spray testing that meets both national and international standards.
Standards we test to
| ASTM B117 | Standard Practice for Operating Salt Spray (Fog) Apparatus |
| ISO9227 | Corrosion Tests in Artificial Atmospheres |
| JIS Z 2371 | Methods of Salt Spray Testing |
| ASTM G85 Annex A1 | Acetic Acid Salt Spray Test (non-cyclic) |
| ASTM G85 Annex A2 | Acidified Salt Fog Test (cyclic) |
| ASTM G85 Annex A3 | Seawater Acidified Test (cyclic) |
| ASTM G85 Annex A4 | SO2 Salt Spray Test (cyclic) |
| ASTM G85 Annex A5 | Dilute Electrolyte Salt Fog/Dry Test (cyclic) |
We offer a variety of test techniques, including but not restricted to:
Neutral Salt Spray Test (NSS) :
Applicable scope: metal coating anodizing film, organic coating on metal substrate
The earliest and most popular method for testing accelerated corrosion is the neutral test. Through a spray apparatus, salt water with a pH of 6.5–7.2 and a concentration of 5% NaCl is sprayed into a designated test chamber. The salt spray settles on the test sample, and after a predetermined amount of time, the surface corrosion state is assessed. The test chamber is (352)°C, has a humidity level of above 95%, reduces fog by 12mL/(hcm2), and has a nozzle pressure of 78.5137.3kPa (0.81.4kgf/cm2).
Acetate Salt Spray Test (ASS) :
Applicable scope: Aluminium anodic oxide film, copper-nickel-chrome or copper-chrome ornamental coating
Based on the Neutral Test, the Acetate Test was created. It is necessary to add some glacial acetic acid to the 5% NaCl solution in order to alter the final solution from neutral to acidic and lower the pH value of the solution to around 3. Its rate of corrosion is almost three times that of the NSS test.
Copper Accelerated Acetic Acid Salt Spray Test (CASS) :
Applicable scope: Aluminium anodic oxide film with decorative copper-nickel-chrome or nickel-chrome coating
An accelerated test procedure specifically created to assess copper-nickel-chromium or multilayer nickel-chromium is the copper accelerated acetic acid test. In order to simulate a harder working environment, CuCl2 (0.260.02) g/L is added to the spray liquid based on the results of the acetate test. This causes the influence of copper ions to accelerate battery deterioration. It corrodes at a pace that is around eight times faster than the NSS test.
Alternating Salt Spray Test :
Applicable scope: Metal substrate with an organic coating and an anodizing layer.
Alternating Test is a complete salt spray test that combines a continual damp-heat test with a neutral test. It is mostly utilized for cavity-type machine items. As a result of tidal environment penetration, corrosion affects both the product’s exterior and interior. It alternatively transforms the products in a hot, humid environment and a salt fog before checking to see if the mechanical and electrical qualities of the entire machine have altered.