Salt spray test is an environmental test that uses artificially simulated salt spray environmental conditions created by salt spray test equipment to confirm the corrosion resistance of products or metal materials. The severity of the test depends on the duration of exposure.

      Commonly used test standards in laboratories: GB/T 2423.17, IEC60068-2-11, GB/T 10125, ISO 9227, ISO4628-3, ASTM B117, JIS-Z2371, JIS-G3141, GJB 150.1, MIL-STD-810F, MIL-STD-883E etc.

       Laboratory simulated salt spray can be divided into three categories: neutral salt spray test, acetic acid salt spray test, and copper salt accelerated acetic acid salt spray test.

Test methods for commonly used test items:

       (1) The neutral salt spray test (NSS test) is the earliest accelerated corrosion test method with the widest application field. It uses 5% sodium chloride salt aqueous solution, the pH value of the solution is adjusted in the neutral range (6.5 ~ 7.2) as the spray solution. The test temperature is 35℃, and the sedimentation rate of the salt spray is required to be 1~2ml/80cm/h.
       (2) The acid salt spray test (ASS test) is developed on the basis of the neutral salt spray test. It is to add some glacial acetic acid to 5% sodium chloride solution to make the pH value of the solution drop to about 3, the solution becomes acidic, and the salt mist formed finally turns from neutral salt mist to acid. Its corrosion rate is about 3 times faster than the NSS test.
       (3) The copper accelerated acetic acid salt spray test (CASS test) is a rapid salt spray corrosion test recently developed abroad. The test temperature is 50°C. A small amount of copper salt-copper chloride is added to the salt solution to strongly induce corrosion. Its corrosion rate is approximately 8 times that of the NSS test.

testing time:

       The test time is selected from the following time points according to the requirements in different standards: 2, 4, 6, 8, 16, 24, 48, 72, 96, 144, 168, 240, 336, 480, 672, 720, 1000 hours

Note: General requirements for the selection of test time: In general, 24 hours of neutral salt spray test simulated in the laboratory is equivalent to 1 year of the product in the real environment; 24 hours simulated acid salt spray test in the laboratory is equivalent to the product 3 years in the real environment; 24 hours of the copper accelerated acetic acid salt spray test simulated in the laboratory is equivalent to 8 years of the product in the real environment; according to the different corrosion rates of the three salt spray tests, the neutral salt spray test The time ratio of acid salt spray test and copper accelerated acetic acid test is 1:3:8, so the test time can be selected according to the life time of the product.