Salt spray test
Project Introduction
Salt spray test is an environmental test that mainly uses artificial simulated salt spray environmental conditions created by salt spray testing equipment to evaluate the corrosion resistance of products or metal materials. It is divided into two categories, one is natural environment exposure test, and the other is artificial accelerated simulated salt spray environment test. The artificial simulated salt spray environment test is to use a test equipment with a certain volume space - a salt spray test chamber, to use artificial methods in its volume space to create a salt spray environment to as_sess the salt spray corrosion resistance performance and quality of the product. . Compared with the natural environment, the salt concentration of chloride in the salt spray environment can be several or dozens of times that of the general natural environment, which greatly increases the corrosion rate. Conduct a salt spray test on the product and obtain the results. The time is also greatly shortened.

Salt spray test clas_sification
(1) Neutral salt spray test (NSS test)

It is the earliest accelerated corrosion test method with the widest application field. It uses 5% sodium chloride salt solution, and the pH value of the solution is adjusted to the neutral range (6 to 7) as the solution for spraying. The test temperature is all 35°C, and the sedimentation rate of salt spray is required to be between 1 and 2ml/80cm2.h.

(2) Acetate salt spray test (A SS test)

It is developed on the basis of neutral salt spray test. It adds some glacial acetic acid to a 5% sodium chloride solution to reduce the pH value of the solution to about 3, making the solution acidic, and the resulting salt spray also changes from neutral salt spray to acidic. Its corrosion rate is about 3 times faster than the NSS test.

(3) Copper salt accelerated acetate salt spray test (C as_s test)

It 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.

(4) Alternating salt spray test

It is a comprehensive salt spray test, which is actually a neutral salt spray test plus a constant humidity and heat test. It is mainly used for cavity-type complete machine products. Through the penetration of the moist environment, salt spray corrosion occurs not only on the surface of the product, but also inside the product. It alternately converts the product under two environmental conditions: salt spray and humid heat, and finally as_sesses whether there are any changes in the electrical and mechanical properties of the complete product.

Test Methods
Test items: Salt mist test Salt mist Test

Reference standards: IEC60068-2-11(GB/T2423.17), ISO 4628.3, ASTM B117, JIS-Z2371...

Common test parameters:

Salt spray can be divided into three categories:

Neutral salt spray test (NSS test) (solution: pH value is adjusted to the neutral range (6.5~7.2), and the test temperature is 35°C)

Acetate salt spray test (as_s test) (solution: add some glacial acetic acid, the pH value drops to about 3)

Copper salt accelerated acetate salt spray test (Cas_s test) (the test temperature is 50°C, a small amount of copper salt-copper chloride is added to the salt solution)

Test time: 16H (minimum)

method standards
GB/T 2423.17; IEC 60068-2-11; GB/T 10125; ISO 9227; ASTM B 117;

GB.T 2423.18; IEC 60068-2-52; ASTM B 368; MIL-STD-202; EIA-364-26