Description:

Salt spray testing is an environmental test that assesses the corrosion resistance performance of products or metal materials by creating artificial simulated salt spray environments using salt spray testing equipment. It can be divided into two categories: natural environment exposure tests and artificial accelerated simulated salt spray environment tests. The artificial accelerated simulated salt spray environment test uses a test device called a salt spray test chamber with a certain volume space. Within this space, an artificial method is used to create a salt spray environment to evaluate the product’s resistance to salt spray corrosion. Compared to natural environments, the salt concentration of the chloride in the salt spray environment can be several times or tens of times higher, significantly increasing the corrosion rate. Conducting salt spray tests on products significantly reduces the time required to obtain results.

Scope of Application:

Metals, electroplated materials, and finished electronic products.

Classification of Salt Spray Test:

(1)Neutral Salt Spray Test (NSS Test):

Neutral Salt Spray Test is the earliest and most widely used accelerated corrosion test method. It uses a 5% NaCl with a pH value adjusted to a neutral range (6-7) as the spray solution. The temperature of the test chamber is set at 35°C, and  the amount of fog reduction is required to be between 1-2 mL/80(h·cm2).

(2)Acetic Acid Salt Spray Test (AASS Test):

Acetic Acid Salt Spray Test is developed on the basis of Neutral Salt Spray Test.  It is to add some glacial acetic acid to the 5% NaCl solution, so that the pH value of the solution is reduced to about 3, the solution becomes acidic, and the final salt spray is changed from neutral salt spray to acidic. Its corrosion rate is approximately 3 times that of the NSS test.

(3)Copper Accelerated Acetic Acid Salt Spray Test (CASS Test):

Copper Accelerated Acetic Acid Salt Spray Test is a recently developed accelerated test method conducted at a temperature of 50°C. Based on the Acetate Salt Spray Test, CuCl2 (0.26±0.02) g/L is added to the spray liquid, so that the effect of copper ions is used to accelerate the corrosion of the battery, thereby simulating more severe working environment. Its corrosion rate is approximately 8 times that of the NSS test.

(4)Alternating Salt Spray Test:

Alternating Salt Spray Test is a comprehensive salt spray test, which is actually a neutral salt spray test plus a constant damp-heat test. It is mainly used for cavity-type machine products, through the penetration of the tidal environment, salt spray corrosion occurs not only on the surface of the product, but also in the interior of the product. It converts the products alternately under the conditions of salt fog and hot and humid environment, and finally examines whether the electrical and mechanical properties of the whole machine have changed or not.

Image of Testing Equipment: