Salt spray testing has clear purposes. It can be used to evaluate, screen, and compare materials (surface films) or surface treatment processes.

It can also identify potential problem areas and parts of products, and discover deficiencies in quality control and design flaws.

However, salt spray testing also has limitations. It only emphasizes environmental factors such as the marine environment or salt – containing air,

rather than all natural salt spray environmental conditions. For example,

it cannot reproduce the influence of a certain marine atmosphere, cannot verify the relationship

between salt spray corrosion and other medium corrosion, cannot directly prove that samples that pass this test

can have satisfactory results under all corrosion conditions, and it is also unreliable to use it to

compare the service life of different materials and coating states.

Moreover, the corrosion caused by salt spray is different from that caused by damp heat and mold,

and they cannot replace each other. Nevertheless, although there is a gap between the results of salt spray testing and the actual situation,

when there is no better testing method at present, it is still an effective method to check the quality and defects of materials

and evaluate the corrosion resistance of electronic equipment. Taking the determination of the results of Huawei structural parts

salt spray testing as an example, materials or films with different surface films

and base materials have different corrosion phenomena in salt spray testing.

For example, for the steel base material with electro – galvanized color passivation,

the original appearance is iridescent, and the corrosion phenomena are black spots / spots,                             

white powdery substances, red powder, etc. in sequence. The corrosion performances of

different combinations have their own characteristics, and the test results can be judged accordingly.