Working principle of salt spray test machine

The salt spray tester operated by Dongguan Zhongzhi Times Testing Equipment Co., Ltd. primarily simulates a salt spray environment to conduct salt spray corrosion tests on samples to determine their corrosion resistance. The specific operating process is as follows:

1. Solution Atomization:

• A compressed air system is used to eject compressed air at high speed from a nozzle. This high-speed airflow creates a negative pressure above the suction pipe.
• Under atmospheric pressure, a salt solution (typically a 5% sodium chloride solution, or salt solutions with other ingredients added depending on the test requirements) rapidly rises along the suction pipe to the nozzle.
• Upon reaching the nozzle, the salt solution is atomized into tiny particles by the high-speed airflow and sprayed toward the conical mist distributor at the top of the spray pipe.

1. Salt Spray Diffusion: After passing through the conical mist distributor, the salt spray particles drift out of the spray nozzle and diffuse into the test chamber, forming a diffuse state.
2. Sample Corrosion: The salt spray that permeates the test chamber naturally falls on the sample placed inside, corroding it. The chloride ions in salt spray have strong penetrating power and can easily penetrate the metal oxide layer and penetrate into the metal interior, destroying the metal’s passivity. Furthermore, the oxygen in the salt solution can cause depolarization on the metal surface, accelerating the dissolution of the anodic metal.
3. Test Process Control: The test can be conducted continuously or in cycles until the sample exhibits the expected corrosion behavior. The tester will record the time from the start of the test to the onset of corrosion as a measure of the sample’s corrosion resistance. A longer time indicates better corrosion resistance.

In addition, salt spray testers are typically equipped with heating systems, temperature control systems, and humidity control systems to ensure the accuracy and stability of test conditions.