Salt Spray Test For Screws

What is a salt spray test?
The salt spray test is a widely used corrosion test method, which is mainly used to evaluate the corrosion resistance of screws and other metal products. By simulating the salt spray environment, the corrosion of screws in a salt spray can be observed, and then their anti-corrosion performance can be judged.

Principle of salt spray test
The salt spray test creates a salt spray environment in a closed test box, exposing the screws to high concentrations of salt spray to simulate the corrosion in the marine environment or other high-salinity environments. The test usually uses a 5% sodium chloride solution and atomizes it through a spray device to form salt spray. After a period of time in the salt spray, the screws will show different degrees of corrosion.

Steps of salt spray test
Prepare samples: Select the screw samples to be tested and ensure that the surface is clean and oil-free.
Salt spray box preparation: Inject 5% sodium chloride solution into the salt spray box, adjust the temperature to about 35°C, and keep the relative humidity above 95%.
Place the sample: Place the screw sample in the salt spray chamber, making sure that the sample does not touch the chamber wall and that the salt spray can evenly cover all surfaces.
Set the test time: Set the test time as needed, usually 24 hours, 48 ​​hours, 72 hours, or even longer.
Observation results: After the test, take out the sample, clean and dry it, and observe and record the corrosion on the surface of the screw.

Standards for salt spray testing
Common salt spray test standards include:

ASTM B117: This is the most widely used salt spray test standard, which specifies the specific operating methods and conditions of salt spray testing.
ISO 9227: Salt spray test standards developed by the International Organization for Standardization, are widely used around the world.
GB/T 10125: Chinese national standard, which specifies the methods and requirements of salt spray testing in detail.