Salt Spray Testing (also known as Salt Spray Testing) is an environmental test used to evaluate the corrosion resistance of materials and coatings in marine or salt-laden environments. When performing the Salt Spray Test, the following five key parameters require special attention:

1. Concentration of the salt solution:

   - The salt solution used for the test is usually a 5% (mass fraction) solution of sodium chloride, and this concentration may vary according to different standards or test requirements.

   - The preparation of the solution needs to be precise to ensure the reliability of the test results.

2. pH of the spray:

   - The pH of the salt solution has a significant effect on the corrosion rate of the material. Generally, the pH should be within the specified range, e.g., the ASTM B117 standard recommends a pH of 6.5 to 7.2.

3. Temperature:

   - The temperature in the Salt Spray Test chamber has a significant effect on the corrosion process and must be strictly controlled. The standard temperature is usually set at about 35°C, but other temperatures may be required for some special tests.

4. Humidity:

   - Salt Spray Tests are usually conducted under high humidity conditions to simulate a humid marine environment. Relative humidity is usually maintained above 85%.

5. Test Duration:

   - The duration of the test depends on the expected life of the product and the corrosion resistance required. The test duration can vary from a few hours to a few weeks and needs to be determined based on specific industry standards or manufacturer's requirements.

In addition to the key parameters listed above, other factors need to be considered, such as the angle at which the sample is placed, the spray pressure, the cleaning and handling of the sample, and the method of evaluating the sample after the test. All of these parameters need to be controlled in strict accordance with relevant standards such as ASTM B117, ISO 9227, etc. to ensure the accuracy and consistency of the test results. Careful control of these critical parameters ensures that the Salt Spray Test provides reliable data to evaluate the corrosion resistance of materials.