To check the corrosion resistance of materials, a test is performed which is commonly known as a salt spray test. This test is done by using a machine called a Salt spray test chamber. In the salt spray testing method, a corrosive attack is produced to check whether the material resists corrosion.
Salt Spray testing has been used for many years for checking the corrosion resistance of metals, paint coatings etc.
The purpose of this testing instrument is to create a corrosive environment and check the resistance of materials against corrosion.
It provides accurate results for measuring corrosion.
What is the Salt Spray Testing Procedure?
First, prepare the sample and place it at an angle of 20 degrees inside the test chamber.
Prepare the salt solution with 5% concentration and set the temperature of the chamber at 37 degrees.
Expose the sample for 24 hours, 72 hours or more based on test requirements.
After the set time, pick out a sample and test it with experts.
Never open the canopy before the completion of the test.
Before opening a canopy, use purging.
The volume of the fog will be 5mL according to the test standard. So, make sure the volume is 5mL.
Never place the specimens more closely to the walls of the chamber.
What solution is used for the Salt Spray Test?
The salt spray test is the most common and important test for measuring the resistance of corrosion of several materials.
In performing a salt spray test, a solution is used which is commonly known as NaCl.
However, the percentage of NaCl used in the Salt Spray test is 5%.
How many hours is a salt spray test?
The set time of a Salt spray test varies accordingly.
It generally ranges from 24, 72-1000 hours.
The time duration depends on the test and sample requirements.
Which coating is tested by the Salt Spray Test?
A Salt Spray chamber can be used to test different coatings.
It assesses the coating’s performance in environmental corrosion.
The following coatings can be tested by using a salt spray test chamber.
- Paint coating on steel
- Electroplated coatings
- Zinc Flake Coating on Bolts
What is the pH of the Salt Spray Test?
The salt spray test is widely used all over the world for checking the corrosion resistance of materials.
Some quality points should be checked in this test, one of them is its pH level.
One should know the pH level of a salt spray test to obtain the best results of the test.
The pH level of a neutral salt spray test is 6.5-7.
However, you can check it regularly to maintain the exact pH level.
Moreover, maintaining the pH is a tip for getting the best results from a salt spray test.
What is the standard for Salt Spray?
For performing different tests, some standards are settled for better results of tests.
A standard is termed as;
- A set of rules and recommendations for improving the quality and efficiency of tests.
- Like all other tests, a salt spray test also has its standard which is ASTM B117.
