Prevent Metal Products From Corrosive Attack
In order to test the potential rust damages of the product, the ability to resist corrosive agents must be tested. Corrosion tests are conducted to test the resistance of a material or a coating to the corrosion process that is activated naturally with the reaction i.e. electrochemical or chemical, to the aggression of oxidising agents like atmospheric oxygen, gas, moisture etc. This process causes deterioration of the material which leads to oxidation and the loss of its characteristics.
A corrosion test chamber also called salt spray chamber help manufacturer to know how corrosion influence the product which materials are suitable in the context of use. There are various salt spray test that a corrosion test chamber performs such as dry corrosion test, continuous salt spray test and alternate salt spray. The one to be selected depends on the application area and on the type and dimension of the product to be tested.
Salt spray chamber performs the salt spray test which is known by another name as Fog Test. Salt spray test is an accelerated environmental corrosion test in which metals or the sample are exposed to the continuous mist of salt water solution that is evaluated to test the corrosion resistance of the coating. The duration of the test depends upon the corrosion resistance of the coating. The period in testing the corrosion resistance becomes longer with more corrosion resistant coating. Salt spray test is a standardised test to check the resistance of coated metals. The coating gives corrosion resistance to metals such as brass, steel etc.
The salt spray machine
is maintained at a constant temperature all through the test process. The test method is defined under testing standards.
Conditions required for the salt spray test are:
- NaCl solution to create the salty fog. It has approx. 5% of salt content. An atomiser is kept at the middle of the chamber to generate fog and uniform distribution.
- The pH level of NaCl solution is kept at 6.5 to 7 and the spray rate is standardised as 1.0 to 2.0/80cm2/hour.
- To maintain the conditions, glass wool insulation is used to protect the chamber and reduce heat loss.
- Multiples of 24 hours are used to set the test period.
- The more stringent test is conducted for critical application.
Presto’s Salt spray tester is designed according to international testing standards that is ASTM B117 and JIS Z 2371. Other features are automated air purging and online fog collection. It is easier for the user to conduct an error free test.
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