The salt spray test is intended to simulate severe corrosion conditions and it is used as a quality control analysis required for all outdoor fixtures. It is a test that determines if the products will corrode prematurely or not. The tests are run for weeks and even months to assure that the fixture can survive the environment in which it is placed.
What is the ASTM B117 standard?
The standard for the implementation of the salt spray corrosion test is defined by the ASTM International, and it sets the test to evaluate the corrosion resistance information on metals surfaces and coated metals. The standard practice and procedure to carry on the test is specified in the B117 that was revised in 1997. It describes the apparatus procedures and conditions required to maintain the salt spray (fog) test environment.
What does the salt spray test consist of?
The test fixture is stored in a special test chamber during the previously established test period and is exposed to a foggy saline environment. The spraying is continuous so the fixtures are always wet and subject to corrosion. Saline water solution (5% NaCl) is continuously spraying in a camera maintained at 35 ℃. The position of the products shall be supported or suspended between 15 ℃ and 30 ℃ from the vertical and no contact with each other. The results are obtained in a few hours for the less protective systems and up to several hundreds of hours for the most powerful. The standard duration of salt spray corrosion tests can change depending on the equipment and the intended environment.
What does the test determine?
The standard on which the test is based ultimately determines whether the material meets the quality requirements. It also allows comparisons between the different materials and finishes. Corrosion tests with salt spray are especially useful for testing products used on the high seas or by the sea. Since these environments have a higher salt load; however, it can simulate, on an accelerated basis, other hash and hazardous conditions. Corrosion tests with salt spray have been used in different industries and it is just recently that started to be used in the LED lighting equipment.
Material’s exposure to different environmental conditions will contribute to the material’s degradation and wear. To know how certain chemicals, present in the different environments, affect metals helps manufacturers to make better decisions about the components used in the production of the luminaries. Manufactures can opt for preventative measures against metal deterioration diminishing the defects of the corrosion and then reducing costs.