This test is performed on different materials and products to see how well they withstand the damage inflicted by salt.
The term “salt-spray test” refers to an accelerated corrosion test used on different materials and products in order to evaluate how well they perform in a saline environment.
The material to be tested is generally introduced into a chamber where it is sprayed with a saline solution. The aim of the test is to confirm that the chosen surface treatment of the parts being tested is suitable for customer requirements.
It is important to note that this test does not take into account many of the natural variables which cause corrosion, given that the materials are exposed to a very high concentration of Sodium Chloride (normally 5% NaCl). This is worryingly high concentration of salt which is normally never found in open-air applications.
Salt-spray tests are carried out using the following parameters:
The samples to be tested are inserted into a chamber at a fixed temperature (normally 35ºC), and are sprayed with a saline solution (5% Sodium Chloride) in the form of a fine spray or mist.
The test can last from 24 hours up to 1000 hours. The samples are kept moist and the temperature constant for the duration of the trial. Furthermore, each sample is rotated at regular intervals to make sure that the whole surface is covered with the saline solution.
The result of the test is the oxidation of the surface of the sample. The number of hours required before the first appearance of oxidation on the surface of the sample is measured. Other methods include the number of hours taken before oxidation of 5% of the surface.
Mikalor clamps are manufactured in different materials and include various surface treatments. The combination of these two factors determines the corrosion resistance of the article. Mikalor clamps are salt-spray tested to ASTM B117 (Standard Practice for Operating Salt Spray).