Customers need to be sure that the slides they buy will have a certain amount of resistance to corrosion. Part of our finish testing includes a salt spray chamber where slides are exposed to a 5% salt solution (similar to a salty fog) to test corrosion resistance. The test procedures and parameters are standardised under national and international standards, such as ASTM B 117 and ISO 9227. These standards lay down the required information to carry out these tests, covering the test parameters, such as the temperature, the air pressure of the sprayed solution, the preparation of the spraying solution, including the Ph concentration.
Slide test procedures
We have our own internal test laboratories and these include salt spray chambers. When we have a new product, we test each of the component parts as well as a complete assembly. These are placed in a chamber so that all parts are fully exposed to the sprayed solution. The solution must also be able to drain off the surfaces and not form pools.
After the required test period, the parts are dried and examined for traces of corrosion. The results are recorded on official test reports, which outline the test piece specification, the type of finish applied, the test standard used and the appearance of any corrosion.
Corrosion can range from none at all, through to white or red rust depending on the severity of the test and the finish used on the slide.
Minor white rust is a cosmetic effect and generally has no effect on the performance of the coating if the underlying zinc coating retains the specified coating thickness.
Corrosion resistance coatings
Accuride has three levels of corrosion resistance within our range of drawer slides, which include a resistance of 12 hours for the majority of our range, plus 96 hours and up to 500 hours for the high performance surface finishes.
Different coatings are used to achieve the standard and enhanced levels of corrosion resistance and these are applied to the electroplated zinc coat during the automated finishing process.