Environmental Testing for the Automotive Industry:

A popular and standardized corrosion test method is used to check corrosion resistance of materials and surface coatings.  Typically, a sample is placed in a closed test chamber where a salt water solution produces a corrosive environment of dense salt water fog in the chamber so that the test samples exposed to this environment are subjected to severely corrosive conditions.

This test method is for evaluating the corrosive performance of decorative copper/nickel/chromium or nickel/chromium coatings on steel, zinc alloys, aluminum alloys, and plastics designed for severe service.  Similar to Salt Spray, a sample is placed in a closed chamber and immersed in a salt fog with the addition of reagent grade copper chloride dehydrate to accelerate the corrosion process.  

Filiform corrosion is a special form of corrosion that occurs under some thin coatings in the form of randomly distributed threadlike filaments.   Wheels and wheel parts are exposed to the same type of corrosion that is found in the field to establish the performance of the material and finish.   Typically, a sample is scribed so that the substrate is exposed before being placed in a CASS chamber for preconditioning before being placed in a Filiform test chamber to see if filaments develop from the substrate.  

This practice is for testing water resistance of coatings in an apparatus similar to that used in salt spray testing.  Water can cause degradation of coatings so coated specimens are placed in an enclosed chamber to permit free settling of fog on all specimens.  This sample is left in the chamber while water permeates the coating to see if color change, blisters, loss of adhesion, softening, or embrittlement are observed.  

This test method evaluates a coating’s resistance to chipping damage.  Standardized gravel is projected at a sample to simulate a wheel or trim piece in service when faced with flying stones, gravel, or other road debris.