In terms of the arithmetic mean of the corrosivity classes for zinc and for carbon steel determined from the results of each test, the agreement in results from the different methods of corrosion testing is remarkably good. However, the results obtained with the VDA method agree better with those obtained from the accelerated outdoor exposure test than the results from the NSS method do. The first method is therefore recommended for qualification testing of corrosion protection capability of inorganic coatings. The accelerated outdoor test may only be used for qualification of coatings of a low corrosion protection class; because of the long exposure periods needed for higher corrosion protection classes.
Output from the project is Nordtest Method:
Assessment of corrosion protection classes for inorganic coatings on steel (NT MAT 003)