Comparison of field and accelerated corrosion tests of zinc alloyed coatings

摘要

The results of long-term atmospheric tests for zinc alloyed coatings are not known, their corrosion rate and so durability can be estimated on the basis of comparison of corrosion mass loss together with knowledge of corrosion mechanisms. Results derived from accelerated corrosion tests with very aggressive conditions, mainly salt spray tests according to EN ISO 9227, cannot be recommended for prediction of corrosion resistance for prediction of the long-term corrosion resistance of materials and coatings, their durability or corrosion rate - these tests are usually qualitative (they should show quality or potential defects at coatings) and they may informative character for comparison of behaviour of protective properties various types of materials and/or coatings. The paper gives a comparison of results for these types of coatings.