Kesternich

Kesternichtest is a common term for corrosion Sulfur dioxide test with general condensation of moisture. This test was developed in 1951 by Wilhelm Kesternich to simulate the damage effects of acid rain. The test can be used for coatings or base materials. The test method is defined by different standards (DIN EN ISO 6988, DIN 50018 ). The parts to be tested are placed in a test chamber and warm, exposed to moist air in conjunction with a certain amount of sulfur dioxide. The test is usually done in cycles of 24 hours.

Test facility

The test chamber usually has a volume of approximately 300 l Larger or smaller test chambers are also possible, but for a standardized flow of the water volume and the amount of sulfur dioxide must be proportionally adjusted to a rate of 300 l deviant chamber volume. The material of construction of the inner casing of the chamber and the means for placing the sample must be made from inert, corrosion- resistant materials, so that there is no reaction between the test pattern and the material of the chamber.

Principle

The principle of the test is simple: in the floor pan of the test chamber, a defined amount of distilled or deionized water is introduced. The samples are placed in the chamber above the water level. The door or cover of the chamber is sealed. It is introduced a fixed amount of sulfur dioxide into the chamber. Caution: observe safety instructions! By a controlled heating apparatus, the chamber is heated to 40 ° C. At the end of the test cycle and before opening the chamber, the sulfur dioxide-containing air in the chamber must be replaced with fresh air. Warning: The sulfur dioxide-containing air must not be conveyed in the air. The test duration depends on the specification.

After the test

Take samples from the chamber and allowed to dry in the air. A first evaluation made prior to removal of possible corrosion products. If the tested parts are cleaned, while the evaluation criteria need to be considered.

Evaluation

Possible features for evaluation: Appearance after the test, appearance after removal of the corrosion products, the number and size of defects, time to first occurrence of corrosion mass loss. The results are described in a test report.

Swell

  • DIN EN ISO 6988 Metallic and other inorganic coatings - Sulfur dioxide test with general condensation of moisture, March 1997.
  • DIN 50018 test to humid climate with schwfeldioxidhaltiger atmosphere, June 1997.
  • The importance of corrosion test methods under special consideration of SO2 test according to DIN 50018, Wilhelm Kesternich, published in Materials and Corrosion Volume 16, Issue 3, pages 193-201, march 1965.
  • Surface Technology
  • Corrosion
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