Cyclic corrosion tests (CCTs) are intended to produce failures representative of the type found in outdoor corrosive environments. They expose specimens to a series of different environments in a repetitive cycle.
Simple corrosion testing like Prohesion may consist of cycling between salt fog and dry conditions. More sophisticated methods call for multi-step cycles that may incorporate immersion, humidity and condensation, along with salt fog, drying and low temperature exposures. They are effective for evaluating a variety of corrosive mechanisms including undercut creep of coatings , galvanic, crevice and filiform corrosion.
Other simple corrosion testing provide accelerated corrosion by acidification of the salt fog combined with high humidity. Typical tests are SWAAT (Sea Water Acetic Acid Test) and CASS (Copper Acid Salt Spray). These are often used to evaluate the relative corrosion performance of anodised coatings and metal bond adhesives.
Steady state salt spray testing is a well-established test method and reasonably repeatable. However, only weak correlation exists between duration in salt spray test and the expected life of a coating since corrosion is a very complex process and can be influenced by many external factors including UV exposure from the sun. Nevertheless, salt spray tests are widely used in the industrial sector for the evaluation of relative corrosion performance of finished surfaces or barrier coatings such as paint and powder-coat.
Specifications include: ASTM B117, ASTM G85, ASTM D5894, ASTM B368, BMW AA-0224, BS 3900-F12, Def Stan 00-35 Part 3 CN2, Def Stan 133 Method 14, Ford APGE, Ford CETP-00.00-L467, GM 9540P, Honda 5100Z-TR0-6001, IEC 68-2-11, IEC 68-2-52, ISO 12944-6, ISO 12944-9, ISO 9227, JASO M609, JASO M610, Nissan CCT-1, CCT-2, CCT-4, SAE J2334, VDA 621-415, VW PV1210 + more.
For more information regarding our corrosion testing facilities, please do not hesitate to contact us to further discuss your requirements.