Nondestructive flaw detection
2016-11-11 Rongda test 791 times
Detection Purpose: Check the corrosion resistance of material to atmosphere
Detection range: Metal and alloy substrate, metal and alloy surface coating, etc
Salt spray test refers to the environmental test that USES the artificial simulated salt spray environment created by salt spray test equipment to evaluate the corrosion resistance of products or metal materials. It is an environmental test which mainly USES the artificial simulated salt spray environment conditions created by salt spray test equipment to test the corrosion resistance of products or metal materials.Salt spray test includes three kinds: neutral salt spray test (NSS), acid salt spray test (AASS), copper accelerated acid salt spray test (CASS) and alternating salt spray test.Neutral salt spray test (NSS)Neutral salt spray test is a method of accelerating corrosion test, which is carried out in a special salt spray chamber.The salt water prepared by the neutral salt spray test was 5% NaCl solution, PH was 6.5 ~ 7.2, and the temperature in the box was 35±. 2 & ordm; C. Relative humidity is above 95%.The spray deposition of neutral salt spray test was 1mL ~ 2Ml/80cm². & middot; H. NaCl concentration of collected salt mist should be 5±. 1%, PH is 6.5 ~ 7.2, nozzle pressure should be 0.07mpa ~ 0.1mpa.Acetate spray test (ASS method)It is mainly used for corrosion resistance test of decorative coatings such as copper-ni-chromium or ni-chromium. The salt spray solution used for resistance test is prepared with pure glacial acetic acid with a PH of 3.0 ~ 3.1, and the spray collection solution with a PH of 3.2±. 0.1, other requirements of the test are the same as the neutral salt spray test method.Copper salt accelerated acetate spray test (CASS)It is mainly suitable for corrosion resistance test of copper - nickel - chromium or nickel - chromium decorative coating on steel and zinc die casting, and also suitable for corrosion resistance test of aluminum and aluminum alloy anodic oxidation film.The preparation method of salt solution used in the experiment is as follows: NaCl solution was prepared according to the neutral salt spray test method, and 0.26± was added into the NaCl solution. Chemical pure copper chloride (CuCl2· 2H2O), the PH is adjusted to 3.0 ~ 3.1 with the chemical pure glacial acetic acid.The test temperature was 50±. 1 & ordm; C. The PH of the spray collection solution is 3.2± 0.1, other requirements and neutral salt spray test the same.Alternating salt spray testIt is a comprehensive salt spray test, which is actually a neutral salt spray test plus a constant humidity and heat test. It is mainly used in the whole machine of cavity type, through the infiltration of the tidal environment, the salt spray corrosion is generated not only on the surface of the product, but also inside the product. It is the product in salt spray and wet and hot two environmental conditions alternating conversion, finally check the electrical and mechanical properties of the machine products have no change.
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