Introduction to salt spray test one. Â Â Â Â Â Â Â Salt spray corrosion Corrosion is the destruction or deterioration of a material or its properties caused by the environment. Most of the corrosion occurs in the atmosphere, which contains corrosive components and corrosive factors such as oxygen, humidity, temperature changes, and pollutants. Salt spray corrosion is a common and devastating atmospheric corrosion. Mentioned here refers to salt spray atmosphere chloride, its main ingredient is corrosive ocean chloride salt - sodium chloride, it is mainly from marine and inland saline areas. The corrosion of the surface of the metal material by the salt spray is caused by the electrochemical reaction between the oxide layer containing the chloride ions penetrating the metal surface and the protective layer and the internal metal. At the same time, chloride ions contain a certain hydration energy, which is easily adsorbed on the pores of the metal surface, and the cracks are displaced and replace the oxygen in the chlorinated layer, turning the insoluble oxide into a soluble chloride, making the passivated surface active. surface. Causes a bad reaction to the product. The weighing determination method is to evaluate the corrosion resistance quality of the sample by calculating the weight of the corrosion loss by weighing the weight of the sample before and after the corrosion test. It is especially suitable for assessing the corrosion resistance quality of a certain metal; The corrosion occurrence determination method is a qualitative determination method, which determines the sample after the salt spray corrosion test, whether the product is corroded or not, and most of the general product standards adopt this method; The statistical analysis method of corrosion data provides a method for designing corrosion tests, analyzing corrosion data, and determining the confidence of corrosion data. It is mainly used for analysis and statistical corrosion, rather than for specific quality determination of a specific product. Neutral salt spray test with a salt spray test (N SS), acetic acid salt (AA SS) and a copper accelerated acetic acid salt spray (CA SS, also known as copper chloride acetic acid salt spray) test three, including application zui Wide is the neutral salt spray test. The basic content of the salt spray test is Pharmaceutical Prefilled Syringes, we are the specialist of prefilled Syringes, prefilled Syringes With Needle, wholesale high-quality products of Glass Prefilled Syringe R & D from China.Finished prefilled syringes can meet the FDA`s authorised 14-day sterility test and bagging with ETO Sterilization.We have the perfect after-sales service and technical support. Prefilled Syringes Prefillable Syringes,Preloaded Syringes,Prefilled Syringes China Lemon Trading Co.,Ltd , https://www.sterilevial.nl
two, Salt spray test and actual
  The salt spray test is an environmental test that uses artificial simulated salt spray environmental conditions created by salt spray test equipment to evaluate the corrosion resistance of products or metal materials. It is divided into two categories, one is the natural environmental exposure test, and the other is the artificial accelerated simulated salt spray environment test. The artificial simulated salt spray environment test uses a test equipment with a certain volume space —the salt spray test chamber, to artificially use the salt spray environment in the volume space to assess the salt spray corrosion resistance quality of the product. . Compared with the natural environment, the salt concentration of the chloride in the salt spray environment can be several times or several times higher than the salt spray content of the general natural environment, so that the corrosion rate is greatly improved, and the product is subjected to a salt spray test to obtain a result. The time is also greatly shortened. If a product sample is tested in a natural exposure environment, it may take 1 year to corrode , and in a simulated simulated salt spray environment, as long as 24 hours, similar results can be obtained.
The artificial simulated salt spray test includes a neutral salt spray test, an acetate spray test, a copper salt accelerated acetate spray test, and an alternating salt spray test.
(1) Neutral salt spray test ( NSS test) is an accelerated corrosion test method that appears in the current application field of Zui. It uses a 5% aqueous solution of sodium chloride solution, and the pH of the solution is adjusted to a neutral range ( 6 to 7 ) as a solution for spraying. Test temperature is taken
(2) The acetate spray test ( ASS test) was developed on the basis of the neutral salt spray test. It is to add some glacial acetic acid to the 5% sodium chloride solution, so that the pH value of the solution is reduced to about 3 , the solution becomes acidic, and the salt spray formed after the Zui also becomes acidic from the neutral salt spray. Its corrosion rate is about 3 times faster than the NSS test .
(3) Copper salt accelerated acetate spray test ( CASS test) is a rapid salt spray corrosion test developed recently in foreign countries. The test temperature is
(4) The alternating salt spray test is a comprehensive salt spray test, which is actually a neutral salt spray test plus a constant damp heat test. It is mainly used for cavity-type machine products. Through the penetration of the tidal environment, salt spray corrosion is generated not only on the surface of the product but also inside the product. It converts the product alternately under the two conditions of salt spray and damp heat. After the test, the electrical and mechanical properties of the whole product are checked.
three, Salt spray test standard and determination of test results
   Standards are uniform rules for repetitive things and summaries. The salt spray test standard specifies the salt spray test conditions, such as temperature, humidity, sodium chloride solution concentration and pH value, and also sets technical requirements for the performance of the salt spray test chamber. The salt spray test standard for the same product is selected according to the characteristics of the salt spray test, the corrosion rate of the metal, and the sensitivity to salt spray. The following describes several salt spray test standards, such as GB/T2423.17-1993 "Basic Environmental Test Procedures for Electrical and Electronic Products" Test Ka : Salt Spray Test Method, GB/T2423.18-2000 "Environmental Test for Electrical and Electronic Products" Part 2 : Testing Test Kb : Salt spray, alternating (sodium chloride solution), GB5938-86 "Test method for corrosion resistance of metal plating and chemical treatment layer of light industrial products", GB/T1771—91 "Paint and varnish" Determination of resistance to neutral salt spray.
The purpose of the salt spray test is to assess the salt spray corrosion quality of products or metal materials. The salt spray test results are judged on the quality of the product. The judgment result is correct and reasonable. It is a correct measure of the product or metal salt spray resistance. The key to corrosion quality. The methods for determining the salt spray test results include: rating determination method, weighing determination method, corrosion occurrence determination method, and corrosion data statistical analysis method. The rating determination method divides the percentage of the ratio of the corrosion area to the total area into several levels according to a certain method, and uses one level as the basis for the qualification judgment, which is suitable for the evaluation of the flat sample;
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