Spring common sense: Spring salt spray test standard
What is salt spray test? Determination of salt spray test standard and test result
Salt spray test is a kind of environmental test, which is mainly used to test the corrosion resistance of products or metal materials by artificial simulation of salt spray environment created by salt spray test equipment. It is divided into two categories, one is the natural environmental exposure test, the other is the artificial accelerated simulation of salt spray environment test. Artificial simulation of salt fog test is the use of a has certain space in the volume of test equipment, salt spray test machine, in the volume space with artificial methods, resulting in salt fog environment of the product resistance to salt fog corrosion performance quality assessment. Compared with the natural environment, the salt spray environment of chloride salt concentration can be natural salt spray environment content several times or dozens of times, the corrosion speed greatly improved. The salt spray test, obtained the result of time is greatly shortened. In the case of natural exposure to a product sample test, the corrosion may be 1 years, and in the artificial simulation of salt spray test environment, as long as 24 hours, you can get a similar result.
Artificial simulation of salt spray test and neutral salt spray test, acetate spray test, copper salt accelerated acetate spray test, cyclic salt fog test.
(1) neutral salt spray test (NSS test) is one of the most widely used in the field of accelerated corrosion test method. It uses 5% sodium chloride solution, the solution pH value is adjusted in the neutral range (7 ~ 6) as a spray solution. The test temperature from 35 DEG C, the requirements of the settlement rate of salt spray between 1 ~ 2ml/80cm -.H.
(2) acetic acid salt spray test (ASS test) is developed based on neutral salt spray test on. It is in the 5% Sodium Chloride Solution to add some ice acetic acid, so that the pH value of the solution is reduced to about 3, the solution becomes acidic, and finally the formation of salt mist from the neutral salt fog into acid. Its corrosion rate is about 3 times faster than the NSS test.
(3) salt of copper accelerated acetic acid salt spray test for testing (CASS) is abroad recently developed a rapid salt fog corrosion test, the test temperature to 50 DEG C, salt solution added a small amount of copper salt, copper chloride, strong corrosion induced by. Its corrosion rate is about 8 times as much as that of the NSS test.
(4) alternative salt spray test is a comprehensive salt spray test, it is actually a neutral salt spray test and constant damp heat test. It is mainly used for the cavity type of the whole product, through the infiltration of the tidal environment, so that the salt spray corrosion not only in the product surface, but also inside the product. It is the product of the two kinds of environmental conditions in salt fog and heat alternating conversion, the final assessment of the electrical performance and mechanical properties of the machine has no change.
Determination of salt spray test standard and test result
The standard is a unified regulation of repetitive things and outlines. Salt spray test standard is the salt spray test conditions, such as temperature, humidity, the concentration and pH value of Sodium Chloride Solution and so on to make specific provisions, in addition to the salt spray test chamber performance technical requirements. The same product using the salt spray test standards to be based on the characteristics of salt spray test and metal corrosion rate and the sensitivity of the salt spray. The following introduction of several salt spray test standards, such as GB/T2423.17 - 1993 "basic environmental test procedures for electrical and electronic products Ka: salt spray test method", GB/T2423.18 - 20
00 "electrician electronic product environmental testing Part 2: Test Kb: salt spray, alternating (sodium chloride solution)", GB5938 - 86 "metal deposits for the light industrial products and chemical processing layer resistance corrosion test method", GB/T1771 - 91 of the paints and varnishes resistant neutral salt fog performance test ".
Is to test products or metal material quality of salt fog corrosion resistance of salt fog test and salt spray test results to determine is the verdict on the quality of the products, it to determine whether the result is correct and reasonable is correctly measure the products or metal salt fog corrosion quality the key. The determination method of the result of salt spray test is: rating decision method, weight determination method, corrosion appearance determination method, corrosion data statistical analysis method. The rating decision is the percentage of corrosion area and total area ratio according to certain method is divided into several levels, as a basis to determine the qualified level, it is suitable for flat sample evaluation; weighing judgment method is through the method of heavy corrosion test samples before and after weight, calculate the corrosion loss the weight of sample quality evaluation of corrosion resistance, it is suitable for assessment on corrosion resistance of a metal corrosion quality; determining method is a qualitative judgement method, it takes the salt fog corrosion test, whether the product is produced to determine the corrosion phenomenon on samples, this method mostly adopts the general product standard; the corrosion data statistical analysis method provides the design of corrosion test, analysis method to determine the degree of confidence of corrosion data of corrosion data, it is mainly used for analys