Salt spray deposition and spray mode of reliability salt spray test

Date：2022-09-07 16:40:56Views：707

The finer the salt spray particles, the larger the surface area formed, the more oxygen absorbed, and the stronger the corrosion. More than 90% of salt spray particles in nature have a diameter of less than 1 micron. Research results show that the oxygen adsorbed on the surface of salt spray particles with a diameter of 1 micron is relatively balanced with the dissolved oxygen in the particles. No matter how small the salt spray particles are, the amount of oxygen adsorbed will no longer increase. Salt spray test is an artificial accelerated corrosion test that simulates the impact of marine atmosphere on products. Salt spray corrosion test chamber is an environmental test equipment that simulates this corrosion effect manually. It mainly tests the adaptability of organic coatings, antirust grease, metal materials, components and fully equipped whole equipment to the marine atmosphere. In order to help you have a deeper understanding, the following contents are sorted out by Chuangxin testing network and provided for your reference.

1、 Salt spray deposition of salt spray test and spray method

Salt spray sedimentation reflects the characteristics of salt spray and is an important parameter in salt spray test. In the past salt spray test method, it was specified that the size of fog particles - the diameter was 1 ~ 5 μ M U.M. However, because most of the test equipment produce fog particle diameter within this range, and it is difficult to measure the fog particle diameter. Therefore, many salt spray test methods do not specify the size of fog particles, but specify the precipitation of fog. That is, insert a funnel with a diameter of 10 cm (the area of the funnel is about 80 cm 2) into a 50ml measuring cylinder, fix it with a rubber stopper, and spray it for several hours continuously (most of the collected liquid is specified as 16h), and convert the collected liquid into sedimentation, with the unit of ml / 80 cm 2 · H. Most of them are specified as 1 ~ 2ml / 80 ㎝ 2 · H. When the sedimentation is less than 0.5ml/80cm2 · h, the salt liquid film on the metal surface is relatively thin, and oxygen will quickly pass through the water film to reach the cathode surface, so the corrosion rate will suddenly rise. With the increase of sedimentation, there is a medium thickness liquid film on the metal surface, and its corrosion rate rises slowly. When the sedimentation continues to increase to more than 2ml / 80cm2 · h, the salt film layer on the metal surface thickens, the oxygen diffusion distance increases, and it is difficult to reach the cathode surface, so the corrosion rate is not significantly accelerated. Therefore, taking a moderate settlement will make the corrosion rate more stable and the test results have good reproducibility.

2、 Salt spray deposition of salt spray test and spray method of spray method

In salt spray test, continuous spray and intermittent spray are generally used. Intermittent spray can make the metal surface have periodic dry and wet alternation, renew the liquid film on the metal surface, and constantly replenish oxygen, which is beneficial to accelerating corrosion and close to the actual working and storage conditions. The continuous spray can keep the metal surface moist and have sufficient thickness of salt film. The test conditions of continuous spray are relatively stable and easy to control. Therefore, many salt spray test methods use continuous spray.

The above is the relevant content of salt spray test compiled by Chuangxin testing. I hope it will be helpful to you. Our company has a team of professional engineers and industry elites, and has three standardized laboratories with an area of more than 1800 square meters. It can undertake various testing projects such as electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, function testing, factory incoming material inspection and tape weaving.