About the Salt Diffusion Test
Salt spray tests can evaluate the salt spray ability of materials and their protective coatings, as well as comparing the quality of similar coatings, as well as the ability of certain products to resist corrosion from salt spray. It is widely used for corrosion testing of parts, electrical equipment, metal parts and industrial products. The salt spray test is mainly to test the effect of the salt spray environment on the product and the atmospheric corrosion environment and provide reference data for product optimization.
The environmental effects of salt can be divided into three categories: corrosion effects, electrical effects and physical effects.
Corrosion effect: corrosion by electrochemical reaction, corrosion under strong pressure, acid-base corrosion.
Electrical effects: Salt deposits damage electrical equipment, producing conductive coatings, coatings, and metals that are damaged.
Physical Effects: Corrosive substances affect the function of moving parts, causing blisters to form.
As long as the product will affect one or more of the effects, it is necessary to do a salt soap test. In the test, the salt diffusion tolerance of the product can be better understood. The product can be improved through data analysis to improve the environmental reliability of the product.
With the increase in environmental testing standards, salt spray testing as an important part of environmental and climate research is being questioned more and more. Simple salt spray testing tools have not been able to meet the growing need for accurate diagnosis. Environmental equipment manufacturers have begun to increase research and development, and more powerful salt spray testing equipment is being released.
Factors affecting the salt diffusion test.
Test the temperature and humidity
Salt corrosion is affected by temperature and humidity. The critical humidity for metal corrosion is 70%, when it reaches or more, the salt spray enters the electrolyte with good conductivity. When the relative humidity decreases, the concentration of the salt solution will increase until salt crystals are formed, and the corrosion rate will decrease.
The higher the test rate, the faster the rate of salt degradation, because the temperature increases, molecular motion increases, and chemical reactions increase. In fact, it is not at high temperature, scientific research is better, for neutral salt spray research, 35 ° C is the best, the salt flow process is the closest to the corrosion environment, and Reference data is very useful.
Saline chewing
The effect of salt concentration on the rate of corrosion is related to the type of material and coating. For steel, nickel and brass, the corrosion rate is above 5% while the corrosion rate is above 5%. This is due to the change of oxygen in the salt solution, which will directly affect the ability of oxygen that is corrosion. However, for metals such as zinc, cadmium and copper, the corrosion rate always increases with increasing saline concentration.
Sample entry part
The aspect ratio of sample loading has a significant effect on corrosion test results. The formation direction of the salt spray is close to the horizontal direction, the corrosion effect of the sample is the greatest when it is placed in a line, while the horizontal direction is the least. The appropriate product input part can be selected based on the standard requirements.
The pH value of the saline solution
The pH value of the saline solution is one of the main factors affecting the salt spray test. The lower the pH, the higher the hydrogen ion in the salt solution, the stronger the acid, the stronger the corrosively.
About Complex Salt Spread Walk Test
A complex salt-penetrating irrigation laboratory is one of the standard equipment of environmental reliability testing. The main research items are mechanical components, electronic components, batteries, insulation, etc. many products or materials will affect the environmental impact of salt during transportation and use. The main task is to simulate the salt corrosion environment in the environment by simulating the operation in a single volume of space. Because the salt spray test time in the environment is long, this test equipment is specially designed to make the concentration of chloride salt in the salt environment reach many or ten times of the salt spray. The speed of corrosion is improved to increase the rate of damage of the salt environment on the surface of the sample, and the temperature control function is increased. It can simulate critical test environments and quickly obtain accurate test data.
