About salt spray test

The salt spray corrosion test can evaluate the ability of salt spray corrosion to materials and their protective layers, and the comparison of process quality of similar protective layers, and also the ability of some products to resist salt spray corrosion. It is mainly used for the corrosion test of parts, electronic components, metal materials and industrial products.

Salt fog test is mainly to test the influence of salt fog environment on the product in atmospheric corrosion environment, and provide data reference for product optimization.

The environmental effects of salt fog can be divided into three categories: corrosion effect, electrical effect and physical effect.

• Corrosion effect: electrochemical reaction corrosion, accelerated stress corrosion, acid-base corrosion
• Electrical effects: salt deposits damage electrical equipment, produce conductive coatings, insulation materials and metal corrosion
• Physical effect: corrosive substances affect the operation of moving parts, resulting in coating bubbles

As long as the product will be affected by one or more of the effects, it is necessary to carry out salt fog test. In the test, the salt fog environment tolerance of the product can be further understood. In the future, the product can be optimized through data analysis to improve the environmental reliability of the product.

With the improvement of environmental testing standards, salt fog environmental testing as an important part of environmental and climate detection has also been challenged seriously. Simple salt fog test equipment has been unable to meet the increasing demand of detection accuracy. More and more environmental detection equipment manufacturers have begun to increase research and development, and more complex salt fog test equipment is launched.

 

The influencing factors of salt spray test

• Test temperature and humidity

Temperature and relative humidity affect the corrosion of salt fog. The critical relative humidity of metal corrosion is 70%, and when it reaches or exceeds, salt fog will be deliquescence into electrolyte with good conductivity. When the relative humidity decreases, the concentration of salt solution will increase until the crystalline salt is produced, and the corrosion rate will decrease.

The higher the test temperature, the faster the corrosion rate of salt spray is, because the temperature increases, the molecular motion is intensified, and the chemical reaction is accelerated. Of course, it is not that the higher the temperature is, the better, the scientific research test, for the neutral salt spray test, 35 ° C is the most appropriate, the mechanism of salt spray corrosion is closest to the actual corrosion environment, and the data reference value is very great.

 

•  Concentration of salt solution

The influence of salt concentration on corrosion rate is related to the types of materials and coatings. For steel, nickel and brass, the corrosion rate is faster than 5% while the corrosion rate is higher than 5%. This is caused by the relative change of oxygen content in salt solution, which will directly affect the depolarization ability of oxygen, namely corrosion. However, for metals such as zinc, cadmium and copper, the corrosion rate is always accelerated with the increase of salt solution concentration.

 

•  Placement angle of sample

The placement angle of the sample has a significant influence on the corrosion test results. The settlement direction of salt fog is close to the vertical direction, the corrosion effect of the sample is the largest when placed horizontally, while the vertical position is the smallest. The suitable product placement angle can be selected according to the standard requirements.

 

•  pH value of salt solution

The pH value of salt solution is one of the main factors that affect the salt spray test. The lower the pH value, the higher the concentration of hydrogen ions in the salt solution, the stronger the acid, the stronger the corrosiveness.

 

About walk in complex salt spray test chamber

Walk in complex salt spray test chamber is one of the series equipment of environmental reliability test. The main test objects are metal equipment, electronic equipment, battery, coating, etc. many products or materials that will be affected by the environmental effects of salt spray during transportation and use. The main function is to simulate the salt fog corrosion environment in natural environment by artificial simulation in a certain volume space. Because the salt fog test period in natural environment is long, this professional test equipment is designed and adjusted to make the salt concentration of chloride in salt fog environment reach several or dozens times of the salt fog content in the general natural environment, The corrosion speed is greatly improved to accelerate the corrosion process of salt spray corrosion environment on the test object, and the temperature controllable function is increased. It can simulate some extreme test environment, and get accurate test data faster.

 

As a kind of composite salt fog test equipment, it is mainly used for alternating salt fog test. Alternating salt spray test is mainly the alternating cycle test of salt fog environment, constant temperature and humidity environment and dry environment. Sodium chloride solution is evenly sprayed in the box, and the primary salt spray corrosion of the test object of the box lasts for one cycle, and then a period of salt solution settlement corrosion is carried out under the set constant temperature and humidity environment, The salt concentration of sodium chloride solution in dry environment is gradually increased during the process of environmental transformation, and the salinity corrosion efficiency of the test object is improved. If the test object has higher requirements for the corrosion resistance environment, the cycle times of the test can be increased to achieve the test goal. Through such an alternate salt fog erosion test, the salt fog environment in the box can greatly simulate the environmental effect of salt fog corrosion in nature on the environmental effects of the test object, and obtain more complete and accurate test data.

 

Equipment parameters

Walk in Complex Salt Spray Test Chamber

Conventional model BE-8209, divided into 12m ³ And 15m ³ Two internal dimensions

Temperature control range: 0 ° C～+85° C. Fluctuation ±0.5° C

Humidity control range: 30% – 98% R.H. fluctuation ± 3%R.H.

Resolution Temperature: 0.01 ° C. Humidity: 0.01% RH

Spray Capacity 1~2mL/80cm²/hr (Collect at least 16 hours, take the average )

Spray Pressure 1.00 ± 0.01kgf/cm²  Spray Solution pH Neutral 6.5～7.2 Acidity 3.1～3.3

 

The above is part of the walk in chamber for complex salt spray test. If you need to know more about it, please visit our official website https://belltestchamber.com/. Our engineering team is strong enough to meet your customization needs. Please contact us if necessary.