What Is Salt Spray Test?
Salt spray test, as a widely used accelerated corrosion testing method, is an important means to evaluate the corrosion resistance of materials or products in a salt spray environment. It quickly detects and predicts corrosion problems that products may encounter during actual use by simulating salt fog conditions in marine climate or industrial environment, providing valuable reference for product design, manufacturing and use.
What Is Salt Spray Test?
Salt spray testing is an environmental simulation test mainly used to evaluate the corrosion resistance of materials or products in specific salt spray environments. This test accelerates the corrosion process of a material or product by simulating salt spray conditions in the ocean, coastal areas, or other salty environments, thereby quickly assessing its corrosion resistance.
Salt spray testing is widely used in many industries, such as automobiles, aerospace, electronics, construction, etc., to test the durability and reliability of metals, coatings, plastics, rubber and other materials and their products in a salt spray environment. Through salt spray testing, the service life of materials or products in actual use environments can be predicted, providing an important basis for product design, material selection and quality control.
During the testing process, the salt spray test chamber creates a closed environment filled with salt spray, and places the samples to be tested in it for a period of time. After the test, the corrosion resistance of the sample was evaluated by observing the corrosion conditions of the sample, such as corrosion area, corrosion depth, corrosion rate and other indicators.
Salt Spray Corrosion Test Conditions
The temperature is 35℃±2℃, 5% NACL solution, and the sedimentation rate of the salt solution is (1-3)mL/(80cm2.h). Carry out 24 hours of salt spray and 24 hours of drying as one cycle, and conduct 2 cycles for a total of 96 hours. In order to provide a higher confidence evaluation of the equipment's ability to withstand a corrosive environment, the number of test cycles can also be increased, or a test procedure of spraying salt spray for 48 hours and drying for 48 hours can be adopted.
Salt Spray Test Test Steps
a) Adjust the temperature of the test chamber to 35 ° C and keep the test pieces under this condition for at least 2 hours before spraying.
b) Spray salt spray for 24 hours or the time specified in relevant documents. During the entire spraying period, the salt mist settlement rate and the pH value of the settled solution are measured at least every 24 hours to ensure that the settlement rate of the salt solution is (1~3)mL/(80 cm'·h).
c) Dry the test piece under standard atmospheric conditions of temperature (15℃~35℃) and relative humidity of not more than 50%, for 24 hours or for the time specified in relevant documents. During drying, the technical state of the test piece cannot be changed or its mechanical state adjusted.
d) At the end of the drying phase, unless otherwise specified, the test piece shall be re-placed in the salt spray test chamber and b) and c) shall be repeated at least once.
e) Conduct physical and electrical performance tests and record test results (take photos if necessary). If this is helpful for subsequent corrosion inspections, the test piece can be gently rinsed with running water under standard atmospheric conditions before testing and recording the test results.
f) Visually inspect the tested parts and record the inspection results.
Judgment Of Test Results Of Salt Spray Test
1) Physical part. Salt deposition can cause clogging or sticking of mechanical parts or components. Any salt deposits produced by this test may represent results from the expected environment.
2) Electrical part. After a 24-hour drying period, residual moisture can cause electrical performance failures. Consideration should be given to linking this failure with the failure in actual use.
3) Corrosive part. From the perspective of short-term and potential long-term effects, the impact of corrosion on the normal function and structural integrity of the specimen was analyzed.
Classification Of Salt Spray Test
One type is natural environmental exposure test, and the other type is artificially accelerated simulated salt spray environment test. The artificial simulated accelerated environmental test uses a test equipment salt spray test chamber with a certain volume space, and uses artificial methods to create a salt spray environment in its volume space to assess the product's salt spray corrosion resistance and quality. This method can obtain the corrosion resistance results of the product in a short period of time, which greatly shortens the test cycle compared with testing in a natural environment.
Standards for salt spray testing usually include clear regulations on salt spray test conditions such as temperature, humidity, sodium chloride solution concentration and pH value, as well as technical requirements for the performance of the salt spray test chamber.
When conducting salt spray testing, appropriate testing methods and standards need to be selected according to the characteristics of the product and the use environment.
Schedule：3000 Hours Salt Spray Test
This is a photo of the salt spray test report after 3000 hours of salt spray testing on the zinc-aluminum-magnesium coated steel pipe produced by Yuantai Derun.
