The corrosion resistance of the coating film means that the coating film can maintain certain physical and chemical properties under corrosive media (such as acid, alkali, salt, etc.). The corrosion resistance of coatings is one of the important indicators for evaluating the quality of coatings.
Coating corrosion resistance measurement is a method to evaluate the stability of coatings in corrosive media. It is mainly used to test the durability and corrosion resistance of coatings in corrosive media.
Coating film corrosion resistance determination is usually tested using a salt spray Test Chamber. This instrument can simulate corrosive media, such as seawater, acid rain, etc., and test the durability and corrosion resistance of coatings in these media. In the salt spray Test Chamber, the coating sample is placed in a constant high temperature, high humidity and salinity environment for a certain period of time. During the test, changes in properties such as appearance, color, adhesion, weight and hardness of the coating sample are detected to evaluate the corrosion resistance of the coating.
Coating corrosion resistance measurement can be used to evaluate the durability and stability of various types of coatings, such as automotive paints, architectural coatings, marine coatings, etc. By measuring the performance changes of coatings in corrosive media, the durability and life of coatings can be predicted, providing basic data for formulating coating maintenance and improvement programs.
The main methods for measuring the corrosion resistance of coating films are as follows:
Salt spray test method
Salt spray test is one of the commonly used methods to evaluate the corrosion resistance of coating films. This method is to place the sample in a salt water spray chamber and evaluate the corrosion resistance of the coating through the corrosion effect of the salt water spray. In the experiment, the coating on the surface of the sample should be flat, free of pores, pitting and pollution.
Damp heat test method
The damp heat test method is an accelerated test that can be used to evaluate the corrosion resistance of coatings under high temperature and humidity conditions. Usually, the sample is placed in a test box with constant temperature and humidity, and the environment of the coating in actual use is simulated by moisture and high temperature. The exposure time of the sample in the humid and hot environment can be adjusted according to the actual situation.
Direct corrosion test method
Direct corrosion test method is a test method that simulates the actual corrosive environment. The sample is placed in the actual corrosive medium, and the corrosion resistance of the coating is evaluated by evaluating the corrosion resistance of the sample in the corrosive medium. During the experiment, the exposure time of the sample and the concentration and temperature of the corrosive medium should be controlled to ensure the reliability of the test results.
Simulation of actual use environment test method
The simulated actual use environment test method is to expose the sample to a test box that simulates the actual use environment for testing. During the experiment, parameters such as temperature, humidity, oxygen concentration and corrosive medium should be controlled to simulate the actual use conditions and evaluate the corrosion resistance of the coating in actual use. This method can more realistically reflect the corrosion resistance of the coating, but the test period is relatively long.