There will be obvious collapse in the corrosion area of aluminum tube

There will be obvious depression in the corrosion area of the aluminum tube. The aluminum tube has been used in the refrigerator evaporator instead of the copper tube and the coated steel tube, and the leakage of the aluminum tube evaporator will lead to the failure of the refrigeration system. The mechanism of aluminum tube corrosion failure is discussed in the experimental methods of micro crystal and chemical analysis. Aluminum tubes are corroded from the outer wall to the inner wall, and the failure of aluminum tubes is a typical intergranular corrosion mechanism.

The uneven distribution of iron impurity elements is the internal cause of aluminum tube corrosion. The foaming materials contain chloride ions and alkaline substances, and the aluminum tube damage is the external cause of aluminum tube corrosion. The aluminum tube operates at low temperature for a long time, and the surface absorbs water vapor. Internal and external factors interact to promote the generation of electrochemical corrosion, which leads to leakage of aluminum tube.

Metallographic microscope investigation and scanning electron microscope analysis were carried out on the micro morphology of aluminum tube corrosion, EDS analysis was carried out on the element composition of aluminum tube corrosion, F - and Cl - detection was carried out on the surrounding environment (foam, water) of the aluminum tube of the refrigerator evaporator, and the cause of water leakage at the refrigerator outlet was analyzed according to the source of the water around the evaporator. In order to understand the corrosion characteristics of aluminum tubes of refrigerator evaporators at various stages of corrosion, salt spray experiments were conducted to simulate the corrosion of aluminum tubes.

The collapse phenomenon shown in picture 7 of 5052 aluminum tube occurs