Medical refrigerator is mainly used for refrigeration, storage and transportation of medicines, reagents, vaccines, blood, etc. The medical refrigerator is a kind of high-speed rotating equipment. If it is not properly maintained and used after purchase, there will be some problems. The most likely problem is corrosion.

What mainly happens to medical freezer is metal corrosion. The forms of metal corrosion are mainly divided into two types, uniform corrosion and localized corrosion. Localized corrosion is more common in medical refrigerators.

1. Pitting corrosion

Pitting corrosion is a highly corrosive phenomenon, which mainly exists in some metals that are easily passivated, such as stainless steel, and due to some local defects on the surface, there are active ions in the solution that can destroy the passivation film. As a result, the passivation film is locally destroyed to form a galvanic pair, resulting in pitting corrosion, and due to the centrifugal force, the dynamic process of the galvanic couple in the hole will be accelerated, resulting in the continuity of the pitting corrosion process until the perforation.

2. Intergranular corrosion

Intergranular corrosion can cause parts to lose strength and elongation, resulting in brittle fracture, a damage phenomenon that develops from the surface inward along the grain boundaries, but there is no evidence of corrosion on the outer surface.

3. Erosion corrosion

Erosion-corrosion refers to the simultaneous damage to the surface of parts by both wear and corrosion.

4. Stress corrosion

This corrosion phenomenon mainly refers to the damage caused by a certain tensile stress in a corrosive environment.

The above are the four common types of localized corrosion, which are very harmful to vaccine refrigerators. Therefore, the strict protection in daily use are required.