The reasons for rusting of stainless steel sand pumps

The rusting of stainless steel sand pumps is due to the damage of the surface film. The following are some common types in daily life:

1. Dust containing other metal elements or particles of dissimilar metals accumulate on the surface of stainless steel. In a humid environment, the condensate water between the adherents and the stainless steel forms a micro-battery, triggering an electrochemical reaction and damaging the protective film. This phenomenon is known as electrochemical corrosion.

2. When organic substances such as vegetable juice, noodle soup, and phlegm adhere to the surface of stainless steel, they form organic acids in the presence of water and oxygen. Over a long period of time, these organic acids will corrode the metal surface.

3. The surface of stainless steel adheres to substances containing acids, alkalis and salts (such as splashed alkali water and lime water during wall decoration), causing local corrosion.

4. In polluted air (such as that containing large amounts of sulfides, carbon oxides, and nitrogen oxides), upon encountering condensation water, liquid spots of sulfuric acid, nitric acid, and acetic acid are formed, causing chemical corrosion.

All the above situations can cause damage to the protective film on the surface of stainless steel, leading to rust.