Why can't stainless steel pipe and carbon steel pipe be mixed

The materials of carbon steel pipe and stainless steel pipe are different, and the two cannot be stacked together. At room temperature, when the carbon steel pipe is in contact with the stainless steel pipe, carburization will not occur immediately. The spotted rust on the stainless steel pipe will only appear in a certain period. In a humid environment, if carbon steel pipes and stainless steel pipes are stacked together, it is easy to produce a chemical reaction, which will damage the protective layer of the stainless steel pipe and cause the stainless steel pipe to rust. 　　

Besides, if different types of steel are stacked together, they will have a potential difference, which will lead to galvanic corrosion, especially when there is water, the galvanic corrosion rate between the stainless steel pipe and carbon steel pipe will increase. Just like the principle of a battery, in a chemical battery, chemical energy is directly converted into electrical energy because of the oxidation-reduction reaction inside the battery. To prevent electrochemical corrosion and carburization of stainless steel pipes, it is best not to stack them together.