Rust on stainless steel heat exchange tubes during use and storage is mostly due to improper maintenance, but it is not just this reason. First of all, we need to know that the stainless steel heat exchange tube itself has excellent corrosion resistance. There is a thin oxide film on its surface to protect it from continued corrosion. If this oxide film is continuously damaged, it may not recover. , which will cause the steel pipe to oxidize and rust.
The following analyzes the main reasons that affect the accelerated rusting of stainless steel heat exchange tubes:
1. Dust containing other metal elements or heterogeneous metal particles is deposited on the surface of stainless steel heat exchange tubes.
When the air is humid, the condensed water between the accessory and the stainless steel will connect the two into a micro-battery, causing an electrochemical reaction and damaging the oxide film on the surface of the stainless steel. This process is called electrochemical corrosion.
2. Organic juice is attached to the surface of the stainless steel heat exchange tube.
The presence of organic juice forms organic acids under the combined action of water and oxygen, which will cause long-term corrosion on the surface of stainless steel heat exchange tubes.
3. Acid, alkali, and salt substances stick to the surface of stainless steel heat exchange tubes, causing local corrosion.
4. Stainless steel heat exchange tubes are used or stored in polluted air.
Similar to air containing a large amount of sulfides, carbon oxides and oxidative inflammation, condensed water forms sulfuric acid, nitric acid, and acetic acid liquid spots, which can cause chemical corrosion.
The above points are common reasons for accelerating the rust of stainless steel heat exchange tubes, and we should try to avoid them.