Stainless steel pipe is a hollow steel pipe that is not easy to rust. Non-magnetic, usually used as a conduit for conveying fluids.
1. The difference between stainless steel and carbon steel
Stainless steel pipe is a kind of high alloy steel with good anti-oxidation, corrosion resistance and resistance to deformation. Stainless steel has a high chromium content, which can form a dense chromide layer to protect the surface from corrosion. This chromide layer is highly stable and extremely difficult to be damaged or corroded, thus enhancing the anti-oxidation and anti-corrosion capabilities of stainless steel.
Carbon steel refers to low-alloy steel with a higher carbon content. Its carbon content is generally less than 0.30%. In other words, the chemical composition of carbon steel does not contain elements such as chromium that can effectively resist corrosion, so it is easy to Rust occurs due to corrosion by oxides.
2. Reasons why stainless steel and carbon steel rust in contact with each other
When stainless steel and carbon steel are in direct contact, an electrochemical reaction may occur due to the large potential difference between the two. In this case, the iron ions in the carbon steel will transfer to the surface of the stainless steel, forming oxides. These oxides may adhere to the surface of the stainless steel, causing rust at the contact point between the stainless steel and the carbon steel. In addition, when media such as sewage and salt water exist on the surface, the process of electrochemical reaction will be accelerated, making it easier to cause rust.
