Stainless steel single headed pipes generally do not rust, but when exposed to chlorine or harsh environments, especially when the passivation layer on their surface is mechanically or chemically damaged, single headed pipes are more prone to rust than usual, so they are more prone to rust in such environments. The surface of stainless steel products we usually use is passivated, and the thickness of the chromium oxide film on its surface is much thicker and denser than the naturally formed oxide film on the fresh surface. So, stainless steel single head pipes can also rust!
Next, we will introduce some stainless steel materials for you:
All metals in life undergo oxidation reactions with oxygen in the atmosphere, forming an oxide film on the surface. However, the iron oxide formed on ordinary carbon steel will continue to oxidize, causing corrosion to expand and ultimately forming pores. Paint or oxidation resistant metals (such as zinc, nickel, and chromium) can be used for electroplating to protect the surface of carbon steel, but as is known, this protection is only a thin film. If the protective layer is damaged, the steel below begins to rust. Chromium is a basic element that gives stainless steel corrosion resistance. When the chromium content in the steel reaches about 12%, chromium reacts with oxygen in the corrosive medium to form a thin oxide film (self passivation film) on the surface of the steel, which can prevent further corrosion of the steel substrate. In addition to chromium, commonly used alloying elements include nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the requirements of various applications for the structure and properties of stainless steel.
chemical composition
The corrosion resistance of stainless steel decreases with the increase of carbon content, therefore, the carbon content of most stainless steels is relatively low, and some steels even have a carbon content lower than 0.03% (such as 00Cr12). The main alloying element in stainless steel is chromium, and when the chromium content reaches a certain level, stainless steel will have corrosion resistance. Therefore, stainless steel generally has a chromium content of over 13%. Stainless steel also contains elements such as Ni, Ti, Mn, N, Nb, etc.
The above are all reasons why stainless steel single head pipes rust.