Stainless steel is now used in many industries, and stainless steel shelters are one of them. The beautiful stainless steel bus shelter has become a beautiful landscape of the city, but it has been used for a long time, various small advertisements have been posted, and rust has seriously affected the appearance.
Some people say that stainless steel does not rust, right?
In fact, it is a misunderstanding that stainless steel will not rust, and stainless steel will rust under certain conditions. remember! Stainless steel is not easy to rust compared to ordinary metals. If exposed to harsh environments such as chlorine, or mechanical or physical damage to the passivation layer on the surface, rust will occur.
Any metal will oxidize with oxygen, and an oxide film will be formed on the surface. Common stainless steels in life have been passivated, and the thickness of the chromium oxide film on the surface is much thicker and denser than the naturally formed oxide film on the fresh surface. However, the iron oxide formed on the ordinary carbon steel continues to oxidize, so that the corrosion continues to expand and eventually forms holes.
In order to improve rust resistance, we often use paint or oxidation-resistant metals (such as zinc, nickel and chromium) for electroplating to protect the surface of carbon steel, but this protection is only a thin film. If this film is destroyed, the steel below will begin to rust. Chromium is the basic element for the corrosion resistance of stainless steel. When the chromium content in the steel reaches about 12%, the chromium interacts with the oxygen in the corrosive medium to form a very thin oxide film (self-passivation film) on the surface of the steel. , Can prevent further corrosion of the steel matrix. In addition to chromium, commonly used alloying elements include nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the requirements of various uses for the structure and performance of stainless steel.
Therefore, the beauty of stainless steel shelters depends not only on the municipal department but also on the joint efforts of all citizens.