How much do you know about the properties of 316L stainless steel tubes

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316L stainless steel welded pipes are widely used in damp and corrosive environments such as the sea, and are extensively applied in industrial transportation pipelines for petroleum, chemical, medical, food, light industry, mechanical and instrumentation industries, as well as mechanical structural components, etc. The reason is that the welded 316L stainless steel pipes have strong corrosion resistance. Why do 316L stainless steel welded pipes have high corrosion resistance? 

Stainless steel can also rust under certain conditions. Although 316L stainless steel has a natural resistance to atmospheric oxidation, that is, the property of not rusting, and can also resist corrosion in environments containing acids, alkalis, salts, etc., that is, corrosion resistance. The corrosion resistance of 316L stainless steel varies with changes in chemical composition, mutual state, working conditions and environmental media. 

For instance, in dry and clean air, the corrosion resistance of 304 stainless steel is definitely good. However, once it is in coastal areas, due to the concentration of smoke, it is prone to rust. But 316 stainless steel is better. Therefore, stainless steel is not resistant to corrosion and rust in any environment. 

The surface of 304 stainless steel bright bar has a very thin yet firm and dense stable chromium-rich oxide film (protective film), which can prevent oxygen atoms from penetrating and oxidizing the base material. This is also the origin of its anti-rust performance. However, due to certain reasons, the film will continue to be damaged, and oxygen atoms in the air or liquid will continue to separate, causing loose iron oxide and rusting on the surface of the stainless steel. 

The surface of 316L stainless steel pipes will also react with oxygen, but due to its high chromium content, and the key to the corrosion resistance of 316L stainless steel pipes lies in the chromium content. When the proportion of chromium content in 316L stainless steel exceeds 10.5%, the corrosion resistance of 316L stainless steel will be greatly enhanced. 

When the chromium content of 316L stainless steel exceeds 10.5%, the corrosion resistance of 316L stainless steel will be greatly enhanced. When chromium element is used to alloy treat the stainless steel company, the type of oxide film formed on the surface of stainless steel material is changed to a surface oxide film similar to that formed on pure chromium metal. This oxide film can better protect the surface of stainless steel and prevent further oxidation. 

This oxide film is very thin, allowing teachers to see the original natural luster of the stainless steel material through it, giving the stainless steel pipe a surface. Besides, if the surface layer is damaged and the stainless steel surface is exposed, it will react with the atmospheric environment. The chromium element will automatically help the stainless steel material surface to self-protect and repair, allowing the stainless steel surface to start forming a passive film again, continuing to protect the stainless steel. 

All stainless steel pipes share a common feature, that is, the chromium content is all above 10.5%. There are usually only six types of steel related to the field of building construction. They all contain 17 to 22% chromium, and most of the steel types also contain nickel. The addition of molybdenum to 316L stainless steel industrial welded pipes can further improve the atmospheric corrosion resistance, especially the resistance to corrosion by chloride-containing atmosphere. This is the reason why 316L stainless steel industrial welded pipes have strong corrosion resistance.