Stainless steel is the abbreviation of stainless and acid-resistant steel, and the steel resistant to weak corrosive media such as air, steam and water or stainless steel is called stainless steel; Steel resistant to chemical corrosive media (acid, alkali, salt and other chemical corrosion) is called acid-resistant steel.
Their corrosion resistance is different due to their different chemical compositions. Ordinary stainless steel is generally not resistant to chemical medium corrosion, and acid-resistant steel is generally stainless. The word "stainless steel" refers not only to one kind of stainless steel, but to 100 kinds of industrial stainless steel, and each developed stainless steel has good performance in its specific application field.
The key to success is to find out the purpose first, and then determine the correct steel grade. There are usually only six kinds of steel related to the application field of building construction. They all contain 17 ~ 22% chromium, and the better steel also contains nickel. Adding molybdenum can further improve the atmospheric corrosivity, especially the corrosion resistance to chlorine-containing atmosphere.
Extended data
International stainless steel marking method:
The American Iron and Steel Association uses three numbers to represent various standard grades of malleable stainless steel. These include:
① Austenitic stainless steel is marked with serial numbers of 200 and 300. For example, some common austenitic stainless steels are marked with numbers of 20 1, 304, 3 16 and 3 10.
② Ferritic and martensitic stainless steels are represented by 400 series numbers.
③ ferritic stainless steel is marked with 430 and 446, and martensitic stainless steel is marked with 4 10, 420 and 440C.
④ Duplex (austenite-ferrite), stainless steel, precipitation hardening stainless steel and high alloy with iron content less than 50% are usually named by patent names or trademarks.
References:
Baidu encyclopedia-stainless steel
References:
Baidu encyclopedia -X45CuMoV 15