In actual production, steel often contains different alloying elements, such as manganese, nickel and vanadium, according to different uses. The application and research of steel has a long history, but before the invention of bainite steelmaking in the19th century, the production of steel was a high-cost and inefficient work.
Steel has become one of the most used materials in the world because of its low price and reliable performance, and it is an indispensable part of architecture, manufacturing and people's daily life. It can be said that steel is the material basis of modern society.
Extended data
The American Iron and Steel Association uses three digits 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 steels are labeled 430 and 446, and martensitic stainless steels are labeled 4 10, 420 and 440C, which are dual-phase (austenite-ferrite).
④ Stainless steel, precipitation hardening stainless steel and high alloy with iron content less than 50% are usually named by patent names or trademarks.