Carbon steel refers to an iron-carbon alloy with a carbon content of less than 1.35%, which also contains impurities such as silicon, manganese, phosphorus, sulfur and other trace residual elements within a limited amount. Carbon steel is the earliest and most used basic material in modern industry. While striving to increase the output of low-alloy high-strength steel and alloy steel, industrial countries in the world also pay great attention to improving the quality of carbon steel and expanding the variety and scope of use. . Especially since the 1950s, new technologies such as oxygen converter steelmaking, out-of-furnace injection, continuous steel casting and continuous rolling have been widely used, further improving the quality of carbon steel and expanding the scope of use. At present, the proportion of carbon steel output in the total steel output of various countries remains at about 80%. It is not only widely used in construction, bridges, railways, vehicles, ships and various machinery manufacturing industries, but also in the modern petrochemical industry. ﹑ Marine development and other aspects, has also been widely used.