Carbon steel is the earliest and most widely used basic material in modern industry. While trying to increase the output of low-alloy high-strength steel and alloy steel, the industrialized countries in the world also pay great attention to improving the quality of carbon steel and expanding the variety and application scope. At present, the output of carbon steel accounts for about 80% of the total steel output in various countries. It is not only widely used in construction, bridges, railways, vehicles, ships and various machinery manufacturing industries, but also widely used in modern petrochemical industry and marine development.