Alloy steels with a total alloying element content of less than 5% are called low alloy steels. Low alloy steel is relative to carbon steel. On the basis of carbon steel, in order to improve one or several properties of steel, one or several alloying elements are intentionally added to the steel. The amount of alloy added exceeds When the normal content of the normal production method of carbon steel is used, the steel is referred to as an alloy steel. When the total amount of the alloy is less than 5%, it is called low alloy steel. Alloy content between 5-10% is called medium alloy steel; more than 10% is called high alloy steel.
China's steel output has exceeded 600 million tons, the amount of steel is no longer the main contradiction, and the contradiction of unreasonable steel product structure is very prominent. The main task of the current industry is to strive to improve the market competitiveness of products, stand on the new starting point of sustainable development, and put the development of low-alloy steel into the important content of development strategy. Many general steel enterprises have realized that the production of low-alloy steel is the key to improve the technical content and added value of steel products in the structural adjustment of steel products and the preparation of scientific and technological development plans. There are countless problems in the development of low-alloy steels. The management cadres feel that "the alloy is also low-alloy steel, and the low-alloy steel is defeated", and it is urgent to have a comprehensive understanding of low-alloy steel.
According to international standards, steel is divided into two categories: unalloyed steel and alloy steel. Unalloyed steel is a large steel type commonly called carbon steel. In addition to iron and carbon, steel contains a small amount of alloying elements brought by the charge. Mn, Si, Al, impurity elements P, S and gases N, H, O, and the like. Alloy steel is another type of steel that intentionally adds a certain amount of alloying elements Cr, Ni, Mo, V, and controls impurities and harmful elements in order to obtain certain physical, chemical or mechanical properties.