How steel is made?

Iron and steel is an alloy of iron and C (carbon), Si (silicon), Mn (manganese), P (phosphorus), S (sulfur), and a small amount of other elements. In addition to Fe (iron), the content of C plays a major role in the mechanical properties of steel, so it is collectively referred to as iron-carbon alloy. It is the most important and the most important, most used metal material in engineering technology.

Iron-carbon alloys are classified into steel and pig iron, and steel is an iron-carbon alloy with a carbon content of 0.03% to 2%. Carbon steel is the most commonly used ordinary steel. It is easy to smelt, easy to process, and inexpensive. It can meet the requirements in most cases, so it is very common. According to different carbon content, carbon steel is divided into low carbon steel, medium carbon steel and high carbon steel. As the carbon content increases, the hardness of carbon steel increases and the toughness decreases. Alloy steel is also called special steel. Adding one or more alloying elements on the basis of carbon steel changes the microstructure and properties of the steel, so it has some special properties, such as high hardness, high wear resistance, high toughness, Corrosion resistance, etc. The alloying elements often added to steel include Si, W, Mn, Cr, Ni, Mo, V, Ti, and the like. The resources of alloy steels are quite abundant, except for Cr and Co. The Mn grades are low, and the reserves of W, Mo, V, Ti and rare earth metals are high. At the beginning of the 21st century, the proportion of alloy steel in the total steel production will increase significantly.

The general rule of carbon steel can be approximated as that the higher the carbon content is, the higher the hardness is, but the greater the hardness, the lower the hardness when the carbon content increases. The hardness of steel materials depends mainly on the chemical composition of the material (steel), high hardness with high carbon content, and heat treatment conditions.

The cyclical fluctuation of steel prices is a comprehensive reflection of the market cycle of the steel industry. It is the result of the chain effect of price-benefit-investment-capacity-supply and demand. Overall, there are several factors that affect steel price changes: First, production costs, which is the basis for changes in steel prices; Second, supply and demand are the key factors affecting changes in steel prices; Third, the market system, defective The market system may amplify the imbalance between supply and demand, causing price fluctuations.