Manufacturing process
Carbon steel smelting is usually carried out in converters and open hearth furnaces. The converter is generally smelted with ordinary carbon steel, and can smelt various high-quality open hearth steel. Converter steelmaking technology is developing rapidly, and there is a trend to replace open hearth steelmaking. Refining injection molding of steel ingots to obtain various steel ingots. The ingots after forging or rolling are processed into steel, steel bars and steels of various cross-sectional shapes. Carbon steel is usually used directly in the hot rolled state. For the manufacture of tools and various mechanical parts, heat treatment must be carried out as required; for steel castings, most of them should be heat treated.


chemical composition
The properties of the chemical composition depend to a large extent on the microstructure of carbon steel and carbon steel. In the annealed or hot rolled state, as the carbon content in the steel increases, the strength, hardness, ductility, toughness and drop of the steel increase. Solderability and cold forming deteriorate. Therefore, in steel structure engineering, the carbon content is often limited. Carbon steel elements and residual impurity elements such as manganese, silicon, nickel, phosphorus, sulfur, oxygen, nitrogen, and carbon steel also affect performance. Sometimes these effects reinforce each other and sometimes confront each other. For example: 1 sulfur, oxygen, nitrogen can increase the hot brittleness of steel, and can reduce the content of manganese or partially offset the hot brittleness of steel. 2 residual elements manganese, nickel and external elements reduce the impact toughness of steel and increase the cold brittleness of steel. 3 In addition to sulfur and oxygen, other impurity elements have lower strength and increase the strength of the steel to varying degrees. 4 Almost all impurity elements reduce their ductility and weldability. Hydrogen in steel can cause many serious defects, such as white spots, point segregation, hydrogen embrittlement, cracks and other surface bubbling and welding heat affected zones. In order to ensure the quality of the steel, the hydrogen content in the steel must be reduced as much as possible (see stress corrosion cracking and hydrogen embrittlement). Deoxidation into residual elements such as aluminum can reduce the aging tendency of low carbon steel, and grain refinement can also improve the toughness of steel at low temperatures, but it cannot leave too much margin. Residual elements in the charge such as nickel, chromium, molybdenum, copper, etc., although high in content can improve the hardenability of the steel, but require special steel to have higher plasticity, such as deep-drawn steel, which is disadvantageous.


Processing performance
Most carbon steel smelting furnaces use converters and flat steel, and high-quality carbon steel is also produced by electric arc furnaces. According to the degree of deoxidation steelmaking process, carbon steel can be classified into killed steel boiling steel and semi-killed steel. The main factor affecting the performance of the steelmaking process is the purity of the steel mill. People use vacuum processing and blowing technology to obtain steel with higher purity, which significantly improves the quality of carbon steel. The plastic working process of carbon steel is usually hot and cold processing. After the heat treatment, defects such as small bubbles and looseness in the steel ingot are welded together to make the steel structure dense. At the same time, the heat treatment can destroy the structure of the casting and refine the grains. Therefore, forged steel has better mechanical properties than cast steel. The cold plastic deformation of steel decreases with the increase of strength and hardness, and the ductility and toughness decrease. In order to increase production, it is widely used in continuous casting processes.