Bar refers to a type of steel with a cross-section similar to a circular shape. The use of bars is very extensive, mainly used in civil engineering construction such as houses, roads, bridges, and the automotive industry. In addition, bars can also be processed into various metal products, such as steel wires for springs, communication wires, various nails, etc. Due to the rapid development of industries such as automobiles, machinery, ships, railways, aviation and aerospace, and national defense and military industry, a large amount of bars are needed in these fields, and the quality requirements for steel are also high. In order to make the chemical composition, microstructure, and mechanical properties of bar steel superior to ordinary steel, more alloy elements are added in the steel smelting process, and special production and processing techniques are used to process alloy steel bars.

The production process of alloy steel bars can be roughly divided into three stages: steelmaking, rolling, and finishing. Some special steel grades still require further rolling and finishing after finishing. Firstly, the molten steel produced by the steelmaking plant is poured into steel billets on the continuous casting machine. In order to obtain the required shape and specifications and improve the internal quality of the steel, the semi-finished steel billets are further processed through the rolling process. Finally, the finished or semi-finished products after rolling undergo a series of treatments, such as shearing, pickling, heat treatment, straightening, and leveling. After processing, the finished product has a shape that meets the specifications, as well as the correct size and performance characteristics.