How to Reasonably Select the Cross Section of Continuous Casting Billets

 　　Due to the fact that some low magnification defects in the billet can be reduced or eliminated through a certain compression ratio, and a certain compression ratio is also a necessary measure to stabilize the performance of the steel. To ensure the quality of large-sized special steel bars, it is necessary to use large billet sections and measures such as blooming. For example, in the 1980s and 1990s, the special steel continuous casting machines produced in Japan had a cross-sectional area of over 300m ². However, due to the smaller degree of segregation and porosity of small section billets compared to large sections under the same conditions, and with the development of clean steel production technology and improvement of continuous casting technology, the total amount of harmful impurities and inclusions in the steel is significantly reduced. The adoption of electromagnetic stirring technology effectively reduces center segregation, making it possible to produce small specification special steel products from small section billets on one heat. Thus, various distinctive EAF (BOF) - LF-VD bloom continuous casting large bar continuous rolling production lines and EAF-LF small billet continuous casting small bar and wire continuous rolling production lines are formed, and the latter has a competitive advantage in the production of small specification materials.

　　Each steel enterprise can select appropriate billet sections based on the production specifications of steel and the characteristics of rolling mills, forming a specialized production line for producing large specifications of large billets, small specifications of square billets, and wire rods.