高碳钢小方坯连铸参数优化及铸坯中心偏析控制

Optimization of Continuous Casting Parameters for High Carbon Steel Billet and Control of Central Segregation of Billets

研究了小方坯连铸采用结晶器电磁搅拌和凝固末端电磁搅拌生产SWRH82B时,拉速、二冷比水量、末端电磁搅拌电流强度及频率对铸坯中心元素偏析的影响。结果表明:C、Mn、Cr相比,C的中心偏析最严重,Mn、Cr也有明显的中心偏析。随末端电磁搅拌电流强度的增加,V型偏析被打散,铸坯中心C偏析先减轻后加重,电流350 A时C偏析指数最小。随搅拌频率的增加,铸坯中心C偏析先减轻后加重,6 Hz频率有利于控制偏析。增大二冷比水量有利于降低小方坯中心C偏析;增加拉速,铸坯的中心偏析加重。使用末端电磁搅拌可在提高拉速条件下,将铸坯的中心C偏析控制在较低的水平。

The effects of casting speed,secondary cooling intensity,F-EMS current intensity and stirring frequency on the central segregation of high carbon steel SWRH82B billets,which were produced by billet casters using both M-EMS and F-EMS,were studied.It was shown that compared with manganese and chromium,carbon has the severest central segregation,the other two obviously have central segregation too.With F-EMS current intensity increases,V-segregation is scattered,and central segregation index for carbon increases after decreases,it has the lowest level when current intensity is 350 A.With F-EMS stirring frequency increases,central segregation index for carbon increases after decreases,it＇s profitable to set stirring frequency as 6 Hz in order to control segregation.It is favorable to control the central segregation of billets by improving secondary cooling intensity.The faster casting speed is,the severer central segregation becomes.Cas ting speed of billet casters can be risen if F-EMS is used,and the central carbon segregation of billets can be control at a low level simultaneously.