连铸复合电磁搅拌对低碳钢碳偏析的影响

Effect of Multiple Electromagnetic Stirring on Carbon Segregation in Concasting Low Carbon Steel

20CrMnTi钢(%:0.17～0.23C、0.80～1.10Mn、1.00～1.30Cr、0.04～0.10Ti)300 mm×340 mm铸坯结晶器-末端电磁搅拌(M-EMS,F-EMS)和3段复合电磁搅拌(M-EMS,S-EMS,F-EMS)对铸坯碳偏析影响的试验结果表明,当M-EMS和F-EMS电流分别从2 HZ/250 A和20 HZ/150 A降至2 HZ/100 A和20 HZ/100 A时,铸坯断面碳成分的极差由0.05%降至0.02%;当采用M-EMS为2 HZ/100 A,S-EMS为20 HZ/50 A,F-EMS为20 HZ/100A三段复合电磁搅拌时,铸坯断面碳成分的极差为0.02%,轧材中心疏松由原2段电磁搅拌的1.0～2.0级降至1.0～1.5级,方框形偏析2.0级出现率由9.7%降至0.8%。

Commercial test for the effect of 300 mm ×340 mm bloom mold electromagnetic stirring-final electromagnetic stirring （M-EMS and F-EMS） and 3-section multiple EMS （M-EMS, S-EMS and F-EMS） on carbon segregation of bloom of steel 20CrMnTi （ % ： 0. 17-0.23C, 0. 80 - 1. 10Mn, 1. 00 - 1. 30Cr, 0. 04 -0. 10Ti） has been carried out. Resuits show that as current intensity of M-EMS and F-EMS for 2-section stirring decreases respectively to 2 HZ/100 A and 20 HZ-100 A from original 2 HZ/250 A and 20 HZ/150 A, the max different of carbon content in steel at section of bloom decreases to 0. 02% from original 0. 05% ; and as using 3-section multiple EMS, i.e. current intensity- 2 HZ/100 A for MEMS, 20 HZ/50 A for S-EMS and 20 HZ/100 A for F-EMS, the max different of carbon content in steel at section of bloom is 0. 02%, while the rating of centre porosity of rolled products decreases to 1.0 - 1.5 from original 1.0 -2. 0 as using 2- section EMS, and the occurred ratio of square segregation decreases to 0. 8% from 9. 7%.