Improving Inner Quality in Continuous Casting Rectangular Billets: Comparison Between Mechanical Soft Reduction and Final Electromagnetic Stirring

Abstract

The comparison between the mechanical soft reduction (MSR) and final electromagnetic stirring (FEMS) on center carbon macrosegregation and v-segregation has been investigated in order to improve the inner quality of high carbon 82A steel with a section of size 180 mm × 240 mm. A heat transfer calculation model by using C++ programming language is developed and applied to calculate the appropriate casting speed of continuous casting during the FEMS and MSR processes. The calculated action zone of FEMS and MSR is at the location with a solid fraction of 0.28–0.41 and 0.30–0.90, respectively. The industrial results show that the effects of MSR in improving the center carbon segregation, reducing the shrinkage cavity and suppressing the V-segregation are more effective than FEMS. The mean center carbon segregation degree reduces from 1.19 to 1.15 with FEMS and decreases from 1.19 to 1.07 with MSR. Besides, compared with FEMS, MSR can eliminate shrinkage cavity and V-segregation but may generate center negative segregation and transverse cracks subjected to reduction pressure.