Mold-Exit Narrow-Face Profile Design for Compensating Billet Broadening During End-of-Solidification Reduction
摘要
In this study, a parameterized compensated profile was proposed to control billet broadening during end-of-solidification reduction. A sequential thermo-mechanical finite element model was first established for a GCr15 billet and validated using plant infrared temperature measurements and room-temperature width measurements. The simulated room-temperature broadening under the 10 mm reduction condition was 2.1 mm, which agreed well with the measured value of approximately 2.0 ± 0.2 mm. The validated model was then used to clarify the deformation limitation of the conventional billet profile. As the reduction amount increased from 10 to 20 mm, the post-reduction final billet width increased from 155.8 to 160.0 mm, exceeding the rolling-entry limit of 158 mm at R = 20 mm. To overcome this limitation, a compensated exit profile was designed by introducing controlled edge recession on the narrow faces while keeping the initial wide-face geometry unchanged. A total of 48 compensated profile cases were simulated by varying the reduction amount R, compensation amplitude B, and shape factor p. The results show that increasing B effectively reduces the final billet width, whereas excessive compensation deteriorates narrow-face flatness. A smaller p provides a more broadly distributed compensation and improves profile regularity. Within the investigated parameter range, B = 1.5 mm and p = 0.8 provide the best overall response for R = 20 mm, satisfying the rolling-entry limit while maintaining a relatively flat narrow-face profile. The proposed compensated profile provides a practical strategy for balancing width control and cross-sectional regularity during billet reduction.