Application of PMO technology in industrial production of ø 250 mm round billets

Based on the production practice of applying Pulsed Magnetic-Oscillation (PMO) solidification homogenization technology on the ø 250 mm round billet continuous caster of Tianjin Rockcheck United Iron & Steel Group Co., Ltd., this study explores the improvement effect of this technology on the center defects and macrosegregation of round billets. The results show that the PMO technology can significantly improve the centerline shrinkage cavities of ø 250 mm round billets, with the best effect achieved when the voltage is controlled at 225k_U-235k_U V (k_U represents the equipment coefficient, i.e., the calibration parameters of different equipment). Additionally, the PMO technology has a significant improvement effect on the macrosegregation of cast billets, and the optimal regulation effect is obtained when the voltage is around 220k_U V and the frequency is medium frequency. Moreover, this technology has high process tolerance; increasing the casting speed by 10%-20% does not affect its regulation effect on the center defects and macrosegregation of cast billets. Meanwhile, production practice indicates that the PMO technical equipment operates stably and reliably, with no product objections since its commissioning nearly a year ago.