Effect of Al2O3 and MgO on crystallization and structure of CaO-SiO2-B2O3-based fluorine-free mold f

• 作 者: Jun-yu Chen Wan-lin Wang Le-jun Zhou Zi-hang Pan
• 机 构: School of Metallurgy and Environment,Central South University,Changsha 410083,Hunan,China;National C
• 出 处: 钢铁研究学报（英文版）
• 发表日期: 2021年5期
• 关键词: Crystallization Single hot thermocouple technique Melt structure Fluorine-free m

The crystallization behavior and melt structure of the CaO-SiO2-B2O3-based fluorine-free mold flux were investigated.The results show that the crystallization of the mold flux was first inhibited and then promoted with the increase in A12O3 content from 4 to 12 wt.％.However,it was enhanced by MgO in the range of 2-10 wt.％.The results of Fourier transform infrared spectroscopy and Raman spectroscopy showed that A12O3 worked as a network former in the mold flux melt when its content was in the range of 4-8 wt.％,whereas it worked as the network breaker to provide O2-when its content was in the range of 8-12 wt.％.In addition,the combined effects from the charge compensation by Mg2+ and the network broken by O2-led to the increase in some typical T-O-T (A1-O-A1,B-O-B,etc.) and simpler structural units (Q0(Si),B-O-in the[BO2O],etc.) when the MgO content was in the range of 2-6 wt.％.The continuous increase in O2-provided by the addition of MgO from 6 to 10 wt.％ further depolymerized the network of the melt and finally caused fast crystallization.