Effect of AI_(2)O_(3)and MgO on crystallization and structure of Ca0-Si0_(2)-B_(2)0_(3)-based fluorine-free mold flux  

作　　者：Jun-yu Chen Wan-lin Wang Le-jun Zhou Zi-hang Pan 

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,Hunan,China [2]National Center for International Cooperation of Clean Metallurgy,Changsha 41(K)83,Hunan,China

出　　处：《Journal of Iron and Steel Research International》2021年第5期552-562,共11页

基　　金：This work was supported by the National Natural Science Foundation of China(51874363,U1760202);Natural Science Foundation of Hunan Province(2019JJ40345);Hunan Scientific Technology Projects(2018RS3022,2018WK2051).

摘　　要：The crytallization behavior and melt structure of the CaO-Si0^(2-)B20_(3)-based fluorine-free mold fux were investigated.The results show that the crytallization of the mold fux was first inhibited and then promoted with the increase in Al_(2)0_(3) 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 Al_(2)0_(3) 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 0^(2-)when its content was in the range of 8-12 wt.%.In addition,the combined efects from the charge compensation by Mg^(2+)and the network broken by 0^(2-)led to the increase in some typicalT-O-T(AI-O-A1,B-O-B,etc.,)and simpler structural units(Q^(2)(Si),B_^(O-)in the[B0_(2)0^(-)],.etc.)when the MgO content was in the range of 2-6 wt.%.The continuous increase in 0^(2-)provided by the addition of MgO from 6 to 10 wt.%further depolymerized the network of the melt and fnally caused fast crystallizationo.

关 键 词：CRYSTALLIZATION Single hot thermocouple technique Melt structure Fluorine-free mold flux 

分 类 号：TF044[冶金工程—冶金物理化学]