Deoxidation of H13 tool steel with CaF_(2)-MgO-CaO-Al_(2)O_(3)-SiO_(2) slags at 1873 K  

1873K下CaF_(2)-MgO-CaO-Al_(2)O_(3)-SiO2渣系对H13模具钢的脱氧研究

作　　者：LI Shao-ying LI Bin DUAN Sheng-chao ZHAO Xing-ming GUO Jing GUO Han-jie 李少英;李彬;段生朝;赵兴明;郭靖;郭汉杰(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Special Melting and Preparation of High-end Metal Materials,Beijing 100083,China;Shandong Tianwu Forming Technology Co.,Ltd.,Liaocheng 252024,China)

机构地区：[1]School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]Beijing Key Laboratory of Special Melting and Preparation of High-end Metal Materials,Beijing 100083,China [3]Shandong Tianwu Forming Technology Co.,Ltd.,Liaocheng 252024,China

出　　处：《Journal of Central South University》2021年第2期370-385,共16页中南大学学报（英文版）

基　　金：Project(18SYXHZ0069)supported by the Science and Technology Program of Sichuan Province,China;Projects(51974139,51664021)supported by the National Natural Science Foundation of China。

摘　　要：Laboratory-scale experiments were performed to investigate the deoxidation of H13 tool steel with CaF_(2)-MgO-Al_(2)O_(3)-CaO-SiO_(2) slags at 1873 K.The calculation of thermodynamics and kinetics was also verified through the experimental results.The results show that[Si]-[O]reaction is the control reaction,and with the increase of basicity of slag,the limitation of deoxidation was decreased.The limitation of deoxidation is the lowest for the slag with basicity of 2.0.Under the conditions of the basicity of 2.0 and the content of CaF_(2) more than 50%,the limitation of deoxidation is less than 10×10^(−6),and it does not depend on the contents of Al_(2)O_(3) and CaF_(2) in slags.The mass transport of oxygen in the metal phase is the rate-controlling step,and the slag composition has no effect on the equilibrium time of deoxidation.Based on this finding,the optimized slag composition is designed and it contains the following components:51.5%CaF_(2),20.3%MgO,16.2%Al_(2)O_(3),8.2%CaO and 3.8%SiO_(2).In the case of the optimized deoxidizing slag,the total oxygen content in H13 steel can be reduced from 25×10^(−6) to 6×10^(−6).本文根据热力学和动力学理论,结合实验室实验,研究了1873 K下CaF_(2)-MgO-Al_(2)O_(3)-CaO-SiO2渣系成分对H13工具钢脱氧极限的影响。理论计算结果与实验结果基本一致。研究结果表明,[Si]-[O]反应为脱氧控制反应,随着炉渣碱度的增大,脱氧极限降低。当碱度为2.0时,脱氧极限最低。在碱度为2.0且CaF_(2)含量大于50%的条件下,脱氧极限小于10×10^(−6),且该值不受炉渣中Al2O3和CaF2的含量的影响。氧在金属相中的传质过程是脱氧反应的限制性环节,因此,脱氧反应速率不受渣系成分的影响。基于上述结果,设计了优化的炉渣成分,即51.5%CaF_(2),20.3%MgO,16.2%Al_(2)O_(3),8.2%CaO和3.8%SiO_(2)。在此成分条件下,H13钢中的全氧含量可以从25×10^(−6)降低到6×10^(−6)。

关 键 词：DEOXIDATION H13 tool steel slag-steel interface reaction slag optimization 

分 类 号：TF704.1[冶金工程—钢铁冶金]