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 th...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).展开更多
基金Project(18SYXHZ0069)supported by the Science and Technology Program of Sichuan Province,ChinaProjects(51974139,51664021)supported by the National Natural Science Foundation of China。
文摘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).
