低真空对电渣重熔工艺和铸锭质量的影响

doi:10.12068/j.issn.1005-3026.2023.01.008

摘要/Abstract

摘要： 脱氧和夹杂物控制是电渣重熔钢锭质量提升的关键.分别在氩气保护的常压和低真空(10kPa)条件下重熔H13电极，结合热力学计算，分析了低真空对电渣重熔工艺过程和铸锭质量的影响.结果表明，相比常压，低真空条件下渣池含气率升高，熔速波动更剧烈，所得电渣锭表面质量较差.常压和低真空条件制得电渣锭中总w_O分别为24×10^-6和18×10^-6，碳脱氧反应随压力降低而加强，并逐渐取代铝脱氧.相比Al-O平衡，10kPa条件下与电极中w_C平衡的溶解w_O更低，因而能够进一步降低钢锭中w_O.碳脱氧产物是CO气体，不会引入新的夹杂物.常压和低真空条件制得电渣锭中夹杂物的类型没有明显区别，最大夹杂物尺寸从14.9μm分别减小到10.5μm和8.3μm，等效直径小于3μm的夹杂物检出比分别为63.85%和75.91%.低真空条件能够进一步细化夹杂物，提高钢锭洁净度.

关键词: 电渣重熔；低真空；脱氧；夹杂物；洁净度；氩气保护

Abstract: Deoxidation and inclusions control are the key to improve the quality of ingots produced by electroslag remelting (ESR). The effect of low vacuum on the ESR process and ingot quality was experimentally studied in combination with thermodynamic calculations. H13 electrodes were remelted under argon protection at atmospheric and low vacuum (10kPa) conditions， respectively. The results show that， compared with atmospheric pressure， a higher gas content in the slag pool， more drastic fluctuations of the electrode melting rate， and a rougher surface of the ESR ingot were observed under low vacuum. The total w_O in the ESR ingots remelted under atmospheric and low vacuum conditions are 24×10^-6 and 18×10^-6， respectively. The carbon deoxidation reaction is greatly enhanced under low vacuum and gradually replaces aluminum deoxidation as the pressure decreases. Compared with Al-O equilibrium， the dissolved w_O in molten steel equilibrated with w_C of the electrode at 10kPa is much lower. Thus， lowering pressure can further reduce the w_O of the ingot. Carbon deoxidation， of which the product is CO gas， will not introduce new inclusions. The pressure has little effect on the type of inclusions in ESR ingots. The biggest inclusions in the ESR ingots remelted under atmospheric and low vacuum conditions decrease from 14.9μm to 10.5μm and 8.3μm， respectively. The ratio of the detected inclusions with equivalent diameters less than 3μm are 63.85% and 75.91%， respectively. ESR under low vacuum condition can further refine the inclusions and improve the cleanliness of ESR ingots.

Key words: electroslag remelting(ESR); low vacuum; deoxidation; inclusions; cleanliness; argon protection

中图分类号:

TF142

黄雪驰，李宝宽，刘承军，刘中秋. 低真空对电渣重熔工艺和铸锭质量的影响[J]. 东北大学学报（自然科学版）, 2023, 44(1): 55-62.

HUANG Xue-chi， LI Bao-kuan， LIU Cheng-jun， LIU Zhong-qiu. Effect of Low Vacuum on Electroslag Remelting Process and Ingot Quality[J]. Journal of Northeastern University(Natural Science), 2023, 44(1): 55-62.

参考文献

[1] Zhang L F，Thomas B G.State of the art in the control of inclusions during steel ingot casting［J］.Metallurgical and Materials Transactions B，2006，37B: 733-761.
[2]Huang X C，Li B K，Liu Z Q，et al.Three-dimensional mathematical model of oxygen transport behavior in electroslag remelting process［J］.Metallurgical and Materials Transactions B，2018，49B: 709-722.
[3]Chen X C，Shi C B，Guo H J，et al.Investigation of oxide inclusions and primary carbonitrides in Inconel 718 superalloy refined through electroslag remelting process［J］.Metallurgical and Materials Transactions B，2012，43B: 1596-1607.
[4]王迪，杨树峰，曲敬龙，等.GH4169电渣重熔铸锭表层夹杂物分布规律［J］.钢铁，2021，56(2):155-161.(Wang Di，Yang Shu-feng，Qu Jing-long，et al.Distribution of inclusions on surface of GH4169 ESR ingot［J］.Iron and Steel，2021，56(2):155-161.)
[5]周德光，徐卫国，王平，等.轴承钢电渣重熔过程中氧的控制及作用研究［J］.钢铁，1998，33(3):13-17.(Zhou De-guang，Xu Wei-guo，Wang Ping，et al.Control and behavior of oxygen during electroslag remelting of bearing steel［J］.Iron and Steel，1998，33(3):13-17.)
[6]宋惠东，李晶，史成斌，等.8Cr13MoV钢电渣重熔过程中夹杂物行为［J］.钢铁，2016，51(8):41-48.(Song Hui-dong，Li Jing，Shi Cheng-bin，et al.Evolution of inclusions in 8Cr13MoV steel during ESR process［J］.Iron and Steel，2016，51(8):41-48.)
[7]李宝宽，王强.基于数值模拟的电渣重熔理论与技术［M］.北京: 科学出版社，2016: 1-2.(Li Bao-kuan，Wang Qiang.Theory and technology of electroslag remelting based on numerical simulation［M］.Beijing: Chinese Science Publishing，2016: 1-2.)
[8]Huang X C，Li B K，Liu Z Q，et al.Numerical study on the removal and distribution of non-metallic inclusions in electroslag remelting process［J］.International Journal of Heat and Mass Transfer，2019，135: 1300-1311.
[9]Du G，Li J，Wang Z B.Effect of operating conditions on inclusion of die steel during electroslag remelting［J］.ISIJ International，2018，58(1):78-87.
[10]Shi C B.Deoxidation of electroslag remelting (ESR)—a review［J］.ISIJ International，2020，60(6):1083-1096.
[11]Shi C B，Chen X C，Guo H J，et al.Assessment of oxygen control and its effect on inclusion characteristics during electroslag remelting of die steel［J］.Steel Research International，2012，83(5):472-486.
[12]侯栋，姜周华，董艳武，等.电渣重熔中脱氧剂种类影响炉渣脱氧的热力学分析［J］.东北大学学报(自然科学版)，2016，37(5):668-672.(Hou Dong，Jiang Zhou-hua，Dong Yan-wu，et al.Thermodynamics analysis of slag deoxidation with different deoxidizers during electroslag remelting process［J］.Journal of Northeastern University (Natural Science)，2016，37(5):668-672.)
[13]Choudhury A.Recent results of the electroslag remelting process under vacuum［C］//Proceeding of the Tenth International Conference on Vacuum Metallurgy.Beijing: Metallurgical Industry Press，1990: 247-251.
[14]Leach J.The application of vacuum to steel making［J］.Vacuum，1969，19(4):155-162.
[15]Steneholm K，Andersson M，Tilliander A，et al.Removal of hydrogen，nitrogen and sulphur from tool steel during vacuum degassing［J］.Ironmaking and Steelmaking，2013，40(3):199-205.
[16]Kuwabara T，Umezawa K，Mori K，et al.Investigation of decarburization behavior in RH-reactor and its operation improvement［J］.Transactions ISIJ，1988，28(4):305-314.
[17]You Z M，Cheng G G，Wang X C，et al.Mathematical model for decarburization of ultra-low carbon steel in single snorkel refining furnace［J］.Metallurgical and Materials Transactions B，2015，46B: 459-472.
[18]Sekiya A，Nakayama S，Taketsuru T.Deoxidation of stainless steel on vacuum electroslag remelting process［J］.Electric Furnace Steel (Denki-Seiko)，1995，66: 47-53.
[19]Radwitz S，Scholz H，Friedrich B.Investigation of slag compositions and pressure ranges suitable for electroslag remelting under vacuum conditions［C］//Proceedings of the 2013 International Symposium on Liquid Metal Processing & Casting.Berlin: Springer-Verlag，2013: 87-93.
[20]Liu Y，Zhang Z，Li G Q，et al.Investigation of fluoride vaporization from CaF₂-CaO-Al₂O₃ slag for vacuum electroslag remelting［J］.Vacuum，2018，158: 6-13.
[21]Chang L Z，Shi X F，Cong J Q.Study on mechanism of oxygen increase and countermeasure to control oxygen content during electroslag remelting process［J］.Ironmaking and Steelmaking，2014，41(3):182-186.
[22]Bjrklund J，Miki T，Andersson M，et al.Effect of temperature on oxygen activity during ladle treatment［J］.ISIJ International，2008，48(4):438-445.
[23]Liu Y，Wang X J，Li G Q，et al.Role of vacuum on cleanliness improvement of steel during electroslag remelting［J］.Vacuum，2018，154: 351-358.(上接第7页)