Study on the Electroslag Remelting Slag for H13 Die Steel Containing Ce and Mg

doi:10.12068/j.issn.1005-3026.2023.08.007

Abstract

Abstract: RE and Mg co-treatment can significantly improve the cleanliness of steel and refine carbide， but RE and Mg are prone to be burned during electroslag remelting. Therefore， two kinds of electroslags containing Ce₂O₃ and MgO were designed， which are 55% CaF₂-30% Ce₂O₃-10% MgO-5% Al₂O₃ (1#) and 60% CaF₂-30% Ce₂O₃-10% MgO (2#)， respectively. Ce and Mg co-treatment of H13 die steel was carried out using a resistance-heated tube furnace， and the slag-metal equilibrium behavior between H13 steel and the aforementioned slags at 1873K was studied. The results show that the main inclusions in H13 steel are Ce₂O₃ and MgO. Some Ce₂O₃ inclusions are coated with MgO. At 15min after adding Ce and Mg， the dissolved Ce in the steel was almost completely burned， and only insoluble Ce in Ce₂O₃ inclusions was remained. During the whole deoxidation period， the content of dissolved Mg in steel changed little. The contents of dissolved Mg in 1# and 2# H13 steel at 60min were 0.0034% and 0.0053%， respectively， MgO solubility in 1# and 2# slags are 10.6% and 6.7%， respectively. Due to MgO supersaturation， both slags have very weak absorption capacity for MgO inclusions. The rmodynamic calculation shows that both the Al₂O₃ component and minor amounts of SiO₂ in the slags lead to serious burning loss of Ce and Mg.

Key words: cerium; magnesium; electroslag remelting; inclusions; yield; die steel

CLC Number:

TF769.2

ZHENG Li-chun， PENG Bo， LOU Jian， JIANG Zhou-hua. Study on the Electroslag Remelting Slag for H13 Die Steel Containing Ce and Mg[J]. Journal of Northeastern University(Natural Science), 2023, 44(8): 1111-1118.

References

[1]Diao S S，Han Q Y，Lin G，et al.Equilibria of Ce-Al-O and Nd-Al-O in molten iron［J］.Steel Research，1997，68(11):469-474.
[2]Katsumata A，Todoroki H.Effect of rare earth metal on inclusion composition in molten stainless steel［J］.Ironmaking & Steelmaking，2002，29:51-57.
[3]Lan J，He J J，Ding W J，et al.Effect of rare earth metals on the microstructure and impact toughness of a cast 0.4C-5Cr-1.2Mo-1.0V steel［J］.ISIJ International，2007，40(12):1275-1282.
[4]贺宝，李晶，史成斌，等.电渣重熔过程冷却强度对含镁H13钢中碳化物的影响［J］.工程科学学报，2016，38(12):1720-1727.(He Bao，Li Jing，Shi Cheng-bin，et al.Effect of cooling intensity on carbides in magnesium-bearing H13 steel during electroslag remelting［J］.Journal of Engineering Science，2016，38(12):1720-1727.)
[5]王德永，姜茂发，刘承军，等.稀土氧化物对连铸保护渣粘度的影响［J］.中国稀土学报，2005(1):100-104.(Wang De-yong，Jiang Mao-fa，Liu Cheng-jun，et al.Influence of rare earth oxides on the viscosity of continuous casting molding powder［J］.Chinese Journal of Rare Earth，2005(1):100-104.)
[6]Михайлов Г Г，Макровец Л А，Смирнов Л А.Термодинамическое моделирование фазовых равновесий с оксидными системами，содержащими РЗМ［J］.Вестник Южно-Уральского Государственного Университета (Серия:Металлургия)，2015，15 (4):5-14.(Mikhailov G G，Makrovets L A，Smirnov L A.Thermodynamic modeling of phase equilibria with oxide systems containing REM［J］.Bulletin of the South Ural State University (Series:Metallurgy)，2015，15 (4):5-14.)
[7]Mizuno M，Berjoan R，Coutures J，et al.Phase diagram of the system Al₂O₃-CeO₂ at liquidus temperature［J］.Yogyo-Kyokai-Shi，1975，83(2):90-96.
[8]Babenko A A，Smirnov L A，Upolovnikova A G，et al.Study of possibility of cerium reduction from slags of CaO-SiO₂-Ce₂O₃-15%Al₂O₃-8% MgO system［J］.IOP Conference Series:Materials Science and Engineering，2020，966(1):012010.
[9]Jung I H，Decterov S A，Pelton A D.Critical thermodynamic evaluation and optimization of the MgO-Al₂O₃，CaO-MgO-Al₂O₃，and MgO-Al₂O₃-SiO₂ systems［J］.Journal of Phase Equilibria and Diffusion，2004，25(4):329-345.
[10]Yang X M，Shi C B，Zhang M，et al.A thermodynamic model for prediction of iron oxide activity in some FeO-containing slag systems［J］.Steel Research International，2012，83(3):244-258.
[11]Bale C W，Chartrand P，Degterov S A，et al.FactSage thermochemical software and databases［J］.Calphad-computer Coupling of Phase Diagrams and Thermochemistry，2002，26(2):189-228.
[12]Hino M，Ito K.Thermodynamic data for steelmaking［M］.Sendai:Tohoku University Press，2010:249-264.
[13]Nishi T，Shinme K.Formation of spinel inclusions in molten stainless steel under Al deoxidation with slags［J］.Tetsu-to-Hagané，1998，84(12):837-843.