Abstract:Based on the practical production of non-oriented silicon steel, the evolution of inclusion type and the formation of MgO?Al2O3 inclusion were analyzed in the process of BOF→RH→CSP. The thermodynamic conditions for forming MgO?Al2O3 inclusion were discussed and the behavior of slag entrapment of molten steel was also simulated by CFD software during RH refining. The results showed that the value of [w([MgO])/w([Al2O3])] was in the range of 0.005?0.020 and no MgO?Al2O3 inclusion was observed at 20 and 30 min in RH refining; on the contrary, the value of [w([MgO])/w([Al2O3])] was in the range of 0.3?0.5 and the MgO?Al2O3 inclusion accounts for 58.5% of total amount of inclusions after RH refining. The compositions of slag were similar to the composition of inclusions; furthermore, the simulation results of CFD software show that the surface velocity was 0.57 m/s, which was greater than the critical velocity of 0.45 m/s. When the test steel was in equilibrium with slag, the [w([Mg])] was 0.000 24%?0.000 28% and [w([Al])] was 0.31%?0.37%, which was in theoretically calculated MgO?Al2O3 formation zone, thereby leading to formation of MgO?Al2O3 inclusion in steel. Thus, the MgO?Al2O3 inclusion was inhibited by reducing the quantity of slag entrapment and roughing slag in casting and controlling composition of slag and the MgO content in the ladle refractory.
收稿日期: 2014-02-21
出版日期: 2014-09-10
引用本文:
曾亚南, 孙彦辉, 蔡开科, 徐 蕊. RH精炼工艺对无取向硅钢MgO·Al2O3夹杂物演变影响及控制[J]. 钢铁, 2014, 49(9): 38-43.
ZENG Ya-nan, SUN Yan-hui, CAI Kai-ke, XU Rui. Effect of RH Refining on Evolution and Control of MgO·Al2O3 Inclusion in Non-Oriented Silicon Steel. Iron and Steel, 2014, 49(9): 38-43.
Itoh H, Hino M , Ban ya S. Thermodynamics on the Forma- tion of Spinel Nonmetallic in Liquid Steel [J]. Metallurgica and Materials Transactions B, 1997, 28B (10): 953-960.
[3]
Itoh H, Hino M , Ban ya S. Thermodynamics on the Forma- tion of Spinel Nonmetallic in Liquid Steel [J]. Metallurgica and Materials Transactions B, 1997, 28B (10): 953-960.
[4]
Beskow K,Tripathi N N,Nzotta M,et al.Impact of Slag-Re- fractory Lining Reactions on the Formation of Inclusions in Steel[J].Ironmaking & Steelmaking, 2004, 31(6): 514-519.
[4]
Beskow K,Tripathi N N,Nzotta M,et al.Impact of Slag-Re- fractory Lining Reactions on the Formation of Inclusions in Steel[J].Ironmaking & Steelmaking, 2004, 31(6): 514-519.
Min JIANG, Xinhua WANG, Bin CHEN, et al. Formation of MgO.Al2O3 inclusions in high strength alloyed structural steel refining by CaO-SiO2-Al2O3-MgO slag [J]. ISIJ international, 2008, 48(7): 885-890.
[6]
Min JIANG, Xinhua WANG, Bin CHEN, et al. Formation of MgO.Al2O3 inclusions in high strength alloyed structural steel refining by CaO-SiO2-Al2O3-MgO slag [J]. ISIJ international, 2008, 48(7): 885-890.
[7]
Hidekazu TODOROKI, Kenji MIZUNO. Effect of silica in slag on inclusion compositions in 304 stainless steel deoxidized with aluminum[J]. ISIJ international, 2004, 44(8): 1350-1357.
[7]
Hidekazu TODOROKI, Kenji MIZUNO. Effect of silica in slag on inclusion compositions in 304 stainless steel deoxidized with aluminum[J]. ISIJ international, 2004, 44(8): 1350-1357.
[8]
Joo Hyun PARK et al. Control of MgO?Al2O3 spinel inclusion in Stainless Steels [J]. ISIJ International, 2010, 50(10): 1333-1346.
[8]
Joo Hyun PARK et al. Control of MgO?Al2O3 spinel inclusion in Stainless Steels [J]. ISIJ International, 2010, 50(10): 1333-1346.
K Fujii, T Nagasaka, M Hino. Activities of the constituents in spinel solid solution and free energies of formation of MgO, MgO?Al2O3 [J]. ISIJ International, 2000, 40(11): 1059-1064.
[10]
K Fujii, T Nagasaka, M Hino. Activities of the constituents in spinel solid solution and free energies of formation of MgO, MgO?Al2O3 [J]. ISIJ International, 2000, 40(11): 1059-1064.