Sulfur content and inclusion control during electroslag remelting of die steel
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摘要: 基于热力学分析了电渣重熔中渣系及冶炼工艺对易切削钢AS136的夹杂物及硫均匀性的控制研究.实验采用4 t的非保护气氛电渣炉, 分析了电渣锭中硫含量及夹杂物级别.实验结果发现:采用渣系S1 (质量分数为50%Ca F2+30%Al2O3+20%Si O2) 冶炼的电渣锭中硫质量分数为0.066%0.075%, 能够满足产品要求 (产品中要求硫质量分数在0.05%0.10%) , 但是B类和C类的夹杂物级别均达不到标准;在渣系S3 (质量分数为70%Ca F2+28%Al2O3+2%MgO) 以及整个重熔中持续地加入质量分数4.5%镁砂的冶炼工艺下, 不仅可以使电渣锭中硫含量呈均匀分布, 同时还能够改善夹杂物的分布和大小.分析结果表明:随着电渣重熔初期渣温的升高以及渣中Si O2质量分数的增加, 持续均匀地补加镁砂可以使得电渣锭中的硫沿轴向呈均匀分布.Abstract: Experimental and theoretical studies were carried out to investigate the effects of the slag and remelting process on sulfur content and steel cleanliness control during electroslag remelting (ESR) process.AS136 die steel was used as the electrode and remelted under three different remelting conditions by using a 4 t ESR furnace.The contents of sulfur and inclusion along the axial direction of ingot products were analyzed.It was found that the sulfur content in ingot remelting with slag S1 (50%Ca F2+30%Al2O3+20%Si O2in mass fraction) ranges from 0.066%to 0.075%in mass fraction, which can satisfy the requirement of AS136 steel (the sulfur content ranges from 0.05%to 0.1%in mass fraction) , but the levels of B-alumina type and C-silicate type inclusions are higher than the standards.Under the condition of slag S3 (70%Ca F2+28%Al2O3+2%MgO in mass fraction) combined with extra 4.5%MgO in mass fraction continuously added into molten slag during the whole ESR process, the macrosegregation of sulfur along the height of ingot can be improved, the oxygen and inclusion contents reduce.Constant addition of extra amounts of MgO to the molten slag with the increase of slag temperature and Si O2content in slag during the remelting process can improve the macrosegregation of sulfur distributed along the axial direction of ESR ingots.
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[1] Weber V, Jardy A, Dussoubs B, et al. A comprehensive model of the electroslag remelting process:description and validation. Metall Mater Trans B, 2009, 40 (3) :271
[2] Matity S K, Ballal N B, Goldhahn G, et al. Development of ultrahigh strength low alloy steel through electroslag refining process.ISIJ Int, 2009, 49 (6) :902
[3] Dong Y W, Jiang Z H, Cao Y L, et al. Effect of slag on inclusions during electroslag remelting process of die steel. Metall Mater Trans B, 2014, 45 (4) :1315
[4] Hou D, Jiang Z H, Dong Y W, et al. Effect of slag composition on the oxidation kinetics of alloying elements during electroslag remelting of stainless steel:part-1 mass-transfer model. ISIJ Int, 2017, 57 (8) :1400
[5] 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. Steel Res Int, 2012, 83 (5) :472
[6] Hou D, Jiang Z H, Dong Y W, et al. Thermodynamic design of electroslag remelting slag for high titanium and low aluminum stainless steel based on IMCT. Ironmaking Steelmaking, 2016, 43 (7) :517
[7] Jiang Z H, Hou D, Dong Y W, et al. Effect of slag on titanium, silicon and aluminum content in superalloy during electroslag remelting. Metall Mater Trans B, 2016, 47 (2) :1465
[8] Hou D, Jiang Z H, Dong Y W, et al. Mass transfer model of desulfurization in the electroslag remelting process. Metall Mater Trans B, 2017, 48 (3) :1885
[9] Yang X M, Jiao J S, Ding R C, et al. A thermodynamic model for calculating sulphur distribution ratio between CaO--SiO2-Mg O--Al2O3ironmaking slags and carbon saturated hot metal based on the ion and molecule coexistence theory. ISIJ Int, 2009, 49 (12) :1828
[10] Yang X M, Shi C B, Zhang M, et al. A thermodynamic model of sulfur distribution ratio between CaO-SiO2--Mg O--Fe O-MnOAl2O3slags and molten steel during LF refining process based on the ion and molecule coexistence theory. Metall Mater Trans B, 2011, 42 (6) :1150
[11] Yang X M, Shi C B, Zhang M, et al. A thermodynamic model of phosphate capacity for CaO-SiO2--Mg O-Fe O--Fe2O3-MnO--Al2O3-P2O5slags equilibrated with molten steel during a top--bottom combined blown converter steelmaking process based on the ion and molecule coexistence theory. Metall Mater Trans B, 2011, 42 (5) :951
[12] Yang X M, Duan J P, Shi C B, et al. A thermodynamic model of phosphorus distribution ratio between CaO--SiO2--Mg O--Fe OFe2O3--MnO--Al2O3-P2O5slags and molten steel during a top--bottom combined blown converter steelmaking process based on the ion and molecule coexistence theory. Metall Mater Trans B, 2011, 42 (4) :738
[13] Hou D, Jiang Z H, Dong Y W, et al. Effect of slag composition on the oxidation kinetics of alloying elements during electroslag remelting of stainless steel:Part-2 control of titanium and aluminum content. ISIJ Int, 2017, 57 (8) :1410
[14] Jiang Z H, Li S J, Li Y. Thermodynamic calculation of inclusion formation in Mg--Al--Si-O system of 430 stainless steel melts. J Iron Steel Res Int, 2011, 18 (2) :14
[15] Hou D, Liu F B, Qu T P, et al. Behavior of alloying elements during drawing--ingot--type electroslag remelting of stainless steel containing titanium. ISIJ Int, 2018, 58 (5) :876
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