Thermodynamic study on design of electroslag remelting slag for Incoloy 825 Alloy

被引：0
作者：
Ju J.-T. [1 ,2 ]
Yang K.-S. [1 ]
Ji G.-H. [1 ]
An J.-L. [1 ]
Liu S.-W. [1 ]
机构：
[1] School of Metallurgical Engineering, Xian University of Architecture and Technology, Xi'an
[2] Metallurgical Engineering Technology Research Center of Shaanxi Province, Xi'an
来源：
Gongcheng Kexue Xuebao/Chinese Journal of Engineering | 2020年 / 42卷
关键词：
Activity ratio; Electroslag remelting; FactSage; Incoloy825; alloy; Thermodynamics;
D O I：
10.13374/j.issn2095-9389.2020.03.07.s01
中图分类号：
学科分类号：
摘要：
Incoloy825 alloy is extensively used in the aerospace and petrochemical industries owing to its excellent corrosion resistance and mechanical properties. It is a solid solution-strengthened Fe−Cr−Ni-based corrosion-resistant alloy. The changes in the Al and Ti contents of the alloy determine the precipitation temperature of the strengthening phases γ '(Ni3AlTi) and Ti (C, N) in the alloy. At present, the main production methods of Incoloy825 alloy are vacuum melting and electroslag remelting. However, owing to the reaction of the components in the slag with the Al and Ti elements in the alloy during the electroslag remelting process, the axial component distribution of the Al and Ti elements in the electroslag ingot is not homogeneous, which seriously affects the quality of the electroslag ingot. It is necessary to control the Al and Ti contents in Incoloy825 alloy and reduce the volatilization of fluoride during the electroslag remelting process. The thermodynamic model of slag metal reaction was established using FactSage thermodynamic software. A low-fluorine slag system suitable for controlling Al and Ti contents was designed, and the relationship between the components in the slag and the activity ratios of Al2O3 and TiO2 was studied, the result was verified by a high-temperature slag metal equilibrium experiment. The results show that the CaO and Al2O3 contents in slag increases with increase in the lg (a2Al/a3TiO) value, while the Ti content in the alloy decreases with increasing Al content. Moreover, as the TiO2 content in the slag increases, the lg (a2Al/a3TiO) value decreases, Ti content increases and Al content decreases. The CaF2 and MgO contents in the slag increase have a little effect with the lg (a2Al/a3TiO) value. When the difference between the Al and Ti contents in the alloy is large, the elemental Ti in the alloy is easy to be oxidized; when difference between the Al and Ti contents is small, the elemental Al is easy to be oxidized. When the mass percent of CaO and Al2O3 in the slag are 30%−33% respectively, the mass percent of TiO2 is 6%−12%, the mass percent of CaF2 is 20%−30%, the mass percent of MgO is 1%−5%, the Al and Ti contents in the alloy can be controlled. © 2020, Science Press. All right reserved.
引用
收藏
页码：119 / 127
页数：8
相关论文
共 28 条
  • [1] Li X, Geng X, Jiang Z H, Et al., Influences of slag system on metallurgical quality for high temperature alloy by electroslag remelting, Iron Steel, 50, 9, (2015)
  • [2] Duan S C, Guo H J, Shi X, Et al., Thermodynamic analysis of the smelting of Inconel 718 superalloy during electroslag remelting process, Chin J Eng, 40, (2018)
  • [3] Hou D, Jiang Z H, Dong Y W, Et al., Thermodynamic design of electroslag remelting slag for high titanium and low aluminium stainless steel based on IMCT, Ironmaking Steelmaking, 43, 7, (2016)
  • [4] Hou D, Jiang Z H, Qu T P, Et al., Aluminum, titanium and oxygen control during electroslag remelting of stainless steel based on thermodynamic analysis, J Iron Steel Res Int, 26, 1, (2019)
  • [5] Hou D, Dong Y W, Jiang Z H, Et al., Deoxidation thermodynamics and slag designing in ESR process for aluminum-titannium alloy, J Northeast Univ Nat Sci, 36, 11, (2015)
  • [6] Duan S C, Shi X, Mao M T, Et al., Investigation of the oxidation behaviour of Ti and Al in Inconel 718 superalloy during electroslag remelting, Sci Rep, 8, (2018)
  • [7] Sun N, Wen C, Liu Z L, Et al., Effect of Al, Ti contents on the microstructure and corrosion resistance of as-forged Incoloy825 alloy, Rare Met Mater Eng, 47, 3, (2018)
  • [8] Chen C X, Wang Y, Fu J, Et al., A study on the titanium loss during electroslag remelting high titanium and low aluminum content superally, Acta Metall Sinica, 17, 1, (1981)
  • [9] Su S., Research on control of Ti content in electroslag remelting of R-26, J Iron Steel Res, 23, (2011)
  • [10] Yang J G, Park J H., Distribution behavior of aluminum and titanium between nickel-based alloys and molten slags in the electroslag remelting (ESR) process, Metall Mater Trans B, 48, 4, (2017)
123