Li Jian,Ling Haitao,Chai Feng,et al.Effect of Slag System on the Cleanliness of Electroslag Ingots during Electroslag Remelting of NiCrMoV Alloy Steel[J].Special Steel,2023,44(04):35-42.
Li Jian,Ling Haitao,Chai Feng,et al.Effect of Slag System on the Cleanliness of Electroslag Ingots during Electroslag Remelting of NiCrMoV Alloy Steel[J].Special Steel,2023,44(04):35-42. DOI: 10.20057/j.1003-8620.2023-00014.
Effect of Slag System on the Cleanliness of Electroslag Ingots during Electroslag Remelting of NiCrMoV Alloy Steel
In order to control the serious loss of Ti element during electroslag remelting of NiCrMoV alloy steel, the effect law of different slag systems on the chemical composition of ESR ingot, the number, composition, and size distribution of inclusions in electroslag ingots were investigated through laboratory experiments and thermodynamic calculation. The results showed that the content of total oxygen in ESR ingots obviously increased after electroslag remelting and it was increased from 15.1×10
-6
in consumable electrode to (31.3-42.1)×10
-6
in ESR ingots. The number density of inclusions was increased to 6.54-15.95 PCS/mm
2
. However, the content of nitrogen was almost unchanged. When the slag systems 70%CaF
2
-30%Al
2
O
3
and 55%CaF
2
-25%Al
2
O
3
-17%CaO-3%MgO were adopted, the Ti loss in ESR ingots became serious and the inclusions were mainly Al
2
O
3
. Furthermore, the Ti loss in ESR ingots could be controlled when a certain amount of TiO
2
was added to the slag. The types of inclusions were mainly composed of Al
2
O
3
, Al
2
O
3
-CaO-TiO
2
, and other oxides. The content of TiO
2
in inclusions was obviously increased. Besides, the mechanism of stabilizing Ti content in ESR ingots by adding TiO
2
to the slag was revealed through thermodynamic calculation. Based on the cleanliness of ESR ingots after electroslag remelting, the composition of the appropriate slag system (50%CaF
2
-25%Al
2
O
3
-17%CaO-3%MgO-5%TiO
2
) was determined.
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references
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