Thermodynamic Characteristics of Y₂O₃ and Y₂S₃ Nonmetallic Phase Formed in Liquid Steel

Abstract

The current work deals the phenomenon of non-metallic inclusions as a result of the addition of Yttrium as an alloying component. The order of introducing individual components determines its final content in steel. This problem was analyzed using the WYK_Stal program developed at AGH-UST. Individual cases were considered using the accepted thermodynamics models based on Wagner’s formalism. The study of Y2O3 and Y2S3 phase precipitation and the relationship between the addition of Y, Al, Ca, O and S in molten steel was studied using the thermodynamic models. Based on the simulation, the authors stated that, the introduction of aluminum as the final deoxidizer into the liquid steel before the yttrium, results in the formation of non-metallic oxide inclusions. The low oxygen content in the metal bath promotes the formation of yttrium sulphide. In the case of calcium dosing, it is reasonable that, the yttrium is introduced after this element, which limits the losses on the formation of the yttrium sulphide phase.

Effect of Rare Earth Yttrium on Inclusion Characteristics of Grain-Oriented Silicon Steel

“…The addition of rare earth elements in steel will form rare earth compounds containing sulfur and oxygen. Four inclusions of Y 2 O 3 , Y 2 O 2 S, Y 2 S 3 , and YS may be formed after the addition of rare earth in grain-oriented silicon steel [31][32][33]. To analyze the formation and change of rare earth inclusions in the test steel, the thermodynamic calculation is used to analyze and discuss them.…”