Iron & Steel Society of Iran International Journal of Iron & Steel Society of Iran 2981-0388 13 1 2016 06 01 The Influence of Hematite on High Speed Continuous Casting of Steel Lubricating Powders: Viscosity and Crystallization The Influence of Hematite on High Speed Continuous Casting of Steel Lubricating Powders: Viscosity and Crystallization 20 26 20873 EN A. Shafieirad Advanced Materials Research Center, Faculty of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran A. Arefpour Advanced Materials Research Center, Faculty of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran A. Monshi Advanced Materials Research Center, Faculty of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran A. Saidi Advanced Materials Research Center, Faculty of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Isfahan, Iran Journal Article 2016 07 24 Mold powders used in the continuous casting of steel contain the harmful CaF₂ as a main substance developing toxic gases such as SiF₄ and HF at elevated temperatures. In this study, three samples of I₁, I₂ and I_3, which contained gypsum free Portland cement clinker with different percentages of Fe₂O₃ (5.68, 6.83, 8.02 ) and F^- (2.09, 1.06, 0), were prepared and their main characteristics were compared with those of the standard and the molten reference powder. The results showed similarity in viscosity between samples I₁, I₂ and the molten reference powder, which was desired. Sample I₃ with no fluorine showed a higher viscosity in comparison to the standard sample and therefore, a complete replacement of CaF₂ with Fe₂O₃ could not be recommended. Furthermore, the XRD of the reference powder, molten reference powder and sample I₂, the SEM of the molten reference powder and sample I₂ and EDS of sample I₂ analyses were also performed. The XRD patterns results demonstrated that by decreasing CaF₂, cuspidine phase was vanished, while other crystalline phases such as gehlenite, fayalite, akermanite, nepheline and Mn₃O₄ were found. In addition, SEM micrographs and EDS analysis of sample I₂ in the white area revealed crystalline particles in the glass matrix. Considering EDS analysis of sample I₂ showed the existence of Mg, Na, Mn, Fe, Si, Al and O. It could be concluded that such crystals as gehlenite, akermanite, nepheline and fayalite were composed in the glass matrix, developing to similar heating properties in the glassy matrix.  https://journal.issiran.com/article_20873_dcf14e14602881b7accd1a312f418830.pdf