Effect of Cr2O3 Addition on Sintering Behavior of Novel Chromite‐Based Ladle Filler Sand

• Published in: Steel research international Vol. 95; no. 2
• Main Authors: Li, Shi-Sen, Kong, Ling-Zhong, Zang, Xi-Min
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.02.2024
• Subjects: Aluminum; Chromite; Chromium oxides; Cr2O3 additions; filler sands; Fillers; high-Mn and high-Al steels; interfacial reactions; Iron; Liquid phases; Magnesium; Manganese; Sand; Sand casting; Silicon dioxide; Sintering; Sintering (powder metallurgy); sintering behaviors; Steel
• ISSN: 1611-3683; 1869-344X
• DOI: 10.1002/srin.202300452

Developing novel filler sands has garnered significant interest in improving the ladle's free‐opening rate and enhancing the cleanliness of high‐Mn and high‐Al steel. Laboratory studies explore the effect of adding Cr2O3 powder on the sintering behavior of chromite‐based filler sands. Furthermore, interfacial phenomena are examined between the sands and the steel grades, varying in Mn contents. The results demonstrate that adding Cr2O3 power plays a role in inhibiting the liquid phase formation in the sand. With a 16% addition, the steel (Mn mass% = 30) reacts with the sand, leading to the shape of a spinel phase, specifically (Mn, Fe, Mg)O·(Al, Cr)2O3, which facilitates the separation of the liquid phase. The reduction of FeO to Fe by Mn, Al, and C in steel, especially Al, is hindered by adding Cr2O3, resulting in a suitable sintering degree that ultimately benefits ladle free‐opening. SiO2 is crucial for forming the liquid phase during the sintering process. The SiO2 content of the sand should be about 20% to achieve optimal sintering effects. Chromite sand for casting is not suitable for the steels. The mixed sand presented in the current study demonstrates potential as a suitable filler sand for the steel (20 ≤ Mn mass% ≤ 30). The study adds Cr2O3 to chromite filler sand for use in high‐Mn and high‐Al steel. It analyzes the effects of Cr2O3 in the sand and Mn content in the steel on sintering behavior. The addition of Cr2O3 inhibits liquid phase formation, with a new spinel phase observed. The modified sand is a potential new material for casting next‐generation steel.