Understanding mould powders for high-speed casting

Abstract

The development and application of mould powder for high-speed continuous casting of steel is described. For thin slab casting, the main requirements are proper powder melting, undisturbed slag infiltration, adequate strand lubrication and the control of mould heat transfer. For increased casting speeds i.e. up to 8 m/min, slag infiltration and in particular the control of mould heat transfer via crystallisation of the slag film becomes even more important. It was found that a low powder consumption and hence a thin slag film is no restriction for an undisturbed thin slab casting process. Given a stable casting process and machine condition, the mould powder properties are not as critical as widely assumed.

Melting Properties and Viscosity of SiO2‐CaO‐Al2O3‐B2O3 System

“…Thus, the value of T br could be higher than that of T f . This is true in this work as shown in Figure 3 where a higher T br is observed than T f , and is also consistent with other reports …”

High-temperature investigation of mould slag crystallization by single and double hot thermocouple techniques

“…Because the structure of the solidified slag film mainly affects the horizontal heat transfer and, furthermore, the strand quality [2], attention has been focused on investigating the crystallization behaviour. Crystallization from a liquid phase has been studied for decades [3][4][5][6][7]. Nevertheless, this process is only valid for the middle area of the slag film.…”

Identification of secondary raw materials in mold powders and their melting behavior

“…Thus, the melting behavior of the mold powder is of major importance since it controls the liquid slag pool depth on the meniscus [1,2]. Furthermore, the size and shape of the slag rims formed in the meniscus zone are affected by the melting properties of the powder [3][4][5]. Usually, only the chemical composition of the material is reported on the data sheet, but the melting procedure is determined by the mineralogical composition (silicates, oxides and carbonates) [1,5,6].…”

“…Usually, only the chemical composition of the material is reported on the data sheet, but the melting procedure is determined by the mineralogical composition (silicates, oxides and carbonates) [1,5,6]. The melting rate is also controlled by the types of carbon added [4,[7][8][9][10].…”