Modification of Al₂O₃inclusions in medium carbon aluminium killed steels by AlCaFe additions

Abstract

Plant trials were carried out to assess the effect of the addition of AlCaFe as an agent for modifying Al 2 O 3 inclusions in medium carbon aluminium killed steels. The size distribution of inclusions in ladle furnace and tundish samples showed that most were smaller than 10 mm. Furthermore, the number of inclusions and the inclusion area fraction at the tundish were significantly smaller compared with those found at the ladle furnace after AlCaFe additions. The modification degree of Al 2 O 3 inclusions was widely heterogeneous after AlCaFe additions. However, the inclusion population was homogeneous for the tundish samples, with CaO/Al 2 O 3 weight ratios corresponding to adequate inclusion modification. These results are similar to those obtained in typical heats in which CaSi was used as an inclusion modifying agent.

Influence of Al on Evolution of the Inclusions in Ti-Bearing Steel with Ca Treatment

“…It is generally the technique of calcium treatment that has been introduced to get liquid phases of calcium aluminate at casting temperature, which relieves the nozzle clogging issue during continuous process of steels, especially of grades of Al-killed steel, and also has benefits for the mechanical performance of final steel products [27][28][29][30][31][32][33][34][35][36][37]. However, the research involving the calcium treatment process of Ti-bearing Al-killed steel have been limited, until now [38][39][40][41][42].…”

Effect of Mg Addition on the Evolution of Inclusions in Al–Ca Deoxidized Melts

“…Therefore, performing calcium treatment is very common in steelworks in order to have complex liquid inclusions, which can avoid or prevent the inclusions from clogging the nozzle. As result, many researches of nonmetallic inclusions in Al-Ca deoxidized steel, such as thermodynamic calculation, [1][2][3] size distribution, [4][5][6] formation mechanism and kinetics, [7][8][9][10] have been intensively studied in recent years. It has been proven by thermodynamic calculation that very small amount of calcium enables the formation of liquid inclusion.…”

An Investigation of Non-Metallic Inclusions in Different Ferroalloys using Electrolytic Extraction

“…Therefore, a large amount of Al 2 O 3 inclusions present in FeV alloys stay in the steel melt without a forced stirring. It is well known that Al 2 O 3 inclusions significantly affect the mechanical properties in a negative manner, as well as result in the generation of surface defects [23]. Furthermore, the problem of nozzle clogging in casting operations is frequently related to the presence of solid Al 2 O 3 inclusions [24].…”