Seznam abstraktů 2024: POSTEROVÁ SEKCE A

The converter process is a process of manufacturing molten steel by removing elements such as carbon(C), silicon(Si), manganese(Mn), and phosphorus(P) contained in molten steel through oxidation. In particular, the phosphorus component induces brittleness, reduces durability, and impairs weldability, so a low phosphorus content is generally required in steel. For the production of ultra-low phosphorus steel, POSCO steelmaking operations are conducting Triple Slag (hereinafter referred to as TS) operation, which performs Slag Formation 3 times, and pre-work to create an environment favorable for phosphorus control for several Ch before ultra-low phosphorus steel.
However, the distinction between slag and metal is unclear because sufficient slag foam is not secured during the second slag exclusion during TS work, and stable control is difficult because effective slag exclusion is not possible. In addition, there is a problem that wasteful operation such as quicklime, intake oxygen amount during pre-work. Therefore, technology development was conducted to correct the problems of the existing TS method and to omit the pre-work of the ultra-low steel manufacturing process.
To address the problem of insufficient generation of secondary Slag Foam in the existing TS process, the timing of primary Slag removal and secondary Slag removal has been advanced. In addition, the lance height and flow rate in the secondary refining section were adjusted according to the control phosphorus, and criteria for raw material input were established to ensure Slag Foam height. Lastly, criteria for lance height and oxygen flow rate were established for the transition to the early stage of third refining, the decarburization period. Furthermore, the improved TS pattern was applied to the ultra-low carbon steel Top Ch without pre-treatment.
It was confirmed that the phosphorus component was controlled below 80 ppm by this TS extraction method. And based on the stable phosphorus component control ability, the TS method could be applied directly to the 1st Ch by omitting the prior work that had to be performed before the ultra-low phosphorus steel.
Through the application of this technology, the phosphorus component was controlled more stably than before, and most of the restrictions on the production of ultra-low phosphorus steel were eliminated through the omission of prior work conducted to manufacture ultra-low phosphorus steel.

The processing of scrap metal as charge in steel furnaces is a relatively broad area, where many different processes and technologies are applied. One of these technologies is waste metal briquetting technology. This technology is mainly used to process swarf from chip machining, which is a relatively valuable raw material as long as the required purity of its chemical composition is maintained. The machines on which this technology is implemented are called briquetting presses. These briquetting presses can process metal chips resulting from the machining of machine parts made of various metallic materials. According to the mechanical properties of the metal chips material, for the processing of which the briquetting press is designed, the individual structural nodes of the briquetting press are designed. The manufacturers of briquetting presses do their best to meet the demands and requirements of customers who want to use these presses in their plants. For the perfect function of the briquetting press the quality of the design is therefore crucial. The aim of this article is to introduce the reader to the main types of briquetting presses for the processing of metal chips as well as the method of determining selected design parameters important for the design of briquetting presses and lines.

The aim of the research in the hot metal desulfurization process is to create a mathematical model that will include both kinetic and thermodynamic aspects of the process. This is intended to increase the accuracy of predicting and obtaining the level of sulfur content in the hot metal, as well as to optimize process costs. By physically modeling the phenomenon of mixing the metal bath, it was possible to determine the influence of the method of supplying the desulfurization agent on the time of complete mixing of the metal bath. This made it possible to determine how the reactants are distributed in metal bath, which influenced further stages of research. By applying the theory of elementary reactors and enriching it with thermodynamic equilibrium calculations using Fact Sage software, it will be possible to model the change in sulfur content during the desulfurization process in individual elementary reactors. This approach to the problem will allow the use of a solution that will enable accurate tracking of the sulfur removal process from the metal bath in a given time step. Such use of knowledge in the field of process kinetics and thermodynamic aspects may lead to even better control of the hot metal desulfurization process.

The submitted contribution is focused on the mathematical determination of temperature and thermal parameters depending on the heat removal from solidifying steel in the mould, respectively in the primary zone during continuous casting of steel. The main task of primary cooling is primarily the heat dissipation from solidifying steel, therefore the knowledge of temperature fields in the billet and mould is important. As part of the research evaluating the thermal work of the mould, the dependencies of the heat flux density between the steel and the cooling water in the mould were expressed in the primary cooling area. For determining the intensity of heat removal from solidifying steel, parameters of cooling water and temperature gradients along the height and circumference of the working surface of the copper insert of the circular cross-section mould with a diameter of 410 mm and a length of 600 m were used. The research of thermal processes was carried out for two grades of steel, which characterise the group of most frequently cast types of steel. Temperature and thermal parameters were determined for solidification and cooling for steel with a carbon content of 0.17 wt.% (grade A) and 0.49 wt.% (grade B). The casting speeds of steel were chosen in the range from 0.46 m·min-1 to 0.62 m·min-1. The obtained dependencies will be further used for numerical simulation.

This paper is focused on the thermal properties of historical La Tène furnaces for the processing of iron ore. The technology itself has been used since 450 BC. It is an examination of the early technologies of iron production. This technology was mainly used in Central Europe by the Celtic tribes. Celtic people were well-known for iron making and, if not for the Roman Empire, the Celtic nation could dominate all of Europe. Via research work high number of experiments was made. There were many experiments with different starting properties and different conditions. This particular paper is primarily oriented towards the thermal properties of a furnace replica. Heat properties were examined. The experimental furnace which was fitted with thermocouples was studied thoroughly. There were twenty thermocouples in total installed. These thermocouples were installed in two layers. Other thermocouples were installed at the top, bottom, and inner end of the tuyere. Subsequently, the chemical properties of the slag were investigated and compared with historical findings. In this case, a striking similarity with the preserved findings was confirmed. Diffraction and fluorescence methods of examination of the samples were used for the analysis. Finally, the iron bloom and its chemical composition were investigated via SEM technology.