Methodology of inclusions removing from steel flowing through the tundish

Obtaining high quality steels mainly depends on the quantity of non-metallic inclusions contained into it and this, in turn, to a large extent on the structure of the flow in the tundish. Optimization of the flow of liquid steel through the tundish makes it possible to control the trajectory of inclusions and thereby to improve the conditions of their outflow into the slag layer. The following article presents an analysis of research opportunities of the inclusions distribution and removing process from the steel flowing through the tundish, resulting in reconstruction of the own research facility

An universal formula for the calculation of nitrogen solubility in liquid nitrogen-alloyed steels

The results of the authors’ own experimental studies on the Fe - N system, its standard state, binary alloys of iron with chromium, molybdenum, manganese, nickel, vanadium, silicon and carbon, as well as ternary alloys with chromium, have made it possible to work out the whole required complex of parameters of nitrogen interaction in liquid iron alloys, including the self-interaction parameters of nitrogen-nitrogen and nitrogen-alloying elements

Univerzalni obrazac za izračun topljivosti dušika u tekućim dušikom legiranim čelicima

The results of the authors’ own experimental studies on the Fe - N system, its standard state, binary alloys of iron with chromium, molybdenum, manganese, nickel, vanadium, silicon and carbon, as well as ternary alloys with chromium, have made it possible to work out the whole required complex of parameters of nitrogen interaction in liquid iron alloys, including the self-interaction parameters of nitrogen-nitrogen and nitrogen-alloying elements.Dana su autorova osobna praktična istraživanja u sustavu Fe – N, u standardnom stanju, binarnim sustavima željeza s kromom, molibdenom, manganom, niklom, vanadijem, silicijem i ugljikom, kao i u ternernom sustavu s kromom. Rezultati omogućuju rad izvan niza propisanih parametara međureakcije dušika u tekućim legiranim željezima, uključujući i vlastite međureakcijske parametre dušik – dušik i dušik – legirajući elementi

Mathematical and Physical Modeling of Alloy Behavior Feeding by Pulse-Step Method to Liquid Steel in One Strand Slab Tundish

The main purpose of the present work was to validate the numerical model for the pulse-step liquid steel alloying method using a physical simulator that enables the observation and recording of phenomena occurring during the continuous steel casting process. The facility under investigation was a single-nozzle tundish equipped with a dam. To physical trials the glass water model was made on a scale of 2:5. For the mathematical description of turbulence during liquid steel alloying process, the k-ε and k-ω models were employed in the simulations. Based on the computer simulations and physical trials carried out, alloy addition behaviour and mixing curves for different tundish alloy addition feeding positions were obtained. The change in the location of alloy addition feeding to the liquid steel had an effect on the process of alloy addition spread in the liquid steel bulk and on the mixing time

External measurements of the surface emissivity of steel ladles with using thermal imaging camera

W artykule przedstawiono badania poświęcone pomiarom emisyjności kadzi stalowniczych. Uzyskano dane dotyczące temperatur w wybranych punktach powierzchni płaszcza analizowanych kadzi, pochodzących z pomiaru stykowego. Dla każdej kadzi zarejestrowano termogramy. Wykazano, że wartość badanego parametru zależy istotnie od stopnia pokrycia kadzi zanieczyszczeniami. Ustalono, że emisyjność powierzchni zewnętrznych badanych kadzi stalowniczych mieści się w zakresie od 0,75 do 0,92.The article presents research performed to obtain the emission coefficient of the investigated steel ladles. The measurements were perfomed for selected points in the mantle surface of the analyzed ladle with the direct contact measurement. Thermal images were recorded for different ladles. It has been shown that the value of the examined parameter significantly depends on the degree of coverage of the ladle impurities. It was found that the emissivity of the outer surfaces of the tested steel ladles are in the range from 0.75 to 0.92

Poprawa efektywności energetycznej procesów stalowniczych poprzez zastosowanie metod CFD

The development of the main sectors of the steelmaking industry is followed directly by the need to increase energy consumption for technological processes, which directly impact the amount of greenhouse gas emissions being emitted into the environment as carbon dioxide, which is a by-product in the combustion of fuels for energy generation purposes, being carried out in power plants supplying steelworks with electricity. Thus, it seems legitimate to search for new production technologies, which combine both, a high quality of steel products together with reduction of production costs, while increasing energy efficiency. A solution for this can be application of computational fluid dynamics (CFD). The article presents capability analysis to determine whether a selected steel-making process is capable of improving its efficiency by applying optimization-based technological parameter specifications with the use of computer software, working based on CFD methods, in the production cycle.Rozwój głównych gałęzi przemysłu hutniczego związany jest bezpośrednio ze zwiększeniem zapotrzebowania na energię ze strony prowadzonych procesów technologicznych, co ostatecznie skutkuje zwiększeniem ilości gazów cieplarnianych emitowanych do środowiska w postaci dwutlenku węgla - jako produktu spalania paliw energetycznych w elektrociepłowniach zaopatrujących huty w energię elektryczną. Słuszne zatem wydaje się poszukiwanie nowych technologii produkcji łączących zarówno wysoką jakość produkowanego wyrobu stalowniczego wraz z obniżeniem kosztów, przy jednoczesnym zwiększeniu efektywności energetycznej. Przykładem może być zastosowanie metod numerycznej mechaniki płynów (ang. Computational Fluid Dynamics, CFD). Artykuł przedstawia analizę możliwości poprawy efektywności wybranego procesu stalowniczego poprzez zastosowanie w cyklu produkcyjnym wytycznych wynikających z optymalizacji parametrów technologicznych, z wykorzystaniem oprogramowania komputerowego pracującego w oparciu o metody CFD

Segregation of Elements in Billets Made of Carbon Steels for Long Products

The article presents the results of investigations performed on segregation of elements in the billets. The research were performed under standard industrial conditions, during high carbon steel production cycle. Probes (templates with the thickness of 20 mm) were taken from billets with square cross-section of 160 mm. Segregation of elements was determined based on the quantitative analysis of results performed by using spark spectrometry pursuant to PN-H-04045. Changes in concentrations of elements were analysed along two cross-sections. Element contents were performed at points distanced from each other by approx. 10 mm. The segregation of carbon, sulphur and phosphorus was determined for different billets

Optimization of Steel Flow in the Tundish by Modifying its Working Area

Presented paper describes model investigations carried out on six-strand continuous casting tundish. Numerical analysis is based on simulations performed with the use of commercial code ANSYS Fluent. The analysis concerns determination of hydrodynamic conditions of the flow in the analysed tundish, with nominal capacity of 22 Mg, and its optimisation by modification of the flow structure in the tundish working area. Four different flow control devices (FCD) were proposed. Results of investigations presented in the paper include the distribution of velocity vectors and distribution of temperature and turbulence kinetic energy. Additionally, for more detailed comparative analysis, the macroscopic characteristics of residence time distribution (RTD) in the reactor, and the transition zone ranges were determined for each of the variants

Segregation of Elements in Continuous Cast Carbon Steel Billets Designated for Long Products

This article presents research results concerning designation of the scope of segregation of elements by analysing the ingot, designated for hot rolling of long products. The research tests were performed under industrial conditions, during continuous casting production cycle of high carbon steels. From cc ingots with square cross-section of 160 mm samples having the length of 400 mm were collected, out of which two samples were cut up, the so-called templates with the thickness of 20 mm. Segregation of elements was determined based on the quantitative analysis of results performed by using spark spectrometry pursuant to PN-H-04045. Changes in concentrations of elements were analysed along the line, which join the opposite sides of the sample in their half length and pass through the geometric centre of the square cross-section. In the further course of the research study, there was also determined the segregation along perpendicular line up to the surface connecting the core of the cross-section with lateral plane. Designations of element contents were performed at points distanced from each other by approx. 10 mm and situated on the lines. There was found segregation of carbon, sulphur and phosphorus