Applying a Numerical Model of the Continuous Steel Casting Process to Control the Length of the Liquid Core in the Strand

Abstract

This paper presents development and the application of a numerical model of the continuous steel casting process to optimise the strand solidification area. The design of the numerical model of the steel continuous casting process was presented and which was developed based on the actual dimensions of the slab continuous casting machine in ArcelorMittal Poland Unit in Kraków. The S235 steel grade and the cast strand format of 220×1280 mm were selected for the tests. Three strand casting speeds were analysed: 0.6, 0.8 and 1 m min −1 . An algorithm was presented, allowing the calculation of the heat transfer coefficient values for the secondary cooling zone. In order to verify the results of numerical simulations, additional temperature measurements of the strand surface within the secondary cooling chamber were made. The ProCAST software was used to construct the numerical model of continuous casting of steel.Keywords: continuous casting of steel, numerical modelling, optimization technological parameters, metallurgical length W pracy przedstawiono zastosowanie numerycznego modelu procesu COS do optymalizacji obszaru krzepnięcia pasma. Zaprezentowano budowę numerycznego modelu procesu ciągłego odlewania stali, który opracowany został na podstawie rzeczywistych wymiarów maszyny do odlewania wlewków płaskich w Arcelor Mittal Poland Oddział Kraków. Do badań wybrano gatunek stali S235 przy odlewanym formacie wlewków 220×1280 mm. Analizowano trzy prędkości odlewania wlewka: 0.6, 0.8 oraz 1 m min −1 . Zaprezentowano algorytm pozwalający obliczyć wartości współczynników wymiany ciepła dla strefy wtórne-go chłodzenia wraz z możliwością wyznaczenia natężenia przepływu w poszczególnych strefach natrysku. W celu weryfikacji wyników symulacji numerycznych przeprowadzono dodatkowe pomiary temperatury powierzchni pasma w komorze wtórnego chłodzenia. Do budowy numerycznego modelu COS wykorzystano pakiet oprogramowania ProCAST.

The Effect of Thermophysical Parameters on Temperature Distribution in the Primary Cooling Zone

“…enthalpy was calculated as a function of temperature using experimental values for the specific heat of steel S235 [6], along with the transformation enthalpy (enthalpy sH) and thermodynamic databases (enthalpy dB). The obtained values as a function of temperature were compared and presented in Fig.…”

“…at a temperature of 950 °c. it is difficult to apply the values of specific heat as a function of the temperature obtained by the thermal analysis directly, due to the analysis of transformations occurring in the solidifying alloy [6,21]. Computing the enthalpy value, including, at the right place, the transformation enthalpy, which accompanies the first order phase transformations occurring during the steel solidification, is an additional difficulty.…”

“…The application of numerical computing for the analysis and identification of the existing processrelated problem can lead to finding an appropriate solution. It results in an improvement of production and the quality of products [1][2][3][4][5][6][7][8][9][10][11][12]. For the continuous casting of steel, it could be analysis of the effect of the interaction between the solidifying metal and the mould wall, the effect of the mould powder, or the effect of the non-metallic inclusions.…”

“…For the continuous casting of steel, it could be analysis of the effect of the interaction between the solidifying metal and the mould wall, the effect of the mould powder, or the effect of the non-metallic inclusions. At present the numerical modelling also includes the prediction of cast strand defects such as cracks, porosity or element segregation [3,6]. Many numerical models of the continuous steel casting process used in numerical computations are based upon material parameter average values, i.e.…”

Developing continuous-casting-process control based on advanced mathematical modelling

“…To illustrate the scale of the problem, the values of the heat-transfer coefficients (HTC) for 12 various models describing the heat transfer in a mould were collected in Table 2. 3,[13][14][15][16][17][18][19][20][21][22][23][24][25] Next, calculations with the specified HTC values were performed, maintaining the constant value of the other process parameters. The obtained calculation results are presented in Table 3.…”