scholarly journals A numerical analysis as a good tool for a prediction of final sulphur steel ladle content

10.30544/76 ◽  
2015 ◽  
Vol 21 (3) ◽  
pp. 143-154
Author(s):  
Z. Slović ◽  
Lj. Nedeljković ◽  
K. Raić ◽  
S. Dević
Keyword(s):  
Sulfur Content ◽  
Material Balance ◽  
Steel Ladle ◽  
Low Carbon ◽  
Good Tool ◽  
Vacuum Degassing ◽  
Slag Chemistry ◽  
Sulfur Level ◽  
Sulfur Capacity ◽  
Slag Weight

This work presents the industrial results of sulfur level prediction at the end of vacuum degassing (VD) of low carbon Al-Si killed steels. The effect of plant conditions, such as slag chemistry, temperature, oxygen levels of the molten steel, and slag weight on desulphurization was investigated based on the measured results and thermodynamic calculations. The variables which influence steel desulfurization such as the sulfur capacity, the initial sulfur content, and the amount of ladle slag at the end of the VD process are also defined. The desulfurization procedure was numerically analyzed using the results of 31 heats under real plant conditions in which the measured final sulfur content had been reduced to less than of 10 ppm. A method for prediction of the slag amount based on the material balance of sulfur and aluminum is also presented. The values of the sulfur capacity were determined according to the well-known KTH and optical basicity based models. The obtained results of the regression equation show a predictive final sulfur level ability of R=0.911. This was proved as satisfactory.

The microstructure change of low-carbon electrical steels by residual aluminum

1989 ◽  
Vol 47 ◽  
pp. 286-287
Author(s):  
C.K. Hou ◽  
C.T. Hu ◽  
Sanboh Lee
Keyword(s):  
Annealing Treatment ◽  
Low Carbon ◽  
Electrical Steels ◽  
Vacuum Degassing ◽  
Spherical Inclusions ◽  
Residual Aluminum ◽  
Average Grain Size ◽  
The Matrix ◽  
Fine Size ◽  
To Come

The fully processed low-carbon electrical steels are generally fabricated through vacuum degassing to reduce the carbon level and to avoid the need for any further decarburization annealing treatment. This investigation was conducted on eighteen heats of such steels with aluminum content ranging from 0.001% to 0.011% which was believed to come from the addition of ferroalloys.The sizes of all the observed grains are less than 24 μm, and gradually decrease as the content of aluminum is increased from 0.001% to 0.007%. For steels with residual aluminum greater than 0. 007%, the average grain size becomes constant and is about 8.8 μm as shown in Fig. 1. When the aluminum is increased, the observed grains are changed from the uniformly coarse and equiaxial shape to the fine size in the region near surfaces and the elongated shape in the central region. SEM and EDAX analysis of large spherical inclusions in the matrix indicate that silicate is the majority compound when the aluminum propotion is less than 0.003%, then the content of aluminum in compound inclusion increases with that in steel.

Computational Fluid Dynamics Study of New Vacuum Degassing Process

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
Manas Kumar Mondal ◽  
Govind Sharan Gupta ◽  
Shin-ya Kitamura ◽  
Nobuhiro Maruoka
Keyword(s):  
Fluid Flow ◽  
Gas Flow ◽  
Low Carbon Steel ◽  
Momentum Balance ◽  
Low Carbon ◽  
Decarburization Rate ◽  
Vacuum Degassing ◽  
Liquid Phases ◽  
New Process ◽  
Flow Phenomena

Recently, the demand of the steel having superior chemical and physical properties has increased for which the content of carbon must be in ultra low range. There are many processes which can produce low carbon steel such as tank degasser and RH (Rheinstahl-Heraeus) processes. It has been claimed that using a new process, called REDA (Revolutionary Degassing Activator), one can achieve the carbon content below 10ppm in less time. REDA process, in terms of installment cost, is in between the tank degasser and RH processes. As such, REDA process has not been studied thoroughly. Fluid flow phenomena affect the decarburization rate the most besides the chemical reaction rate. Therefore, momentum balance equations along with k-? turbulent model have been solved for gas and liquid phases in two-dimension (2D) for REDA process. The fluid flow phenomena have been studied in details for this process by varying gas flow rate, depth of immersed snorkel in the steel, diameter of the snorkel and change in vacuum pressure. It is found that the design of the snorkel affects the melt circulation of the bath significantly.

Objective Laws of Nitrogen Removal in the Vacuum Tank Degasser

2020 ◽  
Vol 989 ◽  
pp. 381-387
Author(s):  
Vlasta D. Tutarova ◽  
Alexey N. Shapovalov ◽  
Alexander N. Kalitaev
Keyword(s):  
Nitrogen Content ◽  
Nitrogen Removal ◽  
Low Carbon Steel ◽  
Regression Equations ◽  
Low Carbon ◽  
Efficient Removal ◽  
Vacuum Degassing ◽  
Rational Combination ◽  
Steel Grades ◽  
Steel Treatment

This article discusses the problems of efficient removal of nitrogen in the vacuum tank degasser operating at the electric arc furnace shop of Uralskaya Stal (Ural Steel) OJSC in the course of manufacturing of high-quality low carbon steel grades by means of steel grades «2» and «T». In order to determine the reasonable and balanced treatment parameters that ensure the required level of nitrogen content in the above steel grades, an analysis of production data for the period of November-December 2016 has been carried out. This analysis is the basis for identifying the vacuum degassing parameters in compliance with the technological capabilities and well-balanced levels, which allow predicting the level of nitrogen content in steel. To assess the cumulative quantitative effect of the main parameters of vacuum degassing on nitrogen removal, there has been performed a regression analysis. As a result, there have been obtained multiple regression equations describing a rational combination of steel treatment parameters for achieving the required nitrogen removal level.

scholarly journals Mathematical Model of Prediction of Nitrogen Pickup in Nitriding Process of Low Carbon Ferromanganese

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Saeed Ghali
Keyword(s):  
Mathematical Model ◽  
Nitrogen Content ◽  
Weight Percent ◽  
Nitrogen Pressure ◽  
Nitriding Process ◽  
Low Carbon ◽  
Good Tool ◽  
Partial Nitrogen Pressure ◽  
Temperature Time ◽  
Good Agreement

Low carbon ferromanganese was nitrided through gas-solid reaction. The nitriding process has been carried out on lab scale at temperature range 800°C–950°C at different nitrogen pressures. Temperature, time, and partial nitrogen pressure of nitriding process of fine low carbon ferromanganese were investigated. Nitrogen content, in weight percent, was more than 9%. MATLAB software was used to derive mathematical model to predict nitrogen content as a function of temperature and nitrogen pressure. According to derived model, nitrogen content can be calculated by the following equation: N content,wt.%=(-30.8882+0.0326*T)/(1+e-((P+0.0038*T-8.4155)/(3.6374-0.0018*T))), where, T is nitriding temperature in K and P is nitrogen pressure in bar. The experimental results are in good agreement with the predicted results. The results showed that nitrogen content, at steady state, is mainly depending on temperature and pressure of nitriding process. MATLAB is a good tool to make precision mathematical model.

scholarly journals Deep Desulfurization of Extensively Hydrodesulfurized Middle Distillate Oil by Rhodococcus sp. Strain ECRD-1

2001 ◽  
Vol 67 (4) ◽  
pp. 1949-1952 ◽  
Author(s):  
M. J. Grossman ◽  
M. K. Lee ◽  
R. C. Prince ◽  
V. Minak-Bernero ◽  
G. N. George ◽  
...  
Keyword(s):  
Sulfur Content ◽  
Middle Distillate ◽  
Deep Desulfurization ◽  
Sulfur Level ◽  
Rhodococcus Sp

ABSTRACT Dibenzothiophene (DBT), and in particular substituted DBTs, are resistant to hydrodesulfurization (HDS) and can persist in fuels even after aggressive HDS treatment. Treatment by Rhodococcussp. strain ECRD-1 of a middle distillate oil whose sulfur content was virtually all substituted DBTs produced extensive desulfurization and a sulfur level of 56 ppm.

Fundamental Research as a Basis for the Creation of New Technologies in Steel Ladle Metallurgy

2019 ◽  
Vol 946 ◽  
pp. 493-499
Author(s):  
Anatoly A. Babenko ◽  
Leonid A. Smirnov ◽  
Alena G. Upolovnikova
Keyword(s):  
New Technologies ◽  
Experimental Studies ◽  
Low Carbon Steel ◽  
Steel Production ◽  
Slag Viscosity ◽  
Steel Ladle ◽  
Low Carbon ◽  
Low Viscosity ◽  
Fundamental Research ◽  
Simplex Lattice

Theoretical and experimental studies including a study of slag viscosity of the CaO-SiO2-B2O3 system containing 25% Al2O3 and 8% MgO and equilibrium interphase distribution of sulfur and boron between slag and a low-carbon metal were carried out using a simplex-lattice experiment design and HSC 6.1 Chemistry software (Outokumpu). Fundamental research has contributed to the development of technology of basic boron-containing slags formation in ladle at ladle-furnace. These slags have a low viscosity, retaining high refining properties and providing direct microalloying of steel by boron. This technology has no analogues in domestic and foreign practice. The development of technology in the converter plant AO "ArcelorMittal Temirtau" (Kazakhstan) provided low-carbon steel production in wide grade composition, containing 0.001-0.008% boron and 0.004-0.014% sulfur, decreased consumption of manganese, high mechanical properties of rolled metal and improved environmental conditions.

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