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TECHNOLOGIES, EQUIPMENT AND AUTOMATIC
CONTROL SYSTEMS FOR THE PROCESSES OF STEELMAKING
SOFTWARE PACKAGE FOR FORECASTING THE STRUCTURE
FORMATION OF THE CONTINUOUS CAST BILLET
Purpose: The package's purpose is to forecast the structure formation of the continuous cast billets with the object of determining the optimal operating practices.
Potentialities: The software allows to model thermal processes while forming the continuous cast billets and to calculate freezing kinetics parameters (width and depth of the molten metal zone, width of the diphasic zone, thickness of the rim) at different points of time.
The software package works with different types of continuous casters (vertical, radial, curvilinear), different types of steel and of the billet cooling modes.
The package is equipped with a convenient graphic interface; the findings are represented in the form of diagrams, graphs and tables (see Fig. 1).
Fig. 1. Results of the billet freezing calculation.
The package can be used to carry out multichoice researches for continuous casters design and to work out the optimal operating practices (cooling circuit, casting parameters, processing line configuration).
Adequacy study. In order to check the adequacy of the offered model, the calculated data (for the temperature pattern) were compared with the results of the experimental temperature measurement at the points of reference on the surface of the billet with 125 mm section. The results of the experiments (see table 1) confirm the software adequacy.
Table 1. Calculated and experimental data comparison.
| Point of reference |
T, °C (calculation) |
T, °C (experiment) |
| Exit from zone N°1 (1,17 m away from the meniscus) |
1008 |
<1050 |
| Exit from the secondary cooling zone (7,27 m away from the meniscus) |
1098 |
1065 |
| Entrance into the cutting zone (the end of the processing line, 22 m away from the meniscus) |
1043 |
~1000 |
AN EXAMPLE OF THE SOFTWARE PACKAGE USE FOR THE DETERMINATION OF THE OPTIMAL BILLET COOLING CIRCUIT.
Table 2. Basic parameters.
| Physico-mechanical parameters |
| Active length of the machine, m |
22 |
| Bending radius, m |
8 |
| Billet geometry |
bar |
| Lateral length, mm |
125 |
| Billet drawing speed, m/min |
2,8 |
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| Mould |
| Total mould length, m |
1 |
| Active mould length, m |
0,77 |
| Thickness of the working wall, mm |
12 |
| Water channel width, mm |
15 |
| Outer wall thickness, mm |
20 |
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| Thermal and physical properties |
| Temper, % |
0,36 |
| Liquidus temperature, °C |
1508 |
| Solidus temperature, °C |
1427 |
| Initial melt temperature, °C |
1516 |
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| Secondary cooling |
| Cooling water temperature, °C |
15 |
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During the experiments the parameters of secondary cooling varied (length of the zones and cooling water discharge).
Mode 0 (standart)
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Parameters of the secondary cooling zone
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| Zone N° |
Length, m |
Water discharge, l/min |
| 1 |
0,4 |
135 |
| 2 |
1,8 |
210 |
| 3 |
4,3 |
144 |
Fig. 2. Temperature along the billet height.
Fig. 3. Freezing kinetics.
Mode 1 (optimal)
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Parameters of the secondary cooling zone
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| Zone N° |
Length, m |
Water discharge, l/min |
| 1 |
0,4 |
135 |
| 2 |
2,3 |
150 |
| 3 |
6,5 |
170 |
Fig. 4. Temperature along the billet height.
Fig. 5. Freezing kinetics.
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