**6.3. Soft reduction**

572 Numerical Simulation – From Theory to Industry

**5.4. Verification of simulation results** 

and measured results are listed in Table 6.

agree with those of the simulation.

Lower width of mold (mm)

**Table 6.** Measured and calculated widths of slabs

Measured width (mm)

**6. Analysis of slab broadening ( FU JianXun et al.2011(a))** 

wear, and deformation. Slab broadening is thus independent of the mold size.

**6.2. Exception of equipment or operating parameters** 

Upper width (mm)

**6.1. Change of mold size** 

Defined width (mm)

width.

To verify the obtained simulation results, the slab broadening cast on the #2 caster in Maanshan Iron and Steel Co. Ltd was measured. The online measuring system was designed to measure the width of the slab. The digital camera was fixed above the exit of the caster. Q235 steel was used for the experiments. The parameters of the continuous caster

The online measured RUB values are greater than the simulation results for all the experimental slabs. This is because the preset width of a cold slab in the experiments was the upper width of the mold. The upper width is always greater than the defined width. For the slab with a preset width of 2050 mm, the upper width of the mold is 2081.3 mm (a broadening of 1.56%). With this difference taken into account, the experimental results well

> Measured RUB (%)

1600 1623.8 1610.4 1630.4 1.90 6.6 7.04 6.7 1850 1877.7 1867.3 1885.9 1.94 8.2 9.25 12.8 2050 2081.3 2067.5 2091.4 2.02 10.3 11.69 13.5 Note: the measured broadening of the slab is the difference between the measured width of the slab and the upper width of the mold, and the calculated broadening of the slab is that between the calculated width and the defined

The slabs broaden in width, which varies with the operating parameters of steel produced. The statistical data of 76 taper samples of the mold revealed that the change is very small for the taper of the mold. The average change of a one-sided taper was 0.37 mm, and only a few samples had changes of 1~2 mm. The slight change of the taper is due to metering errors,

The secondary cooling process is the most important procedure in continuous casting. The temperature field of the slab was checked with the data provided by the producer of the caster. A good agreement was found, indicating that the caster worked well in the secondary cooling process. The monitoring records obtained in a controlled room also reveal that the caster worked well. However, the width of the produced slabs exhibited obvious

Measured broadening (mm)

Calculated broadening (mm)

Deviation rate (%)

Soft reduction may strengthen slab broadening and even cause side bulging. For SPHC and Q235 steels, the slabs were broadened in the process of continuous casting with soft reduction set to 0.5~2.5 mm. The broadening width ranges are 2~19 mm and 2~8 mm for SPHC and Q235 steels, respectively. The ratios of broadening are 0.1%~1.46% and 0.15%~0.62% for SPHC and Q235 steels, respectively. Therefore, soft reduction contributes to slab broadening, but is not the main cause.
