JPS59190327A - Method for keeping hot slab hot - Google Patents

Abstract

PURPOSE:To prevent a drop of the temp. of hot slabs after continuous casting and the formation of scale on the surfaces of the slabs by temporarily placing the slabs in each apparatus for keeping the slabs hot with hot exhaust gas fed from a heating furnace until the slabs are charged into the heating furnace. CONSTITUTION:Hot slabs 2 after continuous casting or cogging are temporarily placed in each apparatus 5 for keeping the slabs 2 hot with hot exhaust gas after combustion introduced partially from a heating furnace 3 through an exhaust gas pipe 4 until the slabs 2 are charged into the furnace 3. Since said exhaust gas is at about 500 deg.C and has about 1.5% low concn. of oxygen, the formation of scale on the surfaces of the slabs 2 is inhibited in the apparatus 5, and a significant effect of keeping the slabs hot is produced.

Description

[Detailed description of the invention] The present invention relates to a heat retention method for hot slabs.

In the hot charge method, in which a hot slab after continuous casting or blooming is charged into a heating furnace without being cooled to room temperature, the hot slab may be charged into the heating furnace immediately due to waiting for a roll chance. You may not be able to enter. In such cases, the hot slab should be temporarily placed in a heat retaining facility as shown in Figure 1 to prevent the temperature from dropping. ing. The heat retention equipment is surrounded on all sides by refractory bricks 1, and is installed near the heating furnace to suppress heat radiation loss of the hot slab 2 as much as possible. However, since the hot slab is in the air at a high temperature of around 600°C in the heat retention equipment, scale is generated on the surface of the slab. Temporary storage time in a heat retention facility is usually 5 to 25 hours, during which time a scale of 0.03 to 0.05% occurs.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for retaining heat while suppressing scale generation in a hot slab until it is charged into a heating furnace.

In the present invention, as shown in FIG. 2, a part of the high-temperature combustion exhaust gas from the heating furnace 3 is guided into the heat retention equipment 5 through the exhaust gas pipe 4, and the hot slab 2 is temporarily placed inside. place The oxygen concentration of the high temperature combustion exhaust gas from heating furnace 3 is approximately 1
．． The temperature is as low as 5, and the gas temperature is about 500°C, so
The oxygen concentration in the heat retention equipment 5 is lower than that in the past, and therefore scale generation is significantly suppressed and the heat retention effect is also enhanced. The heat retention equipment 5 can be surrounded on all sides by fire bricks like the conventional equipment, and can be placed near the heating furnace 3.

The slab temperature at the time of charging into the heat retention equipment is 400 to 45
0°C1 thickness, width, and length are each 210'yam.

When 13 hot slabs of 1,100m and 7,300mm were temporarily stored for 10 hours, scale of 0.03 to 0.05% occurred17, and the temperature of the slabs when taken out was 380 to 440°; 5 from the heating furnace according to the invention
When temporarily placed in a heat storage facility filled with high-temperature combustion gas at 00°C, scale generation was 0.01 to 0.02% under the same conditions, and the slab temperature when taken out was 400°C.
The angle was between 450° and 450°.

As described above, according to the heat retention method of the present invention, the generation of scale in the hot slab until it is charged into the heating furnace is significantly suppressed, and the heat retention effect is also improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing conventional heat retention equipment. FIG. 2 is a schematic diagram showing the heat retention method according to the present invention. 1... Firebrick 2... Hot slab 3...
・Heating furnace 4... Exhaust gas piping 5... Heat retention equipment Figure 1 Figure 2

Claims (1)

[Claims] Heat retention equipment filled with high-temperature combustion exhaust gas from the heating furnace, in a hot slab heat retention method during which the hot slab after continuous casting or blooming is temporarily placed until it is charged into the heating furnace. A hot slab heat retention method characterized by temporarily placing a hot slab inside.