JPH06210403A - Mold device in continuous casting equipment - Google Patents

Abstract

PURPOSE:To uniformize the melting of powder for casting at each forming part of a cast billet having different mold copper plate temps., at the time of casting the cast billet having complicate cross section. CONSTITUTION:In the mold device in a continuous casting equipment providing the mold 4 for continuously casting the cast billet constituted of flange parts 1 and a web part 2 having mutually different thicknesses, near the connecting part of the flange parts 1 and the web part 2, an inflow preventing weir 14 for the powder for casting dipped into the molten metal M at the lower part, is hung down. By this method, the inflow of the powder for casting from the cast billet forming part at a low temp. to the cast billet forming part at a high temp. is prevented to make the structure uniform. Further, the flow of the powder for casting between the cast billet forming parts is prevented and the various kinds of powders for casting suitable to the surface temp. of the mold copper plate are used at each cast billet forming part and the practical melting quantities are uniformized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention continuously casts a slab having a complicated cross-sectional shape such as a beam blank (shaped steel material) or a near net shape (I-shaped steel and H-shaped steel having a cross-sectional shape closer to that of a product) from a mold. The present invention relates to a molding device for continuous casting equipment.

[0002]

2. Description of the Related Art Conventionally, in continuous casting using mold powder, it has been found that there is a close relationship between the melting characteristics and viscosity of powder and the occurrence of vertical cracks. The vertical crack length is shorter and the maintenance rate is lower than when powder is used. It is generally known that if the viscosity of the powder is too low, the melting rate of the powder increases and local excessive melting occurs, which tends to cause uneven cooling of the shell.

By the way, in recent years, in continuous casting, in order to reduce the rolling process of the cast product, casting is carried out by pulling out a slab with a cross-sectional shape close to that of the product. For example, in continuous casting in the case of a beam blank of H-shaped steel material, there are beam blanks in which the thickness of the flange portion is greater than the thickness of the web portion. In this case, the web portion having a small thickness is cooled faster than the flange portion and solidifies. , Vertical cracks may occur in the web part.

[0004]

However, in the continuous casting of the beam blank of the above H-shaped steel material, in order to solve the problem, the cooling speed of the web forming part is made slower than the cooling speed of the flange forming part. It has been proposed that the flange be solidified as uniformly as possible. (For example, JP-A-4
Then, the mold copper plate temperature of the web forming part becomes higher than the mold copper plate temperature of the flange forming part in the mold, and the mold powder dropped on the molten metal surface has a low viscosity at a high temperature in the web forming part. As a result, the melting rate of the powder increases and local excessive melting occurs, which tends to cause uneven cooling of the shell. On the other hand, in the flange forming part, the viscosity becomes low and the amount of penetration decreases, and the remaining powder flows into the high temperature web forming part side, further increasing the penetration rate in the web forming part.

The present invention solves the above problems and provides a molding apparatus for continuous casting equipment capable of preventing uneven distribution of the amount of melted casting powder in a plurality of molding portions having different thicknesses and preventing deterioration of cast slab properties. The purpose is to do.

[0006]

In order to solve the above-mentioned problems, the present invention provides a molding apparatus for a continuous casting facility equipped with a mold for continuously casting a slab having a cross section composed of a plurality of portions having different thicknesses. A weir for preventing the inflow of the casting powder, the lower part of which is immersed in the molten metal, hangs near the connecting portion of each cast piece forming portion.

[0007]

According to the above construction, since the cooling speed is slowed, as a result, the casting powder put into the slab molding part where the mold copper plate temperature is high has a low viscosity, the penetration rate increases, and the cooling speed is high. Even if the casting powder, which has a high viscosity and a small amount of melted into the slab molding part where the copper plate temperature is low, tries to flow from the molten metal surface of the slab molding part to the high temperature slab molding part side, a weir to prevent melting Since the inflow is blocked by the body, it is possible to prevent uneven melting in the cast molding.

Further, since the flow of the casting powder between the forming parts is extremely small, it is possible to use different casting powders for the respective slab forming parts. Correspondingly, it is also possible to use a casting powder that can adjust the viscosity of the casting powder and evenly melt.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a molding apparatus for continuous casting equipment according to the present invention will be described below with reference to the drawings.

This embodiment relates to a molding apparatus for continuously casting a slab (near net shape) 3 consisting of the flange portions 1 and 1 and the web portion 2, in which the thickness WT of the web portion 2 is compared with the thickness FT of the flange portion 1. In the molding apparatus of the continuous casting facility, which is provided with the mold 4 for continuously casting the slab 3 having a small size, the cooling rate of the web forming section 12 is slower than the cooling rate of the flange forming section 11, and the flange forming section of the web forming section 12 is used. A weir 13 for preventing the inflow of the casting powder, the lower part of which is immersed in the molten metal M, is arranged in the vicinity of the connecting portion with 11.

That is, the cast slab 3 has, for example, a height H of 530 mm (product height of 500 mm), a width W of 230 mm (product width of 200 mm), and a flange portion 1 thickness FT of 80 mm.
(The product flange portion 1 has a thickness of 14 to 19 mm), the web portion 2 has a thickness WT of 50 mmm (the product web portion 2 has a thickness of 9 to
11 mm).

The mold 4 is composed of four mold divisions 4a and 4b having cooling water passages formed therein, and the cooling capacity of the mold 4a on the flange forming portion 11 side is on the web forming portion 12 side. 4b, the cooling rate of the flange forming part 11 is set to be greater than 4b.
It is configured to be faster. The inflow prevention weir 1
3 is supported by a weir support 14 arranged on the mold 4, and the lower part is immersed in the molten metal M. A small gap (about several mm) D is provided between the mold wall surface 4c and the mold wall surface 4c.

Further, the flange forming portion 1 of the mold 4
1 and the powder for casting supplied to the web forming unit 12 are
A material having an optimum viscosity and a substantially constant melt amount is selected corresponding to the mold copper plate temperature of the flange forming part 11 and the mold copper plate temperature of the web forming part 12, respectively. It is also possible to use casting powders made of the same material.

In the above-mentioned structure, the molten metal is supplied from a nozzle (not shown) that is hung in an appropriate position in one or both of the flange forming portion 11 and the web forming portion 12, and the flange forming portion 11 and the web forming portion 12 are also supplied. Casting powder is sprinkled and supplied onto each of the molten metal surfaces, and casting is started.
Since the flange forming portion 11 and the web forming portion 12 are separated by the inflow prevention weir 13, the casting powder does not flow and mix with each other on the molten metal surface, and an appropriate amount of casting powder melts into the casting powder. The surface quality of the piece does not deteriorate. If you use the same casting powder,
Although the melting amount of the web forming portion 12 is larger than that of the flange forming portion 11, the inflow prevention weir 13 allows the casting powder to flow from the flange forming portion 11 with a large amount of casting powder remaining to the web forming portion 12 with a small amount of remaining powder. Since the inflow is prevented, it is possible to prevent the difference in the amount of penetration from increasing and further deteriorating the properties of the slab.

According to the above construction, the inflow preventing dam 13 divides the slab forming portion of the mold 4 into the flange forming portions 11 and 11 having the pseudo simple shape and the web forming portion 12 to perform uniform melting. Flange forming part 11, 1
It prevents the movement of the casting powder between the 1 and the web forming part 12 and enables the use of dedicated casting powder,
It is possible to achieve a uniform meltdown as a whole.

[0016]

As described above, according to the present invention, the casting powder introduced into the slab molding portion having a slow cooling rate and a high temperature has a high melting rate and a high cooling rate and a low temperature. Even if the casting powder that has been introduced into the slab molding part and has a small amount of penetration tries to flow from the molten metal surface of the slab molding part to the hot slab molding part side, the penetration preventing weir blocks the inflow. Therefore, it is possible to prevent non-uniform melting in the cast molding portion.

Further, since the flow of the casting powder between the forming parts is extremely small, it is possible to use different casting powders for the respective slab forming parts, and the surface temperature of the mold copper plate of each forming part can be improved. Correspondingly, by selecting a casting powder that allows uniform melting, it is possible to prevent an increase in the amount of casting powder melted in the slab molding part with a small thickness and a high temperature side. It is possible to prevent the occurrence of vertical cracks without deteriorating the properties of the cast product cast in the cast product forming part.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a molding apparatus of a continuous casting facility according to the present invention.

FIG. 2 is a cross-sectional view of a cast piece cast by the molding apparatus.

3 is a cross-sectional view taken along the line AA shown in FIG.

[Explanation of symbols]

 1 Flange Part 2 Web Part 3 Cast Piece 4 Mold 11 Flange Forming Part 12 Web Forming Part 13 Inflow Prevention Dam 14 Weir Support D Gap

Claims (1)

[Claims] 1. In a molding apparatus of a continuous casting facility equipped with a mold for continuously casting a slab having a cross section composed of a plurality of parts having different thicknesses, in the vicinity of the connecting part of each slab forming part, the lower part is inside the molten metal. A molding device for continuous casting equipment, characterized in that a weir for preventing the inflow of casting powder to be dipped in is hung.