JPH01266953A - Tundish refining apparatus for continuous casting machine - Google Patents

Abstract

PURPOSE:To maintain molten metal to suitable temp., to facilitate component adjustment and further to form the clean molten metal by arranging temp. control means and component adjusting means for the molten metal and further arranging vacuum treating means for the molten metal directly connected with a molten metal pouring nozzle. CONSTITUTION:The molten steel poured into a tundish 2 is heated with the channel type inductor 6 in a stirring mixture vessel 24, to control in the suitable temp. range. The component adjusting material 31 is continuously injected into the molten steel through injecting tube 8 melted and diffused by stirring effect with the channel type inductor 6, to execute the component adjustment to the prescribed steel kind. The molten steel adjusting the component is flowed into a distribution pouring vessel 25 and sucked up from a sucking-up tube 14a to a vacuum vessel 15 in a continuous vacuum degassing apparatus and flowed out from a discharging tube 14b. The molten steel 27 sufficiently removes gas and inclusion in the vacuum vessel 15 together with bubbling effect of argon gas blown on the way of the sucking-up tube 14a and made to the prescribed clean steel 28 and poured into a mold 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a continuous refining device applied to a tundish of a continuous casting machine.

[Conventional technology]

The role of the conventional continuous casting machine tundish was merely to serve as an intermediate container for molten metal and a quantitative distributor to each mold.
In order to meet the recent demands for higher quality and cleaner steel, various technological developments have been carried out to adjust temperature and separate inclusions in tandishes. However, there was no tanditshu that performed full-fledged refining operations, including ingredient adjustment.

[Problem to be solved by the invention]

In recent years, market demands for steel products have diversified, and the need for high-mix, low-volume production processes has increased.

On the other hand, the current continuous casting process is a process suitable for mass production, and in particular, with the establishment of continuous operation technology in recent years, production lots have become larger and larger, making it no longer suitable for high-mix, low-volume production.

For this reason, there is an increasing demand for the development of a tundish refining device that can arbitrarily adjust the composition and change the type of cast steel in the tundish of a continuous casting machine, and that can produce high-quality slabs.

At the same time, demands for higher quality are becoming stronger.
It is common knowledge that for continuous casting, sufficient out-of-furnace refining or ladle refining including vacuum degassing must be performed in advance.
There is a problem in that even the refined molten steel is exposed to the risk of re-oxidation during the handling process before it is continuously cast. Therefore, in recent years, attempts have been made to seal the tundish of a continuous casting machine, control the temperature by installing an inert gas seal, provide a heating means, and separate and clean inclusions by using a refractory filter. 1 is insufficient.

The present invention aims to provide a tundish MW device W for a continuous casting machine that solves the above problems.

[Means to solve the problem]

The tundish refining device for a continuous casting machine of the present invention includes a temperature control means for heating the molten metal, a means for adjusting the composition by blowing various composition adjusting materials into the molten metal using the powder blowing device 6, and a tundish tapping nozzle. A means for directly connecting and continuously vacuum-treating the molten metal was provided.

[Effect]

(1) The temperature of the molten metal is controlled to '+li' by providing a temperature control means for heating the molten metal.

(2) By means of blowing a composition adjusting material and performing all composition adjustment, any powder composition adjusting material is blown into the temperature-controlled molten metal to adjust the composition of the molten metal and change the steel type.

(3) Means for continuously vacuum-treating molten metal directly connected to the tapping nozzle (I) By installing the method, the molten metal can be effectively vacuum-treated, degassing and inclusions can be separated, and clean molten metal can be directly supplied. Molten metal is poured into the mold to produce slabs.

〔Example〕

A practical example of the present invention will be explained with reference to FIG.

The present embodiment relates to a continuous casting machine for producing steel slabs, and a tundish 2 is installed between a ladle 1 and a mold 2, and a tundish 2 is installed between a ladle 1 and a mold 2, and a tundish 2 is installed between a ladle 1 and a mold 2, and a tundish 2 is installed between a ladle 1 and a mold 2. 21, and continuous constant supply is performed.

The tundish 2 according to this embodiment is an intermediate container for molten steel lined with a refractory material 3, and is divided by a weir brick 4 into a stirring mixing tank 24 and a distribution pouring tank 25. A groove-shaped inductor 6 for induction heating is provided at the bottom of the stirring mixture @ 24 of the tundish 2 and is connected to a power supply device 7, so that the molten steel can be heated and temperature controlled. . Note that it is also possible to apply arc heating other than induction heating, electric heating such as resistance heating, or burner heating as the molten steel heating means. A lid 12 is provided on the top of the stirring mixing tank 24 to prevent heat radiation.

On the other hand, 1% of the distribution shoyu tank 25! @I (there is a resident nozzle 5
It has a structure in which molten steel is distributed and poured into each mold 21 via a slide gate valve 19 and an immersion nozzle 28. A lid 11 is provided on the top, and argon (Ar) gas or the like is blown in from an inert gas inlet 13 to create an inert atmosphere over the bath surface of the molten steel and prevent re-oxidation.

A continuous refining device is constructed by separately installing a powder blowing device and a continuous vacuum device to such a tundish 2.

The powder blowing device includes a supply hopper 10. Consisting of a powder dispenser 9 and a blowing pipe 8, a powdered component adjusting material (ferroalloy, etc.) 31 is passed through the blowing pipe 8 into a stirring mixing tank 24 using nitrogen (N) gas as a carrier fluid. The components are continuously blown into the molten steel. Although the blowing pipe 8 is coated with a suitable fire material so as to withstand continuous use for a long time, a structure in which a plurality of blowing pipes 8 are used interchangeably may also be adopted.

Continuous vacuum degassing equipment consists of suction pipe 1.4a and discharge pipe 14
a snorkel 14 consisting of b, - a vacuum chamber 15, and a vacuum chamber 1;
3, a snorkel 14, and a suction pipe 1.4.
A is short, and the discharge pipe 14b is long and air-cooled. The vacuum chamber 15 is connected to the snorkel 14 at the bottom, provided with an argon (Ar) gas inlet 1-6 in the middle of the suction pipe 14a, and connected to a vacuum pump via the vacuum exhaust pipe 18 at the top for evacuation 33. By vacuum chamber 1
It has a structure that maintains the inside of 5 in a vacuum state. By bringing the discharge pipe 14b of this vacuum degassing device into close contact with the tapping nozzle 5, the molten steel in the distribution pouring tank 25 is transferred from the suction pipe 14a through the vacuum tank 15 to the discharge pipe as shown by the arrow 27 according to the siphon principle. 1.4b, and is subjected to vacuum degassing treatment in the same vacuum chamber 15.

The molten steel 28 vacuum-treated in this way is continuously poured into the mold 21 through the tapping nozzle 5, the slide gate valve 19, and the immersion nozzle 20, solidified, and guided to the guide rolls 22 as a slab 29. It is designed to be continuously pulled out in the direction shown by arrow 30.

Next, the operation of this embodiment will be explained.

First, a source molten steel is selected for the target steel type to be cast, and the source molten steel 23 is continuously poured into the tundish 2 from the ladle 1.

In the stirring and mixing tank 24 of the tandish, the molten steel is heated by the groove-shaped inductor 6 and the temperature is controlled within an appropriate temperature range of ±5°C. On the other hand, a composition adjusting material 31'ff for adjusting the composition to the target steel type is prepared and continuously blown into the molten steel via the supply hopper 10, powder dispenser 9 and blowing pipe 8. In this case, the component adjustment material 31 can be prepared by mixing each component in advance, or by preparing a plurality of powder blowing devices and blowing each component individually. The injected component adjusting material 32 is stirred by the groove-type inductor 6 (arrow 2
6) is melted and diffused, and the composition of the predetermined steel type is adjusted. If this agitation effect is insufficient, a gas bubbling device may be added to enhance the agitation effect.

The molten steel whose composition has been adjusted flows into the distribution pouring tank 25, is sucked up into the vacuum tank 15 from the suction pipe 14a of the continuous vacuum degassing device, and flows out from the discharge pipe 14b. 1 to 5 inside the vacuum chamber 15
The molten steel 27 is maintained at a vacuum degree of 34 Torr, and in combination with the bubbling effect of the argon gas blown in from the middle, the molten steel 27 is sufficiently degassed and freed of inclusions by passing through the vacuum chamber 15 once. A clean steel 28 of a predetermined composition is manufactured, and a tap nozzle 5, a slide gate valve and a dip pipe 20 are manufactured.
The molten metal is poured into a similar mold 21 through the 4-mold mold 21 and continuously cast.

In this case, the temperature drop during continuous processing is 20 to 30°C, and vacuum processing is sufficiently effective and practically possible.

In this example, as described above, the molten steel in the tundish 2 is maintained at an appropriate temperature, and the composition adjustment material is mixed and the composition is adjusted to obtain a predetermined steel type. Since the inclusions are removed and then the slab 21 is poured and continuously cast, high-quality slabs of various predetermined steel types can be manufactured.

Although the above embodiments are for manufacturing slabs of steel, the present invention is not limited thereto and can be applied to continuous casting machines that manufacture slabs of other metals.

〔Effect of the invention〕

The present invention can have the following effects.

(1) The molten metal in the tundish is maintained at an appropriate temperature by temperature control means such as a groove inductor.

(2) By means of blowing component/rx adjusted material into component adjustment material, component adjustment material can be blown into the molten metal to arbitrarily and easily adjust the component.

(3) Finally, a clean molten metal can be produced by effectively degassing and removing inclusions using a vacuum treatment means.

Moreover, there is no risk of re-oxidation after that.

As described above, various predetermined types of molten metal can be produced in a tundish from a large lot of zero-yuan molten metal, high-quality continuous cast products can be obtained, and high-mix low-volume production can be handled.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Ladle, 2... Tundish, 5... Steel tapping nozzle, 6... Groove inductor, 8... Blow pipe,
9... Powder dispenser, 10... Supply hopper,
11.12...Good, 13...Argon gas supply port,
14... Snorkel, ] 5... Vacuum 4'l, 16.
...Argon gas inlet, 18...Vacuum exhaust port, 19
...Slide gate valve, 20...Immersion pipe, 21
···template.

Claims (1)

[Claims] In the tundish of a continuous casting machine, there is a temperature control means for heating the molten metal, a means for adjusting the composition by blowing various composition adjusting materials into the molten metal using a powder blowing device, and a continuous control means directly connected to the tapping nozzle of the tundish. A tundish refining device for a continuous casting machine, characterized in that it is equipped with means for vacuum processing molten metal.