JPH0683145U - Stopper for supplying wire to molten steel - Google Patents

Abstract

(57) [Abstract] [Purpose] In continuous casting of steel, when supplying a wire containing alloying elements to molten steel through a penetrating stopper, the molten steel is prevented from inserting into the wire outlet at the lower end of the stopper, and a stable wire is provided. Supply is possible. [Structure] The inner surface of the wire outlet portion 8 of the through hole 7 at the lower end of the stopper 2 is made of a material whose main component is BN.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a stopper used when supplying a wire containing alloying elements to molten steel via a through-type stopper.

[0002]

[Prior art]

 Conventionally, in most cases, a stopper for flow rate adjustment used when continuously supplying molten steel from a tundish (TD) into a mold is generally made of a refractory material such as alumina graphite. It has been attempted to add a wire containing an alloying element to the molten steel in the nozzle using the stopper as a through hole and using this as a guide.

[0003]

[Problems to be solved by the device]

 However, when the axial center portion of the TD stopper 2 as shown in FIG. 3 is used as the through hole 7 and the wire 1 containing the alloying element is supplied into the molten steel through the through hole 7 to add the alloy, the tip of the stopper 2 is Since the inner surface of the wire outlet portion 8 and the wire 1 come into contact with each other to cause abrasion, and as a result, the inner diameter is enlarged due to wear, the molten steel 3 may be inserted into the TD stopper 2 and a feed failure of the wire 1 may occur. It was

The present invention supplies a stopper that prevents molten steel from being inserted into the wire outlet at the tip of the stopper and enables stable wire supply.

[0005]

[Means for Solving the Problems]

 The gist of the present invention is a stopper provided at the lower end of the stopper with a through hole for supplying a wire containing an alloying element to the molten steel when continuously casting a slab from the molten steel. A stopper for supplying a wire to molten steel, characterized in that the inner surface of the wire outlet portion of the through hole is made of a material containing boron nitride as a main component and having excellent lubricity at high temperatures.

[0006]

[Action]

 The inner diameter of the wire outlet at the tip of the stopper must be slightly larger than the wire diameter to prevent feed failure due to frictional resistance with the wire. However, if the inner diameter of the outlet is extremely larger than the wire diameter, molten steel will be inserted inside the stopper, and conversely feed failure will occur. This is because when the inner diameter is appropriate, the molten steel, whose penetration into the through hole was suppressed by the balance between the surface tension of the molten steel, the pressure in the stopper, and the static pressure of the molten steel, became too large. It is thought that the balance is broken and it is inserted into the stopper. That is, maintaining an appropriate inner diameter of the wire outlet at the end of the stopper is important for stable wire supply.

When alumina graphite is used for the inner surface of the outlet of the stopper tip, the wire is gradually worn away and becomes unstable when the wire is supplied for a long time. The above problem was solved by using a material containing nitride (BN) as a main component.

[0008]

【Example】

 In the process of manufacturing low carbon aluminum killed steel, a TD stopper 2 for wire supply as shown in Fig. 1 was used as a tundish stopper, and a steel-coated wire 1 containing ferro titanium and having an outer diameter of 7 mm was used from the upper part of the stopper 2. It was supplied at a supply speed of 10 m / min. Further, the inner diameter of the wire outlet portion 8 at the tip of the TD stopper 2 was set to 10 mm, and the inner surface of the tip portion was made of a material containing BN as a main component.

By using such a TD stopper 2 for supplying a wire, the wire could be stably supplied over a long casting time of about 300 minutes. Further, as a result of analyzing the Ti concentration of the cast slab, a slab with a substantially uniform Ti concentration distribution in the casting length direction was obtained.

As another embodiment of the present invention, as shown in FIG. 2, the wire outlet portion 8 at the tip of the TD stopper 2 is configured and the BN portion is fixed to the TD stopper 2 main body by fitting or simple adhesion. However, it can be easily replaced.

[0011]

[Effect of device]

 By using the wire supply stopper of the present invention, it is possible to prevent molten steel from being inserted into the wire outlet at the tip of the stopper, and it is possible to stably supply the alloy addition wire into the molten steel in terms of operation quality.

[Brief description of drawings]

FIG. 1 is a view showing a vertical section of a wire supply stopper of the present invention.

FIG. 2 is a vertical cross-sectional view of a wire supply stopper of the present invention.

FIG. 3 is a view showing a vertical section of a conventional wire supply stopper.

[Explanation of symbols]

 1 Wire 2 TD Stopper 3 Molten Steel 4 Tundish Upper Nozzle 5 Tundish 6 Immersion Nozzle 7 Through Hole 8 Wire Outlet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiichi Takeuchi 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Co., Ltd. Technology Development Division (72) Inventor Tatsuji Aso 20-1 Shintomi, Futtsu-shi, Chiba Made by Shinnihon (72) Inventor, Tomohiro Furuta 1-1, Toibata-cho, Tobata-ku, Kitakyushu City Nippon Steel Corporation Yawata Works Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A stopper having a through hole for supplying a wire containing an alloying element to the molten steel at the axial center when continuously casting a cast piece from the molten steel, wherein the through hole at the lower end of the stopper is formed. A stopper for supplying wire to molten steel, characterized in that the inner surface of the wire outlet is made of a material containing boron nitride as a main component and having excellent lubricity at high temperatures.