JPH0424410B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a gas blowing plug used in a bottom blowing tuyere of a converter or the like.

[Conventional technology]

Conventionally, for example, in the gas blowing plug used for the bottom blowing tuyere of a converter, the gas blowing plug shown in Figs.
As shown in the figure, for example, a 1/2 component part 6 of a fireproof member is formed using a mold 4 having a pipe installation hole forming part 2 at the bottom, and two of these 1/2 component parts 6 are formed.
A split type fireproof member was constructed by joining the pipe installation holes 8 so as to face each other.

However, this split-type fireproof member has joints in the vertical direction, which causes problems such as joint melting.

Therefore, a gas injection plug with a fireproof member integrally molded was developed. That is, as shown in FIG. 8, this gas blowing plug has a gas blowing pipe 14 erected in a mold 12, and a raw material 1 is placed around it.
6 and pressurized while vibrating the mold 12 in the horizontal direction (direction orthogonal to the axial direction of the gas blowing pipe 14) to form the fireproof member 18.

[Problem that the invention seeks to solve]

However, in this case, Figures 9 and 10
As shown in the figure, the graphite contained in the fireproof member 18 is oriented in a direction perpendicular to the axial direction of the gas injection pipe 14, that is, the graphite grains 2 have a scale shape.
0 will be arranged along the direction perpendicular to the axial direction of the gas blowing pipe 14. For this reason, as shown in FIG. 11, when this gas injection plug 26 is attached to the tuyere 24 of the converter 22, there is a problem that corrosion and spalling are likely to occur due to the heat of the molten steel.

The present invention has been made based on the above circumstances, and its purpose is to provide a gas injection plug that can improve corrosion resistance and spalling resistance, and thereby extend its life. There is a particular thing.

[Means for solving problems]

In order to solve the above problem, the present invention includes a gas blowing pipe for blowing gas, and a fireproof member that is provided around the gas blowing pipe, contains graphite, and is formed by integral molding. This fireproof member is characterized in that graphite is oriented along the gas injection pipe.

[Effect]

By orienting the graphite of the refractory member along the gas injection pipe, the occurrence of cracks due to thermal stress is reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

Reference numeral 32 in FIG. 2 is a gas blowing plug attached to the tuyere 36 of the converter 34, and as shown in FIG. It has a configuration in which a fireproof member 40 is provided at the top. The fireproof member 40 contains graphite and is constructed by integral molding. The graphite of this refractory member 40 is oriented along the gas injection pipe 38. That is, the scale-like graphite particles 42 are arranged along the axial direction of the gas blowing pipe 38.

Moreover, this gas blowing plug 32 is installed in a gas blowing pipe 46 in a formwork 44, as shown in FIG.
is laid down, the raw material 48 is filled around it, and the formwork 4 is
4 in the horizontal direction (axial direction of the gas injection pipe 46)
The fireproof member 40 is formed by applying pressure while vibrating the fireproof member 40.

According to the above configuration, by orienting the graphite of the fireproof member 40 along the gas injection pipe 46, it is possible to reduce the occurrence of cracks due to thermal stress. Therefore, corrosion resistance and spalling resistance can be improved, thereby extending life.

The experimental results show that the bending strength of the conventional fireproof member 18 {see FIG. 4b} was 50 to 60% of that of the fireproof member 40 of the present application {see FIG. 4a}.
The erosion depth of the fireproof member 40 of the present invention {see FIG. 5a} was 60% of that of the conventional fireproof member {see FIG. 5b} 18. The rate of erosion of the fireproof member 40 of the present application was 7 to 9% slower than that of the conventional fireproof member 18.

〔Effect of the invention〕

As explained above, the present invention includes a gas blowing pipe for blowing gas, and a fireproof member that is provided around the gas blowing pipe and that contains graphite and is formed by integral molding, Since this refractory member has graphite oriented along the gas injection pipe, corrosion resistance and spalling resistance can be improved, resulting in excellent effects such as extending life.

[Brief explanation of drawings]

Figures 1 to 5 show one embodiment of the present invention, with Figure 1 being a cross-sectional view of the gas injection plug, Figure 2 being a schematic diagram showing the state in which it is attached to the tuyere of a converter, and Figure 3
The figure is a perspective view for explaining the manufacturing method, Figures 4 and 5 are diagrams for comparing and explaining the fireproof member of the present application and a conventional fireproof member, and Figure 6 is a conventional fireproof member of a gas injection plug. FIG. 7 is a perspective view showing the fireproof member, FIG. 8 is a cross-sectional view explaining another conventional gas injection plug manufacturing method, and FIG. FIG. 10 is a perspective view showing the gas blowing plug, FIG. 10 is a sectional view thereof, and FIG. 11 is a schematic view showing the state in which it is attached to the tuyere of a converter. 38... Gas blowing pipe, 40... Fireproof member, 4
2...Graphite grains.

Claims (1)

[Claims] 1 Equipped with a gas blowing pipe for blowing gas, and a fireproof member that is provided around the gas blowing pipe and that contains graphite and is constructed by integral molding, and this fireproof member is made of a gas blowing pipe that blows graphite into the gas blowing pipe. A gas injection plug characterized in that it is oriented along a pipe.