JPS61291917A - Skid button for heating furnace - Google Patents

Abstract

PURPOSE:To reduce the skid marks of a material to be treated and to extend the life of a skid button constituted by coating the ceramic skid button with a heat resistant metal by constituting the skid button in such a manner than the thickness of the heat resistant metal and the diameter of the ceramic skid button satisfy the specific equation. CONSTITUTION:The entire surface of the ceramic skid button 2 or the surface thereof to contact with the metal to form the heated is coated with the heat resistant metal to form the skid button S for a heating furnace. The thickness t1 of the heat resistant metallic surface to contact with the material to be treated is made at least 10mm. The diameter of the button 2, designated as d mm and the thickness of the heat resistant metal 1 on the side face of the button S, designated as t2, are so determined as to satisfy the equation (t1/d)<=0.1+(6/d)(t2/t1).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a skid button for a heating furnace, and more specifically, to a skid button for use in a heating furnace. This relates to a skid button for heating furnaces that can be used in heating furnaces.

[Prior Art 1 Conventionally, in continuous heating furnaces for am or steel materials,
A skid button attached to the top of a skid vibrator installed vertically in the heating furnace allows the g1g ingot or steel material to be slid while being transferred from the charging port to the unloading port of the heating furnace. It is heated.

At this time, if the skid button is made of metal, the contact surface of the skid button with the material to be treated is (The contact surface of the upper part of the skid V button with the material to be processed wears down and the height becomes lower.) Deformation may occur, or only the part of the material to be processed that contacts the skid button is cooled. It is difficult to avoid the appearance of so-called skid marks, and therefore it is necessary to remove skid marks by providing a considerably long soaking zone in the heating furnace.

In this way, with the conventional metal skid button, (1
) Creep deformation and wear are significant and it cannot withstand long-term use. (2) Since the heat is conducted through the skid button, the portion where the material to be processed comes into contact with the skid button is cooled, and so-called skid mater occurs, which adversely affects rolling in the subsequent process. There were other problems.

Also, instead of a metal skid button, for example, S +
Ceramic ski two buttons using C, Sis N, Al□O2, etc. (Japanese Patent Laid-Open No. 56-009
619, Japanese Patent Application Laid-Open No. 57-008754) have been developed and used, but the reaction layer may be worn away due to cracking or reaction with the material to be treated.

That is, (1) the ceramic, which is naturally brittle, is damaged by cracking or the like due to unbalanced load, impact, etc. due to sliding contact between the treated material and the ceramic skid button. (2
) Reaction between treated material and ceramic skid button 5izN+30→3SiO2+2Nz Sio2+Fed-4FeSiO- FeSiOs+Fe0-4FeSi○.

As a result, the responsive part of the ceramic skid button wears out, and the height of the skid button rapidly decreases. There was a problem.

[Problems to be Solved by the Invention] The present invention solves various problems when heating the material to be treated in a heating furnace in a metal skid button or a ceramic skid button as described above. As a result of intensive research by the present inventor, we succeeded in developing a skid button that combines the advantages of metal skid buttons and ceramic skid buttons. By coating with a metallic metal,
Prevents damage to ceramics by softening unbalanced loads and impacts,
In addition, it suppresses creep deformation, shortens the soaking time of the heating furnace for the material to be treated, reduces the occurrence of skid mater, and reduces wear and reaction between the material to be treated and the skid button, reducing the height of the skid button. The present invention provides a skid button for a heating furnace that can significantly extend the period of use without any problems.

[Means for Solving the Problems] The skid button for a heating furnace according to the present invention is characterized by a skind button in which the entire surface of the ceramic skid button or the contact surface of the material to be treated is coated with a heat-resistant metal. , the thickness of the contact surface of the heat-resistant metal to be treated (
t1) is at least 10 mm or more, and the ratio (t, /d) of the contact surface thickness (t1) of the heat-resistant metal to the ceramic diameter (clm-) and the heat resistance of the side surface of the skid button The ratio (t2/b) of the metal thickness t2) and the contact surface thickness (tl) of the heat-resistant metal to be treated is (t1/d)≦0.1 +6/d(t2/t1 ) is to satisfy the formula.

The heating furnace user kid button according to the present invention will be described in detail below.

1 and 2, the side surface (t) of the heat-resistant metal 1 covering the entire surface of the ceramic skid button 2
Considering the restraint of deformation due to 2), the amount of compressive deformation (
The relationship between δ1), the thickness tl) of the contact surface 1' of the heat-resistant metal 1 with the workpiece, the thickness t2) of the side surface 1'' of the heat-resistant metal 1, and the diameter (d) of the ceramic skid button 2 In addition to theoretically elucidating the
' thickness 1+), side surface thickness 1'' of heat-resistant metal 1 t
, ) and the diameter of the ceramic skid button 2 (d
)4 We conducted experiments with various changes, and found that the amount of compressive deformation (δ1) of the contact surface 1' of the heat-resistant metal 1 is the thickness of the contact surface of the heat-resistant metal 1 (tl), and the thickness of the side surface 1'' of the heat-resistant metal 1 is Thickness t2
) and diameter (d) of ceramic skid button 2
We investigated the relationship between the two.

As a result, the amount of compressive deformation (δ
, ) to the thickness (tl) of the contact surface 1' of the heat-resistant metal 1 (δ+/1+> is the thickness t of the side surface of the heat-resistant metal 1
2) to the thickness of the contact surface (tl) (t2/shiI), and the ratio of the thickness (tl) of the contact surface 1' of the heat-resistant metal 1 to the diameter (d) of the ceramic skid button 2. (t, /
It was found that there is a relationship as shown in FIG. 1 with cl) as a parameter. In the figure, mu is (t,/cl)=0.1
66, ○ is (t, /d) = 0.125, Δ is (t, /d
)=0.3.

From this FIG. 1, in order to keep the amount of compressive deformation (δ1) of the contact surface 1' of the heat-resistant metal 1 within a practically acceptable range, for example, 5 mm or less, the diameter of the ceramic skid button (cl ) = 40+u, 60mm, and 100mm, the ratio of the thickness It) of the contact surface 1' of the heat-resistant metal 1 to the diameter (d) of the ceramic skid vibe 2 (
t, /d) and the thickness δ2 of the side surface 1″ of the heat-resistant metal 1
) to the thickness tl) of the contact surface 1' of the heat-resistant metal 1 (
It was found that it is sufficient that t2/ll) is within the range below (in the direction of the arrow) each straight line shown in the vJ2 diagram. Expressing this using the formula, (t, /d)≦0゜i + (6/d
)(tz/l+).

According to this formula, the thinner the thickness (tl) of the contact surface 1' of the heat-resistant metal 1, the smaller the deformation of the skid button due to creep deformation of the metal.
If the thickness (t1) of the contact surface 1' is too thin, this contact surface 1' will be damaged and the ceramic skid button 2 will be exposed, causing the ceramic skid button 2 to be damaged by the load as explained above. Since various other problems may occur, the thickness t,) of the contact surface of the heat-resistant metal 1 must be at least 610ffi+n, as will be described later.

The materials of the heat-resistant metal and ceramic skid button in the heating furnace skid button according to the present invention will be explained.

(1) Ceramic skid button 5i=N, SiC, Al2O, ZrO2 as main components, one type or a mixture of two or more types can be used,
The main component is preferably 80u+t% or more.

(2) Heat-resistant metal Typical examples are shown in Table 1.

Next, an example of a skind button for a heating furnace according to the present invention will be explained with reference to the drawings.

The heating furnace skid button S shown in FIG. 3 has a structure in which the entire surface of a ceramic skid button 2 is coated with a heat-resistant metal 1.

FIG. 4 shows a structure in which the heat-resistant metal 1 is coated only on the surface of the ceramic skid button 2 that comes into contact with the material to be treated.

FIG. 5 shows a structure in which the entire surface of a trapezoidal ceramic skid button 1 and only the surface in contact with the material to be treated are coated with a heat-resistant metal.

In these FIGS. 3, 4, and 5, the thickness of the heat-resistant metal 1 and the contact surface 1' is 10 mm or more, and the thickness of the contact surface 1' of the heat-resistant metal 1 is 1. ), the diameter of the ceramic skid button 2 (, (), and the thickness δ2 of the side surface 1'' of the heat-resistant metal 1) is (tl/cl)≦0.
It goes without saying that the formula 1 + (6/d) (t2/11) is satisfied.

In addition, regarding the skid marks on the material to be treated, the thermal conductivity of the metal skid button, the ceramic skid button, and the heating furnace skid button according to the present invention was investigated, and the results are shown in Figure 6. Test conditions (1) ) Heat-resistant metal skid button (indicated by -0- in Figure 6) 5US310S (2) Ceramic skid button Silicon nitride, commercially available Si with a relative density of 95% or more,
N4 (indicated by ----・---- in Fig. 6) (3) Skid button for heating furnace according to the present invention (indicated by 1△- in Fig. 6) The entire surface of the above (2) is Skid button coated with material 1) (see Figure 3) Thickness of contact surface of heat-resistant metal 10+am Thickness of side surface of heat-resistant metal 1oIIl* Diameter of ceramic skid button 6oI6Ith Height of ceramic skid button 60+m Skid button Height: 80m The three skid buttons S are installed on the three skid pipes R, which are equivalent to an actual heating furnace, placed in a large test furnace, and the material to be treated 4 is placed (
(see FIG. 7), controlled heating was performed at a set temperature of 1200° C. by simulating a heat pattern equivalent to a hot rolling heating furnace.

As shown in Figure 6, the ceramic skid button (
S; 3N-1---・---) and the heating furnace skid pipe (-Δ-) according to the present invention have approximately the same thermal conductivity, but in the heat-resistant metal skid pipe, It is clear that the temperature of the material to be treated is low and the temperature of the top of the skid button is also low.

Therefore, the use of the skid button for a heating furnace according to the present invention can be expected to be effective in preventing skid marks.

[Example J] An example of a skid button for a heating furnace according to the present invention will be described.

Example 1 As shown in Table 2, the entire surface of a skid button made of silicon nitride and silicon carbide ceramics was coated with 5US304 heat-resistant metal of varying thickness, and a skid button for a heating furnace was produced by welding.

The shape is the same as in FIG.

Commercially available silicon nitride and silicon carbide having a relative density of 95% or more were used.

Next, the skid buttons for heating furnaces manufactured in this way are arranged in an actual furnace, moved up and down, and brought into contact with the uniformly heated iron slab, and the durability of the skid buttons for heating furnaces is evaluated by measuring the height of the skid buttons. The results are shown in Table 2.

Test conditions Furnace temperature 1250°C Contact conditions (Skid button for iron slab heating furnace) 5 minutes contact, 5 minutes non-contact test time 6 months Example 2 Thickness of contact surface of heat-resistant metal 10a++.

Thickness of the side surface of the heat-resistant metal: Smm Diameter of the ceramic skid button: 80m Various ceramic skid buttons are built in using the casting method according to NCF323 (see Table 1 J!it) so that the shape is 80 m. , created a skid button for heating furnaces.

As comparative examples, skid buttons made of various materials were manufactured.

The durability of these skid buttons was investigated under the same conditions as in Paper Example 1, and the results are shown in Table 3.

Table 3 shows that the heating furnace skid button according to the present invention has better durability than the comparative example.Table 3 Example 3 Thickness of contact surface of heat-resistant metal 10auaThickness of side surface of aging-resistant metal 10 m5 Ceramic skid buttons (silicon nitride) Skid buttons for heating furnaces having a diameter of 80 io+ (see, for example, FIG. 3) were fabricated using different types of heat-resistant metals.

The durability of this skid button was investigated in the same manner as in Example 1, and the results are shown in Table 4.

[Effects of the Invention 1] As explained above, the skid button for a heating furnace according to the present invention has the above-mentioned configuration, and has less wear and deformation of the upper height of the skid button, and is less susceptible to cracking. Furthermore, it has excellent effects such as no reaction with the object to be treated, durability for long-term use, and greatly increased productivity.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the relationship between the thickness ratio and deformation of the heat-resistant metal contact surface and side surface of a skid button for a heating furnace according to the present invention, and Fig. 2 is a diagram showing the relationship between the thickness ratio of the heat-resistant metal contact surface and side surface and the amount of deformation. Figures 3 to 5 are diagrams showing the relationship between the thickness ratio and the ratio between the thickness of the contact surface of the heat-resistant metal and the diameter of the ceramic skind button, and Figures 3 to 5 are examples of the skid button for a heating furnace according to the present invention. A schematic diagram showing the
Figure 6 is a diagram showing the results of an investigation of the thermal conductivity of buttons with heat-resistant metal skins, ceramic skinned buttons, and skid buttons for heating furnaces according to the present invention. Figure 7 shows the thermal conductivity of Figure 6. FIG. 3 is a diagram showing an arrangement of skid buttons for investigation. 1...Heat-resistant metal, contact surface...1', 1"...side,
2... Ceramic skind button, S... Skid button for heating furnace, tl... Thickness of contact surface, t2... Thickness of side surface. −Big 〇N − 〇 〇 〇″d.

Claims (1)

[Claims] A skind button in which the entire surface of the ceramic skid button or the contact surface of the treated material is coated with a heat-resistant metal, and the thickness of the contact surface of the heat-resistant metal with the treated material (t_
1) is at least 10 mm or more, and the ratio (t_1/d
) and the thickness of the heat-resistant metal on the side of the skid button (t_2
) and the thickness (t_1) of the contact surface of the heat-resistant metal to be treated (t_2/t_1) is (t_1/d)≦0.1.
A skid button for a heating furnace, characterized in that it satisfies the formula: +(6/d)(t_2/t_1).