JPH07103419B2 - Low skid mark Skid button for walking beam furnace - Google Patents

Description

TECHNICAL FIELD The present invention relates to a skid button used for a walking beam furnace for heating a steel slab or the like, and particularly, the maximum temperature in the furnace is 10
The present invention relates to improvement of a skid button of a heating furnace having a high temperature exceeding 00 ° C.

[Prior Art] In a heating furnace, in order to improve the product quality of a material to be heated (hereinafter simply referred to as steel material) such as a steel slab, it is required to minimize the uneven heating temperature of the steel material called a skid mark. There is.

In the past, a pusher type heating furnace was used as the heating furnace, but since the same part was slid and transported between the steel material and the steel material supporting device and it was always in contact with the steel material supporting device, the skid mark was large, so to avoid this In recent years, it is being replaced with a walking beam type heating furnace.

The walking beam type heating furnace steel support device is equipped with a skid beam and a skid button above it,
It is composed of a moving beam and a fixed beam, and the material is conveyed by a rectangular wave repetitive motion in a high temperature furnace.

On the other hand, the inside of the furnace is usually at a high temperature of 1000 ° C or higher, the inside of the walking beam is water-cooled, and the outer periphery is lined with refractory material. The skid button is fixed to the upper surface of the skid button.

Since the skid button is affected by the water cooling of the skid beam, the tip contacting the steel becomes lower than the temperature inside the furnace,
Since it comes into contact with the material in that state, skid marks also occur in the walking beam furnace. The material of the skid button is cobalt-based heat-resistant cast steel or nickel-chrome-based heat-resistant cast steel.In order to reduce the effect of water cooling of the skid beam, raise the button height to bring the temperature of the tip that comes in contact with the steel material to the furnace temperature. Although the buttons are made closer to each other, on the contrary, the button becomes hotter, resulting in insufficient compressive strength of the button material and compression deformation (commonly called sag), which requires replacement of the skid button in a short period of time. There is.

The compressive strength of general heat-resistant cast steel decreases as the temperature used increases. Therefore, the higher the button height, the smaller the compression load per unit area cannot be dealt with, but the larger the contact area between the steel material and the skid button, the less heat input from the non-contact part of the steel material. , Similarly, skid marks occur.

From the above, the skid button is required to have a large resistance to compressive deformation at high temperatures, a small contact area with a steel material, and a high height in order to reduce skid marks.

Also, the skid beam is lined with refractory material to minimize heat loss, but if the thickness of this lining is less than 50 mm, it will not affect the skid button to the left. However, when it becomes thicker than 50 mm, the effect of cooling water reaches the upper part of the skid button due to its heat retaining effect, and the temperature of the surface in contact with the steel material decreases. Therefore, if the lining is thickened, it is necessary to increase the total height of the skid button to some extent.

In a heating furnace in which the maximum temperature in the furnace does not reach 1000 ° C, it is possible to sufficiently reduce skid marks by using a conventional heat-resistant alloy. Therefore, the maximum temperature in the furnace is 1000 It is a furnace with a temperature above ℃.

[Problems to be Solved by the Invention] In a material supporting device for a walking beam furnace, a large dynamic load acts when loading a steel material, and therefore a material having toughness is desirable. A skid button made of a brittle material such as fine ceramics is very unstable under this dynamic load and easily cracks. Further, it is difficult to attach the ceramic button directly to the skid beam, and it is necessary to store it in a box-shaped case (for example, JP-A-60-26).
No. 615), especially when the height of the button becomes high, it becomes very unstable and causes the dropout.

Problems to be solved by the present invention are: (1) A material having both compressive strength and toughness required at high temperature is required.

(2) Manufacture skid buttons integrally.

(3) It should be an economical skid button.

(4) Increase the button height until the skid mark reduction effect is obtained.

Is.

[Means for solving problems]

The present invention is a skid button used in a walking beam furnace having a maximum furnace temperature of over 1000 ° C. and attached to a skid beam whose periphery is lined with a refractory material, and its characteristic technical means is as follows.

(A) The upper part in contact with the material to be heated is made of a composite material of heat-resistant metal and chromium carbide ceramics, the lower part fixed to the skid beam is made of a heat-resistant alloy, and both are welded.

(B) The composite material in the upper part has a ceramic content
30 to 70% by weight.

(C) The height of the skid button must be 140 mm or more.

(D) The height of the heat-resistant alloy at the joint surface between the composite material and the heat-resistant alloy is set so that the maximum compressive deformation resistance value of the heat-resistant alloy is equal to or less than the allowable compressive deformation resistance of the composite material at the maximum temperature in the furnace. I decided to decide.

(E) The thickness of the skid beam at the position in contact with the skid button of the refractory material lining shall be 50 mm or more.

Is.

[Action]

The inventors of the present invention have found that cobalt-based heat-resistant cast steel (there are various types with a Co content of about 40-50% by weight) or nickel-chrome-based heat-resistant cast steel (there are various types with Ni50 and Cr of about 35% by weight)
As a material that has the strength to withstand the compressive load at high temperature and has the high temperature toughness required for the skid button of the walking beam furnace, we have also developed a composite material of ceramics and heat-resistant metal. Kaisho 60-5429
Five). This composite material is chrome carbide (Cr ₃ C ₂ , Cr ₇ C ₃ ).
Carbide ceramics such as Fe-Cr, Cr-Ni-Fe
System, Cr-Nr-Co-Fe-based stainless steel, heat resistant steel, Cr
-Ni-based, Cr-Ni-Co-based alloy, etc. are composites.

When a molten pair of refractory metal and ceramics is mixed and rapidly cooled,
Dispersed particles of fine ceramics of 0.01 to 0.1 μm are uniformly distributed in the matrix of refractory metal. The composite of the dispersed particles and the matrix of the refractory metal exhibits material properties having both compressive strength and toughness at high temperature. This composite material is a material positioned between the brittle material of fine ceramics and the ductile material of metal, and has the characteristic that its characteristics can be changed by changing the composite ratio of ceramics. This composite can be made into a melt using a tungsten inert gas arc source and can be easily integrated with heat resistant cast steel to produce the desired skid button shape.

The construction of the skid button according to the present invention is shown in FIG. In the figure, 1 is a ceramic composite material, and 2 is a heat-resistant alloy such as a cobalt alloy, which are integrally welded as described above. A skid beam 3 is cooled by passing cooling water 4 through the skid beam. Here, the height of the ceramic composite material is a, the height of the heat-resistant alloy is b, and the total height of the skid button is h.

Further, in the lining of the skid beam 3 using five refractory materials, the thickness at the position in contact with the skid button 1 is indicated by t.

FIG. 2 shows the high temperature toughness value of the ceramic composite material in which the ceramics are dispersed particles and the refractory metal of the cobalt-based alloy is used as the matrix. On the other hand, as a result of conducting an evaluation test on the toughness required to exert the performance as a skid button of a walking beam furnace in an actual heating furnace, it was found that the ceramic content was 30 to 70 wt% (toughness value at 1100 ℃ 100 to 30k
Within the range of g-cm), cracking and compression deformation (sag)
It has been found that it can withstand use for a long period of time. The results of this experiment are shown in FIG. Figure 3 shows the furnace ambient temperature of 1280 ℃
In the furnace, the size of the button is 50mm wide x 130mm long
× With a height of 200 mm, a heating slab with a thickness of 220 to 260 mm is randomly loaded, and the number of walking beam operations is approx.
Ceramic content of 10, ^15, 25, 35, ^{5 under} 10 ⁵ times
The table shows the test results when two buttons each of 0, 65, 75, 85, and 90% by weight were attached. In FIG. 3, the horizontal axis represents the ceramic content (% by weight), and the vertical axis represents the three levels of cracking, normal, and deformation. Symbols in the figure are: ×: Large deformation (3 to 10 mm) △: Deformation occurs and progresses (0.5 to 3 mm) ○: Normal (deformation is not a problem in use) ●: On the upper edge of the button It indicates that there are defects or cracks. From Fig. 3, the ceramic content is 30-70
It is known that good results are obtained when the weight% is. The numbers in the horizontal axis () indicate the impact value at 1100 ° C (kg-c
m).

Next, FIG. 4 shows a comparison of the high temperature allowable compressive deformation resistance values of the heat-resistant alloy and the ceramic composite material obtained in the experiment. The allowable compression deformation resistance value should be evaluated by the load per unit area when 0.025% of displacement in the thickness direction per hour occurs in the compression deformation (sagging) evaluation method based on the test results of the actual furnace. Was also found, and Fig. 4 follows the evaluation. As a result, it was confirmed that it has much higher strength than the conventional heat-resistant cast steel.

On the other hand, skid button height h and refractory lining 5
Depending on the thickness t of the skid button, the temperature at the tip of the skid button in contact with the steel material (hereinafter simply referred to as the tip) changes as described above. Naturally, the lower the height h of the skid button is, the more the lining thickness t is The thicker the temperature, the lower the temperature in the furnace.

Fig. 5 shows the skid button height h of 200mm, 150mm, 120m.
The results of investigating the difference between the temperature inside the furnace and the temperature at the tip of the skid button by changing the thickness t of the refractory lining when m is m are shown.

As can be seen from this figure, when the height h of the skid button is 200 mm, the tip temperature of the skid button is almost equal to the furnace temperature when the thickness t of the lining is 110 mm or less, and when the height h of the skid button is 150 mm. Is the lining thickness t is 100 mm
Even if it is below, it will be about 20 ℃ lower than the temperature in the furnace. If the height h of the skid button is set to 120 mm, the tip temperature of the skid button will drop significantly and it cannot be used. Therefore, the height of the skid button is 140 mm or more, preferably 150 mm or more. If the height of the skid button is increased to 200 mm or more, the temperature at the tip of the button can be made almost equal to the temperature inside the furnace even if the lining becomes thicker, but the height h of the skid button is too high. Then, there is a problem with the rigidity of the button itself, and there is a limit for economic reasons as well.
It is estimated to be about 80 mm, and the thickness t of the lining at that time is also
Up to around 200 mm is preferable. The lower limit of the lining thickness is 50 mm. This is because there is no influence on the tip of the skid button at 50 mm or less.

As described above, in the present invention, the height of the skid button is 140 mm or more and the thickness of the lining is 50 mm or more.

Next, it was investigated how the temperature changed at the position Y in the height direction of the skid button, and the results shown in FIG. 6 were obtained. In this survey, the height h of the skid button was measured when the furnace temperature was 1280 ℃.
Experiments were performed by setting the linings to 200 mm and 150 mm, and the thickness t of the refractory material (ceramic fiber) to 50 mm and 100 mm, respectively. From this figure, when the lining thickness is 50 mm, the temperature is almost the same at the same height regardless of the height h of the skid button, and when the lining thickness is 100 mm, it is the same as when it is 50 mm. At the Saano position, the temperature is low. Therefore, in terms of the structure of the skid button, the thickness of the lining is preferably as thick as possible so long as the cooling water does not affect the tip of the skid button, and is preferably about 70 to 80 mm or more.

From this fact, when the skid button is constructed as shown in FIG. ₁ , the temperature of the front end surface A ₁ contacting the ceramic composite material 1 can be made substantially equal to the temperature in the furnace, and the ceramic composite material 1 and the heat-resistant alloy 2 Since the temperature of the connection surface A ₂ is low, the allowable compression deformation resistance of the heat resistant alloy 2 can be sufficiently secured.

As is apparent from the above, in the skid button of the present invention, the height of the heat resistant alloy on the joint surface between the composite material and the heat resistant alloy is determined as follows.

Since the skid beam of the skid button is water-cooled, a temperature gradient occurs in the height direction. On the other hand, the maximum compressive deformation resistance value of the heat resistant alloy changes with temperature. Therefore, the height of the temperature position where the maximum compressive deformation resistance of the heat-resistant alloy is equal to the allowable compression system resistance of the composite material at the maximum temperature in the furnace of the composite material is determined, and the height of the heat-resistant alloy at the joint surface between the composite material and the heat-resistant alloy Let the height be less than or equal to the calculated height. This height can be determined by design according to the usage conditions of the skid button, as illustrated in FIG.

In addition, each position Y in the height direction of the skid button shown in FIG.
The temperature can be determined by experiment or calculation if the conditions of the maximum temperature of the furnace, the total height h of the skid button, and the lining thickness t of the refractory material are determined.

〔Example〕

Example 1 When the maximum temperature in the furnace was 1280 ° C., a composite material containing 30 wt% ceramics was used for the upper part of the skid button and a cobalt alloy for the lower part, and these were welded together. In order to approach the temperature inside the furnace,
The skid button has a total height h of 200 mm and a refractory lining thickness t of 100 mm.

The allowable compression deformation resistance of the composite material containing 30 wt% ceramics at the tip temperature of 1280 ° C is 0.1 kg / mm ² from Fig. 4. On the other hand, if the cobalt alloy forming the lower part of the skid button also has the same allowable compressive deformation resistance value as the ceramic composite material, the volume of the ceramic composite material can be minimized. Therefore, compression deformation resistance of cobalt alloy 0.1k
Obtaining the temperature at which g / mm ² is allowed from Fig. 4, it is 1210 ℃
Becomes Therefore, from FIG. 6, when the height Y at which the temperature of the skid button is 1210 ° C. is calculated under the conditions of h = 200 mm and t = 100 mm, it is about 170 mm. That is, the height a of the composite material 1 containing 30 wt% ceramics is 30 mm, and the height b of the cobalt alloy 2 is 17 mm.
If you set it to 0mm, you can get the most ideal skid button.

Example 2 When the temperature of the tip of the skid button may be slightly low, the total height h of the skid button was set to 150 mm, and the other conditions were the same as in Example 1.

In this case, the tip temperature of the composite material 1 containing 30 wt% ceramics is 1260 ° C from Fig. 6 (that is, 20 ° C lower than the furnace temperature), and the allowable compression deformation resistance at this temperature is about 0.11kg / mm from Fig. 4. ^{Is 2} . And in this case, Ni and Cr alloys were used for the lower part of the skid button. From Fig. 4, Ni,
The temperature at which the allowable compression deformation resistance of Cr alloy 0.11kg / mm ² can be secured is about 1000 ℃. Therefore, from Fig. 6, h = 150 mm, t = 1
The position Y in the height direction of the skid button, which is 1000 ° C under the condition of 00 mm, is 105 mm. Therefore, the height a of the 30 wt% ceramics-containing composite material 1 was set to 45 mm and the height of the Ni and Cr alloys was set to 105 mm to form a skid button having a total height h = 150 mm, and the refractory material was lined to a thickness of 100 mm.

Example 3 If a ceramics composite material having a ceramic content of 70% by weight, for example, is used at a furnace temperature of about 1280 ° C.
A compression deformation resistance of around 4 kg / mm ² is allowed, and the pressure receiving area can be further reduced, but it may be limited by the allowable compression deformation resistance on the steel material side. Generally, when the temperature in the furnace is about 1280 ℃, the allowable compression deformation resistance of the slab is 0.20.
Often employs kg / mm ² . Therefore, the designed compression deformation resistance of the skid button cannot exceed 0.2 kg / mm ² . Therefore, in such a case, if the ceramic content is 50 to 55% by weight, the maximum furnace temperature will be 1280.
If it is about ℃, it is enough only from the allowable compression deformation resistance, but from the viewpoint of long life due to maintenance problems and other reasons, dare to use ceramics with a high ceramic content, for example 70% by weight. In some cases.

However, it is not preferable from the economical and technical viewpoints. When the skid button is increased in overall height, a certain cross-sectional area may be required to maintain the rigidity of the button itself. For example, when using a composite material with a ceramic content of 70% by weight as described above. as the furnace temperature is 1280 ° C., using forced at 0.2 kg / mm ² from despite steel side conditions compressive deformation resistance is allowed to 0.4 kg / mm ^2. In such a case, if the upper part of the skid button is entirely made of a ceramic composite material, it is economically lossy.

In addition, if the ceramic composite material is made thick to some extent, cracks may occur in the ceramic composite material during melt overlaying for welding and integration with the heat resistant alloy.

As a measure against these problems, the present invention opens the skid button as shown in FIGS. 7 and 8.

In FIG. 7, the ceramic composite material 1a in the upper portion is formed into a ring shape so as to surround the top portion of the heat resistant alloy 2. In this case, the thickness e of the ceramic composite material is less than 35 mm. Fig. 9 shows the cracks generated when a ceramic-containing composite material was welded and integrated with a heat-resistant alloy.
The mark indicates normal, and the mark ● indicates occurrence of cracking. The occurrence of cracks is as shown in Fig. 9 regardless of the ceramic content. That is, when the thickness e is 35 mm or more, as shown in FIG. 9, many cracks occur in the process of welding and integrating with the heat resistant alloy.

From the design conditions of the skid beam, if the width of the skid button is 60 mm, the length is 120 mm, the height is 200 mm, the maximum load of one button is 800 kg, and the maximum temperature in the furnace is 1280 ℃, under these conditions, As shown in FIG. 7, a composite material 1a containing 50 wt% ceramics was used for the upper part of the skid button, and a cobalt alloy was used for the lower part. At the furnace temperature of 1280 ℃
Allowable compressive deformation resistance of 50 wt% ceramic containing composite material is 0.18 kg / mm ² from Figure 4, the cross-sectional area required for the composite material becomes ^{800kg ÷ 0.18kg / mm 2 = 4444mm} 2. Therefore, the thickness e of the ring is set to 15 mm (area 4500 mm ² ). The height b of the connection A _{2 with} the cobalt alloy is 0.18 kg for the cobalt alloy.
/ mm ² (substantially 800 ÷ 4500 = 0.178kg / mm ² ) Temperature from 1120 ℃ (Fig. 4) to 145mm (Fig. 6, but refractory lining thickness is 100mm) . Therefore height 2
As shown in Fig. 7, 50% by weight is applied to the outer circumference of the top of the 00mm cobalt alloy.
Ceramic-containing composite 1a with thickness e = 15mm and height a = 55
mm, the refractory lining thickness t = 100 mm.

Example 4 Here, an example will be given in which, when the ceramic composite material is simply formed into a ring shape, the compressive deformation resistance at the tip thereof is insufficient. In the case of Example 3, the load per skid button is 1250 kg and the other conditions are the same. If a composite material with a ceramic content of 50% by weight is formed into a cap shape as shown in Fig. 8, the surface pressure of the A ₁ surface at the tip is 1250 ÷ (60 × 12
0) = 0.174kg / mm ² in becomes allowable compressive deformation resistance 0.18 kg / mm ² or less at a furnace temperature of 1280 ° C. may be used. If the thickness e of the ring-shaped part is 15 mm, the cross-sectional area of the ceramic composite material in this part is 4500 mm ² , and the compressive stress is 1250 kg ÷ 450.
It becomes 0mm ² = 0.28kg / mm ² . Therefore, in order for the cobalt alloy 2 to secure a compressive deformation resistance of 0.28 kg / mm ^{2 on} the connection part A ₂ surface with the ceramic composite material, the temperature of this part is 10
Must be below 50 ° C. Therefore, the total height of the skid button h = 200 mm, lining thickness 100 mm to height Y = 13
0mm can be obtained. Here, it should be noted that the strength may be insufficient near the top lower surface A ₃ of the ceramic composite material 1b. Here, the thickness d of the top is set to 20 mm. Therefore, from Fig. 6, the temperature at the height of Y = 180 mm is 1240 ° C, and the allowable compression deformation resistance of the 50 wt% ceramics composite material and the cobalt alloy at this temperature is 0.12 kg / mm ² , respectively.
0.075 kg / mm ² and the area of each (4500 mm ² and 2700
The allowable load from mm ² ) is 954kg + 202kg = 1147kg, which is less than 1250kg. In this case, either thicken the upper part of the ring part (specifically about 16 mm at the thick part) or thicken the top part d (specifically 28 mm) as shown by the chain line in FIG. The temperature of this part is lowered and the compression deformation resistance of this part is increased.

In the example of FIG. 8, the ceramic composite material is capped.
1b, the upper part of the heat resistant alloy 2 is covered by welding. When the skid button is formed into a ring shape as shown in Fig. 7, or when the allowable compressive deformation resistance of the ceramic composite material 1a tip A ₁ is insufficient, or conversely, as shown in Fig. 1, the ceramic composite material constituting the skid button is formed. If there is too much room for compression deformation resistance (in this case, the composite material may be formed into a ring shape as in Example 3), the ceramic composite material may be formed into a cap shape as shown in FIG. Gives an economical and rational skid button. Also in this case, the thickness e of the ring portion of the ceramic composite material 1b is less than 35 mm as in the example of FIG. The thickness d of the top is 12 mm or more and less than 35 mm. Fig. 10 shows a cap-shaped 50
The relationship between the thickness d of the top portion of the composite material containing wt% ceramics and the deformation is shown. If the top thickness d is less than 12 mm, the amount of deformation becomes large as shown in FIG. 10, which causes a problem. Fig. 10 is a survey of composite materials with a ceramic content of 50% by weight, but other contents showed almost the same tendency. The thickness e of the ring is 35mm as explained in Fig. 9.
Less than is better. The ceramic composite is ring-shaped,
Or when it is cap-shaped, its thickness e is at least 8 m
It should be at least m. It is safer to check the strength of this part even when the cap is made into a cap shape because the allowable compression deformation resistance of the tip A ₁ of the ceramic composite material 1b has too much room.

Based on the above results, skid button total height h = 200m
m, the height a of the cap-shaped composite material 1b containing 50% by weight ceramics = 70 mm, the top thickness d = 20 mm, the ring thickness e is lower 15 mm, upper 16 mm, and the height b of the cobalt alloy is 130 m.
The skid button was constructed with m and lining thickness of 100 mm.

In the above description, the total cross-sectional area of the skid button is the same over the entire height of the same button.However, when selecting the allowable compression deformation resistance of the ceramic-containing composite material and the connection surface A ₂ of the heat-resistant alloy, the tip of the skid button There is an advantage that the allowable compressive deformation resistance of the heat-resistant alloy on the A ₂ surface can be made small by making it slightly larger than the area of the surface A ₁ , which can be obviously applied to the examples of FIGS. 7 and 8.

Further, the example in which the button has a rectangular cross-section has been described above, but a round button can be designed in the same manner.

Next, the results of actual furnace experiments for the above-described Examples 1 to 4 will be described. One skid button of each of Examples 1 to 4 was provided in each actual furnace, and an experiment was conducted in a walking beam furnace having a maximum furnace temperature of 1280 ° C. The material to be heated in this furnace is a slab with a maximum thickness of 260 mm, and the skid buttons were arranged so that the design allowable compressive deformation resistance matched the actual load for this slab thickness.

When used for about one year in this state, no abnormality was found in the four skid buttons for the experiment.

In the above example, the furnace temperature was 1280 ° C., the refractory material lining thickness was 100 mm, and the skid button height was 200 mm except for Example 2. However, other conditions are designed in the same manner as these examples. It goes without saying that you can do it.

〔The invention's effect〕

According to the present invention, a significant reduction in skid marks has contributed significantly to the improvement of product quality. Moreover, the skid button of the present invention exhibited good durability without significant deformation even after a long period of time.

[Brief description of drawings]

FIG. 1 is a side view showing the structure of a skid button of the present invention,
Fig. 2 is a graph showing the relationship between the ceramic content and toughness value, Fig. 3 is a table showing the experimental results of the usage limit by the ceramic content, Fig. 4 is a graph showing the comparison of compression deformation resistance, and Fig. 5 is The skid button height, a graph showing the difference between the skid button tip temperature that changes depending on the lining thickness, and the furnace temperature, FIG. 6 is a graph showing the temperature change at the height direction position of the skid button, FIG. 7, FIG. 8 is a cross-sectional view showing another example of the skid button of the present invention, FIG. 9 is a table showing a crack generation state of the composite material in the step of integrating the ceramic composite material and the heat-resistant alloy, and FIG. 10 is a cap. It is a graph which shows the relationship between the top thickness of a shaped ceramic composite material, and the amount of deformation. 1 …… Ceramics composite 2 …… Heat resistant alloy 3 …… Skid beam 4 …… Cooling water 5 …… Refractory lining

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Naito 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama Prefecture (no address) Inside the Mizushima Works, Kawasaki Steel Co., Ltd. (72) Osamu Nakatani 1-shima-shima Kawasaki, Kurashiki-shi, Okayama Prefecture Chome (No house number) Kawasaki Steel Co., Ltd. Mizushima Steel Works (72) Inventor Hisashi Hiraishi 1-1-1, Nakamiya Oike, Hirakata City, Osaka Prefecture Kubota Iron Works Co., Ltd. Hirakata Works (72) Inventor Shinozaki, Osaka Hirakata Ichi Nakamiya Oike 1-1-1, Kubota Iron Works Co., Ltd. Hirakata Works (72) Inventor Toru Kawai 1-1-1, Nakamiya Oike, Hirakata City, Osaka Prefecture Kubota Iron Works Co., Ltd. Hirakata Works (56) References Special Open Sho-60-54295 (JP, A) Unexamined Japanese Patent Sho-60-200948 (JP, A) Actual open Sho-59-83960 (JP, U) Actual open Sho-61-82949 (JP, U) Actual open Showa 53-73209 (JP, U) Showa 57-172059 (JP, U) Japanese Patent Publication 5-65563 (JP, B2) Showa 57-45259 (JP, Y2)

Claims (3)

[Claims] 1. A skid button for use in a walking beam furnace having a maximum furnace temperature of more than 1000 ° C., which is attached to a skid beam whose periphery is lined with a refractory material to support the material to be heated. The composite material of the upper part which is in contact with the composite material of the heat-resistant metal and the chrome carbide ceramics, and the lower part in contact with the skid beam is made of a heat-resistant alloy and the composite material and the heat-resistant alloy part are welded, and the composite material of the upper part contains ceramics. The ratio is 30 to 70% by weight, and the total height of the skid button is 140 mm or more.
The height of the heat-resistant alloy at the joint surface between the composite material and the heat-resistant alloy is equal to or lower than the height at which the maximum compression deformation resistance value of the heat-resistant alloy becomes equal to the allowable compression deformation resistance of the composite material at the maximum temperature in the furnace of the composite material, and A low skid mark walking beam furnace skid button having a thickness of 50 mm or more at a position in contact with the skid button of the skid beam lining. 2. The skid button for a low skid mark walking beam furnace according to claim 1, wherein the composite material is formed in a ring shape surrounding the upper portion of the heat resistant alloy. 3. The skid button for a low skid mark walking beam furnace according to claim 1, wherein the composite material is formed in a cap shape covering the heat resistant alloy.