JP7772012B2 - Method of extending irregular shaped materials - Google Patents

Description

The present invention relates to a method for adding unshaped materials, and in particular to a method for adding unshaped materials to damaged areas of hardened unshaped materials by adding new unshaped materials made of the same material.

Monolithic materials have fluidity and are constructed at the construction site by mixing raw materials with admixtures and water and pouring the mixture into the construction area under specific construction conditions. Because of their fluidity, monolithic materials can be easily molded into complex shapes, and can be constructed without the need for highly skilled workers. For this reason, monolithic materials are widely used in a variety of applications, including as monolithic refractory linings for high-temperature furnaces and molten metal vessels, and as concrete and cement for use in construction and civil engineering projects.

Depending on the application and use conditions of the monolithic refractory, new monolithic refractory may be added to the surface of the already hardened monolithic refractory. For example, monolithic refractory linings for molten metal vessels are subject to contact with high-temperature molten metal, erosion by molten slag, sudden temperature changes, and physical impacts. Because monolithic refractory linings for molten metal vessels are constantly used under harsh conditions, they may suffer from erosion. When monolithic refractory linings are eroded, in order to reduce manufacturing costs, waste emissions, and environmental impact, rather than replacing the entire monolithic refractory lining, repair monolithic refractory may be added only to the eroded areas, or a monolithic refractory replenishment process may be performed. When such monolithic refractory replenishment is performed, high adhesive strength is always required at the interface of the replenished monolithic refractory.

Various methods have been proposed to prevent the joining surface of monolithic materials from becoming brittle, i.e., to increase the adhesive strength of the joining interface of monolithic materials. For example, Patent Documents 1 and 2 describe a technique for improving the adhesive strength of the interface by applying a coating material such as an inorganic salt paste or liquid silicone resin to the surface of the base material (the joining surface) and then pouring in monolithic refractory. Patent Document 3 describes a method for filling the damaged area with monolithic refractory by inserting monolithic refractory into multiple holes drilled at random positions in the damaged area. Drilling multiple holes increases the surface area of the adhesive surface, which is said to improve the adhesive strength of the interface. Furthermore, Patent Document 4, as a related technology, proposes a system for evaluating the degree of unevenness of a joint surface using an unevenness evaluation device when treating the surface of previously poured and hardened concrete before pouring new concrete.

Japanese Unexamined Patent Publication No. 7-9118 Japanese Patent Application Publication No. 10-274485 Japanese Unexamined Patent Publication No. 54-96506 Japanese Patent Application Laid-Open No. 2021-25220

Patent Documents 1 and 2 require a coating material to be applied to the surface of the base material, which requires labor-intensive processing, reduces construction efficiency, and potentially increases construction costs. Patent Document 3 involves drilling a large number of holes to insert shaped refractory material, which presents similar issues to Patent Documents 1 and 2. Furthermore, because the adhesive strength at the interface varies depending on the material of the unshaped material, the technology in Patent Document 4 may not be able to determine whether the adhesive strength at the interface is sufficient. In these respects, there is still room for improvement.

The present invention was made to solve the above-mentioned problems, and aims to provide a method for adding irregular materials to a base material that can sufficiently adhere the irregular materials to the base material while preventing a decrease in construction efficiency or an increase in construction costs.

In order to achieve the above object, the present invention provides:
[1] A method for adding amorphous material to the surface of a base material, the method comprising: a roughness adjustment step for adjusting the surface roughness of the base material to make the standard deviation of the surface roughness of the base material 500 μm or more; and a construction step for adding new amorphous material to the surface of the base material whose roughness has been adjusted in the roughness adjustment step.
[2] In the roughness adjustment process, the surface roughness of the base material is adjusted while removing surface deposits on the surface of the base material before the amorphous material is added, or the surface roughness of the base material is adjusted after removing surface deposits on the surface of the base material before the amorphous material is added. [1] A method for adding amorphous material described in [1].
[3] The method for extending and constructing irregular materials described in [1] or [ ² ], which includes a water application process in which, after adjusting the surface roughness of the base material in the roughness adjustment process, water is applied to the surface of the base material in an amount of 0.010 g/cm2 or more and 0.250 g/cm2 or ^less .
[4] A method for extending an irregular material described in [1] or [2], wherein the adhesive strength between the new irregular material and the surface of the base material after adjusting the surface roughness of the base material in the roughness adjustment process is at least 50% or more of the bending strength of the base material.
[5] The method for extending and installing an amorphous material described in [1] or [2], wherein the amorphous material is a graphite-containing amorphous refractory material containing graphite.
[6] A method for adding monolithic material described in [5], in which the roughness adjustment process adjusts the surface roughness based on the graphite content of the graphite-containing monolithic refractory material.

In the method for adding monolithic material according to the present invention, the surface roughness of the base material is adjusted to a standard deviation of 500 μm or more. This allows for sufficient adhesion between the new monolithic material and the base material when it is added. Furthermore, adjusting the surface roughness of the base material to a standard deviation of 500 μm or more increases the adhesive strength. Therefore, compared to configurations that increase adhesive strength by applying a coating material to the surface of the new monolithic material to be added or by drilling multiple holes and inserting shaped refractory material, this method is easier to install because it does not require the application of a coating material or the insertion of shaped refractory material. This prevents a decrease in installation efficiency and further reduces installation costs.

FIG. 2 is a partial cross-sectional view of a molten metal container. FIG. 1 is a diagram showing an example of a surface roughness measuring device that quantifies the standard deviation of the surface roughness of the remaining refractory material. FIG. 10 is a diagram showing the relationship between the standard deviation of the surface roughness of the remaining refractory and the proportion of the adhesive strength in the original bending strength of the workpiece refractory layer.

The present invention will be described below through embodiments thereof. Figure 1 is a partial cross-sectional view of a molten metal vessel using unshaped materials according to this embodiment, and Figure 1(A) shows the molten metal vessel (hereinafter simply referred to as the vessel) before topping up. This vessel holds molten metal (not shown) inside. Specific examples of vessels include vessels that hold or refine molten metal such as molten pig iron or molten steel, and vessels that transport these. The vessel has a steel shell 1 that forms the outer shell and is made of iron or an iron-based material. A permanent brick layer 2 is formed inside the steel shell 1, and a work refractory layer 3 is formed inside the permanent brick layer 2. The vessel shown in Figure 1 has a multi-layer structure that, from the outside, is composed of the steel shell 1, the permanent brick layer 2, and the work refractory layer 3, in that order.

The permanent brick layer 2 is formed by arranging permanent bricks in layers. Examples of permanent bricks that can be used include roseki, zircon, clay, chamotte, high alumina, alumina, spinel, SiC, or bricks made from a combination of two or more of these.

The workpiece refractory layer 3 is composed of the amorphous material in this embodiment. Specifically, this amorphous material is a graphite-containing amorphous refractory material containing graphite, and may be any conventionally known material.

When molten metal (sometimes referred to as "molten metal") is supplied to a vessel configured as described above, the molten metal comes into contact with the workpiece refractory layer 3 that forms the vessel's inner surface. The temperature of the molten metal is, for example, as high as 1000°C. Therefore, repeated use of the vessel shown in Figure 1(A) gradually wears down the workpiece refractory layer 3. Specifically, the temperature changes associated with supplying and discharging molten metal to the vessel cause the amorphous material that forms the workpiece refractory layer 3 to expand and contract, resulting in thermal stress. Furthermore, when the workpiece refractory layer 3 is exposed to high-temperature molten metal, the molten metal contains slag, which chemically attacks the amorphous material that forms the workpiece refractory layer 3, creating an altered layer that includes a slag-infiltrated layer. This altered layer of the amorphous material, combined with the repeatedly occurring thermal stress, gradually deteriorates the workpiece refractory layer 3, causing it to wear down and break down.

As a result, slag adheres to the inner surface of the repeatedly used vessel, i.e., the inner surface of the workpiece refractory layer 3, as an attachment, and the attached slag infiltrates the unshaped material, forming an altered layer. Here, "slag" refers to a by-product whose main ingredient is oxide, produced in the process of removing impurity elements such as carbon, phosphorus, and sulfur from molten metal. In this embodiment, the attachment and altered layer are collectively referred to as the surface layer attachment 4. Furthermore, the remaining portion of the workpiece refractory layer 3 located below the surface layer attachment 4 is referred to as the remaining refractory 5.

If new cast iron is added to the surface of the workpiece refractory layer 3 while there is a surface deposit 4, the surface deposit 4 becomes weak, potentially reducing the adhesive strength of the newly added cast iron to the inner surface of the container. This is because there are differences in physical properties between the newly added cast iron and the surface deposit 4. Therefore, for example, if a container is used to which new cast iron has been added without removing the surface deposit 4, cracks may develop on the added surface, i.e., in the newly added cast iron. Furthermore, molten metal may penetrate into the cracks or between the newly added cast iron and the surface deposit 4, causing cracks to develop. The newly added cast iron may then peel off at the boundary between the newly added cast iron and the surface deposit 4. This reduces the durability of the container. In other words, a container in which new monolithic material is added without removing the surface deposits 4 will have a significantly reduced lifespan compared to a molten metal container in which the work refractory layer 3 has been newly re-lined or a brand new molten metal container. This reduces the cost benefit of repairing the container by adding more material.

Therefore, in the method for adding amorphous material according to this embodiment, before adding new amorphous material to the surface of the workpiece refractory layer 3, the surface deposits 4 are scraped off and removed. In addition, the surface roughness of the workpiece refractory layer 3 is adjusted so that the standard deviation of the surface roughness of the surface of the workpiece refractory layer 3 is 500 μm or more. This improves the adhesive strength of the newly added amorphous material to the inner surface of the container.

(Removal process)
The surface deposit 4 may be removed by peeling it off with a hammer, an ice axe, or the like. Alternatively, the surface deposit 4 may be removed by grinding it with a machine such as a heavy machine or a hydraulic drafter. Fig. 1(B) shows a state in which the surface deposit 4 on the surface of the workpiece refractory layer 3 has been scraped off and removed.

The surface deposits 4 are damaged areas where slag has adhered and an altered layer has formed, and can be identified visually or by analyzing image data captured by a camera. Specifically, amorphous materials that do not contain carbon (graphite) are white in color, while amorphous materials that contain carbon (graphite) are dark gray in color. Slag, on the other hand, is black, like tar. In this way, the surface deposits 4 and the workpiece refractory layer 3 differ in color and texture. Therefore, they can be distinguished by visual inspection or image analysis.

It is also preferable to remove the surface deposits 4 until the remaining refractory 5 located underneath is exposed. If there are no surface deposits 4 on the surface of the workpiece refractory layer 3, the roughness adjustment process can be carried out without any special removal work.

(Roughness adjustment process)
With the remaining refractory 5 exposed, the surface roughness of the remaining refractory 5 is adjusted. Specifically, the surface roughness of the remaining refractory 5, i.e., the degree of surface irregularity on the surface of the remaining refractory 5, is measured, and the measured surface roughness is quantified as the standard deviation of the height distribution of the surface irregularities. The surface roughness of the remaining refractory 5 is then adjusted so that the standard deviation is equal to or greater than a predetermined threshold. FIG. 1C shows the state in which the surface roughness of the remaining refractory 5 has been adjusted as described above. In this way, as shown in FIG. 1C, an interface 6 is formed in which the surface of the remaining refractory 5 is roughened. This is because increasing the standard deviation of the surface roughness increases the contact area between the remaining refractory 5 and the newly added monolithic refractory, thereby increasing the adhesive strength therebetween. Furthermore, increasing the standard deviation of the surface roughness reduces the proportion of coarse aggregate in the monolithic refractory at the added surface, thereby increasing the exposed surface area of cement. This is to increase the effective surface area for bonding of the cement in the monolithic refractory, thereby increasing the adhesive strength.

A more detailed explanation will be given. Figure 2 shows an example of a surface roughness measuring device that quantifies the standard deviation of the surface roughness of the remaining refractory 5. The surface roughness measuring device 7 shown in Figure 2 is mainly composed of a microcomputer, and has an image data acquisition unit 8, a 3D model generation unit 9, a standard deviation calculation unit 10, a standard deviation determination unit 11, and an output unit 12. The image data acquisition unit 8 is connected via wire or wirelessly to a camera 13 that photographs the surface of the remaining refractory 5, and acquires image data output from the camera 13. That is, in this embodiment, the camera 13 photographs the surface of the remaining refractory 5, acquires multiple image data, and outputs the image data to the surface roughness measuring device 7. The image data acquisition unit 8 also outputs the acquired image data to the 3D model generation unit 9.

The 3D model generation unit 9 performs calculations based on the image data captured by the camera 13 and pre-stored data and programs to generate a 3D model image of the surface of the remaining refractory material 5. In other words, the 3D model generation unit 9 performs image processing to generate a 3D model image based on the image data acquired by the camera 13. This image processing may be conventionally known. The 3D model image generated by the 3D model generation unit 9 is output from the 3D model generation unit 9 to the calculation unit 10.

The surface of the remaining refractory material 5 has a mountain-valley structure over a wide range, resulting in a surface with varying elevations. Therefore, the calculation unit 10 calculates the standard deviation of the surface roughness of the remaining refractory material 5 as a statistical quantity of the fracture surface height direction distribution based on the profile of the 3D model image. This standard deviation is output from the calculation unit 10 to the determination unit 11. The determination unit 11 determines whether the standard deviation is equal to or greater than a predetermined threshold, and outputs the determination result together with the standard deviation to the output unit 12. The output unit 12 is, for example, a monitor, and displays the above-mentioned standard deviation and the determination result.

Then, while checking the standard deviation of the surface roughness of the remaining refractory material 5 displayed on the output unit 12, the surface roughness of the remaining refractory material 5 is adjusted so that the standard deviation is equal to or greater than a predetermined threshold. The standard deviation threshold is, for example, 500 μm. By setting the standard deviation of the surface roughness to 500 μm or greater, the adhesive strength can be increased to 50% or greater of the original strength of the workpiece refractory layer 3. The relationship between the standard deviation of the surface roughness and the adhesive strength can be determined experimentally. The strength of the workpiece refractory layer 3 refers to the bending strength (sometimes referred to as breaking strength) of the workpiece refractory layer 3 when a three-point support bending test is performed on the workpiece refractory layer 3. The method for calculating the standard deviation of the surface roughness and the adhesive strength will be described in detail in the examples below.

The surface roughness of the remaining refractory 5 may be adjusted in a manner similar to that used to remove the surface deposits 4. That is, the surface roughness may be adjusted by peeling off the surface of the remaining refractory 5 using a hammer, pick, or the like (not shown). Alternatively, the surface roughness may be adjusted by grinding the surface of the remaining refractory 5 using a machine such as heavy machinery or a hydraulic drafter (not shown). In this way, the interface 6, in which the surface of the remaining refractory 5 is roughened, is formed as shown in FIG. 1C . It is not necessary to perform the roughness adjustment process to adjust the surface roughness of the remaining refractory 5 after the removal process to remove the surface deposits 4. It is preferable to adjust the surface roughness of the remaining refractory 5 while removing the surface deposits 4. That is, it is preferable to perform the removal process and the roughness adjustment process described above almost simultaneously. Furthermore, if the standard deviation of the surface roughness of the remaining refractory 5 is equal to or greater than a predetermined threshold value after the surface deposits 4 are removed and the remaining refractory 5 is exposed, there is no need to perform the surface roughness adjustment process thereafter.

(Water application process)
It is also preferable to apply water at a rate of 0.010 g/ ^cm2 or more and 0.250 g/ ^cm2 or less to the interface 6 formed as described above before adding and installing new monolithic refractory. This is to avoid the possibility that if the interface 6 is dry, specifically, if the amount of water applied at the interface 6 is less than 0.010 g/ ^cm2 , the moisture in the newly added monolithic refractory will be absorbed by the remaining refractory 5. As a result, the monolithic refractory with reduced moisture content and the remaining refractory 5 will not be sufficiently bonded, resulting in a weakened bond at the bonded interface. On the other hand, if the amount of water applied at the interface 6 is greater than 0.250 g/ ^cm2 , excess water will be present at the bonded interface. In other words, this is to avoid the possibility that the amount of water in the newly added monolithic refractory will be excessive relative to the binder, resulting in a weakened bond at the bonded interface. Therefore, when moisture is applied to the interface 6, which is the extension surface of the irregular material to be added, the amount of moisture to be applied is preferably within the range of 0.010 g/cm ² or more and 0.250 g/cm ² or less.

Water may be applied to interface 6 using, for example, a watering system with a spray nozzle that can control the water flow rate, or a spray bottle that can spray water in a mist-like manner. After water is applied to interface 6, it is preferable to add new amorphous material within two hours at the latest after the water application to prevent interface 6 from drying out. It is more preferable to add new amorphous material within one hour after the water application. Furthermore, it is preferable that the environment surrounding the container in which new amorphous material is added and applied has a temperature of 0°C or higher and 40°C or lower, and a humidity of 30% RH or higher and 100% RH or lower. This is to prevent evaporation of the water attached to the surface of the amorphous material.

(Construction process)
Thereafter, new monolithic material is applied to the interface 6. It is preferable that the new monolithic material be made of substantially the same material as the remaining refractory 5, and the monolithic material is added and applied until the thickness of the work refractory layer 3 reaches the thickness determined by design, i.e., the original thickness. Fig. 1(D) shows the state in which the monolithic material has been added and applied until the original thickness is reached. The application method may be a conventionally known application method.

(Method for determining the standard deviation of surface roughness)
A method for determining the threshold value of the standard deviation of the surface roughness in the roughness adjustment process will be described. The adhesive strength of amorphous materials varies depending on the type of material used, i.e., its chemical composition. Therefore, the inventors conducted extensive testing and found that the adhesive strength varies depending on the graphite content of the amorphous material. Furthermore, it was found that if the adhesive strength is 50% or more of the bending strength of the workpiece refractory layer 3, i.e., if the adhesive strength is at least half the strength of the original workpiece refractory layer 3, the durability of the container to which the newly added amorphous material is added can be ensured and the adhesive strength is sufficient.

As will be explained in more detail in the examples below, it has been found that the larger the standard deviation of the surface roughness of the interface 6, the higher the aforementioned ratio, i.e., the adhesive strength. It has also been found that the higher the graphite content in the amorphous material, the higher the adhesive strength, even if the standard deviation of the surface roughness is small. Specifically, when the graphite content of the amorphous material is 5% by mass, it has been found that by setting the standard deviation of the surface roughness to 500 μm or more, the adhesive strength becomes 50% or more of the original bending strength of the workpiece refractory layer 3.

For the above reasons, when the amorphous material contains graphite, it is preferable to adjust the surface roughness of the extension surface based on the graphite content, and to adjust the surface roughness of the extension surface, interface 6, so that the standard deviation of the surface roughness is 500 μm or more.

When determining the threshold value for the standard deviation of surface roughness, it is preferable to prepare a table that associates the material that makes up the irregular material with the standard deviation of surface roughness at which the adhesive strength of the irregular material is 50% or more. The table is used to set the target standard deviation of surface roughness for the irregular material to be constructed. Then, the target value of the standard deviation of surface roughness is used as the threshold value to adjust the standard deviation of surface roughness.

Therefore, according to the method for adding monolithic material according to this embodiment, when new monolithic material is added, the new monolithic material can be sufficiently bonded to the remaining refractory material 5, which is the base material. Furthermore, the surface roughness of the remaining refractory material 5 is adjusted while removing the surface deposits 4. Therefore, compared to the methods described in Patent Documents 1 and 2, in which a coating material is applied to the interface and then the monolithic refractory is poured in, or the method described in Patent Document 3, in which monolithic refractory is inserted into multiple holes drilled at the interface and then the monolithic refractory is poured in, the method for adding monolithic material according to this embodiment is easier to install because it does not require the steps of applying a coating material or inserting the monolithic refractory. As a result, the installation efficiency when adding monolithic material to the above-mentioned container can be improved, and material costs and installation costs (repair costs) can be reduced during installation.

Note that, in the method for adding monolithic material according to this embodiment, a graphite-containing monolithic refractory has been described as an example of the monolithic material, but this is not limiting. For example, examples of monolithic materials that can be used in the method for adding monolithic material according to this embodiment include a variety of monolithic refractories with chemical compositions such as alumina, alumina-silica, magnesia, dolomite, spinel, alumina-spinel, alumina-magnesia, alumina-spinel-magnesia, magnesia-carbon, alumina-magnesia-carbon, alumina-spinel-carbon, alumina-silicon carbide-carbon, and alumina-roseki-silicon carbide-carbon.

Furthermore, the monolithic material is not limited to monolithic refractory material, and may be, for example, concrete or cement. In the case of concrete or cement, the present application can be applied when the pouring area is divided into multiple blocks, and concrete that has been poured and hardened first is poured, new concrete is poured on top of the cement, and then cement is poured in sequence. In the case of concrete or cement, an altered layer rarely forms on the surface, so there is no need to remove the altered layer.

Next, an example of the monolithic refractory extension method according to this embodiment will be described. In this example, three types of monolithic refractory test pieces with different graphite contents, manufactured in accordance with JIS R 2553 "Test Method for Strength of Castable Refractories," were used as the monolithic material. Specifically, three types of test pieces with different graphite contents were prepared: alumina-magnesia, alumina-spinel-3% graphite by mass, and alumina-spinel-5% graphite by mass. The alumina-magnesia test piece had a graphite content of 0% by mass, the alumina-spinel-3% graphite by mass test piece had a graphite content of 3% by mass, and the alumina-spinel-5% graphite by mass test piece had a graphite content of 5% by mass. The test pieces measured 40 mm x 40 mm x 160 mm. The effect of the standard deviation of the surface roughness of the extension surface (interface 6) on the adhesive strength of each test piece was then investigated.

(Comparative Example 1)
Each test piece was cut at the longitudinal center of the test piece using a small diamond cutter to form a smooth cut surface. Two split pieces were obtained for each test piece. Water was applied to one of the two split pieces so that the moisture content of the smooth cut surface of the split piece was in the range of 0.010 g/ ^cm² to 0.250 g/ ^cm² . The split piece was then positioned on one side of a formwork with inner dimensions of 40 mm x 40 mm x 160 mm in the longitudinal direction so that the cut surface was located at the longitudinal center of the formwork. A new castable refractory material of the same material as the test piece was mixed and poured into the space on the other side of the formwork in the longitudinal direction to be added to the split piece. The test piece was then cured at room temperature for 24 hours, removed from the formwork, and dried at 110°C for 24 hours. A coking firing treatment was also performed at 1150°C, the estimated temperature of the added surface during actual furnace use. A three-point bending strength test was then conducted on each of the divided pieces to which new monolithic refractory had been added, and the ratio of the adhesive strength (adhesive strength/bending strength) to the bending strength of the test piece that had not been subjected to such processing (bending strength of the original test piece) was calculated. The three points marked as cut surfaces in Figure 3 show the test results for each test piece of Comparative Example 1. The symbol "●" indicates an alumina-magnesia material, the symbol "◆" indicates an alumina-spinel-3% by mass graphite material, and the symbol "▲" indicates an alumina-spinel-5% by mass graphite material.

(Comparative Example 2)
Each test piece was divided into two by a three-point support bending test, and a fracture surface was formed on each. Water was applied to the fracture surfaces in the same manner as in Comparative Example 1, and slag with the chemical composition shown in Table 1 was placed on top and subjected to a slag infiltration treatment at 1600°C for two hours. The ratio was then calculated in the same manner as in Comparative Example 1. The three points in Figure 3 marked with "slag infiltration layer present" represent the test results for each test piece in Comparative Example 2.

(Example 1)
Each test piece was divided into two by a three-point support bending test to form a fracture surface. Otherwise, the ratio was calculated in the same manner as in Comparative Example 1. The three points marked "fracture surface" in Figure 3 show the test results for each test piece in Invention Example 1.

(Example 2)
Each test specimen was divided into two by a three-point support bending test, and fracture surfaces were formed on each. Water was applied to the fracture surfaces as in Comparative Example 1, and slag was placed on each fracture surface of each test specimen as in Comparative Example 2, for slag infiltration treatment. The slag was then removed using a hammer, ice axe, electric sander, etc., and the surface of the test specimen exposed by the slag removal was ground to form irregularities. The ratio was then calculated as in Comparative Example 1. The three points in Figure 3 labeled "Slag infiltration layer removed" represent the test results for each test specimen in Example 2.

Figure 3 shows the relationship between the standard deviation of the surface roughness of the remaining refractory and the proportion of adhesive strength in the bending strength of the workpiece refractory layer. As shown in Figure 3, for all three types of test pieces with different graphite contents, the higher the standard deviation of the surface roughness, the higher the adhesive strength after the extension work.

However, in Comparative Example 2, in which new monolithic refractory was added to a slag-infiltrated layer, the adhesive strength did not even reach 20% of the original strength of the monolithic refractory, and was found to be significantly lower than in Invention Example 1, which had roughly the same standard deviation of surface roughness. On the other hand, in Invention Example 2, the adhesive strength was found to exceed 60% of the original strength of the monolithic refractory.

Furthermore, as shown in Figure 3, the standard deviation of the surface roughness at which the adhesive strength is 50% or more of the original strength of the monolithic refractory varies depending on the graphite content. That is, in Examples 1 and 2, and Comparative Example 2, the higher the graphite content, the lower the standard deviation of the surface roughness at which the adhesive strength is 50% or more of the original strength of the monolithic refractory. These results demonstrate that the presence or absence of a slag-infiltrated layer has a much greater effect on adhesive strength after the extension of the monolithic refractory than the standard deviation of the surface roughness, and that removing the slag-infiltrated layer improves adhesive strength. Furthermore, when there is no slag-infiltrated layer or when the slag-infiltrated layer is removed, as in Examples 1 and 2, the adhesive strength can be improved to 50% or more of the original strength by setting the standard deviation of the surface roughness of interface 6 to 500 μm or more. When tested on an actual machine, by making the adhesive strength of the patched area at least half that of the original material (base material), the strength exhibited at the patched interface can prevent delamination originating from the patched interface.

REFERENCE SIGNS LIST 1 Steel shell 2 Permanent brick layer 3 Work refractory layer 4 Surface deposit 5 Remaining refractory (work refractory layer)
6 Interface 7 Surface roughness measuring device 8 Image data acquisition unit 9 3D model generation unit 10 Calculation unit 11 Determination unit 12 Output unit 13 Camera

Claims (6)

A method for adding irregular materials to the surface of a base material, comprising:
a roughness adjusting step of adjusting the height distribution of the irregularities on the surface of the base material so that the standard deviation of the height distribution of the irregularities on the surface of the base material is 500 μm or more;
and a construction step of adding and constructing a new irregular material to the surface of the base material whose unevenness height distribution on the surface of the base material has been adjusted in the roughness adjustment step ,
In the roughness adjustment process, a 3D model image of the surface of the base material is generated based on image data of the surface of the base material photographed by a camera, and the standard deviation of the height distribution of the unevenness on the surface of the base material is calculated as a statistical quantity of the height distribution of the unevenness on the surface of the base material based on the profile of the 3D model image . The method for extending and constructing irregular materials as described in claim 1, wherein the roughness adjustment process adjusts the height distribution of the unevenness on the surface of the base material while removing surface deposits on the surface of the base material before extending and constructing the irregular material, or adjusts the height distribution of the unevenness on the surface of the base material after removing surface deposits on the surface of the base material before extending and constructing the irregular material. 3. The method for extending and constructing irregular materials according to claim 1 or 2, further comprising a water application process for applying water of 0.010 g/ ^cm2 or more and 0.250 g/ ^cm2 or less to the surface of the base material after adjusting the height distribution of the unevenness on the surface of the base material in the roughness adjustment process. A method for extending and constructing irregular materials as described in claim 1 or 2, wherein the adhesive strength between the new irregular material and the surface of the base material after adjusting the height distribution of the unevenness on the surface of the base material in the roughness adjustment process is at least 50% or more of the bending strength of the base material. The method for extending and installing monolithic material according to claim 1 or 2, wherein the monolithic material is a graphite-containing monolithic refractory material containing graphite. The method for extending and constructing amorphous materials according to claim 5, wherein the roughness adjustment process adjusts the height distribution of the irregularities on the surface of the base material based on the graphite content of the graphite-containing amorphous refractory material.