Casting typecasting repairing mould and typecasting fusion welding repairing method applying same

Abstract

The invention discloses a casting typecasting repairing mould and a typecasting fusion welding repairing method using the same, and relates to the technical field of casting, the casting typecasting repairing mould comprises a fixing seat, a positioning frame and a moulding bed, a magnet block is connected and installed on the fixing seat, the positioning frame is limited and embedded in the fixing seat, the moulding bed is limited and embedded in the positioning frame, and the magnet block is connected and installed on the moulding bed. According to the casting typecasting repair mould, a typecasting cavity and a slag flowing groove are formed in the moulding bed, the slag flowing groove is communicated with the typecasting cavity, and the typecasting fusion welding repair method using the casting typecasting repair mould comprises the steps that under the state that a defective typecasting and the typecasting cavity are matched and embedded, the defective typecasting is fused in the typecasting cavity through a low-heat input pulse electric arc welding process to fill a casting gap space in the typecasting; according to the casting typecasting repairing mould, the defect typecasting can be repaired, the requirement for the operation skill level can be lowered, the labor intensity is lowered, the repairing cost is reduced, the repairing effect is guaranteed, control over coarse positioning, fine adjustment and strong locking of the mould can be further achieved through the casting typecasting repairing mould, the typecasting repairing precision is improved, and the typecasting repairing quality is improved.

Description

Technical Field

[0001] This invention relates to the field of casting technology, specifically to a casting lettering repair jig and a method for welding and repairing casting letters using the same jig. Background Technology

[0002] Cast lettering refers to the connected characters marked on casting products. Because the structure of these characters usually varies greatly from the specifications of the casting, improper processing during casting production often results in casting defects. These casting defects are prone to occur in defect-sensitive areas and are difficult to control effectively, becoming a thorny problem in the production of casting products. In particular, for castings with high requirements for the precision of the font structure, it is very difficult to repair poorly formed castings, resulting in the inability to guarantee the appearance quality of the castings. Although in reality, production generally focuses on source control to eliminate poorly formed casting defects, a large proportion of poorly formed casting lettering still occurs. The repair of casting defects remains an indispensable and crucial production process. Currently, the main methods for repairing casting defects include laser melting deposition repair and manual welding shaping. Laser melting deposition repair, which uses metal powder or wire as raw materials and employs a high-energy laser beam to melt and deposit the castings, can quickly, efficiently, and with high quality repairs. However, it requires advanced technology and has high equipment costs, resulting in poor versatility and cost-effectiveness, making it unsuitable for widespread use in traditional industries. Manual welding shaping, while not relying on high-cost equipment and having lower technological requirements, is heavily reliant on operator skills. It typically requires additional grinding and finishing during the welding process, leading to high labor intensity, low repair efficiency, and inconsistent quality. The repair of casting defects has become a bottleneck in the industrial production of casting products. Therefore, it is necessary to research and improve casting lettering repair methods suitable for widespread application in traditional industries, and to develop supporting auxiliary tooling for casting lettering repair to solve the existing technical problems. Summary of the Invention

[0003] The purpose of this invention is to provide a casting lettering repair jig and a casting lettering welding repair method using the casting lettering repair jig, thereby improving the casting lettering repair method, reducing the casting lettering repair cost, increasing the casting lettering repair efficiency, and ensuring the casting lettering repair quality.

[0004] A casting lettering repair jig includes: a fixing base, a positioning frame, and a jig mold; the fixing base and the positioning frame are rectangular frames with corresponding and compatible structures; evenly distributed magnet blocks are connected and installed on the fixing base, and the fixing base can be stably and evenly attracted and fixed to the surface of the casting by the magnetic attraction of the magnet blocks; the positioning frame can be correspondingly and limitingly fitted into the frame of the fixing base; the jig mold is a rectangular block with corresponding and compatible structure to the positioning frame, and can be correspondingly and limitingly fitted into the frame of the positioning frame; the jig mold is provided with a through-hole casting lettering cavity and a slag flow groove, the slag flow groove being connected to the casting... The letter cavities are connected, and the connecting groove between the slag flow groove and the letter cavity is set at a height H corresponding to the thickness of the first layer of welding. This allows the welding slag generated during the first layer of welding to overflow from the letter cavity and flow into the slag flow groove, solving the problem that welding slag can block the current and prevent multi-layer continuous welding. When the fixing seat is attracted and fixed on the surface of the casting, the positioning frame is restricted and fixed between the fixing seat and the casting, and the mold is restricted and fixed between the positioning frame and the casting, so that the letter cavity on the mold corresponds to the letter to be repaired on the surface of the casting.

[0005] The aforementioned casting and lettering repair jig preferably features a slag channel that extends outward in a fan shape from the connecting slot between the slag channel and the lettering cavity. The bottom surface is an inclined surface sloping downward along the slag discharge direction. The fan-shaped widening of the slag channel effectively increases the accumulation space for welding slag, while the inclined surface ensures the smooth discharge of the welding slag. Simultaneously, an anti-adhesion coating is applied to the bottom surface and sidewalls of the slag channel to reduce the adhesion between the welding slag and the jig, ensuring that the welding slag can automatically detach from the jig after welding is completed.

[0006] The aforementioned casting and lettering repair jig is preferably made of artificial special sand with high refractoriness to ensure the uniformity of the raw sand particle size and improve the manufacturing accuracy of the jig.

[0007] The aforementioned casting and lettering repair jig preferably includes a lateral adjustment mechanism mounted on a set of opposing side frames of the fixed base. This mechanism drives and adjusts the positioning frame relative to the fixed base in a direction perpendicular to the side frames, thereby improving the fitting accuracy between the casting cavity and the character to be repaired. The lateral adjustment mechanism includes an adjusting bolt and a spring, which are respectively disposed on two corresponding side frames of the fixed base. The adjusting bolt is threaded onto the fixed base, with its end abutting inward against the side frame of the positioning frame. The spring is disposed between the fixed base and the positioning frame, applying an elastic force relative to the fixed base to the positioning frame, elastically fitting the positioning frame within the fixed base. Rotating the adjusting bolt drives the positioning frame to move linearly relative to the fixed base.

[0008] The aforementioned casting and lettering repair fixture preferably includes a longitudinal adjustment mechanism installed on another side of the fixed base perpendicular to the side frame assembly on which the lateral adjustment mechanism is installed. The longitudinal adjustment mechanism includes a ball-end bolt and a ball-end connecting rod. A ball-end bolt is fixedly connected to its front end and threadedly mounted on the fixed base. One end of the ball-end connecting rod is fixedly connected to the positioning frame, and a ball-end is fixedly connected to its other end. The ball-end and the ball-end are structurally compatible and fitted within the ball-end, so that the ball-end connecting rod and the ball-end bolt are aligned... The ball joints are interconnected, and rotating the ball sleeve bolt allows the positioning frame to move linearly in a direction perpendicular to the adjustment direction of the lateral adjustment mechanism via the ball head connecting rod. This is used to precisely adjust the fitting accuracy between the casting cavity and the casting to be repaired. At the same time, the fitting of the ball head and the ball sleeve allows the positioning frame to have the freedom to make three-dimensional adaptive adjustments relative to the surface of the casting. This optimizes the adaptation to the curvature or flatness deviation of the casting surface, adjusts and improves the fit between the mold and the casting surface, and thus ensures the fitting accuracy between the casting cavity and the casting.

[0009] A method for repairing lettering on castings by welding, using a casting lettering repair jig, includes the following steps: Step 1. Determine the welding process based on the defect height of the casting defects on the casting. If the defect height is small, only single-layer fusion welding is required. If the defect height is large, double-layer fusion welding is required. Based on this, prepare a mold according to the determined welding process. When only single-layer fusion welding is required, the height H of the connecting groove between the slag flow channel and the casting cavity on the mold is set to be level with the upper end face of the mold. When double-layer fusion welding is required, the height H of the connecting groove between the slag flow channel and the casting cavity corresponds to the thickness of the first layer of welding. Step 2. Pre-treat the defective area of ​​the casting, remove the dirt and impurities attached to the surface and grind away the oxide scale in the defective area to expose the metal body, ensure the effective fusion of the solder and the casting, improve the welding strength and ensure the welding quality; Step 3. Combine the mold prepared in Step 1 with the fixing seat and positioning frame to form a casting letter repair mold. Then, align the letter cavity on the mold with the defective letter on the casting. Place the fixing seat flat on the surface of the casting and use the magnet on the fixing seat to attract and fix the fixing seat to the casting, so that the letter to be repaired fits into the letter cavity. Then, rotate the adjusting bolt and the ball sleeve bolt in sequence to finely adjust the position of the positioning frame relative to the fixing seat in the horizontal and vertical directions, respectively, to further adjust the corresponding fitting accuracy of the letter and the letter cavity. During the horizontal and vertical position adjustment of the positioning frame, the positioning frame can adaptively adjust the fitting angle between the mold and the casting mating surface by means of the connection between the ball sleeve on the ball sleeve bolt and the ball head on the ball head connecting rod, thus optimizing the surface contact fit between the mold and the casting. Step 4. Using a low-heat-input pulsed arc welding method, melt the welding rod of the same grade as the casting material and fill the missing space formed in the casting cavity in the defect area of ​​the casting in 1 to 2 layers. When filling in 2 layers, the second layer can be filled after the first layer is completed, with an interval of 5 to 10 seconds, until the missing space is completely filled. Step 5. After the mold 3 has cooled sufficiently, directly pull off the magnetic connection between the fixing seat and the casting. Clean and reshape the repaired characters on the casting, remove the solidified welding slag and adhering impurities, and polish and tidy the shape of the characters. At the same time, maintain and repair the fixed seat and the positioning frame that have been pulled off, in preparation for subsequent character repair.

[0010] The method for repairing typefaces using a casting typeface repair jig is preferably described in step 1, in which the jig is prepared using coated sand with a high refractoriness ceramic material as the skeleton and a hot core box process, and an anti-adhesion coating is applied to the bottom and side walls of the slag trough.

[0011] The method for repairing characters using a casting repair jig is preferably described in step 4, before welding the characters. The casting substrate and the jig are preheated to 200-300°C in a localized area. During the two-layer filling process, the jig temperature is maintained at no less than 150°C between the first and second layers to reduce welding stress between the weld layer and the casting substrate, as well as between the two weld layers, preventing cracking defects and ensuring welding quality.

[0012] The beneficial effects of this invention are that it provides a casting lettering repair jig and a method for repairing casting letters using this jig. A mold is embedded in the casting lettering repair jig, and a lettering cavity corresponding to the defective character is formed in the mold. When the defective character and the lettering cavity are properly fitted, the defective character can be repaired simply by using a low-heat-input pulsed arc welding method to melt and fill the missing space in the lettering cavity. This significantly reduces the stringent requirements on the individual skill level of the operator, achieving standardization and process implementation of the repair process. This improves stability, reduces labor intensity, lowers repair costs, and ensures repair results. Furthermore, the casting and lettering repair jig can be used to precisely adjust the three-dimensional position of the jig relative to the casting in terms of lateral, longitudinal, and surface fit through the lateral and longitudinal adjustment mechanisms after the jig is coarsely positioned and magnetically fixed to the surface of the casting. This achieves reliable control of the entire process of "coarse positioning, fine adjustment, and strong locking," effectively improving the fitting accuracy between the casting cavity on the jig and the defective casting, thereby improving the repair accuracy and quality of the casting and lettering. Attached Figure Description

[0013] Figure 1 Diagram of the assembly structure of the jig for repairing lettering on castings.

[0014] Figure 2 for Figure 1 Sectional view of section AA.

[0015] Figure 3 for Figure 1 Sectional view of section BB.

[0016] Figure 4 for Figure 1 Sectional view of the CC section.

[0017] Figure 5 for Figure 1 Sectional view of the DD section.

[0018] Among them: 1 is the fixed seat, 2 is the positioning frame, 3 is the mold, 4 is the magnet block, 5 is the adjusting bolt, 6 is the spring, 7 is the ball sleeve bolt, 8 is the ball head connecting rod, 9 is the limiting flange, 10 is the casting cavity, 11 is the slag channel, 12 is the ball sleeve, 13 is the ball head, and 14 is the locking block. Detailed Implementation

[0019] The bolster is a core safety component on railway freight trains that bears heavy loads and impacts. Casting lettering on its surface is a mandatory requirement to ensure railway transportation safety and achieve refined management. Based on actual production practices, this invention takes the bolster of a railway freight train as an example and provides the following detailed description of the technical solution for which protection is sought, in order to further explain the technical solution. Example 1

[0020] A type of jig for repairing the typeface of a freight train bolster, such as Figures 1 to 5 As shown, it is composed of a fixed base 1, a positioning frame 2 and a mold 3. The fixed base 1 and the positioning frame 2 are both rectangular frames, and the mold 3 is a rectangular coated sand mold. The positioning frame 2 is fitted inside the fixed base 1, and the mold 3 is fitted inside the positioning frame 2.

[0021] Magnet blocks 4 are symmetrically arranged and installed at the four apex corners of the fixed base 1. An adjusting bolt 5 is threaded onto the left side frame, with its end abutting inward against the frame of the positioning frame 2. A spring 6 is correspondingly installed on the right side frame, supporting the fixed base 1 and the positioning frame 2. The spring 6, together with the adjusting bolt 5, forms a lateral adjustment mechanism. Rotating the adjusting bolt 5 allows for fine lateral adjustment of the positioning frame 2's position relative to the fixed base 1. Meanwhile, a threaded... A ball-end bolt 7 is installed in conjunction with the positioning frame 2. A ball-end bolt 7 has a ball-end bolt 12 fixedly connected to its front end. The ball-end bolt 12 has a split assembly structure and corresponds to the ball-end bolt 7. A ball-end connecting rod 8 is fixedly connected to the upper edge of the positioning frame 2. A ball-end connecting rod 8 has a ball-end bolt 13 fixedly connected to its end. The ball-end connecting rod 8 connects to the ball-end bolt 7 through the ball-end bolt 12 fitting with the ball-end bolt 13. Together, they form a longitudinal adjustment mechanism. Rotating the ball-end bolt 7 allows for fine longitudinal adjustment of the positioning frame 2 relative to the positioning frame 2. The fixed base 1 is positioned such that the ball head 13 and the ball sleeve 12 are fitted together, giving the positioning frame 2 a three-dimensional adaptive adjustment degree of freedom. A locking block 14 is connected and installed on the front end face of the lower frame of the fixed base 1, limiting and constraining the positioning frame 2 within the frame of the fixed base 1. The mold 3 is a sand mold prepared from coated sand with pearl sand as the raw material skeleton. The sand mold has a casting cavity 10, and a slag flow channel 11 extending outwards is opened in the casting cavity 10 corresponding to the area of ​​the casting defect to be repaired. The slag trough 11 extends outward in a fan shape from the connecting slot between it and the casting cavity 10. The bottom surface is an inclined surface that slopes downward outward. The height H of the connecting slot corresponds to the thickness of the first layer of welding. The bottom surface and side wall of the slag trough 11 are coated with a nano-alumina coating. The upper and lower ends of the mold 3 are respectively provided with stepped grooves. At the same time, the upper and lower ends of the positioning frame 2 are respectively provided with limiting flanges 9. The limiting flanges 9 can be fitted into the stepped grooves to limit and constrain the mold 3 within the frame of the positioning frame 2. Example 2

[0022] On the casting blank of freight train bolster products, the design height of the cast characters is usually 7-8 mm. In the casting production, the defect height of the cast characters in the defect area is mostly concentrated in the range of 1-4 mm. When using the freight train bolster cast character repair jig described in Example 1 for fusion welding repair, for defect areas with a defect height of less than 2 mm, only single-layer fusion welding is required, while for defect areas with a defect height in the range of 2-4 mm, double-layer fusion welding is required. This embodiment takes double-layer fusion welding as an example to further illustrate the technical solution for which protection is requested.

[0023] A method for welding repair of lettering on a freight train bolster comprises the following steps: Step 1. Design the structure of the mold 3 according to the defect height of the casting defects area on the casting. The thickness of the first fusion weld layer is 2 mm. The height H of the connecting groove between the slag flow channel 11 and the casting cavity 10 on the mold 3 is set to be the same as the height reached by the first fusion weld layer. Then, using coated sand with pearl sand as the skeleton material as raw material, the mold 3 is prepared by the hot core box process. The bottom surface and side wall of the slag flow channel 11 on the prepared mold 3 are coated with a nano alumina coating with a thickness of 50-100 micrometers. After drying, it is ready for use. Step 2. Use an angle grinder to grind the defective area on the cast lettering, remove the dirt and impurities attached to the surface and remove the oxide scale in the defective area, so that the defective area exposes the metal body, and the surface roughness Ra of the defective area is ≤12.5 micrometers; Step 3. Combine the mold 3 prepared in Step 1 with the fixing seat 1 and the positioning frame 2 to form a freight train bolster lettering repair mold. Then, align the lettering cavity 10 on the mold 3 with the lettering to be repaired on the casting. Next, place the fixing seat 1 flat on the surface of the casting and use the magnet 4 to attract and fix the fixing seat 1 to the casting, so that the lettering fits into the lettering cavity 10. Then, rotate the adjusting bolt 5 and the ball sleeve bolt 7 respectively to finely adjust the setting position of the positioning frame 2 relative to the fixing seat 1 in the horizontal and vertical directions to accurately adjust and position the mold 3. Finally, press the positioning frame 2 to check and determine the fit between the mold 3 and the casting mating surface. After confirming that the contact fit is stable, proceed to the next step. Step 4. Using a low-heat-input pulsed arc welding method, melt the defective areas of the cast characters in two layers to form the missing spaces in the character cavity 10. Before performing the first layer of fusion welding, use an infrared heating gun to heat the casting substrate and the mold 3 in the local area of ​​the cast characters to above 250°C. Then, perform the first layer of fusion welding under the welding process parameters of pulse current 80A (base value) / 110A (peak value) and frequency 10Hz. After completing the first layer of fusion welding, let it stand for 5 to 10 seconds. When the first layer of fusion welding solidifies and the temperature is not lower than 150°C, the second layer of fusion welding can be performed directly. The second layer of fusion welding uses the same welding process parameters as the first layer of fusion welding until the missing spaces are completely filled. Step 5. After the second weld layer and the mold 3 have cooled sufficiently, directly pull off the magnetic connection between the fixing seat 1 and the casting, clean and reshape the repaired characters on the casting, remove the surface welding slag, grind and tidy the shape of the characters, and complete the welding repair of the bolster characters; at the same time, maintain and repair the fixing seat 1 and the positioning frame 2 for future reuse.

Claims

1. A jig for repairing lettering on castings, characterized in that, include: The fixture (1), positioning frame (2), and mold (3) are provided. The fixture (1) and positioning frame (2) are rectangular frames with corresponding structures. Magnet blocks (4) are evenly distributed on the fixture (1). The fixture (1) can be stably and evenly attracted to the surface of the casting by the magnetic attraction of the magnet blocks (4). The positioning frame (2) can be correspondingly fitted and positioned within the frame of the fixture (1). The mold (3) is a rectangular block with a corresponding structure to the positioning frame (2). It can be correspondingly fitted and positioned within the frame of the positioning frame (2). A through-hole casting cavity (10) and a slag groove (11) are provided on the mold (3). The slag trough (11) is connected to the casting cavity (10). The height H of the connecting slot between the slag trough (11) and the casting cavity (10) corresponds to the thickness of the first layer of welding. This allows the welding slag generated during the first layer of welding to overflow from the casting cavity (10) and flow into the slag trough (11). When the fixing seat (1) is attracted and fixed on the surface of the casting, the positioning frame (2) is restricted and fixed between the fixing seat (1) and the casting. The mold (3) is restricted and fixed between the positioning frame (2) and the casting, so that the casting cavity (10) on the mold (3) is fitted with the casting to be repaired on the surface of the casting.

2. The casting lettering repair jig as described in claim 1, characterized in that: The slag trough (11) extends outward in a fan shape from the connecting slot between it and the casting cavity (10), and the bottom surface is an inclined surface that slopes downward along the slag discharge direction; at the same time, the bottom surface and side wall of the slag trough (11) are respectively coated with an anti-adhesion coating.

3. The casting lettering repair jig as described in claim 2, characterized in that: The mold (3) is made of artificial special sand with high refractoriness.

4. A casting lettering repair jig as described in any one of claims 1 to 3, characterized in that: A lateral adjustment mechanism is installed on a set of opposing frame sides of the fixed base (1); the lateral adjustment mechanism includes: an adjusting bolt (5) and a spring (6), the adjusting bolt (5) and the spring (6) are respectively set on two corresponding frame sides of the fixed base (1), wherein the adjusting bolt (5) is threadedly installed on the fixed base (1) and its end abuts against the frame side of the positioning frame (2), the spring (6) is set between the fixed base (1) and the positioning frame (2) and applies an elastic force to the positioning frame (2) relative to the fixed base (1) to elastically fit the positioning frame (2) into the fixed base (1), and rotating the adjusting bolt (5) can drive the positioning frame (2) to move linearly relative to the fixed base (1).

5. The casting lettering repair jig as described in claim 4, characterized in that: A longitudinal adjustment mechanism is installed on another frame perpendicular to the frame assembly on which the lateral adjustment mechanism is installed in the fixed base (1); the longitudinal adjustment mechanism includes: a ball sleeve bolt (7) and a ball head connecting rod (8), a ball sleeve (12) is fixedly connected to the front end of the ball sleeve bolt (7), and is threadedly installed on the fixed base (1); one end of the ball head connecting rod (8) is fixedly connected to the positioning frame (2), and a ball head (13) is fixedly connected to the other end; the ball head (13) The ball head (13) is adapted to the structure of the ball sleeve (12) and fitted inside the ball sleeve (12), so that the ball head connecting rod (8) and the ball sleeve bolt (7) are connected to each other. Rotating the ball sleeve bolt (7) can push and pull the positioning frame (2) through the ball head connecting rod (8) to move linearly in a direction perpendicular to the adjustment direction of the lateral adjustment mechanism. At the same time, the positioning frame (2) has a degree of freedom to make three-dimensional adaptive adjustments relative to the surface of the casting through the fitting of the ball head (13) and the ball sleeve (12).

6. A method for welding and repairing lettering on castings, using the aforementioned jig for repairing lettering on castings, characterized in that... Includes the following steps: Step 1. Determine the welding process based on the defect height of the casting defects on the casting. When the defect height is small, only single-layer fusion welding is required. When the defect height is large, double-layer fusion welding is required. Based on this, prepare the mold (3) according to the determined welding process. When only single-layer fusion welding is required, the height H of the connecting groove between the slag flow groove (11) and the casting cavity (10) on the mold (3) is set to be level with the upper end face of the mold (3). When double-layer fusion welding is required, the height H of the connecting groove between the slag flow groove (11) and the casting cavity (10) is set to correspond to the thickness of the first layer of welding. Step 2. Pre-treat the defective areas of the cast characters by removing surface dirt and impurities and grinding to remove oxide scale from the defective areas, exposing the metal body to ensure effective fusion of the solder and the casting. Step 3. Combine the mold (3) prepared in Step 1 with the fixing seat (1) and the positioning frame (2) to form a casting letter repair mold. Then, align the casting cavity (10) on the mold (3) with the defective casting letter on the casting. Place the fixing seat (1) flat on the surface of the casting. Use the magnet (4) installed on the fixing seat (1) to attract and fix the fixing seat (1) to the casting, so that the casting letter to be repaired fits into the casting cavity (10). Then, rotate the adjusting bolt (5) and the ball sleeve bolt (2) in sequence. 7) Finely adjust the setting position of the positioning frame (2) relative to the fixed seat (1) in the horizontal and vertical directions respectively, and further adjust the corresponding fitting accuracy of the casting and the casting cavity (10). During the horizontal and vertical position adjustment of the positioning frame (2), the positioning frame (2) can adaptively adjust the fitting angle between the mold (3) and the casting mating surface by means of the connection between the ball sleeve (12) on the ball sleeve bolt (7) and the ball head (13) on the ball head connecting rod (8), and optimize the surface contact mating state between the mold (3) and the casting. Step 4. Using a low heat input pulsed arc welding method, melt the welding rod of the same grade as the casting material and fill the missing space formed in the casting cavity (10) of the defect area of ​​the casting in 1 to 2 layers. When filling in 2 layers, the second layer can be filled after the first layer is completed, with an interval of 5 to 10 seconds, until the missing space is completely filled. Step 5. After the mold (3) has cooled down sufficiently, directly pull off the magnetic connection between the fixing seat (1) and the casting. Clean and reshape the repaired characters on the casting, remove the solidified welding slag and adhering impurities, and polish and tidy the shape of the characters. At the same time, maintain and repair the fixed seat (1) and the positioning frame (2) that have been pulled off, in preparation for subsequent character repair.

7. The method for repairing typefaces using a casting typeface repair jig as described in claim 6, characterized in that: In step 1, the mold (3) is prepared using coated sand with a high refractoriness ceramic material as the skeleton and a hot core box process. An anti-adhesion coating is applied to the bottom and side walls of the slag trough (11).

8. The method for repairing typefaces using a casting typeface repair jig as described in claim 6, characterized in that: Before performing welding repair on the cast characters in step 4, the casting substrate and the mold (3) in the local area of ​​the cast characters are preheated to 200-300°C. When filling in two layers, the temperature of the mold (3) is kept not lower than 150°C during the time interval between the second layer filling and the first layer filling.

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