Repair method suitable for pit defect of hammer anvil and application of repair method

Abstract

The invention belongs to the technical field of machining and manufacturing, and relates to a repairing method suitable for a pit defect of a hammer anvil and application of the repairing method. The method specifically comprises the following steps that S1, shot blasting is conducted on the surface with the pit defect needing to be repaired; s2, measuring the size of the surface which needs to be repaired and has the pit defect; s3, a steel plate suitable for the pit defect surface is prepared; s4, a steel plate is welded to the surface of the pit to be repaired; s5, filling powder into a closed space formed by the steel plate and the surface of the pit defect; S6, sealing and welding by using a sealing cover after the powder filling is completed; s7, carrying out hot isostatic pressing; and S8, the repaired surface is milled and flattened. And the hammer anvil with large defects can also be repaired, machining treatment is not needed, the repairing rate is high, the repairing cost is low, time and labor are saved, and economic waste is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of processing and manufacturing, and relates to a method for repairing a pit defect of a hammer anvil and an application thereof. Background Art

[0002] The free forging hammer is the core production equipment of the forging plant. Both the manufacturing of free forgings and the forming of die forging blanks are completed on the hammer anvil.

[0003] The impact force of the forging hammer is mainly concentrated on the upper and lower anvil surfaces of the forging hammer. When working, in addition to bearing a large impact load, the part of the forging hammer in contact with the workpiece is also very easy to wear and deform, resulting in defects on the working surface of the forging hammer, which in turn affects the appearance quality of the forging product. In severe cases, it may even cause the forging hammer to be scrapped and cannot be put into use any further. In addition, the hammer anvil is in contact with high-temperature heated forgings at a temperature of up to 900℃-1200℃. In just half an hour, the temperature can rise to about 300℃-400℃, and even reach 500℃-800℃ locally. During the forging or hammering process, it will be repeatedly cooled by air, lubricating oil, and water. Under such harsh conditions of rapid cooling and heating, the hammer anvil is prone to deformation, pit defects, and even fatigue cracks. This not only greatly shortens the service life of the hammer anvil, but also directly has an adverse effect on the surface quality of the forging, and increases the workload of the forging material finishing.

[0004] There are usually two traditional treatment methods for hammer anvils with deformed pits on the surface: one is surfacing. During surfacing, the pits or cracks need to be enlarged and cleaned first, and then the surfacing operation is carried out. However, the surfacing material and the hammer anvil material are only combined by welding, and the bonding surface strength is poor. The surfacing material may fall off, which will cause safety accidents during the forging process. The second is to machine the hammer anvil to make it into a small hammer anvil when the defects are large and cannot be surfacing. However, the machining cost is quite high and the scrap rate is high. In addition, the free forging hammer anvil generally presents a square three-dimensional structure with a large size. The raw materials used to make the hammer anvil are very huge, ranging from tens of tons to hundreds of tons. If it is scrapped just because part of the working surface is sunken, it will cause great economic losses to the company. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and to provide a method for repairing a pit defect of a hammer anvil.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a method for repairing a pit defect of a hammer anvil, specifically comprising the following steps:

[0007] S1. Shot peening is performed on the surface of the pit defect to be repaired;

[0008] S2. Measure the size of the surface of the pit defect to be repaired, and prepare a bent steel plate suitable for the surface of the pit defect according to the size, and a powder loading hole is provided on the bent surface of the bent steel plate;

[0009] S3, welding the bent steel plate to the hammer anvil so that the bent protrusion of the bent steel plate covers the pit defect;

[0010] S4, welding two flat steel plates to the two ends of the bent steel plate respectively, so that a closed space is formed between the bent steel plate and the pit defect;

[0011] S5. Powder that is the same as the material of the hammer and anvil is loaded into the closed space through the powder loading hole;

[0012] S6. After the powder is loaded, the plugging cover is placed behind the powder loading port for sealing welding;

[0013] S7, performing hot isostatic pressing;

[0014] S8. Mill the surface of the repaired pit defect to make it smooth.

[0015] Furthermore, in the shot peening process in step S1, stainless steel shots are used, and the particle size of the stainless steel shots is 0.2 mm-0.3 mm.

[0016] Furthermore, in step S2, the thickness of the bent steel plate and the flat steel plate are both 4 mm-5 mm.

[0017] Furthermore, the bent steel plate in step S2 is prepared by a bending process, and the depth of the bending protrusion is 1.1-1.3 times the maximum depth of the pit defect.

[0018] Furthermore, in step S2, the bent steel plate suitable for the pit defect surface is prepared as follows: the length of the bent steel plate is 18mm-22mm longer than the length of the pit defect, and the width of the bent steel plate is 18mm-22mm wider than the width of the pit defect.

[0019] Furthermore, the welding in steps S3 and S4 and the sealing welding in S6 are both performed by tungsten inert gas arc welding, which requires 3-5 times of filler wire welding and a welding current of 110A-130A.

[0020] Furthermore, the diameter of the powder loading hole in step S3 is 10 mm-15 mm.

[0021] Furthermore, the particle size of the powder in step S5 is 53 μm-150 μm.

[0022] Furthermore, in step S7, the hot isostatic pressing temperature is 1200° C.-1300° C., and the pressure is 120 MPa-140 MPa.

[0023] The present application also provides a method for repairing a pit defect of a hammer anvil, which is applicable to a hammer anvil whose repair material is 5CrNiMo steel, 5CrNiMoV steel, H13 steel or GH4169 high-temperature alloy.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention avoids the problem of the surfacing welding part falling off after a period of use when repairing the pits on the surface of the hammer anvil by surfacing welding, and can also repair the hammer anvil with larger defects without machining, and has a high repair rate and low repair cost, saving time and effort and avoiding economic waste; in addition, the present invention can repair hammer anvils of various materials, has a wide repair range, can increase the service life of the hammer anvil, and save resources and production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] Figure 1 It is a front view schematic diagram of welding a steel plate and a hammer anvil in the present invention;

[0029] Figure 2 It is a side view schematic diagram of the welding of the steel plate and the hammer anvil in the present invention.

[0030] Among them: 1 is the hammer anvil; 2 is the bent steel plate; 3 is the welding point between the sealing cover and the steel plate; 4 is the powder; 5 is the welding point between the steel plate and the hammer anvil; 6 is the sealing cover; 7 is the powder loading hole; 8 is the pit defect. DETAILED DESCRIPTION

[0031] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples of devices consistent with some aspects of the present invention as detailed in the appended claims.

[0032] like Figures 1-2 As shown, a method for repairing a pit defect of a hammer anvil specifically comprises the following steps:

[0033] S1, performing shot peening on the surface of the pit defect 8 to be repaired;

[0034] S2, measuring the size of the surface of the pit defect 8 to be repaired, and preparing a bent steel plate 2 suitable for the surface of the pit defect 8 according to the size, and a powder loading hole 7 is provided on the bent steel plate 2, wherein: the bent steel plate 2 is prepared by a bending process in the middle of an ordinary steel plate, and the middle of the bent steel plate 2 has a bending protrusion;

[0035] S3, welding the bent steel plate 2 to the pit defect 8 to be repaired, so that the bent protrusion of the bent steel plate 2 covers the pit defect 8; the welding point 3 between the sealing cover and the steel plate is located at the welding point between the hammer anvil and the steel plate;

[0036] S4, welding two flat steel plates 9 to the two ends of the bent steel plate 2, so that a closed space is formed between the bent steel plate 2 and the pit defect 8. The two ends of the bent steel plate 2 are the bent sides of the bent steel plate. Two places are mainly welded during welding, one is the connection between the bent side and the flat steel plate 9, and the other is the connection between the flat steel plate 9 and the hammer anvil 1;

[0037] S4, loading powder 4 of the same material as the anvil 1 into the closed space formed by the bent steel plate 2 and the pit defect 8 through the powder loading hole 7;

[0038] S5, after the powder filling is completed, the plugging cover 6 is placed behind the powder filling port for sealing welding; the welding point 5 between the steel plate and the hammer anvil is located at the welding point between the plugging cover 6 and the bent steel plate 2;

[0039] S6. performing hot isostatic pressing;

[0040] S7, milling the surface of the repaired pit defect 8 to make it smooth.

[0041] Furthermore, in the shot peening process in step S1, stainless steel shots are used, and the particle size of the stainless steel shots is 0.2 mm-0.3 mm.

[0042] Furthermore, in step S2, the thickness of the bent steel plate 2 is 4 mm to 5 mm.

[0043] Furthermore, a circular protrusion is provided at a position on the bent steel plate 2 in the step S2 that is opposite to the pit, and a diameter of the circular protrusion is 1.1-1.3 times the maximum depth of the pit defect 8 .

[0044] Furthermore, in step S2, the bent steel plate 2 suitable for the surface of the pit defect 8 is prepared as follows: the length of the bent steel plate 2 is 18mm-22mm longer than the length of the pit defect, and the width of the bent steel plate 2 is 18mm-22mm wider than the width of the pit defect.

[0045] Furthermore, the welding in steps S3 and S4 and the sealing welding in S6 are both performed by tungsten inert gas arc welding, which requires 3-5 times of filler wire welding and a welding current of 110A-130A.

[0046] Furthermore, the diameter of the powder loading hole 7 in step S2 is 10 mm, and the powder loading hole 7 is located at the center of the steel plate.

[0047] Furthermore, the particle size of the powder 4 in step S5 is 53 μm-150 μm.

[0048] Furthermore, in step S7, the hot isostatic pressing temperature is 1200° C.-1300° C., and the pressure is 120 MPa-140 MPa.

[0049] Furthermore, the present invention also provides a method for repairing a pit defect of an anvil, which is applicable to an anvil 1 whose repairing material is 5CrNiMo steel, 5CrNiMoV steel, H13 steel or GH4169 high-temperature alloy.

[0050] Example 1

[0051] A method for repairing a pit defect of a hammer anvil comprises the following steps:

[0052] S1. Shot peening is performed on the surface of the pit defect 8 to be repaired. The size of the shot used in the shot peening is 0.2 mm.

[0053] S2. Measure the size of the surface of the pit defect 8 to be repaired, and prepare a bent steel plate 2 that is suitable for the surface of the pit defect 8 according to the size. The bent steel plate 2 is provided with a powder loading hole 7; the powder loading hole 7 is located at the center of the bent steel plate 2. The length of the bent steel plate 2 is 18 mm longer than the length of the pit defect, the width of the bent steel plate 2 is 18 mm wider than the width of the pit defect, the pit defect is located below the bending protrusion of the bent steel plate, the bending protrusion is located in the middle of the bent steel plate, and the depth of the bending protrusion is 1.1 times the maximum depth of the pit defect 8.

[0054] S3, weld the bent steel plate 2 on the hammer anvil 1 to be repaired, so that the bent steel plate 2 covers the pit defect; use manual tungsten inert gas arc welding to weld the steel plate to the surface of the pit to be repaired, wipe and clean the steel plate with an alcohol rag before welding, and filler wire welding is required 3 times, the welding current is 110A, and the air tightness and internal cleanliness are ensured at the same time; weld two flat steel plates 9 at both ends of the bent steel plate 2, similarly, filler wire welding is performed 3 times, the welding current is 110A, so that a closed space is formed between the bent steel plate 2 and the pit defect 8. Among them, the thickness of the bent steel plate 2 and the flat steel plate 9 are both 4mm.

[0055] S4, loading powder 4 of the same material as the anvil 1 into the closed space formed by the bent steel plate 2, the flat steel plate 9 and the pit defect 8 through the powder loading hole 7, the steel plate is provided with a powder loading hole with a hole size of 10 mm in diameter, and is equipped with a plugging cover matching the powder loading hole, and the powder particle size is 53-106 μm;

[0056] S5. After the powder is loaded, the plugging cover 6 is placed on the powder loading port for sealing welding. After the powder is loaded, the plugging cover is placed on the powder loading port and manual tungsten inert gas arc welding is used. The wire is filled and welded for 3 times. The welding current is 110A.

[0057] S6, hot isostatic pressing, the hot isostatic pressing temperature is 1200°C, and the pressure is 120Mpa;

[0058] S7, the surface of the repaired pit defect 8 is milled and flattened, and the surface is milled and flattened using a milling cutter, and the steel plate and the raised defect repair area are removed.

[0059] Example 2

[0060] A method for repairing a pit defect of a hammer anvil comprises the following steps:

[0061] S1. Shot peening is performed on the surface of the pit defect 8 to be repaired. The size of the shot used in the shot peening is 0.25 mm.

[0062] S2. Measure the size of the surface of the pit defect 8 to be repaired, and prepare a bent steel plate 2 that is suitable for the surface of the pit defect 8 according to the size. The bent steel plate 2 is provided with a powder loading hole 7; the powder loading hole 7 is located at the center of the bent steel plate 2. The length of the bent steel plate 2 is 20 mm longer than the length of the pit defect, the width of the bent steel plate 2 is 20 mm wider than the width of the pit defect, the pit defect is located below the bending protrusion of the bent steel plate, the bending protrusion is located in the middle of the bent steel plate, and the depth of the bending protrusion is 1.2 times the maximum depth of the pit defect 8.

[0063] S3, weld the bent steel plate 2 to the hammer anvil 1 to be repaired, so that the bent steel plate 2 covers the pit defect 8; use manual tungsten inert gas arc welding to weld the steel plate to the surface of the pit to be repaired, wipe and clean the steel plate with an alcohol rag before welding, and filler wire welding 4 times, the welding current is 120A, and the air tightness and internal cleanliness are guaranteed at the same time; weld two flat steel plates 9 to the two ends of the bent steel plate 2 respectively, similarly, filler wire welding 4 times, the welding current is 120A, so that a closed space is formed between the bent steel plate 2 and the pit defect 8. Among them, the thickness of the bent steel plate 2 and the flat steel plate 9 are both 4.5mm.

[0064] S4, loading powder 4 of the same material as the anvil 1 into the closed space formed by the bent steel plate 2 and the pit defect 8 through the powder loading hole 7, the steel plate is provided with a powder loading hole with a hole size of 12.5 mm in diameter, and equipped with a plugging cover matching the powder loading hole, and the powder particle size is 106-150 μm;

[0065] S5. After powder loading is completed, the plugging cover 6 is placed behind the powder loading port for sealing welding. After powder loading, the plugging cover is placed on the powder loading port and manual tungsten inert gas arc welding is used. The wire is filled and welded 4 times, and the welding current is 120A.

[0066] S6, hot isostatic pressing, the hot isostatic pressing temperature is 1250°C, and the pressure is 130Mpa;

[0067] S7, the surface of the repaired pit defect 8 is milled and flattened, and the surface is milled and flattened using a milling cutter, and the steel plate and the raised defect repair area are removed.

[0068] Example 3

[0069] A method for repairing a pit defect of a hammer anvil comprises the following steps:

[0070] S1. Shot peening is performed on the surface of the pit defect 8 to be repaired. The size of the shot used in the shot peening is 0.3 mm.

[0071] S2. Measure the size of the surface of the pit defect 8 to be repaired, and prepare a bent steel plate 2 that is suitable for the surface of the pit defect 8 according to the size. The bent steel plate 2 is provided with a powder loading hole 7; the powder loading hole 7 is located at the center of the bent steel plate 2. The length of the bent steel plate 2 is 22 mm longer than the length of the pit defect, the width of the bent steel plate 2 is 22 mm wider than the width of the pit defect, the pit defect is located below the bending protrusion of the bent steel plate, the bending protrusion is located in the middle of the bent steel plate, and the depth of the bending protrusion is 1.3 times the maximum depth of the pit defect 8.

[0072] S3, weld the bent steel plate 2 on the hammer anvil 1 to be repaired, so that the bent steel plate 2 covers the pit defect 8; use manual tungsten inert gas arc welding to weld the steel plate to the surface of the pit to be repaired, wipe and clean the steel plate with an alcohol rag before welding, and filler wire welding 5 times, the welding current is 130A, and the air tightness and internal cleanliness are ensured at the same time; weld two flat steel plates 9 at both ends of the bent steel plate 2, similarly, filler wire welding 5 times, the welding current is 130A, so that a closed space is formed between the bent steel plate 2 and the pit defect 8. Among them, the thickness of the bent steel plate 2 and the flat steel plate 9 are both 5mm.

[0073] S4, loading powder 4 of the same material as the anvil 1 into the closed space formed by the bent steel plate 2 and the pit defect 8 through the powder loading hole 7, the steel plate is provided with a powder loading hole with a hole size of 15 mm in diameter, and equipped with a plugging cover matching the powder loading hole, and the powder particle size is 53-150 μm;

[0074] S5. After powder loading is completed, the plugging cover 6 is placed behind the powder loading port for sealing welding. After powder loading, the plugging cover is placed on the powder loading port and manual tungsten inert gas arc welding is used. Filler wire welding is performed 5 times with a welding current of 130A.

[0075] S6, hot isostatic pressing, the hot isostatic pressing temperature is 1300°C, and the pressure is 140Mpa;

[0076] S7, the surface of the repaired pit defect 8 is milled and flattened, and the surface is milled and flattened using a milling cutter, and the steel plate and the raised defect repair area are removed.

[0077] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0078] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for repairing a pit defect of a hammer anvil, characterized in that: The specific steps include: S1. Shot peening is performed on the surface of the pit defect (8) to be repaired; S2, measuring the size of the pit defect (8) to be repaired, and preparing a bent steel plate (2) suitable for the pit defect (8) according to the size, wherein a powder filling hole (7) is provided on the bent surface of the bent steel plate (2); S3, welding the bent steel plate (2) to the hammer anvil (1), so that the bent protrusion of the bent steel plate (2) covers the pit defect (8); S4, welding two flat steel plates (9) to the two ends of the bent steel plate (2) respectively, so that a closed space is formed between the bent steel plate (2), the flat steel plate (9) and the pit defect (8); S5, charging powder (4) of the same material as that of the anvil (1) into the closed space through the powder charging hole (7); S6, after the powder filling is completed, the plugging cover (6) is placed behind the powder filling port for sealing welding; S7, performing hot isostatic pressing; S8, milling the surface of the repaired pit defect (8) to make it smooth.

2. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: Stainless steel shots are used in the shot peening process in step S1, and the particle size of the stainless steel shots is 0.2 mm-0.3 mm.

3. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: The thickness of the bent steel plate (2) in step S2 and the flat steel plate (9) in step S4 are both 4 mm to 5 mm.

4. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: The bent steel plate (2) in step S2 is prepared by a bending process, and the depth of the bent protrusion is 1.1-1.3 times the maximum depth of the pit defect (8).

5. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: In step S2, the bent steel plate (2) that is compatible with the surface of the pit defect (8) is prepared specifically as follows: the length of the bent steel plate (2) is 18mm-22mm longer than the length of the pit defect, and the width of the bent steel plate (2) is 18mm-22mm wider than the width of the pit defect.

6. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: The welding in steps S3 and S4 and the sealing welding in S6 are both performed by tungsten inert gas arc welding, which requires 3-5 times of filler wire welding and a welding current of 110A-130A.

7. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: The diameter of the powder loading hole (7) in step S2 is 10 mm to 15 mm.

8. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: The particle size of the powder (4) in step S5 is 53 μm-150 μm.

9. A method for repairing a pit defect of a hammer anvil according to claim 1, characterized in that: In step S7, the hot isostatic pressing temperature is 1200° C.-1300° C., and the pressure is 120 MPa-140 MPa.

10. A method for repairing a pit defect of a hammer anvil as claimed in any one of claims 1 to 9, wherein the method is applied to a hammer anvil (1) whose repairing material is 5CrNiMo steel, 5CrNiMoV steel, H13 steel or GH4169 high temperature alloy.

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