A welding rod for hot forging die repair and its preparation method and use

Abstract

The present invention provides a welding rod for hot forging die repair, and a preparation method and use thereof, and specifically relates to the field of welding materials. The welding rod for hot forging die repair includes a welding core and a coating, and the coating includes the following components and the weight proportions of each component are: 20-30 parts of marble, 10-15 parts of fluorite, 1-3 parts of ferrosilicon, 2-5 parts of ferrotitanium, 25-35 parts of rutile, 2-5 parts of feldspar, 0.8-1.5 parts of ferrovanadium, 2-4 parts of medium carbon ferromanganese, 1.5-2.5 parts of graphite, and 0.5-1 parts of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core includes the following components and the content of each component is: cobalt content is 90-95wt%, iron content is 4-8wt%, and manganese content is 1-2wt%. The welding rod for hot forging die repair of the present application has good welding processability, and the deposited metal not only has good hardness, wear resistance and crack resistance, but also has uniform and stable hardness of the deposited metal.

Description

Technical Field

[0001] The invention relates to the technical field of welding materials, and in particular to a welding rod for repairing a hot forging die, and a preparation method and application thereof. Background Art

[0002] Hot forging products are mainly used in the mold repair industry. Hot forgings exist in the machinery industry and the metallurgical industry. During forging, the deformed metal flows violently, and the forging is in contact with the mold for a long time. Therefore, the mold material is required to have high thermal stability, high temperature strength and hardness, impact toughness, thermal fatigue resistance and wear resistance, and be easy to process. Hot forging molds are a basic equipment for industrial production, and have been used more and more widely with the continuous development of process technology. The working environment of hot forging molds is harsh, and they are constantly subjected to mechanical and thermal loads during the forging cycle. Summary of the invention

[0003] In view of the above problems existing in the prior art, the present invention provides a welding rod for repairing a hot forging die and a preparation method and use thereof, so as to improve the problem of low service life of the hot forging die.

[0004] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present invention provides a welding rod for hot forging die repair, the welding rod for hot forging die repair comprising a welding core and a coating, the coating comprising the following components and the weight proportions of each component are respectively: 20-30 parts of marble, 10-15 parts of fluorite, 1-3 parts of ferrosilicon, 2-5 parts of ferrotitanium, 25-35 parts of rutile, 2-5 parts of feldspar, 0.8-1.5 parts of ferrovanadium, 2-4 parts of medium carbon ferromanganese, 1.5-2.5 parts of graphite, and 0.5-1 part of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core comprises the following components and the content of each component is: 90-95wt% of cobalt, 4-8wt% of iron, and 1-2 wt% of manganese.

[0005] In one embodiment of the present invention, the calcium carbonate content in the marble is ≥96 wt%, the calcium fluoride content in the fluorite is ≥95 wt%, the silicon content in the ferrosilicon is 45-50 wt%, the titanium content in the ferrotitanium is 30-35 wt%, and the vanadium content in the ferrovanadium is 50-55 wt%.

[0006] In one embodiment of the present invention, the particle size of the graphite and the sodium carboxymethyl cellulose is 60-100 mesh, and the particle size of the remaining components is 40-80 mesh.

[0007] In one embodiment of the present invention, the diameter of the welding core is 2.5-4.0 mm.

[0008] A second aspect of the present invention provides a method for preparing a welding rod for hot forging die repair, comprising the following steps:

[0009] Weigh each component according to weight and mix them evenly to prepare the coating;

[0010] Adding a binder to the coating and stirring evenly to form a coating mixture;

[0011] The coating mixture is pressed onto the surface of the welding core and dried to obtain the welding rod for hot forging die repair.

[0012] In one embodiment of the present invention, the adhesive is a water glass adhesive, and the mass of the adhesive is 20-23% of the total mass of the coating.

[0013] In one embodiment of the present invention, the weight of the coating mixture after drying is 40-45% of the total weight of the welding rod for hot forging die repairing.

[0014] In one embodiment of the present invention, the pressure of the press coating is 8-12 MPa.

[0015] In one embodiment of the present invention, the drying temperature is 350-380° C., and the drying time is 1-2 hours.

[0016] A third aspect of the present invention provides a use of a welding rod for hot forging die repair, wherein the welding rod for hot forging die repair is used for hot forging die repair.

[0017] The welding rod for hot forging die repair of the present invention uses a cobalt-based alloy as the welding core. The cobalt-based alloy is a hard alloy that can resist various types of wear and corrosion as well as high-temperature oxidation, and has excellent oxidation resistance, corrosion resistance and heat resistance. Adding marble to the coating can play a slag-forming and gas-forming function at the arc temperature, which can improve the anti-pore performance of the welding rod; adding medium-carbon ferromanganese, ferrovanadium and graphite can refine the structure of the deposited metal and improve the toughness of the weld. The welding rod for hot forging die repair prepared by the present invention has a smooth surface and good pressure coating properties. It still has good tensile strength, toughness and wear resistance in high-temperature application scenarios, and is suitable for the repair of hot forging dies. After being repaired using the welding rod of the present application, the hot forging die is resistant to high temperatures, has good thermal stability, and has good impact toughness and thermal fatigue resistance, which can greatly improve the service life of the hot forging die. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0019] Figure 1The figure is a flow chart of the preparation of a welding rod for hot forging die repair in one embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0021] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0022] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" etc. used in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0023] The invention provides a welding rod for repairing a hot forging die, comprising a welding core and a coating, wherein the coating comprises the following components, and the weight percentage of each component is respectively: 20-30 parts of marble, 10-15 parts of fluorite, 1-3 parts of ferrosilicon, 2-5 parts of ferrotitanium, 25-35 parts of rutile, 2-5 parts of feldspar, 0.8-1.5 parts of ferrovanadium, 2-4 parts of medium-carbon ferromanganese, 1.5-2.5 parts of graphite, and 0.5-1 part of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core comprises the following components, and the content of each component is: 90-95wt% of cobalt, 4-8wt% of iron, and 1-2wt% of manganese.

[0024] The functions of each component in the drug skin are as follows:

[0025] Marble: It mainly plays the role of gasification and slag formation. During the welding process, calcium carbonate decomposes into calcium oxide and carbon dioxide gas. The generated carbon dioxide can keep the molten pool in an inert gas protection. The weight proportion of marble in the coating of the present invention is 20 to 30 parts, such as 20 parts, 23 parts, 25 parts, 28 parts or 30 parts, etc., any value within the range of 20 to 30 parts.

[0026] Fluorite: It mainly plays a role in slag formation. During welding, calcium can play a role in deoxidation and desulfurization, and fluorine can play a role in dehydrogenation. Therefore, fluorite can also play a role in purifying the deposited metal. The weight proportion of fluorite in the coating of the present invention is 10 to 15 parts, such as 10 parts, 12 parts, 14 parts or 15 parts, etc., any value within the range of 10 to 15 parts.

[0027] Graphite: Its main function is to transfer carbon elements to the deposited metal, thereby increasing the hardness of the deposited metal. It can also deoxidize and improve the pressure coating properties, but too much graphite will increase splashing. Therefore, the weight of graphite in the coating of the present invention is 1.5 to 2.5 parts, such as 1.5 parts, 2 parts or 2.5 parts, etc. Any value within the range of 1.5 to 2.5 parts.

[0028] Medium carbon ferromanganese: mainly used as a deoxidizer, alloying agent and desulfurizer, too much of which will increase splashing. Therefore, the weight percentage of medium carbon ferromanganese in the coating of the present invention is 2 to 4 parts, such as 2 parts, 3 parts or 4 parts, etc., any value within the range of 2 to 4 parts.

[0029] Ferrosilicon: mainly used as a deoxidizer and alloying agent, too much of which will increase splashing and reduce toughness. The weight percentage of ferrosilicon in the coating of the present invention is 1 to 3 parts, such as 1 part, 2 parts or 3 parts, etc., any value within the range of 1 to 3 parts.

[0030] Ferrotitanium: Mainly used as a deoxidizer, too much of which will increase splashing. Therefore, the weight percentage of ferrotitanium in the coating of the present invention is 2 to 5 parts, such as 2 parts, 4 parts or 5 parts, etc., any value within the range of 2 to 5 parts.

[0031] Feldspar: mainly used for slag making and arc stabilization, and can adjust the melting point and tension of welding slag. The weight proportion of feldspar in the coating of the present invention is 2 to 5 parts, such as 2 parts, 4 parts or 5 parts, etc., any value within the range of 2 to 5 parts.

[0032] Rutile: The main component of rutile is titanium dioxide, which can stabilize the arc, reduce spatter, and improve slag removal when used with other slag-forming agents. The weight percentage of rutile in the coating of the present invention is 25 to 35 parts, such as 25 parts, 28 parts, 30 parts, 33 parts or 35 parts, etc., any value within the range of 25 to 35 parts.

[0033] Sodium carboxymethyl cellulose: Sodium carboxymethyl cellulose increases the fluidity of the powder, making it easy for the electrode to be evenly pressed on the surface of the steel core, and improving the crack resistance of the electrode coating. Too much sodium carboxymethyl cellulose increases the moisture absorption of the coating and is easy to produce pores. The weight percentage of sodium carboxymethyl cellulose in the coating of the present invention is 0.5 to 1 part, such as 0.5 part, 0.8 part or 1 part, and any value within the range of 0.5 to 1 part.

[0034] Ferrovanadium: It is mainly used for alloying. Vanadium can improve the wear resistance of welds, refine grains, and improve the impact toughness of steel. However, excessive vanadium will reduce wear resistance. The weight percentage of ferrovanadium in the coating of the present invention is 0.8 to 1.5 parts, such as 0.8 parts, 1 part, 1.2 parts or 1.5 parts, etc., any value within the range of 0.8 to 1.5 parts.

[0035] In one embodiment, the calcium carbonate content in the marble is ≥96wt%, the calcium fluoride content in the fluorite is ≥95wt%, the silicon content in the ferrosilicon is 45-50wt%, the titanium content in the ferrotitanium is 30-35wt%, and the vanadium content in the ferrovanadium is 50-55wt%.

[0036] In one embodiment, the particle size of graphite and sodium carboxymethyl cellulose is 60-100 mesh, and the particle size of the remaining components is 40-80 mesh.

[0037] The welding rod for hot forging die repair of the present application has good welding processability. The deposited metal not only has good hardness, wear resistance and crack resistance, but also has uniform and stable hardness, which is suitable for repairing hot forging dies.

[0038] See also Figure 1 The present invention provides a method for preparing a welding rod for hot forging die repair, comprising the following steps:

[0039] S1. Weigh each component according to weight and mix them evenly to prepare a coating;

[0040] S2, adding a binder to the coating, stirring evenly to form a coating mixture;

[0041] S3. Press the coating mixture onto the surface of the welding core and dry it to obtain a welding rod for hot forging die repair.

[0042] In step S1, the components in the coating are mixed and stirred evenly according to the ratio of 20-30 parts of marble, 10-15 parts of fluorite, 1-3 parts of ferrosilicon, 2-5 parts of ferrotitanium, 25-35 parts of rutile, 2-5 parts of feldspar, 0.8-1.5 parts of ferrovanadium, 2-4 parts of medium carbon ferromanganese, 1.5-2.5 parts of graphite, and 0.5-1 parts of sodium carboxymethyl cellulose. Among them, the particle size of graphite and sodium carboxymethyl cellulose is 60-100 mesh, and the particle size of marble, fluorite, ferrosilicon, ferrotitanium, rutile, feldspar, ferrovanadium and medium carbon ferromanganese is 40-80 mesh.

[0043] In step S2, the binder is a water glass binder, and the mass of the binder is 20-23% of the total mass of the coating, such as 20%, 21%, 22% or 23%, etc., any value within the range of 20-23%. The weight of the coating mixture after drying is 40-45% of the total weight of the welding rod for hot forging die repair, such as 40%, 42% or 45%, etc., any value within the range of 40-45.

[0044] In step S3, the welding core includes the following components and the content of each component in terms of the mass percentage of the welding core: the cobalt content is 90-95wt%, the iron content is 4-8wt%, and the manganese content is 1-2wt%. Cobalt not only has high hardness and strength, but also has good corrosion resistance and excellent high temperature performance. In the present application, the diameter of the welding core is 2.5-4.0mm, for example, the diameter of the welding core can be any value within the range of 2.5-4.0mm, such as 2.5mm, 3mm, 3.5mm or 4mm. When the coating mixture is pressed on the welding core, a press coating method commonly used in the art is adopted. In the present application, the press coating pressure is 8-12MPa, for example, any value within the range of 8-12MPa, such as 8MPa, 10MPa or 12MPa. During drying, the drying temperature is 350-380°C, such as 350°C, 360°C, 370°C or 380°C, any value within the range of 350-380°C; the drying time is 1-2h, such as 1h, 1.5h or 2h, any value within the range of 1-2h.

[0045] The technical scheme of the present invention is described in detail below through several specific examples. Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products, or can be prepared by conventional methods in the art, and the instruments used in the examples are all commercially available.

[0046] Example 1

[0047] The hot forging die repair welding rod of this embodiment includes a welding core and a coating, and the coating includes the following components and the weight percentage of each component is: 25 parts of marble, 12 parts of fluorite, 3 parts of ferrosilicon, 2 parts of ferrotitanium, 25 parts of rutile, 2 parts of feldspar, 1.5 parts of ferrovanadium, 4 parts of medium carbon ferromanganese, 1.5 parts of graphite, and 0.5 parts of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core includes the following components and the content of each component is: 90wt% of cobalt, 8wt% of iron, and 2wt% of manganese. Add 23% of the total mass of the dry powder mixture to the above-mentioned coating, stir and mix evenly to form a coating mixture, apply the coating mixture to the surface of the welding core at 8MPa, and dry at 350℃ for 1h to obtain the hot forging die repair welding rod. In this embodiment, the diameter of the welding core is 2.5mm, and the mass of the coating mixture after drying accounts for 40% of the total mass of the hot forging die repair welding rod.

[0048] Example 2

[0049] The hot forging die repair welding rod of this embodiment includes a welding core and a coating, and the coating includes the following components and the weight percentage of each component is: 27 parts of marble, 10 parts of fluorite, 2 parts of ferrosilicon, 3.5 parts of ferrotitanium, 35 parts of rutile, 3.5 parts of feldspar, 1.2 parts of ferrovanadium, 3 parts of medium carbon ferromanganese, 2 parts of graphite, and 0.8 parts of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core includes the following components and the content of each component is: 95wt% of cobalt, 4wt% of iron, and 1wt% of manganese. Add 22% of the total mass of the dry powder mixture to the above-mentioned coating, stir and mix evenly to form a coating mixture, apply the coating mixture to the surface of the welding core at 12MPa, and dry at 360℃ for 1.5h to obtain the hot forging die repair welding rod. In this embodiment, the diameter of the welding core is 3.2mm, and the mass of the coating mixture after drying accounts for 43% of the total mass of the hot forging die repair welding rod.

[0050] Example 3

[0051] The hot forging die repair welding rod of this embodiment includes a welding core and a coating, wherein the coating includes the following components and the weight percentage of each component is: 29 parts of marble, 12 parts of fluorite, 1 part of ferrosilicon, 5 parts of ferrotitanium, 30 parts of rutile, 5 parts of feldspar, 0.8 parts of ferrovanadium, 2 parts of medium carbon ferromanganese, 2.5 parts of graphite, and 1 part of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core includes the following components and the content of each component is: 93wt% of cobalt, 5wt% of iron, and 2wt% of manganese. Add 20% of the total mass of the dry powder mixture to the above-mentioned coating, stir and mix evenly to form a coating mixture, apply the coating mixture to the surface of the welding core at 10MPa, and dry at 380℃ for 2h to obtain the hot forging die repair welding rod. In this embodiment, the diameter of the welding core is 4mm, and the mass of the coating mixture after drying accounts for 45% of the total mass of the hot forging die repair welding rod.

[0052] Example 4

[0053] The hot forging die repair welding rod of this embodiment includes a welding core and a coating, wherein the coating includes the following components and the weight percentage of each component is: 20 parts of marble, 10 parts of fluorite, 2.5 parts of ferrosilicon, 4 parts of ferrotitanium, 28 parts of rutile, 3 parts of feldspar, 1 part of ferrovanadium, 3.5 parts of medium carbon ferromanganese, 1.8 parts of graphite, and 0.5 parts of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core includes the following components and the content of each component is: 94wt% of cobalt, 4wt% of iron, and 2wt% of manganese. Add 21% of the total mass of the dry powder mixture to the above-mentioned coating, stir and mix evenly to form a coating mixture, apply the coating mixture to the surface of the welding core at 11MPa, and dry at 360℃ for 1.5h to obtain the hot forging die repair welding rod. In this embodiment, the diameter of the welding core is 3.5mm, and the mass of the coating mixture after drying accounts for 42% of the total mass of the hot forging die repair welding rod.

[0054] Example 5

[0055] The hot forging die repair welding rod of this embodiment includes a welding core and a coating, wherein the coating includes the following components and the weight percentage of each component is: 30 parts of marble, 15 parts of fluorite, 3 parts of ferrosilicon, 3 parts of ferrotitanium, 33 parts of rutile, 4 parts of feldspar, 1 part of ferrovanadium, 3 parts of medium carbon ferromanganese, 2.5 parts of graphite, and 1 part of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the welding core includes the following components and the content of each component is: 94wt% of cobalt, 4.5wt% of iron, and 1.5wt% of manganese. Add 23% of the total mass of the dry powder mixture to the above-mentioned coating, stir and mix evenly to form a coating mixture, apply the coating mixture to the surface of the welding core at 12MPa, and dry at 380℃ for 2h to obtain the hot forging die repair welding rod. In this embodiment, the diameter of the welding core is 3mm, and the mass of the coating mixture after drying accounts for 44% of the total mass of the hot forging die repair welding rod.

[0056] The hot forging die repair welding rods provided in the above-mentioned Examples 1 to 5 were subjected to hardness tests, tempering stability tests, crack resistance tests and high-temperature tensile strength tests. The welded hardness and welding process performance of the deposited metal are shown in Table 1; the tempering stability, crack resistance and high-temperature tensile strength are shown in Table 2.

[0057] Table 1 Welded hardness and crack resistance of deposited metal of hot forging die repair welding rod prepared in Examples 1 to 5

[0058]

[0059] Table 2 Tempering stability, crack resistance and high temperature strength of the deposited metal of the hot forging die repair electrode prepared in Examples 1 to 5 of the present invention

[0060]

[0061] The experimental results of Examples 1 to 5 show that the welding process of the welding rod for repairing hot forging dies of the present invention is good, the deposited metal has good hardness and wear resistance, and the hardness of the deposited metal remains stable after tempering at 650°C and 1000°C, and no cracks are generated, indicating that the deposited metal has good tempering stability and heat fatigue resistance, and the deposited metal has good high-temperature tensile strength.

[0062] The welding rod for hot forging die repair of the present invention uses cobalt-based alloy as the welding core. Cobalt-based alloy is a hard alloy that can resist various types of wear and corrosion and high-temperature oxidation, and has good oxidation resistance, corrosion resistance and heat resistance. Adding marble to the coating can play the function of slag formation and gasification at the arc temperature, which can improve the anti-porosity performance of the welding rod; adding medium-carbon ferromanganese, ferrovanadium and graphite can refine the structure of the deposited metal and improve the toughness of the weld. The welding rod for hot forging die repair prepared by the present invention has a smooth surface and good pressure coating performance. It still has good tensile strength, toughness and wear resistance in high-temperature application scenarios, and is suitable for repairing hot forging dies. After being repaired by the welding rod of the present application, the hot forging die is resistant to high temperature, has good thermal stability, good impact toughness and thermal fatigue resistance, and can greatly improve the service life of the hot forging die. Therefore, the present invention effectively overcomes some practical problems in the prior art and has high utilization value and use significance. The above embodiments only illustrate the principles and effects of the present invention, and are not used to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person skilled in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A welding rod for hot forging die repair, characterized in that: The invention comprises a welding core and a coating, wherein the coating comprises the following components and the weight proportions of the components are: 20-30 parts of marble, 10-15 parts of fluorite, 1-3 parts of ferrosilicon, 2-5 parts of ferrotitanium, 25-35 parts of rutile, 2-5 parts of feldspar, 0.8-1.5 parts of ferrovanadium, 2-4 parts of medium-carbon ferromanganese, 1.5-2.5 parts of graphite, and 0.5-1 part of sodium carboxymethyl cellulose; in terms of the mass percentage of the welding core, the content of calcium carbonate in the marble is ≥96wt%, and the content of calcium carbonate in the fluorite is ≥96wt%. The calcium fluoride content in the stone is ≥95wt%; the silicon content in the ferrosilicon is 45-50wt%; the titanium content in the ferrotitanium is 30-35wt%; the vanadium content in the ferrovanadium is 50-55wt%; the particle size of the graphite and the sodium carboxymethyl cellulose is 60-100 mesh, and the particle size of the remaining components is 40-80 mesh; the welding core includes the following components and the content of each component is: cobalt content is 90-95wt%, iron content is 4-8wt%, and manganese content is 1-2wt%.

2. The hot forging die repair welding rod according to claim 1, characterized in that: The diameter of the welding core is 2.5-4.0 mm.

3. A method for preparing a welding rod for hot forging die repair according to any one of claims 1 and 2, characterized in that: The steps include: Weigh each component according to weight and mix them evenly to prepare the coating; Adding a binder to the coating and stirring evenly to form a coating mixture; The coating mixture is pressed onto the surface of the welding core and dried to obtain the welding rod for hot forging die repair.

4. The preparation method according to claim 3, characterized in that: The adhesive is a water glass adhesive, and the mass of the adhesive is 20-23% of the total mass of the coating.

5. The preparation method according to claim 3, characterized in that: The weight of the coating mixture after drying is 40-45% of the total weight of the welding rod for hot forging die repairing.

6. The preparation method according to claim 3, characterized in that: The pressure of the press coating is 8-12 MPa.

7. The preparation method according to claim 3, characterized in that The drying temperature is 350-380° C., and the drying time is 1-2 h.

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