Welding rod for heat-resistant steel welding and preparation method thereof

Abstract

The present invention provides a welding rod for heat-resistant steel welding and a preparation method thereof, specifically relating to the field of welding materials. The welding rod for heat-resistant steel welding of the present invention comprises a welding core and a coating, wherein the coating comprises the following components and the weight proportions of each component are as follows: 10-13 parts of marble, 3-5 parts of calcium fluoride, 0.2-0.5 parts of graphite, 1-2 parts of silicon micropowder, 1-2 parts of rutile, 1-2 parts of 45 ferrosilicon, 0.5-1.5 parts of low-carbon ferromanganese, 9-12 parts of low-carbon ferrochromium, 1-2 parts of molybdenum powder, 0.2-0.5 parts of ferrovanadium, 35-50 parts of reduced iron powder, 0.3-0.6 parts of potassium chloride, 0.3-0.6 parts of synthetic mica, and 0.5-1.5 parts of rare earth ferrosilicon. The welding rod for heat-resistant steel welding of the present invention has the advantages of high strength, good toughness, good crack resistance, high deposition rate, stable arc, low spatter, easy slag removal, and beautiful weld formation. It is suitable for welding heat-resistant steel for hydrogenation reactors.

Description

Technical Field

[0001] The present invention relates to the field of welding materials, and in particular to a welding rod for heat-resistant steel welding and a preparation method thereof. Background Art

[0002] With the research of science and technology, my country's chemical industry has been vigorously developed, and hydrogenation reactors are being used more and more widely. Hydrogenation reactors are the core equipment of the hydrocracking process of petroleum refining equipment and are important key equipment in modern oil refining. Generally, the operating temperature of hydrogenation reactors is above 400°C and the working pressure is about 20Mpa. Due to its excellent high-temperature strength, oxidation resistance, corrosion resistance, good structural stability and weldability, heat-resistant steel has become an ideal material for manufacturing high-temperature and high-pressure equipment such as hydrogenation reactors, such as 2.25Cr-1Mo-0.25V steel. However, the supporting welding materials required in the manufacturing process of hydrogenation reactors have long been dependent on imports, which has become a link that restricts the complete localization of hydrogenation reactor manufacturing. Under high temperature and high pressure conditions, welds welded with heat-resistant steel are prone to failure in the form of temper embrittlement and reduced low-temperature toughness. Summary of the Invention

[0003] In view of the above shortcomings of the prior art, the present invention provides a welding rod for heat-resistant steel welding and a preparation method thereof, so as to improve the problem that the weld layer is prone to temper embrittlement and low-temperature toughness reduction.

[0004] To achieve the above-mentioned and other related purposes, the present invention provides a welding rod for heat-resistant steel welding, comprising a welding core and a coating, wherein the coating comprises the following components, and the weight proportions of the components are: 10-13 parts of marble, 3-5 parts of calcium fluoride, 0.2-0.5 parts of graphite, 1-2 parts of silicon micropowder, 1-2 parts of rutile, 1-2 parts of 45 ferrosilicon, 0.5-1.5 parts of low-carbon ferromanganese, 9-12 parts of low-carbon ferrochrome, 1-2 parts of molybdenum powder, 0.2-0.5 parts of ferrovanadium, 35-50 parts of reduced iron powder, 0.3-0.6 parts of potassium chloride, 0.3-0.6 parts of synthetic mica, and 0.5-1.5 parts of rare earth ferrosilicon.

[0005] In one example of the present invention, the calcium carbonate content in the marble is ≥96wt%; the silicon dioxide content in the silicon micropowder is ≥98wt%; the manganese content in the low-carbon ferromanganese is ≥80wt%; the chromium content in the low-carbon ferrochrome is ≥70wt% and the carbon content is ≤0.06wt%; the molybdenum content in the molybdenum powder is ≥99wt%; the vanadium content in the ferrovanadium is 50-55wt%; and the iron content in the reduced iron powder is ≥98wt%.

[0006] In one example of the present invention, the particle size of the graphite, the silicon powder and the rare earth ferrosilicon is 80-120 mesh, and the particle size of the remaining components is 40-80 mesh.

[0007] In an example of the present invention, the welding core is made of low-sulfur and low-phosphorus H08 steel core, and the P content of the welding core is ≤0.015wt%, and the S content is ≤0.010wt%.

[0008] In an example of the present invention, the diameter of the welding core is 3.2-5.0 mm.

[0009] The present invention also provides a method for preparing a welding rod for heat-resistant steel welding, comprising the following steps: weighing the components of the coating according to a ratio and mixing them evenly to obtain a coating powder; adding a binder to the coating powder and stirring evenly to form a coating mixture; pressing the coating mixture onto the surface of the welding core and drying it to obtain the welding rod for heat-resistant steel welding.

[0010] In one example of the present invention, the binder is a water glass binder, and the mass of the binder is 23-25% of the total mass of the coating powder.

[0011] In one example of the present invention, the weight of the coating mixture in the heat-resistant steel welding rod after drying is 40-45% of the total weight of the heat-resistant steel welding rod.

[0012] In an example of the present invention, the pressure during the press coating is 9-15 MPa.

[0013] In one example of the present invention, the drying temperature is 280-350° C., and the drying time is 1-2 hours.

[0014] The heat-resistant steel welding rod of the present invention utilizes an alkaline slag system to ensure a low oxygen content in the weld and high weld metal toughness. The addition of marble to the flux coating acts as a slag and gas generator at arc temperatures, improving the rod's anti-porosity properties. Low-carbon ferromanganese, low-carbon ferrochrome, 45% ferrosilicon, ferrovanadium, molybdenum powder, and graphite are added to alloy the weld. The chromium, molybdenum, and carbon elements enhance weld strength, while the rare earth ferrosilicon, molybdenum, and vanadium elements refine the deposited metal structure and enhance weld toughness. The heat-resistant steel welding rod prepared by the present invention has a smooth surface, good press-coatability, a high deposition rate, and exhibits strong strength, toughness, and crack resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 The present invention is a flow chart of the preparation of welding rods for heat-resistant steel welding. DETAILED DESCRIPTION

[0017] The following describes the embodiments of the present invention through specific examples. 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 based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following examples and the features in the examples can be combined with each other unless they conflict. It should also be understood that the terms used in the examples of the present invention are for the purpose of describing specific embodiments, not for the purpose of limiting the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0018] It should be noted that "%" and "wt%" in this specification represent mass percentages, and "parts" represent parts by weight.

[0019] The welding rod for heat-resistant steel welding of the present invention comprises a welding core and a coating, wherein the coating comprises the following components, and the weight proportions of the components are respectively: 10-13 parts of marble, 3-5 parts of calcium fluoride, 0.2-0.5 parts of graphite, 1-2 parts of silicon micropowder, 1-2 parts of rutile, 1-2 parts of 45 ferrosilicon, 0.5-1.5 parts of low-carbon ferromanganese, 9-12 parts of low-carbon ferrochrome, 1-2 parts of molybdenum powder, 0.2-0.5 parts of ferrovanadium, 35-50 parts of reduced iron powder, 0.3-0.6 parts of potassium chloride, 0.3-0.6 parts of synthetic mica, and 0.5-1.5 parts of rare earth ferrosilicon.

[0020] The functions of each component in the drug cover are as follows:

[0021] Marble: Primarily serves as a gasifier and alkaline slag. The calcium carbonate content in marble is ≥96 wt%. During welding, the calcium carbonate decomposes into calcium oxide and carbon dioxide gas. The generated carbon dioxide ensures that the molten pool remains protected by an inert gas atmosphere. The weight percentage of marble in the coating of the present invention is 10-13 parts. For example, the weight percentage of marble can be any value within the range of 10-13 parts, such as 10, 11, 12, or 13 parts.

[0022] Calcium fluoride: It primarily serves as a slag-forming agent. During welding, calcium deoxidizes and desulfurizes, while fluorine removes hydrogen and purifies the deposited metal. The coating of the present invention contains 3 to 5 parts by weight of calcium fluoride. For example, the amount of calcium fluoride can be any value within the range of 3 to 5 parts, such as 3 parts, 3.5 parts, 4 parts, or 5 parts.

[0023] Graphite: Its primary function is to transfer carbon to the deposited metal, thereby increasing its hardness. It also deoxidizes and improves press coatability. However, excessive addition of graphite can increase spattering. The weight percentage of graphite in the coating of the present invention is 0.2 to 0.5 parts. For example, the weight percentage of graphite can be any value within the range of 0.2 to 0.5 parts, such as 0.2, 0.25, 0.4, or 0.5 parts.

[0024] Silica powder: Silica powder has a silica content of ≥98 wt% and is primarily used for slag formation, which can adjust the melting point and tension of the welding slag. The weight percentage of silica powder in the coating of the present invention is 1-2 parts. For example, the weight percentage of silica powder can be any value within the range of 1-2 parts, such as 1 part, 1.5 parts, or 2 parts.

[0025] Rutile: Rutile, primarily composed of titanium dioxide, stabilizes the arc, reduces spatter, and, when combined with other slagging agents, improves slagging. The weight percentage of rutile in the coating of the present invention is 1-2 parts. For example, the weight percentage of rutile can be anywhere within the range of 1-2 parts, such as 1 part, 1.5 parts, 1.8 parts, or 2 parts.

[0026] 45% Ferrosilicon: Mainly used as a deoxidizer and alloying agent, excessive content can increase spattering and reduce toughness. The weight percentage of 45% Ferrosilicon in the coating of the present invention is 1-2 parts. For example, the weight percentage of 45% Ferrosilicon can be any value within the range of 1-2 parts, such as 1 part, 1.5 parts, or 2 parts.

[0027] Low-carbon ferromanganese: Mainly used as a deoxidizer, alloying agent, and desulfurizer. Excessive content can increase spatter. The weight percentage of low-carbon ferromanganese in the coating of the present invention is 0.5 to 1.5 parts. For example, the weight percentage of low-carbon ferromanganese can be any value within the range of 0.5 to 1.5 parts, such as 0.5 parts, 0.8 parts, 1 part, or 1.5 parts.

[0028] Low-carbon ferrochrome: Low-carbon ferrochrome has a chromium content of ≥70wt% and a carbon content of ≤0.06wt%. It is primarily used for alloying. Adding a suitable amount of low-carbon ferrochrome can improve weld strength and hardness. The low-carbon ferrochrome in the coating of the present invention comprises 9 to 12 parts by weight. For example, the low-carbon ferrochrome can comprise any value within the range of 9 to 12 parts, such as 9, 10, or 12 parts.

[0029] Molybdenum powder: Primarily used for alloying, molybdenum dissolves into carbides, improving the hardness and strength of (Fe,Cr)7C3, and correspondingly improving the material's wear resistance. The weight percentage of ferromolybdenum in the coating of the present invention is 1-2 parts. For example, the weight percentage of ferromolybdenum can be any value within the range of 1-2 parts, such as 1 part, 1.5 parts, or 2 parts.

[0030] Ferrovanadium: Ferrovanadium contains 50-55% vanadium by weight and is primarily used for alloying. Vanadium improves weld wear resistance, refines grain size, and enhances steel impact toughness. However, excessive vanadium can reduce the wear resistance of welding wire. The weight percentage of ferrovanadium in the coating of the present invention is 0.2-0.5 parts. For example, the weight percentage of ferrovanadium can be any value within the range of 0.2-0.5 parts, such as 0.2, 0.3, 0.4, or 0.5 parts.

[0031] Reduced iron powder: Mainly used as a deoxidizer and alloying agent to ensure the alloying element composition in the weld and ensure weld strength. The reduced iron powder in the coating of the present invention has a weight ratio of 35 to 50 parts. For example, the weight ratio of the reduced iron powder can be any value within the range of 35 to 50 parts, such as 35 parts, 36 parts, 40 parts, or 50 parts.

[0032] Potassium chloride: Mainly improves slag viscosity, stabilizes the arc, optimizes weld formation, and improves weld slag removal performance. The weight percentage of potassium chloride in the coating of the present invention is 0.3 to 0.6 parts. For example, the weight percentage of potassium chloride can be any value within the range of 0.3 to 0.6 parts, such as 0.3 parts, 0.35 parts, 0.4 parts, 0.55 parts, or 0.6 parts.

[0033] Synthetic mica: This increases the fluidity of the powder, facilitating even coating of the coating on the core surface and improving the crack resistance of the electrode coating. The synthetic mica in the coating of the present invention comprises 0.3 to 0.6 parts by weight. For example, the synthetic mica may comprise any value within the range of 0.3 to 0.6 parts by weight, such as 0.3, 0.4, or 0.6 parts.

[0034] Rare earth ferrosilicon: Used to refine grain size and improve the low-temperature impact toughness of the weld metal. The weight percentage of rare earth ferrosilicon in the coating of the present invention is 0.5 to 1.5 parts. For example, the weight percentage of rare earth ferrosilicon can be any value within the range of 0.5 to 1.5 parts, such as 0.5, 0.6, 1, 1.4, or 1.5 parts.

[0035] In one embodiment, the particle size of graphite, silicon powder and rare earth ferrosilicon is 80-120 mesh, and the particle size of the remaining components is 40-80 mesh.

[0036] See also Figure 1 The present invention provides a method for preparing a welding rod for heat-resistant steel welding, comprising the following steps:

[0037] S1. Weigh the components of the coating according to the ratio and mix them evenly to obtain coating powder;

[0038] S2. Add a binder to the coating powder and stir evenly to form a coating mixture;

[0039] S3. Press-coat the coating mixture on the surface of the welding core and dry it to obtain a welding rod for heat-resistant steel welding.

[0040] In step S1, the coating includes the following components and the weight proportions of each component are: 10-13 parts of marble, 3-5 parts of calcium fluoride, 0.2-0.5 parts of graphite, 1-2 parts of silicon micropowder, 1-2 parts of rutile, 1-2 parts of 45 ferrosilicon, 0.5-1.5 parts of low-carbon ferromanganese, 9-12 parts of low-carbon ferrochrome, 1-2 parts of molybdenum powder, 0.2-0.5 parts of ferrovanadium, 35-50 parts of reduced iron powder, 0.3-0.6 parts of potassium chloride, 0.3-0.6 parts of synthetic mica, and 0.5-1.5 parts of rare earth ferrosilicon.

[0041] In step S2, a water glass binder is used as the binder, and the mass of the binder is 23-25% of the total mass of the coating powder, for example, 23%, 24%, or 25%. Furthermore, the binder is a potassium-sodium water glass binder, wherein the mass ratio of potassium to sodium in the potassium-sodium water glass binder is 1:1, and the modulus of the binder is 2.5-2.8.

[0042] In step S3, the welding core uses an H08 steel core, the P content of the welding core is ≤0.015wt%, and the S content is ≤0.010wt%; the diameter of the welding core is 3.2-5.0mm, for example, the welding core diameter can be any value within the range of 3.2-5.0mm, such as 3.2mm, 4mm or 5mm.

[0043] During pressure coating, pressure coating, forming, and other operations are performed on conventional hydraulic welding rod production equipment to uniformly pressure-coat the coating mixture on the surface of the welding core. The pressure coating pressure is 9 to 15 MPa, for example, any value within the range of 9 to 15 MPa, such as 9 MPa, 12 MPa, or 15 MPa. After pressure coating, the welding core coated with the coating mixture is dried at a temperature of 280 to 350°C, for example, 280°C, 320°C, or 350°C, and for a drying time of 1 to 2 hours, for example, 1 hour, 1.5 hours, or 2 hours. Furthermore, after the coating mixture is pressure-coated on the welding core surface, the drying process also includes low-temperature drying, for example, drying at 80°C for 1 hour, to partially remove moisture from the coating mixture, prepare for high-temperature drying, prevent adhesion and blistering of the prepared welding rod, and improve the drying quality of the welding rod.

[0044] The technical solutions of the present invention are described in detail below through several specific examples. Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by conventional methods in the art, and the instruments used in the examples are all commercially available.

[0045] Example 1

[0046] The heat-resistant steel welding electrode of this embodiment includes a welding core and a coating, wherein the coating includes the following components, and the weight percentages of each component are as follows: 11 parts of marble, 5 parts of calcium fluoride, 0.25 parts of graphite, 1.5 parts of silicon micropowder, 1.5 parts of rutile, 1.5 parts of 45-ferrosilicon, 0.8 parts of low-carbon ferromanganese, 10 parts of low-carbon ferrochrome, 2 parts of molybdenum powder, 0.4 parts of ferrovanadium, 40 parts of reduced iron powder, 0.4 parts of potassium chloride, 0.4 parts of synthetic mica, and 1 part of rare earth ferrosilicon. The above components are mixed uniformly to obtain a coating powder, a water glass binder is added to the coating powder and stirred uniformly to form a coating mixture, the coating mixture is press-coated on the surface of the welding core at a pressure of 9 MPa, and dried at 80°C for 1 hour and 320°C for 1 hour, respectively, to obtain the heat-resistant steel welding electrode. In this embodiment, the welding core is a 3.2 mm H08A steel core, the amount of water glass binder added is 23% of the total mass of the coating powder, and the mass of the coating mixture after drying accounts for 43% of the total mass of the heat-resistant steel welding electrode.

[0047] Example 2

[0048] The heat-resistant steel welding electrode of this embodiment includes a welding core and a coating, wherein the coating includes the following components, and the weight percentages of each component are as follows: 12 parts marble, 4 parts calcium fluoride, 0.4 parts graphite, 1 part silicon micropowder, 2 parts rutile, 2 parts 45 ferrosilicon, 1.5 parts low-carbon ferromanganese, 9 parts low-carbon ferrochrome, 1.5 parts molybdenum powder, 0.5 parts ferrovanadium, 50 parts reduced iron powder, 0.55 parts potassium chloride, 0.6 parts synthetic mica, and 1.4 parts rare earth ferrosilicon. The above components are mixed uniformly to obtain a coating powder, a water glass binder is added to the coating powder, and the mixture is stirred uniformly to form a coating mixture, which is press-coated on the surface of the welding core at a pressure of 15 MPa, and dried at 80°C for 1 hour and 280°C for 1.5 hours to obtain the heat-resistant steel welding electrode. In this embodiment, the welding core is a 4 mm H08A steel core, the amount of water glass binder added is 24% of the total mass of the coating powder, and the mass of the coating mixture after drying accounts for 40% of the total mass of the heat-resistant steel welding electrode.

[0049] Example 3

[0050] The heat-resistant steel welding electrode of this embodiment includes a welding core and a coating, wherein the coating includes the following components, and the weight percentages of each component are as follows: 13 parts of marble, 3.5 parts of calcium fluoride, 0.5 parts of graphite, 2 parts of silicon micropowder, 1.8 parts of rutile, 1 part of 45-ferrosilicon, 1 part of low-carbon ferromanganese, 12 parts of low-carbon ferrochrome, 1 part of molybdenum powder, 0.3 parts of ferrovanadium, 36 parts of reduced iron powder, 0.35 parts of potassium chloride, 0.3 parts of synthetic mica, and 0.6 parts of rare earth ferrosilicon. The above components are mixed uniformly to obtain a coating powder, a water glass binder is added to the coating powder and stirred uniformly to form a coating mixture, the coating mixture is press-coated on the surface of the welding core at a pressure of 15 MPa, and dried at 80°C for 1 hour and 350°C for 2 hours to obtain the heat-resistant steel welding electrode. In this embodiment, the welding core is a 5mm H08A steel core, the amount of water glass binder added is 25% of the total mass of the coating powder, and the mass of the coating mixture after drying accounts for 45% of the total mass of the heat-resistant steel welding electrode.

[0051] Example 4

[0052] The heat-resistant steel welding electrode of this embodiment includes a welding core and a coating, wherein the coating includes the following components, and the weight percentages of each component are as follows: 10 parts marble, 4.5 parts calcium fluoride, 0.3 parts graphite, 1.8 parts silicon micropowder, 1.2 parts rutile, 1.3 parts 45 ferrosilicon, 1.2 parts low-carbon ferromanganese, 11 parts low-carbon ferrochromium, 1.2 parts molybdenum powder, 0.4 parts ferrovanadium, 45 parts reduced iron powder, 0.6 parts potassium chloride, 0.5 parts synthetic mica, and 1.5 parts rare earth ferrosilicon. The above components are mixed uniformly to obtain a coating powder, a water glass binder is added to the coating powder and stirred uniformly to form a coating mixture, the coating mixture is press-coated on the surface of the welding core at a pressure of 13 MPa, and dried at 80°C for 1 hour and 330°C for 2 hours to obtain the heat-resistant steel welding electrode. In this embodiment, the welding core is a 3.5 mm H08A steel core, the amount of water glass binder added is 23% of the total mass of the coating powder, and the mass of the coating mixture after drying accounts for 42% of the total mass of the heat-resistant steel welding electrode.

[0053] Example 5

[0054] The heat-resistant steel welding electrode of this embodiment includes a welding core and a coating, wherein the coating includes the following components, and the weight percentages of each component are as follows: 12 parts of marble, 3 parts of calcium fluoride, 0.2 parts of graphite, 1.3 parts of silicon micropowder, 1 part of rutile, 1.8 parts of 45-ferrosilicon, 0.5 parts of low-carbon ferromanganese, 10 parts of low-carbon ferrochrome, 1.8 parts of molybdenum powder, 0.2 parts of ferrovanadium, 35 parts of reduced iron powder, 0.3 parts of potassium chloride, 0.4 parts of synthetic mica, and 0.5 parts of rare earth ferrosilicon. The above components are mixed uniformly to obtain a coating powder, a water glass binder is added to the coating powder and stirred uniformly to form a coating mixture, the coating mixture is press-coated on the surface of the welding core at a pressure of 10 MPa, and dried at 80°C for 1 hour and 320°C for 1.8 hours to obtain the heat-resistant steel welding electrode. In this embodiment, the welding core is a 4.5 mm H08A steel core, the amount of water glass binder added is 25% of the total mass of the coating powder, and the mass of the coating mixture after drying accounts for 41% of the total mass of the heat-resistant steel welding electrode.

[0055] The contents of the coating components in the heat-resistant steel welding electrodes of Examples 1 to 5 are shown in Table 1. The deposited metal chemical composition and welding processability tests were conducted on the heat-resistant steel welding electrodes provided in Examples 1 to 5 in accordance with GB / T 25776-2010. The chemical composition of the deposited metal is shown in Table 2; the mechanical properties and high-temperature tensile strength of the deposited metal are shown in Table 3; and the crack resistance, deposition rate, and welding processability of the deposited metal are shown in Table 4.

[0056] Table 1: Coating composition of heat-resistant steel welding rods of Examples 1 to 5

[0057]

[0058] Table 2: Chemical composition of deposited metal of heat-resistant steel welding electrodes of Examples 1 to 5

[0059]

[0060]

[0061] Table 3: Properties of deposited metal of heat-resistant steel welding electrodes of Examples 1 to 5

[0062]

[0063] Table 4: Crack resistance, deposition rate, and welding processability of the deposited metal of the heat-resistant steel welding electrodes of Examples 1 to 5

[0064]

[0065] As can be seen from Tables 3 and 4, the welding rod for heat-resistant steel welding of the present invention has good welding processability, a high welding deposition rate, and has strong strength, toughness, and crack resistance. It is suitable for welding heat-resistant steel, and the strength of the deposited metal is maintained well at high temperatures. It can be used in hydrogenation reactors.

[0066] The welding rod for heat-resistant steel welding of the present invention adopts an alkaline slag system to ensure that the weld has a low oxygen content and ensures high toughness of the weld metal; marble is added to the coating to play a slag-forming and gas-forming function at the arc temperature, which can improve the anti-porosity performance of the welding rod; low-carbon ferromanganese, micro-carbon ferrochromium, 45 ferrosilicon, ferrovanadium, ferromolybdenum, and graphite are added to the weld to infiltrate alloys, wherein chromium, molybdenum, and carbon elements can improve the strength of the weld, and rare earth ferrosilicon, molybdenum, and vanadium elements can refine the structure of the deposited metal and improve the toughness of the weld. The welding rod for heat-resistant steel welding prepared by the present invention has a smooth surface, good pressure coating properties, a high welding deposition rate, and has strong strength, toughness, and crack resistance. Therefore, the present invention effectively overcomes some practical problems in the prior art and thus has high utilization value and use significance.

[0067] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art 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 one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A welding rod for heat-resistant steel welding, characterized in that: The welding rod includes a welding core and a coating, and the coating is composed of the following components, and the weight parts of each component are respectively: 10-13 parts of marble, 3-5 parts of calcium fluoride, 0.2-0.5 parts of graphite, 1-2 parts of silicon micropowder, 1-2 parts of rutile, 1-2 parts of 45 ferrosilicon, 0.5-1.5 parts of low-carbon ferromanganese, 9-12 parts of low-carbon ferrochrome, 1-2 parts of molybdenum powder, 0.2-0.5 parts of ferrovanadium, 35-50 parts of reduced iron powder, 0.3-0.6 parts of potassium chloride, 0.3-0.6 parts of synthetic mica, and 0.5-1.5 parts of rare earth ferrosilicon.

2. The welding rod for heat-resistant steel welding according to claim 1, characterized in that: The marble has a calcium carbonate content of ≥96 wt%; the silicon dioxide content of the silicon micropowder is ≥98 wt%; the low-carbon ferromanganese has a manganese content of ≥80 wt%; the micro-carbon ferrochrome has a chromium content of ≥70 wt% and a carbon content of ≤0.06 wt%; the molybdenum content of the molybdenum powder is ≥99 wt%; the vanadium content of the ferrovanadium is 50-55 wt%; and the iron content of the reduced iron powder is ≥98 wt%.

3. The welding rod for heat-resistant steel welding according to claim 1, characterized in that: The particle sizes of the graphite, the silicon powder and the rare earth ferrosilicon are 80-120 meshes, and the particle sizes of the remaining components are 40-80 meshes.

4. The welding rod for heat-resistant steel welding according to claim 1, characterized in that: The welding core adopts H08 steel core, and the P content of the welding core is ≤0.015wt%, and the S content is ≤0.010wt%.

5. The welding rod for heat-resistant steel welding according to claim 1, characterized in that: The diameter of the welding core is 3.2-5.0 mm.

6. A method for preparing a heat-resistant steel welding electrode according to any one of claims 1 to 5, characterized in that: The steps include: Weigh the various components of the coating according to the ratio and mix them evenly to obtain coating powder; Adding a binder to the coating powder and stirring evenly to form a coating mixture; The coating mixture is press-coated on the surface of the welding core and dried to obtain the welding rod for heat-resistant steel welding.

7. The preparation method according to claim 6, characterized in that The binder is a water glass binder, and the mass of the binder is 23-25% of the total mass of the coating powder.

8. The preparation method according to claim 6, characterized in that The weight of the coating mixture in the heat-resistant steel welding rod after drying is 40-45% of the total weight of the heat-resistant steel welding rod.

9. The preparation method according to claim 6, characterized in that The pressure during the press coating is 9-15 MPa.

10. The preparation method according to claim 6, characterized in that The drying temperature is 280~350℃ and the drying time is 1~2h.

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