Chromium-free flux-cored wire and preparation method and application thereof

Abstract

The invention provides a chromium-free flux-cored wire as well as a preparation method and application thereof, and relates to the technical field of flux-cored wires. A flux core of the flux-cored wire comprises, by mass, 1%-3% of zinc, 8%-15% of silicon iron, 6%-10% of graphite, 3%-7% of boron sulfide, 6%-10% of high-carbon ferromanganese, 1%-5% of rutile, 1%-2% of aluminum, 1%-2% of magnesium, 6%-12% of ferroniobium and the balance iron. According to the chromium-containing flux-cored wire, the technical problems that in the prior art, a chromium-containing flux-cored wire pollutes the environment and causes risks to human health in the production and use process are solved, and the technical effects of reducing environment pollution, avoiding the risks to human health and exerting better welding process performance are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of flux-cored welding wires, and in particular to a chromium-free flux-cored welding wire and a preparation method and application thereof. Background Art

[0002] Flux-cored welding wire is one of the important materials in the field of welding, and its quality directly affects the quality and performance of the welded joint. Good flux-cored welding wire can provide stable welding process parameters, ensure the firmness, sealing and corrosion resistance of the welded joint, and ensure that the welded joint has good performance during use.

[0003] The production process of flux-cored welding wire involves a variety of raw materials, among which the addition of chromium is particularly important. The increase in chromium content can improve the hardness, corrosion resistance and wear resistance of the weld metal in an oxidizing environment, especially in steel with a high carbon content, where chromium can form stable carbides, thereby improving the mechanical properties of the weld. However, as a heavy metal element, chromium poses risks to environmental pollution and human health; chromium-containing flux-cored welding wires will also produce more smoke and spatter during welding, which will increase the difficulty of welding operations; in certain environments, welds with high chromium content are more prone to stress corrosion cracking; at the same time, chromium-containing weld metals require special heat treatment processes after welding to optimize performance, which increases production costs and complexity.

[0004] Therefore, flux-cored welding wires that do not contain chromium and have excellent performance are increasingly valued in modern welding processes. Prior art CN118180695A discloses a high-performance flux-cored welding wire, which does not add chromium in the production process. Through specific steps and material combinations, the toughness and wear resistance of the flux-cored welding wire are improved, the quality and performance of the welded joint are ensured, and the diffusible hydrogen content is low. The welding wire is suitable for automated welding of 690Mpa long-distance pipelines, but its performance in other application scenarios has not been verified and may not be suitable for other types of welding operations.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] One of the purposes of the present invention is to provide a chromium-free flux-cored welding wire, which can reduce environmental pollution and avoid human health risks, while being able to exert better welding process performance, significantly improve wear resistance, and have beautiful weld formation. It adopts gas-slag combined protection and has the characteristics of good forming, strong resistance to pores and cracks.

[0007] The second object of the present invention is to provide a method for preparing a chromium-free flux-cored welding wire, which has a simple process, high efficiency, high success rate and is suitable for industrial production.

[0008] The third object of the present invention is to provide an application of a chromium-free flux-cored welding wire, which is beneficial to improving the manufacturing quality of equipment and instruments, reducing pollution to the environment and avoiding adverse effects on human health, and can achieve outstanding application effects.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] In a first aspect, a chromium-free flux-cored welding wire, the flux core of the flux-cored welding wire comprises the following components by mass percentage:

[0011] Zinc powder 1%-3%, ferrosilicon 8%-15%, graphite 6%-10%, boron sulfide 3%-7%, high carbon ferromanganese 6%-10%, rutile 1%-5%, aluminum powder 1%-2%, magnesium powder 1%-2%, ferroniobium 6%-12%, and the balance iron.

[0012] Furthermore, the ferrosilicon includes 45 ferrosilicon.

[0013] Furthermore, the particle size of the drug core is 80 meshes-100 meshes.

[0014] Furthermore, the coating of the flux-cored welding wire includes a carbon steel strip.

[0015] Furthermore, the flux core filling rate of the flux cored welding wire is 28%-35%.

[0016] Furthermore, the diameter of the flux-cored welding wire is 1.2 mm-1.6 mm.

[0017] In a second aspect, a method for preparing the flux-cored welding wire according to any one of the above items comprises the following steps:

[0018] (a) mixing the components in proportion to obtain a drug core;

[0019] (b) adding the flux core into the steel strip groove and then sealing it to obtain the flux cored welding wire.

[0020] Furthermore, after the sealing, a step of wire drawing and reducing the diameter is also included.

[0021] Furthermore, the diameter of the welding wire before the wire drawing and diameter reduction is 2.9 mm-3.1 mm.

[0022] A third aspect is the use of a flux-cored welding wire as described in any one of the above items in the manufacture of food processing equipment and medical devices.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] The chromium-free flux-cored welding wire provided by the present invention does not contain heavy metal chromium, so it can reduce pollution to the environment during production and use, and can avoid risks to human health. At the same time, with the coordinated cooperation of various components and their specific proportions, the flux-cored welding wire also has better welding process performance under special processing conditions, such as arc stability, wear resistance, uniformity of droplet transition, fewer pores, and beautiful weld formation; the flux-cored welding wire is suitable for fields that require special welding materials, such as the manufacture of food processing equipment and medical equipment, which is beneficial to improving the manufacturing quality of equipment and instruments and can avoid adverse effects on human health.

[0025] The method for preparing the chromium-free flux-cored welding wire provided by the invention has the advantages of simple process, high efficiency and high success rate, and is suitable for industrial production.

[0026] The application of the chromium-free flux-cored welding wire provided by the present invention is beneficial to improving the manufacturing quality of equipment and instruments, reducing pollution to the environment and avoiding adverse effects on human health, and meets the requirements of modern industry for green, environmental protection and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 1 A flow chart for preparing a chromium-free flux-cored welding wire provided in accordance with one embodiment of the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] According to a first aspect of the present invention, there is provided a chromium-free flux-cored welding wire, the flux core of which comprises the following components by mass percentage:

[0031] Zinc powder 1%-3%, ferrosilicon 8%-15%, graphite 6%-10%, boron sulfide 3%-7%, high carbon ferromanganese 6%-10%, rutile 1%-5%, aluminum powder 1%-2%, magnesium powder 1%-2%, ferroniobium 6%-12%, and the balance iron.

[0032] In the present invention, the typical but non-limiting mass percentage of zinc powder is, for example, 1%, 2%, and 3%; the typical but non-limiting mass percentage of ferrosilicon is, for example, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%; the typical but non-limiting mass percentage of graphite is, for example, 6%, 7%, 8%, 9%, and 10%; the typical but non-limiting mass percentage of boron sulfide is, for example, 3%, 4%, 5%, 6%, and 7%; the typical but non-limiting mass percentage of high carbon ferromanganese is, for example, 6%, 7%. , 8%, 9%, 10%; typical but non-limiting mass percentages of rutile are, for example, 1%, 2%, 3%, 4%, 5%; typical but non-limiting mass percentages of aluminum powder are, for example, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%; typical but non-limiting mass percentages of magnesium powder are, for example, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%; typical but non-limiting mass percentages of ferroniobium are, for example, 6%, 7%, 8%, 9%, 10%, 11%, 12%.

[0033] The chromium-free flux-cored welding wire provided by the present invention does not contain heavy metal chromium, so it can reduce pollution to the environment during production and use, and can avoid risks to human health. At the same time, with the coordinated cooperation of various components and their specific proportions, the flux-cored welding wire also has better welding process performance under special processing conditions, such as arc stability, wear resistance, uniformity of droplet transition, fewer pores, and beautiful weld formation; the flux-cored welding wire is suitable for fields that require special welding materials, such as the manufacture of food processing equipment and medical equipment, which is beneficial to improving the manufacturing quality of equipment and instruments and can avoid adverse effects on human health.

[0034] In a preferred embodiment, ferrosilicon includes but is not limited to 45 ferrosilicon.

[0035] It should be noted that the specific ratio of the flux core components in the flux cored welding wire is extremely important and is the key to achieving the technical effect of the present invention. Each component needs to be accurately weighed and fully dried in proportion; the ratio of the flux core components will directly affect the slag formation, arc stability and chemical composition of the weld metal during welding; if the ratio of the flux core components is not within the scope of the present invention, it will not only lead to weld quality problems, such as easy occurrence of pores, cracks and inclusions, but also cause the mechanical properties (such as strength, toughness and hardness) and corrosion resistance of the weld to fail to meet specific technical requirements, affecting the safety and service life of the welded structure; in short, the precise ratio of the flux core components is crucial to ensuring the welding performance and quality of the flux cored welding wire.

[0036] In a preferred embodiment, the particle size of the flux core may be 80 mesh-100 mesh, and its typical but non-limiting particle size is, for example, 80 mesh, 85 mesh, 90 mesh, 95 mesh, and 100 mesh. The appropriate particle size of the flux core is more conducive to further improving the welding process performance.

[0037] It should be noted that if the particle size of the drug core is too small, the following problems will occur:

[0038] 1. Increased production difficulty: During the production process of flux-cored welding wire, the fluidity of the powder decreases, which easily causes problems such as uneven distribution of the powder, thus affecting the quality and welding performance of the welding wire;

[0039] 2. The smaller the powder particle size, the better the thermal conductivity. However, the higher temperature inside the molten droplet may cause the arc stability to deteriorate, because the molten droplet transition may cause explosion and splashing, resulting in drastic changes in current and voltage, causing the arc stability to decrease.

[0040] It should be noted that if the particle size of the drug core is too large, the following problems will occur:

[0041] 1. The arc stability becomes worse: the larger the powder particle size, the worse the thermal conductivity, which leads to drastic changes in current and voltage, thus reducing the arc stability;

[0042] 2. Filling stability problem: Too large a powder particle size will affect the fluidity of the powder, thereby affecting the filling stability of the flux-cored welding wire; poor fluidity will lead to uneven distribution of the powder, causing looseness or powder breakage inside the welding wire, which is not conducive to stable welding and ensuring welding quality.

[0043] In a preferred embodiment, the coating of the flux-cored welding wire includes but is not limited to a carbon steel strip.

[0044] In the present invention, the flux core filling rate of the flux cored welding wire may be 28%-35%, and typical but non-limiting filling rates thereof are, for example, 28%, 29%, 30%, 31%, 32%, 33%, 34%, and 35%.

[0045] In a preferred embodiment, the diameter of the flux-cored welding wire may be 1.2 mm-1.6 mm, and typical but non-limiting diameters thereof are, for example, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, and 1.6 mm.

[0046] According to a second aspect of the present invention, there is provided a method for preparing the flux-cored welding wire as described in any one of the above, comprising the following steps:

[0047] (a) mixing the components in proportion to obtain a drug core;

[0048] (b) adding the flux core into the steel strip groove and then sealing it to obtain the flux cored welding wire.

[0049] The method for preparing the chromium-free flux-cored welding wire provided by the invention has the advantages of simple process, high efficiency and high success rate, and is suitable for industrial production.

[0050] In a preferred embodiment, the step of wire drawing and reducing the diameter is further included after sealing.

[0051] In the present invention, the diameter of the welding wire before wire drawing and diameter reduction may be 2.9 mm-3.1 mm, for example, 2.9 mm, 2.95 mm, 3 mm, 3.05 mm, 3.1 mm, but not limited thereto.

[0052] A typical preparation method of flux-cored welding wire, see Figure 1 , including the following steps:

[0053] (1) Weigh the components of the core according to the ratio;

[0054] (2) mixing the components in powder form, drying and sieving to obtain drug core powder;

[0055] (3) When the steel belt gradually closes from U-shape to O-shape, a powder feeder is used to add the core powder into the steel belt groove;

[0056] (4) After the steel strip is formed, it is immediately transferred to the wire drawing machine for wire drawing and diameter reduction. After multiple wire drawing, it reaches the target specification and is collected by the wire collecting machine to obtain the finished flux-cored welding wire.

[0057] According to a third aspect of the present invention, there is provided a use of any of the above-mentioned flux-cored welding wires in the manufacture of food processing equipment and medical devices.

[0058] Since chromium-free flux-cored welding wire does not contain heavy metal chromium during production and use, it reduces pollution to the environment and avoids adverse effects on human health. This welding wire is suitable for fields that require special welding materials. These fields usually require avoiding the use of materials that may affect health or product quality, such as the manufacture of food processing equipment and medical devices, which meets the requirements of modern industry for green, environmental protection and sustainable development.

[0059] In summary, the application of the chromium-free flux-cored welding wire provided by the present invention is beneficial to improving the manufacturing quality of equipment and instruments, reducing pollution to the environment and avoiding adverse effects on human health, and meets the requirements of modern industry for green, environmental protection and sustainable development.

[0060] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0061] Examples 1-6

[0062] Embodiment 1-6 provides a chromium-free flux-cored welding wire, which consists of a flux coating and a flux core;

[0063] The coating is a carbon steel strip; the components in the core and their mass percentages are shown in Table 1.

[0064] Table 1

[0065]

[0066] Example 7

[0067] This embodiment is a method for preparing the chromium-free flux-cored welding wire of Embodiments 1-6, which sequentially includes the steps of raw material inspection, powder preparation, powder mixing, drying, screening, steel strip slitting and rewinding, powder adding, steel strip forming, wire drawing and reducing, and cleaning and storage;

[0068] The details are as follows:

[0069] S1 Raw material inspection:

[0070] Carbon steel strip inspection: The surface of the steel strip should be bright, smooth, without cracks, holes, oxide scale and corrosion holes;

[0071] Drug powder testing: The particle size of drug powder is 80-100 mesh;

[0072] S2 powder preparation:

[0073] The components of zinc powder, 45 ferrosilicon, graphite, boron sulfide, high carbon ferromanganese, rutile, aluminum powder, magnesium powder, ferroniobium and iron powder are added and mixed in the form of powders, and the particle size is between 80-100 meshes;

[0074] S3 mixing, drying and sieving:

[0075] The components of the powder are poured into a powder mixing furnace in proportion for mixing, the powder mixing furnace is heated to 120°C and dried for 2 hours, and then taken out and filtered with an 80-100 mesh screen to remove larger particles to obtain the flux core powder used in the preparation of welding wire;

[0076] S4 steel strip slitting and rewinding:

[0077] Cut the qualified carbon steel strip into 12mm width and 0.5mm thickness according to the process requirements, and use the take-up machine to rewind the slit steel strip onto the I-shaped wheel for standby use;

[0078] S5 powder adding and steel strip forming:

[0079] The welding wire is made by carbon steel strip forming method. The forming unit is composed of 7 pairs of upper and lower rollers in sequence. The steel strip is pulled into the forming unit for rolling. Between the third and fourth pairs of rollers of the forming machine, when the steel strip gradually closes from U-shape to O-shape, the powder feeder adds the pre-prepared flux core powder into the steel strip groove. Then the steel strip is sealed under the rolling pressure of the next set of rollers. The diameter of the obtained primary welding wire is 2.9mm-3.1mm, and the flux core filling rate of the welding wire is 28%-35%;

[0080] S6 wire drawing reduction:

[0081] After the steel strip is formed, it is immediately transferred to the wire drawing machine and enters the wire drawing and diameter reduction stage. After multiple wire drawing, the welding wire reaches the target size of 1.2mm-1.6mm, and then it is collected by the wire collecting machine to obtain flux-cored welding wire;

[0082] S7 Clean and Save:

[0083] After the welding wire is processed, first clean and remove the wire drawing powder remaining on the surface of the welding wire during the wire drawing process, and then store it in a dry environment until it is used for welding.

[0084] Comparative Example 1

[0085] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the flux core composition of this comparative example does not contain zinc, but is supplemented with an equal amount of iron;

[0086] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0087] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the absence of zinc element will reduce the toughness and plasticity of the weld metal and affect the mechanical properties of the weld joint; the weld without zinc is more susceptible to corrosion by corrosive media, shortening the service life of the structure.

[0088] Comparative Example 2

[0089] This comparative example provides a flux-cored welding wire, which differs from Example 6 only in that the mass percentage of zinc in the flux core composition of this comparative example is 0.5%;

[0090] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0091] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the insufficient zinc content will reduce the toughness and plasticity of the weld metal and affect the mechanical properties of the weld joint.

[0092] Comparative Example 3

[0093] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of zinc in the flux core composition of this comparative example is 4%;

[0094] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0095] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that excessive zinc will be oxidized and evaporated under the action of arc heat, which can easily cause pores in the weld; the more zinc content, the more serious the evaporation and the greater the pore sensitivity.

[0096] Comparative Example 4

[0097] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the flux core composition of this comparative example does not contain boron sulfide, but is supplemented with an equal amount of iron;

[0098] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0099] Compared with Example 6, the defects of the flux-cored welding wire in this comparative example are that the lack of boron sulfide may cause sulfur to exist in the form of iron sulfide, reducing the plasticity and toughness of the weld metal and increasing the risk of thermal cracks; the lack of the desulfurization effect of boron sulfide makes it impossible to effectively control the harmful effects of sulfur, thereby affecting the plasticity and toughness of the weld metal.

[0100] Comparative Example 5

[0101] This comparative example provides a flux-cored welding wire, which differs from Example 6 only in that the mass percentage of aluminum in the flux core composition of this comparative example is 0.5%;

[0102] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0103] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that insufficient aluminum powder content may cause the strength and toughness of the weld metal to decrease, affecting the mechanical properties of the weld joint; aluminum powder in the welding material can refine the grains of the weld metal and improve the strength and toughness of the weld; due to the low content of aluminum powder, the thermal conductivity of the welding material will be affected, resulting in uneven temperature distribution during heating and cooling, which may cause welding deformation.

[0104] Comparative Example 6

[0105] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of aluminum in the flux core composition of this comparative example is 3%;

[0106] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0107] Compared with Example 6, the defects of the flux-cored welding wire in this comparative example are that too much aluminum powder may form pores during welding; too much aluminum powder added will lead to insufficient gas escape, thereby forming welding defects such as pores; excessive aluminum powder content will cause cracks in the weld joint during solidification; and since the melting range of aluminum is narrow, thermal cracks are easily generated.

[0108] Comparative Example 7

[0109] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the flux core composition of this comparative example does not contain magnesium, but is supplemented with an equal amount of iron;

[0110] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0111] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the absence of magnesium may lead to reduced welding performance, reduced joint strength, poor performance of the heat-affected zone, porosity problems, welding deformation, reduced corrosion resistance, and increased complexity of the welding process.

[0112] Comparative Example 8

[0113] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of ferroniobium in the flux core composition of this comparative example is 5%;

[0114] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0115] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that the lower niobium iron content may cause the strength, toughness and wear resistance of the weld joint to decrease, and increase the cold crack sensitivity during welding; because niobium can delay the recrystallization of austenite in the weld metal and reduce the phase transformation temperature, thereby promoting the formation of acicular ferrite, which helps to improve the toughness and plasticity of the weld joint, especially the impact toughness under low temperature conditions, so the lower niobium content will increase the sensitivity of the weld to hydrogen-induced cold cracking.

[0116] Comparative Example 9

[0117] This comparative example provides a flux-cored welding wire, which is different from Example 6 only in that the mass percentage of ferroniobium in the flux core composition of this comparative example is 13%;

[0118] The remaining components and their proportions are the same as those in Example 6, and the preparation method is similar to that in Example 7.

[0119] Compared with Example 6, the defect of the flux-cored welding wire in this comparative example is that excessive niobium may cause the coarsening of carbonitrides, thereby reducing its effect on grain refinement and precipitation strengthening; at the same time, excessive niobium will cause the performance of the heat-affected zone during welding to deteriorate, increasing the risk of welding cracks.

[0120] Test example

[0121] The performance of the flux-cored welding wires obtained in the embodiments and comparative examples was tested, and the results are shown in Table 2.

[0122] Table 2

[0123]

[0124] As can be seen from Table 2, the chromium-free flux-cored welding wires provided in Examples 1-6 of the present invention have better welding process performance under the synergistic combination of various components and their specific proportions, which are significantly better than the flux-cored welding wires in Comparative Examples 1-9, and can be applied to fields requiring special welding materials, such as the manufacture of food processing equipment and medical devices, which is beneficial to improving the manufacturing quality of equipment and instruments, and avoiding adverse effects on human health.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chromium-free flux-cored welding wire, characterized in that: The flux core of the flux cored welding wire comprises the following components by mass percentage: Zinc 1%-3%, ferrosilicon 8%-15%, graphite 6%-10%, boron sulfide 3%-7%, high carbon ferromanganese 6%-10%, rutile 1%-5%, aluminum 1%-2%, magnesium 1%-2%, ferroniobium 6%-12%, and the balance iron.

2. The flux-cored welding wire according to claim 1, characterized in that: The ferrosilicon includes 45 ferrosilicon.

3. The flux-cored welding wire according to claim 1 or 2, characterized in that: The particle size of the drug core is 80-100 meshes.

4. The flux-cored welding wire according to claim 1 or 2, characterized in that: The coating of the flux-cored welding wire includes a carbon steel strip.

5. The flux-cored welding wire according to claim 1 or 2, characterized in that: The flux core filling rate of the flux cored welding wire is 28%-35%.

6. The flux-cored welding wire according to claim 5, characterized in that: The diameter of the flux-cored welding wire is 1.2 mm-1.6 mm.

7. A method for preparing a flux-cored welding wire according to any one of claims 1 to 6, characterized in that: The following steps are involved: (a) mixing the components in proportion to obtain a drug core; (b) adding the flux core into the steel strip groove and then sealing it to obtain the flux cored welding wire.

8. The preparation method according to claim 7, characterized in that: The step of wire drawing and reducing diameter is also included after the sealing.

9. The preparation method according to claim 8, characterized in that: The diameter of the welding wire before the wire drawing and reducing is 2.9mm-3.1mm.

10. Use of the flux-cored welding wire according to any one of claims 1 to 6 in the manufacture of food processing equipment and medical devices.

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