High-wear-resistance impact-resistance iron-based surfacing flux-cored wire

Abstract

The invention discloses a high-wear-resistance impact-resistance surfacing flux-cored wire, and belongs to the technical field of metal surfacing materials. Flux core powder is wrapped by a carbon steel strip, and alloy elements of the flux core powder comprise, by mass, 0.5%-2.3% of ferrosilicon, 0.5%-2.3% of ferromanganese, 10%-30% of ferrovanadium, 0.5%-4.5% of ferrocolumbium, 10%-30% of molybdenum powder, 0.5%-3.5% of nickel powder, 1.0%-3.5% of boron powder, 1.0%-3.0% of carbon powder and the balance iron powder. The cladding layer with the thickness of about 1-5 mm is formed on the surface of the mechanical component through surfacing, and the cladding layer has excellent wear resistance, good toughness and impact resistance; the cladding layer structure is composed of a matrix martensite phase and in-situ synthesis petal-shaped and skeleton-shaped precipitated phases. And surfacing manufacturability is good, splashing is small, welding seam forming is good, surfacing can be repeatedly used, and wide application prospects are achieved.

Description

Technical Field

[0001] The present invention relates to the field of welding materials for material processing, and particularly to a flux-cored wire for wear-resistant surfacing of mechanical components. Background Art

[0002] Among the main failure forms of mechanical parts, wear failure accounts for 60 - 80%. Equipment failure or material damage caused by wear every year is also one of the problems that cause the most economic losses, greatly affecting the service life of construction machinery. Therefore, surface modification of materials, improving the wear resistance of materials, and extending their service life are of great significance for improving economic benefits.

[0003] As an economical and rapid process method for material surface modification, surfacing is increasingly widely used in the additive manufacturing and repair of parts in various industrial sectors. A flux-cored wire refers to a wire with a metal shell on the outside and various medicaments and alloy powders filled inside. These fillers melt during the welding process and form the required alloy components and chemical reactions in the weld. Compared with solid wires, flux-cored wires have the advantages of high welding efficiency, fast cladding speed, easy adjustment of composition, and strong welding adaptability. In recent years, flux-cored wires have become the preferred welding materials for wear-resistant surfacing.

[0004] It can be obtained from the reports of Chinese patent document numbers (CN 109175780 B and CN 104289826 B) that the currently commonly used wear-resistant surfacing flux-cored wires are mainly flux-cored wires based on high-chromium and high-boron iron-based alloys. By controlling the contents of chromium and boron elements, primary M7C3 and Fe2B-type hard phases are formed in the structure to improve the hardness and wear resistance of the cladding layer. Both primary M7C3 and eutectic Fe2B-type hard phases have high microhardness values, so they play an important role in improving the wear resistance of the alloy. However, due to the large brittleness and large particle size of these two hard phases, the toughness of the alloy is insufficient, increasing the crack tendency during the surfacing process, and may cause the surfacing layer to detach during long-term wear. In order to avoid the detachment caused by the cracking of the surfacing alloy, V and Nb elements are used to replace Cr elements to avoid the formation of coarse M7C3 in the structure, adjust the Mo / B ratio to promote the in-situ eutectic reaction, and at the same time, the combined action of multi-element microalloy strengthening such as Ni, Mn, and Si is used to further improve the impact resistance of the wear-resistant belt surfacing alloy while ensuring the wear resistance of the alloy.

[0005] Therefore, the technical personnel in this field are committed to developing a high wear-resistant and impact-resistant iron-based surfacing flux-cored wire. By adjusting the contents of alloy elements in the flux powder and using the surfacing process, a high wear-resistant and impact-resistant iron-based cladding layer is prepared to overcome the deficiencies of the prior art and meet the requirements of construction machinery for high wear resistance and impact resistance. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the purpose of the present invention is to solve the problem that the wear resistance and toughness of most current surfacing materials cannot be reasonably matched, and to provide a high wear-resistant and impact-resistant iron-based surfacing flux-cored wire, which replaces the coarse primary hard-phase structure that appears in the traditional wear-resistant alloy structure with petal-shaped and eutectic skeleton-shaped in-situ precipitation phase structures.

[0007] To achieve the above object, the present invention provides a high wear-resistant and impact-resistant surfacing flux-cored wire, which uses a carbon steel strip to wrap the flux-cored powder. The flux-cored powder includes the following substances in mass percentage: ferrosilicon 0.5-2.3%, ferromanganese 0.5-2.3%, ferrovanadium 10-30%, ferroniobium 0.5-4.5%, molybdenum powder 10-30%, nickel powder 0.5-3.5%, boron powder 1.0-3.5%, carbon powder 1.0-3.0%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 1.0-3.0%, Si 0.5-1.5%, Mn 0.5-1.5%, Ni 0.5-3.5%, Nb 0.1-2.0%, V 3-15%, Mo 8-30%, B 1.0-3.5%, and the balance is Fe.

[0008] Preferably, for the high wear-resistant and impact-resistant surfacing flux-cored wire, the mass percentage of the flux-cored powder components is: ferrosilicon 0.8-1.5%, ferromanganese 1.6-2.3%, ferrovanadium 20-25%, ferroniobium 0.5-1.5%, molybdenum powder 10-15%, nickel powder 0.5-1.5%, boron powder 1.5-2.0%, carbon powder 2.4-2.8%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 2.4-2.8%, Si 0.5-1.0%, Mn 1.2-1.7%, Ni 0.5-1.5%, Nb 0.3-0.8%, V 10-13%, Mo 10-15%, B 1.5-2.0%, and the balance is Fe.

[0009] Preferably, for the high wear-resistant and impact-resistant surfacing flux-cored wire, the mass percentage of the flux-cored powder components is: ferrosilicon 0.8-1.5%, ferromanganese 1.6-2.3%, ferrovanadium 15-20%, ferroniobium 1.5-2.5%, molybdenum powder 15-20%, nickel powder 1.5-2.5%, boron powder 2.0-2.5%, carbon powder 1.6-2.2%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 1.6-2.2%, Si 0.5-1.0%, Mn 1.2-1.7%, Ni 1.5-2.5%, Nb 0.7-1.3%, V 7-10%, Mo 15-20%, B 2.0-2.5%, and the balance is Fe.

[0010] Preferably, the high wear-resistant and impact-resistant surfacing flux-cored wire is characterized in that the mass percentage content of the flux powder components is as follows: ferrosilicon 1.6-2.3%, ferromanganese 0.8-1.5%, ferrovanadium 10-15%, ferroniobium 2.5-3.5%, molybdenum powder 20-25%, nickel powder 2.5-3.5%, boron powder 2.5-3.0%, carbon powder 1.0-1.6%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 1.0-1.6%, Si 1.2-1.7%, Mn 0.5-1.0%, Ni 2.5-3.5%, Nb 1.3-1.8%, V 5-8%, Mo 20-25%, B 2.5-3.0%, and the balance is Fe.

[0011] The present invention also provides a preparation method of a high wear-resistant and impact-resistant iron-based alloy surfacing flux-cored wire for preparing the iron-based alloy surfacing flux-cored wire according to claims 1-5, and the method comprises the following steps:

[0012] Step 1: Roll the steel strip into a U-shaped groove, and then add iron-based alloy flux powder into the U-shaped groove, and the flux powder accounts for 30-60% of the total weight of the flux-cored wire of the present invention;

[0013] Step 2: Close the U-shaped groove to wrap the flux therein, and draw and reduce the diameter step by step through a wire drawing die until the diameter reaches the requirement, and the diameter of the metal powder cored flux-cored wire is 1.6-3.2 mm.

[0014] By adding components such as ferrosilicon, ferromanganese, ferrovanadium, ferroniobium, molybdenum, nickel, boron, and carbon to the flux powder, optimizing the reasonable ranges of each component, and adopting a surfacing process to regulate the reaction path to in-situ generate petal-shaped MC-type and skeleton-shaped eutectic M2B-type precipitated phases, the present invention realizes high hardness, high wear resistance, and impact resistance characteristics. To inhibit the coarse primary M7C3 phase, the present invention uses V and Nb elements to replace Cr elements to form a dispersed petal-shaped MC phase; at the same time, adjust the Mo / B ratio to promote the eutectic reaction to precipitate a skeleton-shaped M2B / Fe eutectic structure, improving toughness and impact resistance; considering the possible hardenability brought by B elements, by adding an appropriate amount of nickel powder, the toughness and strength of the matrix are enhanced; and manganese and silicon are used jointly to deoxidize the molten pool.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0016] 1. Replace the use of Cr elements, reduce environmental pollution, and is an environmentally friendly welding material.

[0017] 2. The cladding layer structure grains welded by the iron-based flux-cored wire of the present invention are fine, and the formed petal-shaped MC phase and eutectic skeleton-shaped M2B phase are distributed on the martensite matrix, thereby ensuring the comprehensive performance of high hardness, high wear resistance, and impact resistance.

[0018] 3. Good surfacing processability, no need for preheating before welding, little spatter during the welding process, and no cracks appear in the cladding layer after surfacing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the surfacing weld morphology diagram of the iron-based flux-cored wire in a preferred embodiment of the present invention;

[0020] Figure 2 is the metallographic structure diagram of the surfacing sample of the iron-based alloy flux-cored wire in Embodiment 1 of the present invention;

[0021] Figure 3 is the metallographic structure diagram of the surfacing sample of the iron-based alloy flux-cored wire in Embodiment 2 of the present invention;

[0022] Figure 4 is the metallographic structure diagram of the surfacing sample of the iron-based alloy flux-cored wire in Embodiment 3 of the present invention. Figure 5 is the metallographic structure diagram of the low magnification (left) and high magnification (right) of the surfacing sample of the iron-based alloy flux-cored wire in Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following introduces multiple preferred embodiments of the present invention with reference to the accompanying drawings of the specification, making its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0024] Embodiment 1

[0025] A cold-rolled carbon steel strip with a width of 12 mm and a thickness of 0.3 mm is used, pressed into a U shape by a forming machine, and then the flux powder is filled into the U-shaped groove. The flux powder accounts for 46% of the mass of the flux-cored wire; then the opening of the U-shaped groove is closed to form an O shape, so that the flux powder is wrapped therein, and it is drawn and reduced in diameter step by step by a wire drawing machine according to the conventional method to obtain a Φ2.8 mm iron-based flux-cored wire.

[0026] For the high wear-resistant and impact-resistant surfacing flux-cored wire, the mass percentage content of the flux powder components is: ferrosilicon 0.8 - 1.5%, ferromanganese 1.6 - 2.3%, ferrovanadium 20 - 25%, ferroniobium 0.5 - 1.5%, molybdenum powder 10 - 15%, nickel powder 0.5 - 1.5%, boron powder 1.5 - 2.0%, carbon powder 2.4 - 2.8%, and the balance is iron powder, and they are mixed evenly.

[0027] Embodiment 2

[0028] Use cold-rolled carbon steel strip with a width of 12 mm and a thickness of 0.3 mm, press it into a U shape by a forming machine, then fill the flux powder into the U-shaped groove, and the flux powder accounts for 40% of the mass of the flux-cored wire; then close the opening of the U-shaped groove to form an O shape, so that the flux powder is wrapped therein, and draw and reduce the diameter step by step through a wire drawing machine according to the conventional method to obtain a Φ2.0 mm iron-based flux-cored wire.

[0029] For the high wear-resistant and impact-resistant surfacing flux-cored wire, the mass percentage content of the flux powder components is: ferrosilicon 0.8-1.5%, ferromanganese 1.6-2.3%, ferrovanadium 15-20%, ferroniobium 1.5-2.5%, molybdenum powder 15-20%, nickel powder 1.5-2.5%, boron powder 2.0-2.5%, carbon powder 1.6-2.2%, and the balance is iron powder, which is mixed evenly.

[0030] Example 3

[0031] Use cold-rolled carbon steel strip with a width of 12 mm and a thickness of 0.3 mm, press it into a U shape by a forming machine, then fill the flux powder into the U-shaped groove, and the flux powder accounts for 36% of the mass of the flux-cored wire; then close the opening of the U-shaped groove to form an O shape, so that the flux powder is wrapped therein, and draw and reduce the diameter step by step through a wire drawing machine according to the conventional method to obtain a Φ1.6 mm iron-based flux-cored wire.

[0032] For the high wear-resistant and impact-resistant surfacing flux-cored wire, the mass percentage content of the flux powder components is: ferrosilicon 1.6-2.3%, ferromanganese 0.8-1.5%, ferrovanadium 10-15%, ferroniobium 2.5-3.5%, molybdenum powder 20-25%, nickel powder 2.5-3.5%, boron powder 2.5-3.0%, carbon powder 1.0-1.6%, and the balance is iron powder, which is mixed evenly.

[0033] The flux in Examples 1-3 is in powder form, and the particle size requirements are: the passing rate of 60 mesh is 100%, and the passing rate of particles larger than 200 mesh is <20%.

[0034] Select the iron-based flux-cored wires described in Examples 1-3 of the present invention, and respectively build a single-pass clad layer on a common carbon steel (Q235) steel plate (such as Figure 1 ), the thickness of the clad layer is 3 mm, and the surfacing process parameters are shown in Table 1.

[0035] Table 1 Surfacing process parameters

[0036]

[0037] Take samples at the same position on the surface of the surfacing metal layer on the test plate, and after grinding and polishing, wipe it 5 times with 4% nitric acid alcohol for corrosion, observe the microstructure of the surfacing clad layer and conduct hardness tests. The microstructures are as shown in Figure 2 、 Figure 3 and Figure 4As shown, it can be seen that the cladding layer structure is composed of a matrix martensite phase, in-situ self-generated petal-shaped and skeletal precipitated phases; the hardness test results are shown in Table 2, and it can be seen that the hardness of the cladding layer exceeds 900 HV 0.5 or above.

[0038] Table 2 Hardness of the surfacing layer

[0039] Item Vickers hardness HV (loading force 0.5 kgf) Example 1 945±30 Example 2 926±28 Example 3 908±42

[0040] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations according to the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A high wear-resistant and impact-resistant iron-based surfacing flux-cored wire, characterized in that, The flux-cored powder is wrapped with a carbon steel strip. The flux-cored powder comprises the following substances in mass percentage: ferrosilicon 0.5 - 2.3%, ferromanganese 0.5 - 2.3%, ferrovanadium 10 - 30%, ferroniobium 0.5 - 4.5%, molybdenum powder 10 - 30%, nickel powder 0.5 - 3.5%, boron powder 1.0 - 3.5%, carbon powder 1.0 - 3.0%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 1.0 - 3.0%, Si 0.5 - 1.5%, Mn 0.5 - 1.5%, Ni 0.5 - 3.5%, Nb 0.1 - 2.0%, V 3 - 15%, Mo 8 - 30%, B 1.0 - 3.5%, and the balance is Fe.

2. The high wear-resistant and impact-resistant iron-based surfacing flux-cored wire according to claim 1, wherein, The strip used for the outer skin of the flux-cored wire is a cold-rolled carbon steel strip.

3. The high wear-resistant and impact-resistant iron-based surfacing flux-cored wire according to claim 1, characterized in that, The mass of the flux-cored powder accounts for 30 - 60% of the total mass of the wire.

4. The high wear-resistant and impact-resistant iron-based surfacing flux-cored wire according to claim 1, wherein, The diameter of the flux-cored wire is 1.6 - 3.2 mm.

5. A high wear-resistant and impact-resistant surfacing flux-cored wire as claimed in claim 1, characterized in that, The mass percentage of the flux-cored composition is: ferrosilicon 0.8 - 1.5%, ferromanganese 1.6 - 2.3%, ferrovanadium 20 - 25%, ferroniobium 0.5 - 1.5%, molybdenum powder 10 - 15%, nickel powder 0.5 - 1.5%, boron powder 1.5 - 2.0%, carbon powder 2.4 - 2.8%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 2.4 - 2.8%, Si 0.5 - 1.0%, Mn 1.2 - 1.7%, Ni 0.5 - 1.5%, Nb 0.3 - 0.8%, V 10 - 13%, Mo 10 - 15%, B 1.5 - 2.0%, and the balance is Fe.

6. A highly wear-resistant and impact-resistant surfacing flux-cored wire as claimed in claim 1, wherein, The mass percentage of the flux-cored composition is: ferrosilicon 0.8 - 1.5%, ferromanganese 1.6 - 2.3%, ferrovanadium 15 - 20%, ferroniobium 1.5 - 2.5%, molybdenum powder 15 - 20%, nickel powder 1.5 - 2.5%, boron powder 2.0 - 2.5%, carbon powder 1.6 - 2.2%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 1.6 - 2.2%, Si 0.5 - 1.0%, Mn 1.2 - 1.7%, Ni 1.5 - 2.5%, Nb 0.7 - 1.3%, V 7 - 10%, Mo 15 - 20%, B 2.0 - 2.5%, and the balance is Fe.

7. A high wear-resistant and impact-resistant surfacing flux-cored wire as claimed in claim 1, characterized in that, The mass percentage of the flux-cored composition is: ferrosilicon 1.6 - 2.3%, ferromanganese 0.8 - 1.5%, ferrovanadium 10 - 15%, ferroniobium 2.5 - 3.5%, molybdenum powder 20 - 25%, nickel powder 2.5 - 3.5%, boron powder 2.5 - 3.0%, carbon powder 1.0 - 1.6%, and the balance is iron powder; the elements in the surfacing cladding layer prepared by the flux-cored wire include, by mass percentage: C 1.0 - 1.6%, Si 1.2 - 1.7%, Mn 0.5 - 1.0%, Ni 2.5 - 3.5%, Nb 1.3 - 1.8%, V 5 - 8%, Mo 20 - 25%, B 2.5 - 3.0%, and the balance is Fe.

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