A highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire and a preparation method thereof

Abstract

The present invention discloses a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire and a preparation method thereof. The flux-cored welding wire is filled with a flux core in the welding skin. The raw material of the flux core is solid-solution strengthened by adding C, Cr, Ni, W, and Mo elements. On this basis, WC is generated by the reaction of C and W, and boride is generated by the reaction of B and C, so as to further achieve the strength of the metal coating. Compared with the single strengthening of alloy elements, the combined strengthening adopted by the present invention has a better and more obvious strengthening effect; the flux-cored welding wire proposed by the present invention is used for laser cladding to prepare corrosion-resistant and high-hardness laser metal coatings, the flux core formula is easy to obtain, the wire production efficiency is high, the cost is low, and the application prospect is broad.

Description

Technical Field

[0001] The invention belongs to the field of new material preparation, and specifically relates to a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire and a preparation method thereof. Background Art

[0002] With the development of modern industry, the requirements for the surface performance of various mechanical equipment parts are getting higher and higher. Some parts working under conditions such as high speed, high temperature, high pressure, heavy load, corrosive media, etc. are often scrapped due to local damage on their surface, which eventually leads to the suspension of equipment or equipment. In order to improve the reliability of mechanical equipment and extend its service life, a lot of research and exploration have been carried out internationally on improving the surface performance of parts. Among them, preparing metal coatings on the surface of parts by wire laser cladding is one of the means.

[0003] The performance of the metal coating prepared by wire laser cladding technology is mainly determined by the chemical composition of the wire, and different compositions correspond to different performances. Due to the harsh service environment of coal mine hydraulic support columns, the metal coating required for surface repair needs to have the characteristics of corrosion resistance and high wear resistance. However, due to the particularity of the manufacturing process of traditional solid welding wire, the preparation of solid wire needs to overcome the influence of factors such as work hardening during the drawing process, resulting in the carbon content, wear-resistant elements and corrosion-resistant elements in the material being lower than metal powder. It is difficult to meet the demand for surface metal coatings of coal mine hydraulic support columns. At the same time, the wear resistance of traditional solid wire laser metal coatings on coal mine hydraulic columns is generally low, and the corrosion resistance is poor. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire and a preparation method thereof, so as to solve the problem that it is difficult to prepare highly wear-resistant and corrosion-resistant metal coatings from existing solid welding wires through laser cladding technology, thereby meeting the harsh service environment of coal mine hydraulic support pillars.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire is used for preparing a metal coating, wherein the composition of the metal coating is, by mass fraction, C: 0.17-0.24%; Si: 0.30-0.60%; Mn: 0.60-1.10%; Cr: 17.50-20.80%; Ni: 1.50-2.2%; Mo: 0.80-1.40%; W: 0.50-1.00%;

[0007] B: 0.20-0.70%; the balance is Fe; the metal coating contains WC particles and metal borides;

[0008] After laser cladding treatment of the flux-cored welding wire on the surface of the stent, a metal coating is formed on the surface of the stent; the wear amount G of the metal coating is less than 0.6g, and the neutral salt spray corrosion resistance time of the metal coating is greater than 300 hours;

[0009] The flux-cored welding wire comprises a flux core and a welding sheath, wherein the flux core is wrapped by the welding sheath; the flux core is a metal mixed powder, and the welding sheath is stainless steel.

[0010] A further improvement of the present invention is:

[0011] Preferably, the metal boride is a metal boride formed by B and Cr, or B and Mo.

[0012] Preferably, when the weld skin is 430 stainless steel, the composition of the flux core is C: 0.50-0.70%; Si: 1.00-1.50%; Mn: 3.00-4.00%; Cr: 25.00-30.00%; Ni: 5.00-7.50%; Mo: 3.00-5.00%; W: 2.00-3.50%; B: 2.00-4.00%, and the balance is Fe.

[0013] Preferably, when the weld skin is 410 stainless steel, the composition of the flux core is C: 0.50-0.70%; Si: 0.90-1.40%; Mn: 3.00-4.00%; Cr: 35.50-40.50%; Ni: 5.50-8.00%; Mo: 3.00-5.00%; W: 2.00-3.50%; B: 2.00-4.00%; the balance is Fe.

[0014] Preferably, the filling rate of the flux core in the flux-cored welding wire is 30wt.%-32wt.%.

[0015] Preferably, the diameter of the flux-cored welding wire is φ1.0mm-φ1.2mm.

[0016] A method for preparing a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire comprises the following steps:

[0017] Step 1, weighing and mixing metal powders according to the target composition of the raw materials to prepare the flux core raw materials; Step 2, after mixing the flux core raw materials, placing them in a welding skin, and drawing and deforming the welding skin wrapped with the flux core to obtain a highly wear-resistant and corrosion-resistant laser cladding flux cored welding wire.

[0018] Preferably, in step 2, the weighed raw materials are heated, dried and then mixed.

[0019] Preferably, in step 2, the drawing deformation is staged drawing.

[0020] Preferably, in step 2, the diameter of the flux-cored welding wire after the first drawing is 2.6 mm, and the flux-cored welding wire is drawn to the target diameter after the second drawing.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The invention discloses a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire. By adding a proper amount of Cr element in the flux core, the excellent corrosion resistance and partial strength improvement of the metal coating are achieved; by adding a proper amount of various alloy elements such as Mo and W, under the action of high temperature of laser cladding, the precipitated carbon element forms a variety of carbides with other alloy elements, wherein the generated solid solution can play a solid solution strengthening role, while avoiding the problem of cracking of the metal coating due to excessive carbides; the addition of B is mainly to form metal borides with Cr, Mo, etc. to improve the strength of the matrix; the addition of W element and the C element in the flux core will react in situ to generate nanoparticles such as WC, and the hard WC particles themselves have a strengthening effect on the matrix. In addition, the dispersed and fine WC carbides are evenly distributed on the matrix, and also have the effect of dispersion strengthening. Through the combined action of precipitation dispersion strengthening and fine grain strengthening, the wear resistance of the metal coating is further improved. In order to improve the industrial application of wire laser cladding technology on coal mine hydraulic pillars, it is necessary to solve the problem of improving the performance of the wire itself. The flux-cored welding wire disclosed in the present invention is used to prepare a metal coating and belongs to a martensitic stainless steel type material. By adding alloy elements that improve wear resistance, the material has good corrosion resistance and high wear resistance, so that it can be prepared into a metal wire by drawing and used for wire laser cladding. At present, there is a lack of such Fe-based materials that are both highly wear-resistant and corrosion-resistant (resistant to 300 hours of neutral salt spray corrosion test) and do not corrode on the market. The present invention develops a high-hardness, corrosion-resistant flux-cored welding wire by rationally designing a metal coating alloy system and optimizing alloy components. It is specially used for laser cladding of wires and is mainly used for surface modification of parts, so that it has both excellent corrosion resistance and high wear resistance.

[0023] Furthermore, the flux-cored welding wire of the present invention is a flux-cored welding wire, in which a flux core is coated in a stainless steel weld skin. In order to achieve the composition of the final metal coating, flux cores and weld skins with different compositions are used, so that the final prepared coating can meet the design requirements. The composition of the internal flux core can be adjusted according to the surface of the actual repaired material, and the composition of the flux core can be adjusted at the same time, so that the laser cladding welding wire is suitable for the laser cladding process. When the welding wire coated with the flux core is used for laser cladding, the molten pool has good fluidity, less smoke and dust, less spatter, and less slag generated in the process. Even if a small amount of slag is generated, it can be floated twice without affecting multiple cladding. Compared with the solid welding wire, the flux-cored welding wire has the precise controllability of the composition, so that the corrosion resistance and wear resistance of the final prepared metal coating meet the requirements. The present invention uses powder core wire as laser cladding material, and optimizes the laser cladding process in a targeted manner based on the characteristics of arc-free stirring and uneven microstructure. By rationally regulating and selecting the metal powder ratio, the wear resistance and corrosion resistance of the wire laser metal coating are improved, and the application scope of wire laser cladding is promoted. The present invention can achieve rapid adjustment of the performance of the laser metal coating by adjusting the powder, which meets the needs of the rapid development of modern industry.

[0024] Furthermore, the present invention adopts a method of wrapping alloy powder with stainless steel strip to prepare flux-cored welding wire, which has a short production cycle and simple preparation process compared with traditional solid welding wire. If the metal coating of traditional solid welding wire is required to have high hardness, the hardness of the welding wire itself will also be high, and the work hardening is serious due to the increase of alloy elements, which brings great difficulties to drawing. However, the present invention uses stainless steel strip to draw, which completely overcomes this technical bottleneck.

[0025] Furthermore, the present invention can adjust the molten pool solidification process by adjusting the powder alloy composition, reduce tissue segregation to avoid microstructure inhomogeneity, promote uniform distribution of WC, and avoid cracking caused by carbide aggregation.

[0026] The invention also discloses a method for preparing a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire. The preparation method forms a flux-cored welding wire that meets the requirements through multi-stage drawing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The microstructure of the metal coating after laser cladding of the flux-cored welding wire prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0029] One of the embodiments disclosed in the present invention discloses a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire, which is used to prepare a metal coating on the surface of a hydraulic support by a laser cladding method. The metal coating contains WC particles and metal borides, and the metal borides are metal borides formed by B and Cr, B and Mo. Specific borides include CrB and Mo2NiB2, Mo2FeB2. The metal coating has high corrosion resistance and high wear resistance, and belongs to a martensitic stainless steel type material formula. The metal coating has a metal coating wear amount G of less than 0.6g under the ASTMG105-2016 standard, and has excellent wear resistance. Moreover, when the material is tested under the conditions of the "GBT10125 Artificial Atmosphere Corrosion Test Salt Spray Test", the corrosion rating of the surface of the material after 300 hours of corrosion can reach the highest level of 9 or above according to the "GBT6461 Rating of samples and test pieces of metal and other inorganic covering layers on metal substrates after corrosion tests" under the neutral salt spray corrosion test. In order to achieve the above-mentioned performance, the composition of the metal coating is: C: 0.17-0.24wt%, Si: 0.30-0.60wt%, Mn: 0.60-1.10wt%, Cr: 17.50-20.80wt%, Ni: 1.50-2.2wt%, Mo: 0.80-1.40wt%, W: 0.50-1.00wt%, B: 0.20-0.70wt%; the balance is Fe.

[0030] The invention discloses a flux-cored welding wire. The flux-cored welding wire comprises a flux core and a stainless steel strip. The flux core is wrapped by the stainless steel strip, and the welding skin is the stainless steel strip.

[0031] When 430 stainless steel strip is preferably used, the core is composed of the following raw material components by mass percentage:

[0032] C: 0.50-0.70%;

[0033] Si: 1.00-1.50%;

[0034] Mn: 3.00-4.00%;

[0035] Cr: 25.00-30.00%;

[0036] Ni: 5.00-7.50%;

[0037] Mo: 3.00-5.00%;

[0038] W: 2.00-3.50%;

[0039] B: 2.00-4.00%,

[0040] The balance is Fe.

[0041] The flux core filling rate of the flux cored welding wire is 30wt.%-32wt.%.

[0042] When 410 stainless steel strip is preferably used, the core is composed of the following raw material components by mass percentage:

[0043] C: 0.50-0.70%;

[0044] Si: 0.90-1.40%;

[0045] Mn: 3.00-4.00%;

[0046] Cr: 35.50-40.50%;

[0047] Ni: 5.50-8.00%;

[0048] Mo: 3.00-5.00%;

[0049] W: 2.00-3.50%;

[0050] B: 2.00-4.00%;

[0051] The balance is Fe.

[0052] The flux core filling rate of the flux cored welding wire is 30wt.%-32wt.%.

[0053] The preferred embodiments of the present invention do not limit the technical solutions of the present invention to this. Based on the main technical concept of the present invention, those skilled in the art only change the composition of the stainless steel strip (for example, 430 stainless steel strip is replaced with 410 stainless steel strip, etc.) to cause the core composition to change. However, if the chemical composition is the same after multi-layer cladding using the test method specified by the present invention, it still falls within the protection scope of the present invention.

[0054] The present invention ensures that the metal coating has both high wear resistance and corrosion resistance through the reasonable allocation of elements. The functions of the main alloying elements in the metal wire material formula of the present invention are as follows:

[0055] Carbon (C): C is the element that has the most obvious effect on improving strength and hardness among all elements. C is a ferrite-forming element, which is dissolved in α-Fe as an interstitial solid solution to improve strength and ensure the formation of martensitic structure. With the increase of C content, the hardness and strength of the metal coating both show a linear increase. In the present invention, C has another function, which is to react with W in situ to generate WC particles, further strengthening the matrix. However, under the premise that the metal coating does not crack, it is necessary to control the C content to avoid the occurrence of cracks in the metal coating. In the present invention, 0.50-0.70% of C element is added to the core with 430 stainless steel strip or 410 stainless steel strip and a filling rate of 30-32wt.%.

[0056] Chromium (Cr): Cr is a ferrite-forming element, which helps the metal coating to form a martensitic target structure. Cr can first be dissolved in α-Fe, which has a solid solution strengthening effect. Another notable feature of Cr is its excellent corrosion resistance, so the required neutral salt spray corrosion resistance test of the welding wire is mainly guaranteed by the Cr element. The target structure of the metal coating of the present invention is a martensitic stainless steel structure, and 25.00-30.00% of the Cr element is added to the flux core in combination with a preferred 430 stainless steel strip and a filling rate of 30-32wt.%. 35.50-40.50% of the Cr element is added to the flux core in combination with a preferred 410 stainless steel strip and a filling rate of 30-32wt.%.

[0057] Nickel (Ni): The Ni element can also improve corrosion resistance. The addition of Ni can improve the plasticity and toughness of the metal coating and ensure the stability of the metal coating during service. However, since Ni is an austenite stabilizing element, in order to ensure the martensitic main structure + a small amount of residual austenite structure of the metal coating, the Ni content needs to be controlled in the present invention. In the present invention, 5.00-7.50% of Ni element is added to the core with a preferred 430 stainless steel strip and a filling rate of 30-32wt.%. 5.50-8.00% of Ni element is added to the core with a preferred 410 stainless steel strip and a filling rate of 30-32wt.%.

[0058] Molybdenum (Mo): Mo can be dissolved in the α-Fe matrix to play a role in solid solution strengthening, and the strengthening effect is very obvious. In the present invention, 3.00-5.00% of Mo element is added to the core with 430 stainless steel strip or 410 stainless steel strip and a filling rate of 30-32wt.%.

[0059] Boron (B): As a light element, B has a relatively small coefficient of transition to the metal coating. B exists as an interstitial solid solution in α-Fe and γ-Fe, and will replace part of the position of C, but its solid solubility is very low. Therefore, B is added mainly to form metal borides with Cr, Mo, etc. to improve the strength of the matrix. In the present invention, 2.00-4.00% of B element is added to the core with 430 stainless steel strip or 410 stainless steel strip and a filling rate of 30-32wt.%.

[0060] Silicon (Si) and manganese (Mn): Si and Mn have a combined deoxidation effect, which can reduce the oxygen content in the metal coating and prevent the generation of pores. Mn oxides usually have a higher melting point and are easier to float. The Si content usually cannot be lower than 0.4%. When it is too low, it is easy to produce oxidation pores and increase the burnout of alloy elements, which does not play a deoxidation role. Mn dissolves into austenite to expand the γ phase region, has a strong effect of promoting the stability of austenite, further promotes the formation of residual austenite, and indirectly improves the strength of the surfacing metal. In the present invention, 1.00-1.50% of Si elements and 3.00-4.00% of Mn elements are added to the flux core in combination with 430 stainless steel strip and a filling rate of 30-32wt.%. In combination with 410 stainless steel strip and a filling rate of 30-32wt.%, 0.9-1.40% of Si elements and 3.00-4.00% of Mn elements are added to the flux core.

[0061] Tungsten (W) is a high melting point metal. When added to a metal coating, it can form a WC hard phase, increase the high temperature hardness of the metal coating, and significantly improve the wear resistance of the metal coating.

[0062] Preferably, the material of the welding skin is stainless steel strip, preferably 430 stainless steel strip or 410 stainless steel strip or other commonly used steel strips, and the flux core filling rate in the flux-cored welding wire is 30wt.%-32wt.%.

[0063] Preferably, the metal flux-cored welding wire for laser cladding is a martensitic stainless steel wire material with a diameter of φ1.0 mm-φ1.2 mm.

[0064] One embodiment of the present invention discloses a method for preparing a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire, comprising the following steps:

[0065] Step 1: When 430 stainless steel strip is preferably used, the following raw material powders are weighed respectively by mass percentage: C: 0.50-0.70%, Si: 1.00-1.50%, Mn: 3.00-4.00%, Cr: 25.00-30.00%, Ni: 5.00-7.50%, Mo: 3.00-5.00%, W: 2.00-3.50%, B: 2.0-4.0%, and the balance is Fe. The sum of the mass percentages of the above components is 100%.

[0066] When 410 stainless steel strip is preferably used, the following raw material powders are weighed according to mass percentage: C: 0.50-0.70%, Si: 0.90-1.40%, Mn: 3.00-4.00%, Cr: 35.50-40.50%, Ni: 5.50-8.00%, Mo: 3.00-5.00%, W: 2.00-3.50%, B: 2.0-4.0%, and the balance is Fe. The sum of the mass percentages of the above components is 100%.

[0067] Step 2: Place the raw materials weighed in step 1 in a vacuum heating furnace for heating to remove crystal water in the raw materials; place the dried raw materials in a powder mixer for thorough mixing;

[0068] Step 3: The weld skin is a stainless steel strip, alcohol is used to remove grease on the surface of the stainless steel strip, and the flux core prepared in step 2 is wrapped in the stainless steel strip through a flux-cored wire drawing device to form a process flux-cored wire; the process flux-cored wire is drawn;

[0069] Step 4: After the first drawing process is completed, the diameter of the flux-cored welding wire is reduced in turn by multiple drawing processes, and finally a flux-cored welding wire with a diameter of 1.0-1.2mm is obtained. For example, it can be 1.0mm, 1.1mm or 1.2mm, and the workpiece with the required size is layered to obtain a formed stainless steel flux-cored welding wire.

[0070] Specifically, the diameter of the welding wire is obtained by placing a stainless steel strip with a width of 7 mm and a thickness of 0.3 mm on a tape unwinding machine of a welding wire forming machine, rolling the stainless steel strip into a U-shaped groove through a groove pressing machine, and a flux-cored welding wire making machine wraps the powder in a welding skin, and uses a forming machine to close the welding skin to obtain a semi-finished flux-cored welding wire. The welding skin is wiped clean with acetone, and then the first drawing process is performed. The aperture of the abrasive used in the first drawing process is 2.6 mm. After the first drawing process is completed, the aperture of the drawing abrasive is reduced for subsequent drawing until the diameter of the flux-cored welding wire is 1.0 mm to 1.2 mm.

[0071] The laser cladding wire is used for laser cladding treatment of the surface of the hydraulic support cylinder. The invention optimizes the formula ratio so that the stainless steel wire has excellent corrosion resistance and wear resistance.

[0072] Furthermore, after the laser cladding wire was used to laser clad the surface of relevant components in the hydraulic support, the wear loss G of the surface laser cladding metal coating was less than 0.6g under the ASTMG105-2016 standard, and the neutral salt spray corrosion (NSS) resistance of the surface laser cladding metal coating reached more than 300 hours.

[0073] Example

[0074] Specific embodiments of the present invention are given below to illustrate the implementation effects of the present invention through the embodiments.

[0075] Embodiment 1:

[0076] The composition formula of the drug core shown in Example 1 is shown in Table 1:

[0077] Table 1. Example 1 Core ingredient formula

[0078] C Si Mn Cr Ni Mo W B Fe 0.5 1.5 4.0 25.0 5.0 5.0 3.0 2.0 Bal.

[0079] The flux core formula of Example 1 was used, and 430 stainless steel strip was used for wrapping. The filling rate of the flux core was controlled at 30wt.%, and the flux cored welding wire was prepared by drawing. The wear amount of the obtained metal coating was shown in Table 2 when the flux cored welding wire was used for laser cladding:

[0080] Table 2. Wear amount of metal coating of Example 1 material

[0081] Wear conditions Wear amount (g) Implementation Standards Wear test (3000 rpm) 0.58 ASTMG105-2016

[0082] Case 1: The wire is clad by TIG welding for multiple layers (not less than 5 layers). The cladding metal composition is shown in Table 3:

[0083] Table 3. Cladding metal composition of Example 1

[0084] C Si Mn Cr Ni Mo W B Fe 0.18 0.60 1.1 17.3 1.53 1.38 0.5 0.2 Bal.

[0085] Embodiment 2:

[0086] The composition formula of the drug core shown in Example 1 is shown in Table 1:

[0087] Table 4. Example 2 Core Component Formula

[0088] C Si Mn Cr Ni Mo W B Fe 0.7 1.3 3.6 30.0 7.5 4.0 3.5 3.0 Bal.

[0089] The flux core formula of Example 2 was used, and 430 stainless steel strip was used for wrapping. The filling rate of the flux core was controlled at 32wt.%, and the flux cored welding wire was prepared by drawing. The wear amount of the obtained metal coating was shown in Table 5 when the flux cored welding wire was used for laser cladding:

[0090] Table 5. Wear amount of metal coating of Example 1

[0091] Wear conditions Wear amount (g) Implementation Standards Wear test (3000 rpm) 0.48 ASTMG105-2016

[0092] Example 2 The wire is clad by TIG welding for multiple layers (not less than 5 layers). The cladding metal composition is shown in Table 6:

[0093] Table 6. Cladding metal composition of Example 2

[0094] C Si Mn Cr Ni Mo W B Fe 0.24 0.42 0.88 20 2.2 0.91 1.0 0.5 Bal.

[0095] The laser metal coating prepared in Example 2 has a structure as follows Figure 1 As shown: the metal coating structure is mainly martensite, the structure is evenly distributed, and there are no defects such as cracks and pores.

[0096] Embodiment 3:

[0097] The composition formula of the drug core shown in Example 3 is shown in Table 7:

[0098] Table 7. Example 3 Core Component Formula

[0099] C Si Mn Cr Ni Mo W B Fe 0.6 1.0 3.0 28.2 6.3 3.0 2.7 4.0 Bal.

[0100] The flux core formula of Example 3 was used, and 430 stainless steel strip was used for wrapping. The filling rate of the flux core was controlled at 31wt.%, and the flux cored welding wire was prepared by drawing. The wear amount of the obtained metal coating was shown in Table 8 when the flux cored welding wire was used for laser cladding:

[0101] Table 8. Wear amount of metal coating of Example 3

[0102] Wear conditions Wear amount (g) Implementation Standards Wear test (3000 rpm) 0.54 ASTMG105-2016

[0103] Case 3: The wire is clad by TIG welding for multiple layers (not less than 5 layers). The cladding metal composition is shown in Table 9:

[0104] Table 9. Cladding metal composition of Example 3

[0105] C Si Mn Cr Ni Mo W B Fe 0.2 0.30 0.6 19 1.9 0.8 0.76 0.68 Bal.

[0106] Embodiment 4:

[0107] The composition formula of the drug core shown in Example 4 is shown in Table 10:

[0108] Table 10. Example 4 Core Component Formula

[0109] C Si Mn Cr Ni Mo W B Fe 0.6 0.9 3.5 40.5 8.0 5.0 2 2 Bal.

[0110] The flux core formula of Example 4 was used, and 410 stainless steel strip was used for wrapping. The filling rate of the flux core was controlled at 31wt.%, and the flux cored welding wire was prepared by drawing. The flux cored welding wire was used for laser cladding, and the wear amount of the obtained metal coating was shown in Table 11:

[0111] Table 11. Wear amount of metal coating of Example 4 material

[0112] Wear conditions Wear amount (g) Implementation Standards Wear test (3000 rpm) 0.59 ASTMG105-2016

[0113] Case 4: The wire is clad by TIG welding for multiple layers (not less than 5 layers). The cladding metal composition is shown in Table 12:

[0114] Table 12. Cladding metal composition of Example 4

[0115] C Si Mn Cr Ni Mo W B Fe 0.21 0.31 0.84 19.88 2.2 1.40 0.5 0.21 Bal.

[0116] Embodiment 5:

[0117] The composition formula of the drug core shown in Example 5 is shown in Table 13:

[0118] Table 13. Example 5 Core Component Formula

[0119] C Si Mn Cr Ni Mo W B Fe 0.5 1.4 3 35.5 5.5 4.0 3.5 4 Bal.

[0120] The flux core formula of Example 5 was used, and 410 stainless steel strip was used for wrapping. The filling rate of the flux core was controlled at 30wt.%, and the flux cored welding wire was prepared by drawing. The wear amount of the obtained metal coating was shown in Table 14 by using the flux cored welding wire for laser cladding:

[0121] Table 14. Wear amount of metal coating of Example 5 material

[0122] Wear conditions Wear amount (g) Implementation Standards Wear test (3000 rpm) 0.52 ASTMG105-2016

[0123] Case 5: The wire is clad by TIG welding for multiple layers (not less than 5 layers). The cladding metal composition is shown in Table 15:

[0124] Table 15. Cladding metal composition of Example 5

[0125] C Si Mn Cr Ni Mo W B Fe 0.17 0.60 0.62 17.6 1.5 1.23 0.98 0.7 Bal.

[0126] Embodiment 6:

[0127] The composition formula of the drug core shown in Example 6 is shown in Table 16:

[0128] Table 16. Example 6 Core Component Formula

[0129] C Si Mn Cr Ni Mo W B Fe 0.7 1.2 4.0 38 6.7 3.0 2.8 3 Bal.

[0130] The flux core formula of Example 6 was used, and 430 stainless steel strip was used for wrapping. The filling rate of the flux core was controlled at 32wt.%, and the flux cored welding wire was prepared by drawing. The flux cored welding wire was used for laser cladding, and the wear amount of the obtained metal coating was shown in Table 17:

[0131] Table 17. Wear amount of metal coating of Example 6 material

[0132] Wear conditions Wear amount (g) Implementation Standards Wear test (3000 rpm) 0.50 ASTMG105-2016

[0133] Case 6: The wire is clad by TIG welding for multiple layers (not less than 5 layers). The cladding metal composition is shown in Table 18:

[0134] Table 18 Cladding metal composition of Example 6

[0135] C Si Mn Cr Ni Mo W B Fe 0.23 0.46 1.08 18.57 1.89 0.80 0.74 0.43 Bal.

[0136] The flux core formula provided by the present invention is matched with 430 stainless steel strip or 410 stainless steel strip, and C, Cr, Ni, W, and Mo elements are added to achieve solid solution strengthening. On this basis, C and W react to generate WC, and B and C react to generate borides, so as to further achieve the wear resistance of the metal coating while avoiding the cracking of the metal coating, wherein the microstructure generated is uniform due to the large number of carbides. Compared with the single strengthening of alloy elements, the combined strengthening adopted by the present invention has a better and more obvious strengthening effect; the flux cored welding wire proposed by the present invention is used for laser cladding to prepare corrosion-resistant and high-hardness laser metal coatings, the flux core formula is easy to obtain, the wire production efficiency is high, the cost is low, and the application prospect is broad.

[0137] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire, characterized in that: For preparing a metal coating, the composition of the metal coating is, by mass fraction: C: 0.17-0.24%; Si: 0.30-0.60%; Mn: 0.60-1.10%; Cr: 17.50-20.80%; Ni: 1.50-2.2%; Mo: 0.80-1.40%; W: 0.50-1.00%; B: 0.20-0.70%; the balance is Fe; the metal coating contains WC particles and metal borides; After laser cladding treatment of the flux-cored welding wire on the surface of the stent, a metal coating is formed on the surface of the stent; the wear amount G of the metal coating is less than 0.6g, and the neutral salt spray corrosion resistance time of the metal coating is greater than 300 hours; The flux-cored welding wire comprises a flux core and a welding sheath, wherein the flux core is wrapped by the welding sheath; the flux core is a metal mixed powder, and the welding sheath is stainless steel; The metal boride is a metal boride formed by B and Cr, or B and Mo; When the weld skin is 430 stainless steel, the composition of the flux core is C: 0.50-0.70%; Si: 1.00-1.50%; Mn: 3.00-4.00%; Cr: 25.00-30.00%; Ni: 5.00-7.50%; Mo: 3.00-5.00%; W: 2.00-3.50%; B: 2.00-4.00%, the balance is Fe; When the weld skin is 410 stainless steel, the composition of the flux core is C: 0.50-0.70%; Si: 0.90-1.40%; Mn: 3.00-4.00%; Cr: 35.50-40.50%; Ni: 5.50-8.00%; Mo: 3.00-5.00%; W: 2.00-3.50%; B: 2.00-4.00%; the balance is Fe.

2. The highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire according to claim 1, characterized in that: The filling rate of the flux core in the flux-cored welding wire is 30wt.%-32wt.%.

3. The highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire according to claim 1, characterized in that: The diameter of the flux-cored welding wire is φ1.0mm-φ1.2mm.

4. A method for preparing the highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire according to claim 1, characterized in that: The following steps are involved: Step 1, weighing and mixing metal powders according to the target raw material composition to prepare a flux core raw material; Step 2, after mixing the flux core raw materials, placing them in a welding skin, and drawing and deforming the welding skin wrapped with the flux core to obtain a highly wear-resistant and corrosion-resistant laser cladding flux cored welding wire.

5. The method for preparing a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire according to claim 4, characterized in that: In step 2, the weighed raw materials are heated, dried and then mixed.

6. The method for preparing a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire according to claim 4, characterized in that: In step 2, the drawing deformation is staged drawing.

7. The method for preparing a highly wear-resistant and corrosion-resistant laser cladding flux-cored welding wire according to claim 4, characterized in that: In step 2, the diameter of the flux-cored welding wire after the first drawing is 2.6 mm, and the flux-cored welding wire is drawn to the target diameter after the second drawing.

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