Self-protection alloy powder for preparing high-temperature wear-resistant coating, preparation method of self-protection alloy powder and product containing self-protection alloy powder

Abstract

The invention discloses self-protection alloy powder for preparing a high-temperature wear-resistant coating, a preparation method of the self-protection alloy powder and a product containing the self-protection alloy powder, and belongs to the technical field of wear-resistant surfacing materials.The self-protection alloy powder for preparing the high-temperature wear-resistant coating comprises, by mass, 10.0%-15.0% of C, 3.0%-6% of Mo, 25.0%-30.0% of Cr, 2.0%-5.0% of Ni, 0.5%-0.8% of Mn, 0.5%-1.2% of Si, 1.6%-8.0% of W and the balance Fe and inevitable impurities. 0.5%-1.6% of CaF, 0.8%-1.0% of CaCO3 and the balance Fe; furthermore, a metal ceramic reinforced phase TiC can be added. The self-protection alloy powder disclosed by the invention is specially used for a high-temperature severe wear working condition, and on the basis of ensuring the hardness, the wear resistance, the self-lubricating property, the high-temperature oxidation resistance and the metallurgical bonding property of a coating at a high temperature, by improving the wettability of the alloy powder, the problems of cracking and cracking tendency of a surfacing layer in the surfacing process can be solved.

Description

Technical Field

[0001] This invention belongs to the field of wear-resistant surfacing materials technology, and particularly relates to a self-protective alloy powder for preparing high-temperature wear-resistant coatings, its preparation method, and products containing the same. Background Technology

[0002] The single-roll crusher is one of the key pieces of equipment in sintering production, responsible for crushing sinter cakes. Due to its harsh working environment, components such as the roller teeth suffer severe wear, resulting in short service life and rapid component consumption. This complex and harsh working environment and process place high demands on equipment performance. Therefore, improving the high-temperature wear resistance of the single-roll crusher and extending the service life of related components to improve the quality and efficiency of sinter production has become a key research objective.

[0003] Welding is a common additive manufacturing technique. It involves depositing one or more layers of alloy material onto the surface of mechanical parts using welding energy to restore the original part's dimensions or to provide a surface coating with special properties such as wear resistance, corrosion resistance, or high-temperature resistance. Therefore, welding technology is widely used in aerospace, shipbuilding, automotive, mining and metallurgy, and petrochemical industries. In recent years, with the rapid development of the construction machinery industry, welding technology has also played a crucial role in repair and remanufacturing.

[0004] Currently, flux-cored welding wire is commonly used in open arc welding. However, the filler content of flux-cored welding wire limits the amount of alloying elements that can be added. Companies like Faaudi have improved the hardness and wear resistance of materials at high temperatures by adding large amounts of elements such as Mo and Ni, but the addition of precious metals has led to a sharp increase in product costs. On the other hand, when welding different base materials, the composition of the welding wire should be appropriately adjusted to achieve a gradient transition in the mechanical and thermophysical properties of the cladding layer, thereby improving the service performance and service life of the cladding layer. In the process of adjusting the welding wire composition, the rolling and drawing processes of flux-cored welding wire are quite complex, which not only increases production costs but also prolongs the adjustment cycle and results in slow response to new materials and new working conditions. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a self-protective alloy powder for preparing high-temperature wear-resistant coatings, a method for preparing the powder, and a product containing the powder.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A self-protective alloy powder for preparing high-temperature wear-resistant coatings comprises the following components by mass percentage:

[0008] C 10.0–15.0%, Mo 3.0%–6%, Cr 25.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 1.6%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, balance Fe.

[0009] Optionally, the self-protective alloy powder used to prepare the high-temperature wear-resistant coating comprises, by mass percentage, the following components:

[0010] C 14.0–15.0%, Mo 3.0%–6%, Cr 29.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 6%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, balance Fe.

[0011] Optionally, the self-protective alloy powder used to prepare the high-temperature wear-resistant coating comprises, by mass percentage, the following components:

[0012] C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 8.0%, CaF 1.6%, CaCO3 1.0%, balance Fe.

[0013] Optionally, the self-protective alloy powder used to prepare the high-temperature wear-resistant coating further includes a cermet-reinforcing phase TiC, the amount of which is 4 wt.% to 8 wt.% of the total components. Preferably, it is 8 wt.%.

[0014] Furthermore, the average particle size of the metal-ceramic reinforced phase TiC is 10-50 μm.

[0015] The above-mentioned method for preparing the self-protective alloy powder for high-temperature wear-resistant coating includes the following steps:

[0016] The above components are mixed, ground, and dried according to their mass percentages to obtain the self-protecting alloy powder.

[0017] Optionally, the drying conditions are: drying in an oven at 120°C for 3 hours.

[0018] A high-temperature wear-resistant coating (weld overlay) comprises the above-mentioned self-protective alloy powder and flux-cored welding wire, wherein the mass ratio of the two is 1:(1.1 to 1.2).

[0019] Optionally, the flux-cored wire is a YB3 self-shielded flux-cored wire.

[0020] The preparation method of the above-mentioned high-temperature wear-resistant coating includes the following steps:

[0021] The self-protected alloy powder and flux-cored welding wire are subjected to open arc welding using a pre-fabricated powder-laying method to prepare the high-temperature wear-resistant coating.

[0022] Beneficial Effects: This invention proposes a welding method using "flux-cored wire + external powder" for cladding. The flux-cored wire primarily ensures smooth droplet transfer, stabilizes the arc, minimizes harmful impurities such as sulfur and phosphorus, produces aesthetically pleasing welds, and ensures a smooth transition of alloy components to the cladding layer, reducing burn-off. Gas shielding, slag shielding, or a combination of these methods safeguard the entire welding process, achieving a good metallurgical bond between the cladding layer and the substrate. The external powder can be adaptively adjusted according to actual working conditions. In high-temperature and highly abrasive environments, alloying elements such as Cr and W are added to enhance its performance, compensating for the low powder filling rate of the flux-cored wire. This allows for timely adjustments to different working conditions, eliminating the need for wire rolling and drawing processes, shortening the production cycle, and improving work efficiency.

[0023] This invention breaks through the limitations of traditional flux-cored welding wire filler ratio, facilitating the addition of alloying elements and eliminating the need for large amounts of precious metals, thereby reducing welding costs. Furthermore, when the welding substrate or operating conditions change, only the external powder needs adjustment, significantly improving response speed.

[0024] The coating performance obtained by surfacing with flux-cored wire and powder as defined in this invention is affected by many factors, with the powder material being one of the most significant. To obtain a well-formed surfacing layer, the powder must possess good self-fluxing properties and good flowability. If the composition of the powder and the welding wire is not complementary, or if the difference between the wire feed rate and the powder usage is too large, problems such as porosity, cracks, and numerous inclusions will occur in the coating after surfacing. Simultaneously, the powder material must have good self-protection properties. Since no additional inert gas is added for protection during the surfacing of powder with flux-cored wire, surfacing without a shielding gas necessitates that the powder composition possess good self-protection properties; otherwise, it will significantly affect the final shape of the surfacing layer.

[0025] Optionally, the conditions during the open arc welding process are: welding current 240-280A, welding speed 90-110mm / min, powder coating mass 30-70g, dry extension 10-25mm, and welding torch oscillation frequency 0.1-0.5Hz.

[0026] Optionally, the thickness of the high-temperature wear-resistant coating is 3-4 mm; the hardness is 55-65 HRC.

[0027] Compared with the prior art, the present invention has the following advantages and technical effects:

[0028] (1) The welding powder (self-protecting alloy powder) disclosed in this invention is used in key components such as crusher liners in high-temperature environments. The thickness of the welding layer is 3-4 mm. The surface of the welding layer is smooth and flat, without obvious cracks and pores, and it achieves good metallurgical bonding with the substrate.

[0029] (2) The TiC reinforcing phase introduced in this invention has high hardness, high strength, and good wear and corrosion resistance. By dispersing the TiC ceramic phase in the weld overlay, the ceramic phase grains are fine and can refine the matrix structure. On the other hand, TiC also improves the wettability between the weld overlay and the matrix.

[0030] (3) The addition of self-protective components in this invention reduces instability factors during the welding process. Specifically, the addition of Mn, Si, and CaCO3 components plays a role in slag formation and gas generation. The CO2 produced by the thermal decomposition of CaCO3 can ensure the isolation of air and prevent oxidation. The combined slag formation of Mn and Si can further reduce the influence of harmful impurities and purify the molten pool. At the same time, it can also protect the welding droplets and molten pool metal and improve the weld formation.

[0031] (4) The weld overlay prepared by the present invention has less weight loss under high temperature wear than the substrate. The weld overlay remains stable and has high hardness under high temperature conditions, which improves the high temperature wear resistance of the coating.

[0032] (5) The high-temperature wear-resistant surfacing powder of the present invention is easy to prepare. It can be used after simple mixing and drying. It does not require the addition of inert gas for protection during the surfacing process, which greatly improves the surfacing efficiency and reduces the cost. Attached Figure Description

[0033] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0034] Figure 1 The image shows the microstructure of the self-protecting alloy powder prepared in Example 1 of this invention.

[0035] Figure 2 This is a metallographic image of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire according to Example 1 of the present invention.

[0036] Figure 3 This is a graph showing the change in the friction coefficient over time at 600°C of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire in Example 1 of the present invention.

[0037] Figure 4SEM images of the wear surface of different parts of the weld overlay sample obtained by welding self-protected alloy powder and flux-cored wire in Example 1 of the present invention at 600°C.

[0038] Figure 5 The image shows a white light scan of the worn surface of the weld overlay obtained by welding self-protected alloy powder and flux-cored wire in Example 1 of the present invention at 600°C.

[0039] Figure 6 This is a SEM image of the surface morphology of the weld overlay obtained by welding self-protected alloy powder and flux-cored wire in Example 1 of the present invention after high-temperature oxidation for 36 hours.

[0040] Figure 7 This is a SEM microstructure image of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire in Example 2 of the present invention.

[0041] Figure 8 Comparison of the friction coefficient versus time curves of the weld layers obtained after welding self-protected alloy powder and flux-cored wire in Examples 2-5 at 600°C;

[0042] Figure 9 The image shows the microscopic sliding wear morphology of the weld overlay obtained after welding self-shielded alloy powder and flux-cored wire in Comparative Example 1.

[0043] Figure 10 The image shows the microscopic sliding wear morphology of the weld layer obtained after welding self-protected alloy powder and flux-cored wire in Comparative Example 2.

[0044] Figure 11 The graph shows the variation of the friction coefficient over time at 600℃ for the weld layers obtained by welding self-shielded alloy powder and flux-cored wire in Examples 1-2. Detailed Implementation

[0045] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0046] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0047] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0048] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0049] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0050] This invention aims to solve the problem of short service life of key components such as crusher liners due to insufficient wear resistance in high-temperature environments, and provides a dedicated welding powder. This welding powder is an iron-based (Fe-based) alloy powder with a composition similar to the base material, which is beneficial for achieving good metallurgical bonding. This invention also introduces self-protective components, effectively ensuring the stability of the welding process. This powder is specifically designed for operating conditions subject to severe wear at high temperatures, maintaining high hardness, excellent wear resistance, self-lubrication, high-temperature oxidation resistance, and good metallurgical bonding performance of the coating in high-temperature environments. Simultaneously, the welding powder disclosed in this invention significantly improves its wettability, effectively suppressing the cracking tendency of the weld layer during the welding process, and improving the integrity and reliability of the weld layer.

[0051] The flux-cored wire used in this embodiment of the invention is YB3 self-shielded flux-cored wire, which has good surfacing performance. The flux composition is the Fe-Cr-C system commonly used in wear-resistant surfacing, and the specific composition is shown in Table 1.

[0052] During the welding process, the welding powder disclosed in this invention and the above-mentioned flux-cored welding wire participate in the metallurgical reaction together, thereby preparing a high-temperature friction and wear resistant welding layer that meets the requirements of key components of a single-tooth roll crusher.

[0053] Table 1 Composition of Flux-Cored Welding Wire

[0054] element C Cr Mn Si Ni Mo Standard value 2.5-4.5 23-28 1.0-2.0 1.5-2.5 0.1-0.2 0.1-0.2

[0055] Specifically, this invention discloses a high-temperature wear-resistant surfacing powder for key components of crushers, comprising the following components by mass percentage:

[0056] C 10.0–15.0%, Mo 3.0%–6%, Cr 25.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 1.6%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, balance Fe.

[0057] In some alternative embodiments, a high-temperature wear-resistant surfacing powder for key crusher components comprises the following components by mass percentage:

[0058] C 13.0–15.0%, Mo 3.0%–6%, Cr 28.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 4%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, balance Fe.

[0059] In some alternative embodiments, a high-temperature wear-resistant surfacing powder for key crusher components comprises the following components by mass percentage:

[0060] C 14.0–15.0%, Mo 3.0%–6%, Cr 29.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 6%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, balance Fe.

[0061] This invention discloses a self-protective alloy powder for preparing high-temperature wear-resistant coatings using flux-cored welding wire in open-arc welding. The powder has a micron-sized particle size with an average particle size of 10-50 μm and a spherical microstructure. This invention enhances the wear resistance of the TiC weld overlay layer under high-temperature conditions by introducing a cermet-reinforcing phase into the aforementioned high-temperature wear-resistant welding powder. The self-protective alloy powder, by mass percentage, comprises the following components:

[0062] C 14.0–15.0%, Mo 3.0%–6%, Cr 29.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 6%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, TiC 4%–8%, balance Fe.

[0063] In some alternative embodiments, the self-protective alloy powder comprises, by weight percentage, the following components:

[0064] C 14.0–15.0%, Mo 3.0%–6%, Cr 29.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 6%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, TiC 5%–8%, balance Fe.

[0065] In some alternative embodiments, the self-protective alloy powder comprises, by weight percentage, the following components:

[0066] C 14.0–15.0%, Mo 3.0%–6%, Cr 29.0%–30.0%, Ni 2.0%–5.0%, Mn 0.5%–0.8%, Si 0.5%–1.2%, W 6%–8.0%, CaF 0.5%–1.6%, CaCO3 0.8%–1.0%, TiC 7%–8%, balance Fe.

[0067] In some optional embodiments, the average particle size of the metal ceramic reinforcing phase TiC is 10-50 μm, the microstructure is spherical, and the purity is 99.9% laboratory grade. Before use, it is mechanically ball-milled and mixed evenly with special wear-resistant welding powder, and then sieved. Powder with a particle size of less than 50 μm is selected, dried, and then used for later use.

[0068] All raw materials used in this invention were purchased from the market.

[0069] The technical solution of the present invention will be further illustrated by the following embodiments.

[0070] Example 1

[0071] A method for preparing a high-temperature wear-resistant coating by open-arc welding with self-shielded alloy powder and flux-cored wire includes the following steps:

[0072] Step 1: Pre-processing:

[0073] Low-carbon steel (Q235) with dimensions of 90mm×100mm×10mm was selected as the substrate for welding. Before welding, the surface of the substrate material was ground clean with a grinding wheel, and then cleaned with anhydrous alcohol to remove surface rust and oil. After cleaning, the substrate was placed in a drying oven and kept at 120℃ for 3 hours to ensure complete removal of moisture and prevent defects such as porosity during the welding process.

[0074] A self-protective alloy powder for preparing high-temperature wear-resistant coatings by open-arc welding with flux-cored welding wire, comprising the following raw materials by mass percentage:

[0075] C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 8.0%, CaF 1.6%, CaCO3 1.0%, balance Fe;

[0076] The powder components were thoroughly ground and mixed in a mortar for at least 0.5 hours to ensure uniform distribution of the components. The mixed powder was then dried in an oven at 120°C for 3 hours to remove adsorbed moisture, resulting in a self-protected alloy powder. Subsequently, the dried self-protected alloy powder was pre-placed on the surface of the substrate material using a water glass solution (Na2O·nSiO2:H2O=1:3, vol.%).

[0077] Step 2: Overlay welding process

[0078] An open-arc welding process was performed using a combination of a submerged arc welding machine and a robotic arm. The welding method was a pre-laid powder-coating mode (i.e., the flux-cored wire was laid on the substrate surface pre-placed with self-shielding alloy powder in step one, and then open-arc welding was performed), without the need for additional inert shielding gas. The flux-cored wire was the widely applicable YB3 self-shielded flux-cored wire, with a mass ratio of 1:1.15 to the self-shielding alloy powder. The specific welding process parameters were set as follows: welding current 260A, welding speed 100mm / min, powder-coating mass 50g, dry extension 12mm, and welding torch oscillation frequency 0.3Hz. Under these conditions, a welding layer (high-temperature wear-resistant coating) with a thickness of 3-4mm was obtained.

[0079] Step 3: Performance Testing

[0080] The welded sample was cut into standard test blocks of 10mm×10mm×14mm for microhardness and high-temperature friction and wear performance testing.

[0081] The hardness test conditions were: a loading load of 200g and a loading time of 15s.

[0082] The high-temperature friction and wear test conditions are: temperature 600℃, load 70N, frequency 4Hz, stroke 4mm, and wear time 1h.

[0083] Figure 1 The image shows the microstructure of the self-protective alloy powder prepared in Example 1 of this invention. As can be seen from the image, the size of the self-protective alloy powder used in open arc welding with flux-cored wire to prepare a high-temperature wear-resistant coating is 10-50 μm. The powder has good flowability during the welding process. Furthermore, the scanning electron microscope image shows that the powder has a regular shape and uniform size, exhibiting excellent welding performance.

[0084] Figure 2The image shows the metallographic effect of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire according to Example 1 of the present invention. As can be seen from the image, the weld overlay prepared in Example 1 has no obvious impurities and a dense internal structure, greatly reducing the generation of defects within the weld overlay and significantly ensuring its wear resistance. Furthermore, performance testing of the weld overlay showed that the coating (weld overlay) prepared in Example 1 has a hardness of 58 HRC, exhibiting excellent wear resistance.

[0085] Figure 3 The graph shows the change in friction coefficient over time at 600°C for the weld overlay obtained after welding self-protected alloy powder and flux-cored wire in Example 1 of the present invention. As can be seen from the graph, the friction coefficient is relatively stable and fluctuates little, generally remaining below 0.4.

[0086] Figure 4 This is an SEM image of the wear surface of the weld overlay obtained by welding self-protected alloy powder and flux-cored wire in Example 1 of the present invention at 600°C. The measured material weight loss was 10.4 mg. The wear surface of the weld overlay showed narrow and shallow furrows and was relatively smooth.

[0087] Figure 5 The image shows a white light scanning image of the worn surface of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire in Example 1 of this invention at 600°C. As shown in the figure, the worn area has a relatively regular shape and a shallow wear depth, indicating good wear resistance.

[0088] Figure 6 The SEM image shows the surface morphology of the weld overlay obtained by self-protecting alloy powder and flux-cored wire in Example 1 of this invention after high-temperature oxidation for 36 hours. As can be seen from (a), the macroscopic surface of the coating is relatively smooth. In (b), the grain boundaries of the coating surface are obviously oxidized, and the microstructure of the entire surface can be clearly observed. In (c), granular and blocky oxide films are distributed in the intergranular region, indicating that the weld overlay has strong high-temperature oxidation resistance.

[0089] Example 2

[0090] A method for preparing a high-temperature wear-resistant coating by open-arc welding with self-shielded alloy powder and flux-cored wire includes the following steps:

[0091] Step 1: Pre-processing:

[0092] Low-carbon steel (Q235) with dimensions of 90mm×100mm×10mm was selected as the substrate for welding. Before welding, the surface of the substrate material was ground clean with a grinding wheel, and then cleaned with anhydrous alcohol to remove surface rust and oil. After cleaning, the substrate was placed in a drying oven and kept at 120℃ for 3 hours to ensure complete removal of moisture and prevent defects such as porosity during the welding process.

[0093] A self-protective alloy powder for preparing high-temperature wear-resistant coatings by open-arc welding with flux-cored welding wire, comprising the following raw materials by mass percentage:

[0094] The composition is as follows: C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 8.0%, CaF 1.6%, CaCO3 1.0%, TiC 8%, with the balance being Fe.

[0095] The powder components and the cermet-reinforcing phase TiC were thoroughly ground and mixed in a mortar for more than 1 hour to ensure uniform mixing and distribution of components. The mixed powder was then dried in an oven at 120 °C for 3 hours to remove adsorbed moisture, yielding a self-protected alloy powder. Subsequently, the dried self-protected alloy powder was pre-placed on the surface of the matrix material using a water glass solution (Na2O·nSiO2:H2O=1:3, vol.%).

[0096] Step 2: Overlay welding process

[0097] An open arc welding process was performed using a combination of a submerged arc welding machine and a robotic arm. The welding method was a pre-formulated powder-laying mode, eliminating the need for additional inert shielding gas. The flux-cored wire used was the widely applicable YB3 self-shielded flux-cored wire, with a mass ratio of 1:1.15 between the flux-cored wire and the self-shielded alloy powder. The specific welding process parameters were set as follows: welding current 260A, welding speed 100mm / min, powder-laying mass 50g, dry extension 12mm, and welding torch oscillation frequency 0.3Hz. Under these conditions, a 3-4mm thick weld overlay (high-temperature wear-resistant coating) was obtained.

[0098] Step 3: Performance Testing

[0099] The welded sample was cut into standard test blocks of 10mm×10mm×14mm for microhardness and high-temperature friction and wear performance testing.

[0100] The hardness test conditions were: a loading load of 200g and a loading time of 15s.

[0101] The high-temperature friction and wear test conditions are: temperature 600℃, load 70N, frequency 4Hz, stroke 4mm, and wear time 1h.

[0102] The solid welding wire self-shielded alloy powder prepared by the above preparation method in Example 2 still maintains a size of 10-50 μm and has good flow properties.

[0103] Under the same welding process and testing conditions as in Example 1, the coating (weld overlay) prepared in Example 2 of the present invention has a hardness of 63 HRC, a weight loss of 6 mg, and significantly improved wear resistance compared to Example 1.

[0104] Figure 7 This is a SEM microstructure image of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire in Example 2 of the present invention; it can be seen that the carbides are distributed in a dispersed form, the internal structure is uniform, and the grains are significantly refined.

[0105] Example 3

[0106] A method for preparing a high-temperature wear-resistant coating by open-arc welding with self-shielded alloy powder and flux-cored wire includes the following steps:

[0107] Step 1: Pre-processing:

[0108] Low-carbon steel (Q235) with dimensions of 90mm×100mm×10mm was selected as the substrate for welding. Before welding, the surface of the substrate material was ground clean with a grinding wheel, and then cleaned with anhydrous alcohol to remove surface rust and oil. After cleaning, the substrate was placed in a drying oven and kept at 120℃ for 3 hours to ensure complete removal of moisture and prevent defects such as porosity during the welding process.

[0109] A self-protective alloy powder for preparing high-temperature wear-resistant coatings by open-arc welding with flux-cored welding wire, comprising the following raw materials by mass percentage:

[0110] The composition is as follows: C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 8.0%, CaF 1.6%, CaCO3 1.0%, TiC 4.0%, with the balance being Fe.

[0111] The powder components and the cermet-reinforcing phase TiC were thoroughly ground and mixed in a mortar for more than 1 hour to ensure uniform mixing and distribution of components. The mixed powder was then dried in an oven at 120 °C for 3 hours to remove adsorbed moisture, yielding a self-protected alloy powder. Subsequently, the dried self-protected alloy powder was pre-placed on the surface of the matrix material using a water glass solution (Na2O·nSiO2:H2O=1:3, vol.%).

[0112] Step 2: Overlay welding process

[0113] An open arc welding process was performed using a combination of a submerged arc welding machine and a robotic arm. The welding method was a pre-formulated powder-laying mode, eliminating the need for additional inert shielding gas. The flux-cored wire used was the widely applicable YB3 self-shielded flux-cored wire, with a mass ratio of 1:1.15 between the flux-cored wire and the self-shielded alloy powder. The specific welding process parameters were set as follows: welding current 260A, welding speed 100mm / min, powder-laying mass 50g, dry extension 12mm, and welding torch oscillation frequency 0.3Hz. Under these conditions, a 3-4mm thick weld overlay (high-temperature wear-resistant coating) was obtained.

[0114] Step 3: Performance Testing

[0115] The welded sample was cut into standard test blocks of 10mm×10mm×14mm for microhardness and high-temperature friction and wear performance testing.

[0116] The hardness test conditions were: a loading load of 200g and a loading time of 15s.

[0117] The high-temperature friction and wear test conditions are: temperature 600℃, load 70N, frequency 4Hz, stroke 4mm, and wear time 1h.

[0118] The solid welding wire self-shielded alloy powder prepared by the above preparation method in Example 3 still maintains a size of 10-50 μm and has good flow properties.

[0119] Under the same welding process and testing conditions as in Example 1, the coating (weld overlay) prepared in Example 3 of the present invention has a hardness of 56 HRC, a weight loss of 13.2 mg, and slightly lower wear resistance than that in Example 1.

[0120] Example 4

[0121] A method for preparing a high-temperature wear-resistant coating by open-arc welding with self-shielded alloy powder and flux-cored wire includes the following steps:

[0122] Step 1: Pre-processing:

[0123] Low-carbon steel (Q235) with dimensions of 90mm×100mm×10mm was selected as the substrate for welding. Before welding, the surface of the substrate material was ground clean with a grinding wheel, and then cleaned with anhydrous alcohol to remove surface rust and oil. After cleaning, the substrate was placed in a drying oven and kept at 120℃ for 3 hours to ensure complete removal of moisture and prevent defects such as porosity during the welding process.

[0124] A self-protective alloy powder for preparing high-temperature wear-resistant coatings by open-arc welding with flux-cored welding wire, comprising the following raw materials by mass percentage:

[0125] The composition is as follows: C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 6.0%, CaF 1.6%, CaCO3 1.0%, TiC 8.0%, with the balance being Fe.

[0126] The powder components and the cermet-reinforcing phase TiC were thoroughly ground and mixed in a mortar for more than 1 hour to ensure uniform mixing and distribution of components. The mixed powder was then dried in an oven at 120 °C for 3 hours to remove adsorbed moisture, yielding a self-protected alloy powder. Subsequently, the dried self-protected alloy powder was pre-placed on the surface of the matrix material using a water glass solution (Na2O·nSiO2:H2O=1:3, vol.%).

[0127] Step 2: Overlay welding process

[0128] An open arc welding process was performed using a combination of a submerged arc welding machine and a robotic arm. The welding method was a pre-formulated powder-laying mode, eliminating the need for additional inert shielding gas. The flux-cored wire used was the widely applicable YB3 self-shielded flux-cored wire, with a mass ratio of 1:1.15 between the flux-cored wire and the self-shielded alloy powder. The specific welding process parameters were set as follows: welding current 260A, welding speed 100mm / min, powder-laying mass 50g, dry extension 12mm, and welding torch oscillation frequency 0.3Hz. Under these conditions, a 3-4mm thick weld overlay (high-temperature wear-resistant coating) was obtained.

[0129] Step 3: Performance Testing

[0130] The welded sample was cut into standard test blocks of 10mm×10mm×14mm for microhardness and high-temperature friction and wear performance testing.

[0131] The hardness test conditions were: a loading load of 200g and a loading time of 15s.

[0132] The high-temperature friction and wear test conditions are: temperature 600℃, load 70N, frequency 4Hz, stroke 4mm, and wear time 1h.

[0133] The solid welding wire self-shielded alloy powder prepared by the above preparation method in Example 4 still maintains a size of 10-50 μm and has good flow properties.

[0134] Under the same welding process and testing conditions as in Example 1, the coating (weld overlay) prepared in Example 4 of the present invention has a hardness of 54 HRC, a weight loss of 14.1 mg, and lower wear resistance than that in Example 1.

[0135] Example 5

[0136] A method for preparing a high-temperature wear-resistant coating by open-arc welding with self-shielded alloy powder and flux-cored wire includes the following steps:

[0137] Step 1: Pre-processing:

[0138] Low-carbon steel (Q235) with dimensions of 90mm×100mm×10mm was selected as the substrate for welding. Before welding, the surface of the substrate material was ground clean with a grinding wheel, and then cleaned with anhydrous alcohol to remove surface rust and oil. After cleaning, the substrate was placed in a drying oven and kept at 120℃ for 3 hours to ensure complete removal of moisture and prevent defects such as porosity during the welding process.

[0139] A self-protective alloy powder for preparing high-temperature wear-resistant coatings by open-arc welding with flux-cored welding wire, comprising the following raw materials by mass percentage:

[0140] The composition is as follows: C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 8.0%, CaF 1.6%, CaCO3 1.0%, TiC 6.0%, with the balance being Fe.

[0141] The powder components and the cermet-reinforcing phase TiC were thoroughly ground and mixed in a mortar for more than 1 hour to ensure uniform mixing and distribution of components. The mixed powder was then dried in an oven at 120 °C for 3 hours to remove adsorbed moisture, yielding a self-protected alloy powder. Subsequently, the dried self-protected alloy powder was pre-placed on the surface of the matrix material using a water glass solution (Na2O·nSiO2:H2O=1:3, vol.%).

[0142] Step 2: Overlay welding process

[0143] An open arc welding process was performed using a combination of a submerged arc welding machine and a robotic arm. The welding method was a pre-formulated powder-laying mode, eliminating the need for additional inert shielding gas. The flux-cored wire used was the widely applicable YB3 self-shielded flux-cored wire, with a mass ratio of 1:1.15 between the flux-cored wire and the self-shielded alloy powder. The specific welding process parameters were set as follows: welding current 260A, welding speed 100mm / min, powder-laying mass 50g, dry extension 12mm, and welding torch oscillation frequency 0.3Hz. Under these conditions, a 3-4mm thick weld overlay (high-temperature wear-resistant coating) was obtained.

[0144] Step 3: Performance Testing

[0145] The welded sample was cut into standard test blocks of 10mm×10mm×14mm for microhardness and high-temperature friction and wear performance testing.

[0146] The hardness test conditions were: a loading load of 200g and a loading time of 15s.

[0147] The high-temperature friction and wear test conditions are: temperature 600℃, load 70N, frequency 4Hz, stroke 4mm, and wear time 1h.

[0148] The solid welding wire self-shielded alloy powder prepared by the above preparation method in Example 5 still maintains a size of 10-50 μm and has good flow properties.

[0149] Under the same welding process and testing conditions as in Example 1, the coating (weld overlay) prepared in Example 5 of the present invention has a hardness of 56 HRC, a weight loss of 12.1 mg, and slightly lower wear resistance than that in Example 1.

[0150] Figure 8 The graph shows a comparison of the friction coefficient over time at 600°C for the weld layers obtained after welding self-protected alloy powder and flux-cored wire in Examples 2-5.

[0151] Comparative Example 1

[0152] A method for preparing a high-temperature wear-resistant coating by open-arc welding with self-shielded alloy powder and flux-cored wire includes the following steps:

[0153] Step 1: Pre-processing:

[0154] Low-carbon steel (Q235) with dimensions of 90mm×100mm×10mm was selected as the substrate for welding. Before welding, the surface of the substrate material was ground clean with a grinding wheel, and then cleaned with anhydrous alcohol to remove surface rust and oil. After cleaning, the substrate was placed in a drying oven and kept at 120℃ for 3 hours to ensure complete removal of moisture and prevent defects such as porosity during the welding process.

[0155] A self-protective alloy powder for preparing high-temperature wear-resistant coatings by open-arc welding with flux-cored welding wire, comprising the following raw materials by mass percentage:

[0156] The composition is as follows: C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, CaF 1.6%, CaCO3 1.0%, TiC 8.0%, with the balance being Fe.

[0157] The powder components and the cermet-reinforcing phase TiC were thoroughly ground and mixed in a mortar for more than 1 hour to ensure uniform mixing and distribution of components. The mixed powder was then dried in an oven at 120 °C for 3 hours to remove adsorbed moisture, yielding a self-protected alloy powder. Subsequently, the dried self-protected alloy powder was pre-placed on the surface of the matrix material using a water glass solution (Na2O·nSiO2:H2O=1:3, vol.%).

[0158] Step 2: Overlay welding process

[0159] An open arc welding process was performed using a combination of a submerged arc welding machine and a robotic arm. The welding method was a pre-formulated powder-laying mode, eliminating the need for additional inert shielding gas. The flux-cored wire used was the widely applicable YB3 self-shielded flux-cored wire, with a mass ratio of 1:1.15 between the flux-cored wire and the self-shielded alloy powder. The specific welding process parameters were set as follows: welding current 260A, welding speed 100mm / min, powder-laying mass 50g, dry extension 12mm, and welding torch oscillation frequency 0.3Hz. Under these conditions, a 3-4mm thick weld overlay (high-temperature wear-resistant coating) was obtained.

[0160] Step 3: Performance Testing

[0161] The welded sample was cut into standard test blocks of 10mm×10mm×14mm for microhardness and high-temperature friction and wear performance testing.

[0162] The hardness test conditions were: a loading load of 200g and a loading time of 15s.

[0163] The high-temperature friction and wear test conditions are: temperature 600℃, load 70N, frequency 4Hz, stroke 4mm, and wear time 1h.

[0164] The solid welding wire self-shielded alloy powder prepared by the above preparation method in Comparative Example 1 still maintains a size of 10-50 μm and has good flow properties.

[0165] Under the same welding process and testing conditions as in Example 1, the coating (weld overlay) prepared in Comparative Example 1 of the present invention has a hardness of 48 HRC, a weight loss of 20.5 mg, and lower wear resistance than that in Example 1.

[0166] Figure 9 The image shows the microscopic sliding wear morphology of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire in Comparative Example 1. The surface of the weld overlay is mainly composed of austenitic matrix with low hardness, with a large amount of oxide layer and deep wear marks.

[0167] Comparative Example 2

[0168] A method for preparing a high-temperature wear-resistant coating by open-arc welding with self-shielded alloy powder and flux-cored wire includes the following steps:

[0169] Step 1: Pre-processing:

[0170] Low-carbon steel (Q235) with dimensions of 90mm×100mm×10mm was selected as the substrate for welding. Before welding, the surface of the substrate material was ground clean with a grinding wheel, and then cleaned with anhydrous alcohol to remove surface rust and oil. After cleaning, the substrate was placed in a drying oven and kept at 120℃ for 3 hours to ensure complete removal of moisture and prevent defects such as porosity during the welding process.

[0171] A self-protective alloy powder for preparing high-temperature wear-resistant coatings by open-arc welding with flux-cored welding wire, comprising the following raw materials by mass percentage:

[0172] The composition is as follows: C 15.0%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 8.0%, CaF 1.6%, CaCO3 1.0%, TiC 8.0%, with the balance being Fe.

[0173] The powder components and the cermet-reinforcing phase TiC were thoroughly ground and mixed in a mortar for more than 1 hour to ensure uniform mixing and distribution of components. The mixed powder was then dried in an oven at 120 °C for 3 hours to remove adsorbed moisture, yielding a self-protected alloy powder. Subsequently, the dried self-protected alloy powder was pre-placed on the surface of the matrix material using a water glass solution (Na2O·nSiO2:H2O=1:3, vol.%).

[0174] Step 2: Overlay welding process

[0175] An open arc welding process was performed using a combination of a submerged arc welding machine and a robotic arm. The welding method was a pre-formulated powder-laying mode, eliminating the need for additional inert shielding gas. The flux-cored wire used was the widely applicable YB3 self-shielded flux-cored wire, with a mass ratio of 1:1.15 between the flux-cored wire and the self-shielded alloy powder. The specific welding process parameters were set as follows: welding current 260A, welding speed 100mm / min, powder-laying mass 50g, dry extension 12mm, and welding torch oscillation frequency 0.3Hz. Under these conditions, a 3-4mm thick weld overlay (high-temperature wear-resistant coating) was obtained.

[0176] Step 3: Performance Testing

[0177] The welded sample was cut into standard test blocks of 10mm×10mm×14mm for microhardness and high-temperature friction and wear performance testing.

[0178] The hardness test conditions were: a loading load of 200g and a loading time of 15s.

[0179] The high-temperature friction and wear test conditions are: temperature 600℃, load 70N, frequency 4Hz, stroke 4mm, and wear time 1h.

[0180] The solid welding wire self-shielded alloy powder prepared by the above preparation method in Comparative Example 2 still maintains a size of 10-50 μm and has good flow properties.

[0181] Under the same welding process and testing conditions as in Example 1, the coating (weld overlay) prepared in Comparative Example 2 of the present invention has a hardness of 50 HRC, a weight loss of 18.3 mg, and lower wear resistance than that in Example 1.

[0182] Figure 10 The image shows the microscopic sliding wear morphology of the weld overlay obtained after welding self-protected alloy powder and flux-cored wire in Comparative Example 2. Under repeated shearing forces, brittle fracture occurs, forming microcracks that gradually develop into spalling pits.

[0183] Figure 11 The graph shows the variation of the friction coefficient over time at 600℃ for the weld layers obtained by welding self-shielded alloy powder and flux-cored wire in Examples 1-2.

[0184] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A self-protecting alloy powder for the production of high temperature wear resistant coatings, characterized in that, According to mass percentage, the following components are included: C 10.0-15.0%, Mo 3.0%-6%, Cr 25.0%-30.0%, Ni 2.0%-5.0%, Mn 0.5%-0.8%, Si 0.5%-1.2%, W 1.6%-8.0%, CaF 0.5%-1.6%, CaCO3 0.8%-1.0%, and the balance of Fe.

2. A self-protecting alloy powder for producing high-temperature wear- resistant coating according to claim 1, characterized in that, According to mass percentage, the following components are included: C 14.0-15.0%, Mo 3.0%-6%, Cr 29.0%-30.0%, Ni 2.0%-5.0%, Mn 0.5%-0.8%, Si 0.5%-1.2%, W 6%-8.0%, CaF 0.5%-1.6%, CaCO3 0.8%-1.0%, and the balance of Fe.

3. A self-protecting alloy powder for producing high-temperature wear- resistant coatings according to claim 2, characterized in that According to mass percentage, the following components are included: C 15.0%, Mo 6%, Cr 30.0%, Ni 5.0%, Mn 0.8%, Si 1.2%, W 8.0%, CaF 1.6%, CaCO3 1.0%, and the balance of Fe.

4. A self-protecting alloy powder for producing high-temperature wear- resistant coating according to claim 1, characterized in that, Further including TiC; according to mass percentage, the self-protecting alloy powder for preparing high-temperature wear-resistant coating includes the following components: C 14.0-15.0%, Mo 3.0%-6%, Cr 29.0%-30.0%, Ni 2.0%-5.0%, Mn 0.5%-0.8%, Si 0.5%-1.2%, W 6%-8.0%, CaF 0.5%-1.6%, CaCO3 0.8%-1.0%, TiC 4%-8%, and the balance of Fe.

5. A self-protecting alloy powder for producing high-temperature wear- resistant coatings according to claim 4, characterized in that The average particle size of the TiC is 10-50 μm.

6. A method for producing a self-protecting alloy powder for high-temperature wear-resistant coatings, characterized in that The following steps are included: The components are mixed, ground and dried according to mass percentage to obtain the self-protecting alloy powder for preparing high-temperature wear-resistant coating according to any one of claims 1-5.

7. A high temperature wear resistant coating characterized by, The self-protecting alloy powder for preparing high-temperature wear-resistant coating according to any one of claims 1-5 and the flux-cored wire are included, and the mass ratio of the two is 1:(1.1-1.2).

8. A method of producing a high temperature wear resistant coating, characterized by, The following steps are included: The self-protecting alloy powder for preparing high-temperature wear-resistant coating according to any one of claims 1-5 and the flux-cored wire are used in the open-arc surfacing process in the pre-powder laying mode to prepare the high-temperature wear-resistant coating according to claim 7.

9. The method of claim 8, wherein the high temperature wear resistant coating is prepared by a process comprising: The conditions in the open-arc surfacing process are as follows: The welding current is 240-280 A, the surfacing speed is 90-110 mm / min, the powder laying mass is 30-70 g, the dry elongation is 10-25 mm, and the welding gun swing frequency is 0.1-0.5 Hz.

10. A method of producing a high temperature wear resistant coating according to claim 8 or 9, characterised in that, The thickness of the prepared high-temperature wear-resistant coating is 3-4 mm, and the hardness is 55-65 HRC.

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