A composite heat-resistant slider for a walking beam in a heating furnace and its preparation method.

Abstract

This invention provides a composite heat-resistant slider for a walking beam in a heating furnace. The composite heat-resistant slider comprises a metal-ceramic layer and a nickel-chromium alloy layer sequentially connected by a high-temperature alloy layer. This composite heat-resistant slider for a walking beam in a heating furnace exhibits extremely high high-temperature strength, oxidation resistance, and wear resistance, avoids black mark problems, is easy to weld, and has low production costs and a simple process, making it suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of metal material preparation and relates to a composite heat-resistant slider for a walking beam in a heating furnace and its preparation method. Background Technology

[0002] Walking beam furnaces are commonly used in metallurgical and forging industries to transport heavy workpieces, such as steel plates and billets. The slider is a key component of the walking beam system, responsible for movement and support, and must withstand complex conditions including high loads, high temperatures, and high wear resistance. Currently, walking beam sliders are mostly made of cobalt-based and nickel-based alloys, including:

[0003] Co20 alloy: This alloy contains high levels of cobalt and chromium. Cobalt provides good high-temperature strength and toughness, while chromium helps form a dense chromium oxide protective film, enhancing oxidation resistance. Co20 alloy sliders can play a good role in the water beam section of walking beam furnaces where temperatures are not particularly high (e.g., below 1100℃). Its price is relatively reasonable compared to some high-end cobalt-based alloys, and it can withstand a certain weight and friction, effectively preventing direct contact wear between the water beam and the steel billet.

[0004] Co50 alloy: For the high-temperature (up to 1300℃) water beam environment of heating furnaces, Co50 alloy is a better choice. It has excellent high-temperature resistance, maintaining good strength and hardness at high temperatures without easily deforming. At the same time, it has excellent resistance to thermal fatigue, able to withstand frequent thermal shocks. For example, in the high-temperature zone water beams of large, high-temperature walking beam furnaces, Co50 alloy sliders can operate stably for a long time, reducing maintenance and replacement frequency.

[0005] Nickel-based superalloys: These alloys possess excellent high-temperature strength, oxidation resistance, and corrosion resistance. They maintain good mechanical properties at high temperatures, making them suitable for water beams in walking beam furnaces operating in high-temperature and complex environments (such as those containing corrosive gases). Nickel-based superalloys can withstand the weight and friction of steel billets, and their corrosion resistance prevents corrosion in furnace environments containing corrosive media, thus extending the service life of the slide block.

[0006] The existing materials used in heating furnace walking beam sliders mainly have the following problems:

[0007] 1) The slider at the end of the walking beam is prone to falling off, mainly due to operational errors, billet deviation, inaccurate billet positioning, and improper installation.

[0008] 2) The contact area between the upper surface of the slider and the steel billet is too small, and the pressure per unit area is too large, which can easily cause scratches on the lower surface of the steel billet.

[0009] 3) Due to the extremely poor weldability of cobalt alloys, welding the slider to the walking beam is a major challenge. In domestic steel-pushing furnaces using Co50 material sliders, the base material often cracks in the fusion zone (resulting in water leakage). This necessitates furnace shutdown for repairs, significantly impacting steel plant production and profitability. Currently, to avoid welding difficulties, Co50 material sliders are typically installed using a saddle-type mounting method, which easily leads to slider detachment.

[0010] 4) Black Mark Problem: Generally, the walking beam has water cooling, and the slider is fixed to the walking beam. At the support of the heat-resistant slider, the billet conducts heat faster, creating a temperature difference of 30-80°C between the billet and the non-supported areas. This results in a low-temperature black mark area at the support, significantly impacting billet quality. The upper surface of the slider is in direct contact with the lower surface of the billet, while the lower surface of the slider is in contact with the water beam. This results in a relatively lower temperature on the upper surface of the slider, leading to a lower temperature at the contact surface between the billet and the slider. During heating, the localized low temperature on the billet surface forms a "black mark" area, causing numerous product defects and production failures. In production practice, to reduce the impact of "heating black marks" on the rolling process and product quality, measures are usually taken such as increasing the heating temperature or extending the heating and homogenization time of the billet, slowing down the rolling pace, and sometimes even delaying rolling. Even so, the "heating black mark" problem has not been completely solved.

[0011] In summary, the slider of the walking beam in the heating furnace needs to operate under conditions of high temperature, high load, high oxidation, and high wear resistance. Currently, cobalt-based alloy Co50 is the best slider material, capable of operating at 1300℃ while maintaining oxidation resistance and suitable compressive strength. Due to the sufficiently high temperature, the black marking problem is resolved. However, this material is very expensive, and more importantly, its weldability is extremely poor, requiring assembly with the walking beam via a saddle-and-stick method, which carries a serious risk of detachment. Other materials can only be used at lower temperatures; although welding issues are improved, high-temperature strength, oxidation resistance, and wear resistance are significantly reduced, and heating black marking cannot be completely avoided, severely impacting product quality and production efficiency. Summary of the Invention

[0012] To address the technical problems existing in the prior art, the present invention provides a composite heat-resistant slider for a walking beam in a heating furnace and its preparation method. The composite heat-resistant slider for a walking beam in a heating furnace has extremely high high-temperature strength and resistance to oxidation and wear, avoids the problem of black marks, is easy to weld, and has low production cost and simple production process, making it suitable for industrial production.

[0013] To achieve the above-mentioned technical effects, the present invention adopts the following technical solution:

[0014] One objective of this invention is to provide a composite heat-resistant slider for a walking beam in a heating furnace, which comprises a metal-ceramic layer and a nickel-chromium alloy layer connected in sequence by a high-temperature alloy layer.

[0015] As a preferred embodiment of the present invention, the method for preparing the metal-based ceramic layer includes:

[0016] The activated powder is mixed with hard particles, so that the activated powder coats the surface of the hard particles. Then, sintering and reduction treatments are performed in sequence to obtain surface-metallized hard particles.

[0017] Hard particles are mixed with metal matrix powder and pressed to obtain a metal-based ceramic layer.

[0018] As a preferred technical solution of the present invention, the activated powder comprises, by weight, 1-3 parts of silicon dioxide powder, 1-3 parts of ferric oxide powder, 4-6 parts of manganese oxide powder and 0.5-1.5 parts of calcium oxide powder.

[0019] As a preferred technical solution of the present invention, the hard particles include any one or a combination of at least two of Al2O3, ZrO2, WC, Cr3C2, SiC ceramics or ZTA ceramics.

[0020] As a preferred embodiment of the present invention, the mass ratio of the activated powder to the hard particles is 1:3~5.

[0021] As a preferred technical solution of the present invention, the sintering temperature of the surface-metallized hard particles is 1300~1400℃ and the time is 1~3 h.

[0022] Preferably, the reduction treatment of the surface-metallized hard particles is carried out in a reducing atmosphere, and the reduction treatment temperature is 700~1000℃ for 0.5~1 h.

[0023] Preferably, the reducing atmosphere includes a hydrogen-containing atmosphere or a carbon-containing atmosphere.

[0024] As a preferred technical solution of the present invention, the metal matrix powder comprises, by mass, 0-50% Co, 10-50% Cr, 5-60% Ni, 0-10% Mo, 0-40% W, 0-1% Si, 0.1-1% C, 0-6% Mn and the balance being Fe.

[0025] As a preferred technical solution of the present invention, the mass ratio of the metal matrix powder to the surface metallized hard particles is 5~7:4~2.

[0026] As a preferred technical solution of the present invention, the pressing pressure is 200~400 MPa.

[0027] As a preferred technical solution of the present invention, the high-temperature alloy layer comprises, by mass fraction: C≤0.25%, Co 0~60%, Mo≤2.5%, Ni 2~50%, Mn≤1.5%, Si 1~15%, Al 0~5%, Cr 20~80%, with the balance being Fe.

[0028] As a preferred technical solution of the present invention, the nickel-chromium alloy layer comprises, by mass fraction: C≤0.15%, Ni 10~50%, Mo 1~3%, Nb≤1.5%, Mn≤1.5%, Si≤1.5%, Cr 10~40%, with the balance being Fe.

[0029] A second objective of this invention is to provide a method for preparing the composite heat-resistant slider for the walking beam of a heating furnace, as provided in one of the objectives. This method includes:

[0030] The composite heat-resistant slider for the heating furnace walking beam is obtained by sequentially stacking a high-temperature alloy layer, a metal ceramic layer, and a nickel-chromium alloy layer in a mold and sintering it under a protective atmosphere.

[0031] As a preferred technical solution of the present invention, the sintering temperature is 1350~1450℃ and the time is 2~6 h.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] (1) The present invention provides a composite heat-resistant slider for a walking beam of a heating furnace and its preparation method. The composite heat-resistant slider for a walking beam of a heating furnace has extremely high high-temperature strength (ceramic particles have a supporting effect) and anti-oxidation and anti-wear capabilities, avoids the problem of black marks (ceramic particles have a heat insulation effect), and the bottom nickel-chromium alloy layer is easy to weld.

[0034] (2) The present invention provides a composite heat-resistant slider for a heating furnace walking beam and its preparation method. The heating furnace walking beam reduces the use of cobalt alloy and lowers the production cost. The implementation process is simple and suitable for industrial production. Attached Figure Description

[0035] Figure 1 The images show a front view and a side view of the composite heat-resistant slider for the walking beam of the heating furnace provided by the present invention.

[0036] Figure 2 This is a SEM side view of the metal-ceramic layer and its metallurgical fusion interface in the composite heat-resistant slider for the walking beam of the heating furnace prepared in Example 3 of the present invention.

[0037] Figure 3 The image shows the XRD pattern of the composite heat-resistant slider metal-ceramic layer for the heating furnace walking beam prepared in Example 3 of this invention.

[0038] Figure 4 A physical image of the composite heat-resistant slider for the walking beam of the heating furnace provided by the present invention.

[0039] In the diagram: 1-High-temperature alloy layer, 2-Metal-ceramic layer, 3-Ni-chromium alloy layer.

[0040] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0041] The technical solution of this application will be further described below through specific embodiments.

[0042] The present invention provides a composite heat-resistant slider for a walking beam in a heating furnace, which includes a metal-ceramic layer and a nickel-chromium alloy layer connected in sequence by a high-temperature alloy layer.

[0043] In this invention, a high-temperature alloy is used as the matrix, with a heat resistance temperature reaching 1300 degrees Celsius. It makes smooth contact with the steel billet requiring support within the heating furnace, exhibiting strong impact resistance and preventing defects such as scratches. The metal-based ceramic composite layer provides high-temperature support and insulation. The ceramic material possesses excellent high-temperature resistance and strong oxidation resistance. Its high hardness provides stable support for the steel billet. The composite of ceramic and metal matrix allows the metal matrix to provide toughness, preventing the possibility of the ceramic material breaking under impact from the steel billet. Due to the thermal insulation effect of the ceramic material, the temperature loss of the first high-temperature alloy layer is minimal, thus avoiding the "black mark" phenomenon in the low-temperature zone on the steel billet surface. The nickel-chromium alloy layer has excellent weldability, easily welded to the walking beam, avoiding problems such as slider detachment.

[0044] In one specific embodiment of the present invention, the method for preparing the metal-based ceramic layer includes:

[0045] The activated powder is mixed with hard particles, so that the activated powder coats the surface of the hard particles. Then, sintering and reduction treatments are performed in sequence to obtain surface-metallized hard particles.

[0046] Hard particles are mixed with metal matrix powder and pressed to obtain a metal-based ceramic layer.

[0047] In one specific embodiment of the present invention, the activated powder comprises, by weight, 1-3 parts of silicon dioxide powder, 1-3 parts of ferric oxide powder, 4-6 parts of manganese oxide powder and 0.5-1.5 parts of calcium oxide powder. The mass fractions of silicon dioxide powder can be 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, or 3 parts, etc.; the mass fractions of ferric oxide powder can be 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, or 3 parts, etc.; the mass fractions of manganese oxide powder can be 4 parts, 4.2 parts, 4.5 parts, 4.8 parts, 5 parts, 5.2 parts, 5.5 parts, 5.8 parts, or 6 parts, etc.; and the mass fractions of calcium oxide powder can be 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, or 1.5 parts, etc., but are not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0048] In one specific embodiment of the present invention, the powders used in the activation powder should be larger than 800 mesh.

[0049] In one specific embodiment of the present invention, the activated powder is ball-milled for 8-12 hours before use. The ball-milling conditions, such as rotation speed, size and material of the grinding balls, can be adjusted according to the mixing situation and are not further limited here.

[0050] In one specific embodiment of the present invention, the hard particles include any one or a combination of at least two of Al2O3, ZrO2, WC, Cr3C2, SiC ceramics or ZTA ceramics.

[0051] In one specific embodiment of the present invention, the particle size of the hard particles can be 0.5~8 mm.

[0052] In one specific embodiment of the present invention, a small amount of binder is added when the activated powder is mixed with the hard particles. The amount and type of binder added can be adjusted according to the mixing situation, and are not further limited here. The binder can be hydroxycellulose, etc.

[0053] In one specific embodiment of the present invention, the activated powder and hard particles can be mixed by ball milling. The ball milling conditions, such as rotation speed, size and material of the grinding balls, can be adjusted according to the mixing situation and are not further limited here. The mixing time can be 2 to 6 hours.

[0054] In one specific embodiment of the present invention, the mass ratio of the activated powder to the hard particles is 1:3 to 5, such as 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, 1:4.2, 1:4.5, 1:4.8 or 1:5, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0055] In one specific embodiment of the present invention, the sintering temperature of the surface-metallized hard particles is 1300~1400℃, and the time is 1~3 h. The sintering temperature can be 1300℃, 1310℃, 1320℃, 1340℃, 1350℃, 1360℃, 1370℃, 1380℃, 1390℃, or 1400℃, etc., and the time can be 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h, 2.8 h, or 3 h, etc., but is not limited to the listed values; other unlisted values ​​within the above range are also applicable.

[0056] In one specific embodiment of the present invention, the sintering treatment serves to enable the activated powder to form a metallurgical bond with the surface of the hard particles.

[0057] In one specific embodiment of the present invention, the reduction treatment of the surface-metallized hard particles is carried out in a reducing atmosphere. The temperature of the reduction treatment is 700~1000℃, and the time is 0.5~1 h. The temperature of the reduction treatment can be 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, or 1000℃, etc., and the time can be 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h, or 1 h, etc., but is not limited to the listed values; other unlisted values ​​within the above ranges are also applicable.

[0058] In one specific embodiment of the present invention, the reducing atmosphere includes a hydrogen-containing atmosphere or a carbon-containing atmosphere. The hydrogen-containing atmosphere can be ammonia and / or hydrogen gas, preferably a mixture of ammonia and hydrogen gas, with a volume ratio of ammonia to hydrogen of 3:1.

[0059] In one specific embodiment of the present invention, the reduction treatment reduces the metal elements in the oxide coating on the surface of the sintered particles to elemental metals, thereby achieving surface metallization of the hard particles.

[0060] In one specific embodiment of the present invention, the metal matrix powder comprises, by mass fraction, 0-50% Co, 10-50% Cr, 5-60% Ni, 0-10% Mo, 0-40% W, 0-1% Si, 0.1-1% C, 0-6% Mn, and the balance being Fe. The mass percentage of Co can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%, etc.; the mass percentage of Cr can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%, etc.; the mass percentage of Ni can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60%, etc.; the mass percentage of Mo can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%, etc.; and the mass percentage of W can be 5%, 10%, 15%, or 20%, etc. The mass percentages of Si can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%, etc.; the mass percentages of C can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%, etc.; and the mass percentages of Mn can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, or 6%, etc., but are not limited to the listed values. Other unlisted values ​​within the above ranges also apply.

[0061] In one specific embodiment of the present invention, the metal matrix powder is obtained by mixing the raw materials in a mixing device for 4 to 10 hours, wherein the mixing device can be a powder mixer.

[0062] In one specific embodiment of the present invention, the mass ratio of the metal matrix powder to the surface-metallized hard particles is 5~7:4~2, such as 5:2, 5.2:2.2, 5.5:2.5, 5.8:2.8, 6:3, 6.2:3.2, 6.5:3.5, 6.8:3.8, or 7:4, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0063] In one specific embodiment of the present invention, a binder is added to the mixture of metal matrix powder and surface metallized hard particles, and the mass ratio of metal matrix powder to binder is 5~7:1.

[0064] In one specific embodiment of the present invention, the mixing of the metal matrix powder and the surface-metallized hard particles can be achieved through ball milling. The ball milling conditions, such as rotation speed, size and material of the grinding balls, can be adjusted according to the mixing situation and are not further limited here. The mixing time can be 4 to 6 hours.

[0065] In one specific embodiment of the present invention, the pressing pressure is 200~400 MPa, such as 200 MPa, 220 MPa, 250 MPa, 280 MPa, 300 MPa, 320 MPa, 350 MPa, 380 MPa or 400 MPa, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0066] In one specific embodiment of the present invention, before pressing, the mixed metal matrix powder and surface-metallized hard particles are loaded into a mold, such as a steel mold.

[0067] In one specific embodiment of the present invention, the size of the pressed metal-ceramic layer is the same as that of the high-temperature alloy layer.

[0068] In one specific embodiment of the present invention, the thickness of the metal-ceramic layer can be 20-30 mm, such as 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm or 30 mm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0069] In one specific embodiment of the present invention, the high-temperature alloy layer comprises, by mass fraction: C≤0.25%, Co 0~60%, Mo≤2.5%, Ni 2~50%, Mn≤1.5%, Si 1~15%, Al 0~5%, Cr 20~80%, with the balance being Fe.

[0070] In one specific embodiment of the present invention, the high-temperature alloy layer can be cast using conventional lost foam or wax pattern casting.

[0071] In one specific embodiment of the present invention, the thickness of the high-temperature alloy layer can be 20~30 mm, such as 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm or 30 mm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0072] In one specific embodiment of the present invention, the nickel-chromium alloy layer comprises, by mass fraction: C≤0.15%, Ni 10~50%, Mo 1~3%, Nb≤1.5%, Mn≤1.5%, Si≤1.5%, Cr 10~40%, with the balance being Fe.

[0073] In one specific embodiment of the present invention, the nickel-chromium alloy layer can be cast using conventional lost foam or wax casting.

[0074] In one specific embodiment of the present invention, the thickness of the nickel-chromium alloy layer can be 30~60 mm, such as 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm or 60 mm, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0075] In one specific embodiment of the present invention, the method for preparing a composite heat-resistant slider for a walking beam in a heating furnace includes:

[0076] The composite heat-resistant slider for the heating furnace walking beam is obtained by sequentially stacking a high-temperature alloy layer, a metal ceramic layer, and a nickel-chromium alloy layer in a mold and sintering it under a protective atmosphere.

[0077] In one specific embodiment of the present invention, the sintering temperature is 1350~1450℃, and the time is 2~6 h. The sintering temperature can be 1350℃, 1360℃, 1370℃, 1380℃, 1390℃, 1400℃, 1410℃, 1420℃, 1430℃, 1440℃, or 1450℃, etc., and the time can be 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, or 6 h, etc., but is not limited to the listed values; other unlisted values ​​within the above ranges are also applicable.

[0078] In one specific embodiment of the present invention, the protective atmosphere may be nitrogen, helium, or argon, etc.

[0079] In one specific embodiment of the present invention, the composite metal material obtained after sintering is subjected to post-processing such as grinding and trimming to obtain a composite heat-resistant slider for a heating furnace walking beam.

[0080] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0081] Example 1

[0082] This embodiment provides a method for preparing a composite heat-resistant slider for a walking beam in a heating furnace, including:

[0083] (1) The high-temperature alloy layer is made by lost foam casting, with a size of 150 mm × 50 mm and a thickness of 20 mm;

[0084] (2) Mix 2 parts by mass of silicon dioxide powder, 2 parts by mass of ferric oxide powder, 5 parts by mass of manganese oxide powder and 1 part by mass of calcium oxide powder in a ball mill for 10 h. The powder mesh size is 800~1000 mesh to obtain activated powder.

[0085] The activated powder and silicon carbide ceramic particles were ball-milled at a mass ratio of 1:4, with a particle diameter of 1~3 mm. A small amount of binder was added and mixed for 3 h to allow the activated powder to coat the surface of the hard particles. The mixture was then sintered at 1400℃ for 2 h to form a metallurgical bond between the activated powder and the surface of the hard particles. The mixture was then reduced using an ammonia-hydrogen mixed gas (volume ratio of 3:1) at 850℃ for 1 h to obtain surface-metallized hard particles.

[0086] Hard particles with surface metallization, metal-based powder (400~600 mesh) and binder are ball-milled and mixed at a mass ratio of 6:3:1 for 4 h. The mixture is then placed in a steel mold and pressed at 300 MPa to obtain a metal-ceramic layer with the same dimensions as the high-temperature alloy layer and a thickness of 25 mm.

[0087] (3) The nickel-chromium alloy layer is cast using lost foam casting, and has the same dimensions as the high-temperature alloy layer, with a thickness of 50 mm;

[0088] (4) The high-temperature alloy layer, the metal ceramic layer and the nickel-chromium alloy layer are stacked in sequence in an alumina mold and sintered at 1450°C for 3 h in an argon atmosphere to obtain the composite heat-resistant slider for the heating furnace walking beam.

[0089] Example 2

[0090] This embodiment provides a method for preparing a composite heat-resistant slider for a walking beam in a heating furnace, including:

[0091] (1) The high-temperature alloy layer is made by lost foam casting, with a size of 150 mm × 50 mm and a thickness of 10 mm;

[0092] (2) Mix 2 parts by mass of silicon dioxide powder, 2 parts by mass of ferric oxide powder, 5 parts by mass of manganese oxide powder and 1 part by mass of calcium oxide powder in a ball mill for 8 h. The powder mesh size is 800~1000 mesh to obtain activated powder.

[0093] The activated powder and zirconium dioxide particles were ball-milled at a mass ratio of 1:3, with a particle diameter of 5-8 mm. A small amount of binder was added and mixed for 2 h to coat the surface of the hard particles with the activated powder. The mixture was then sintered at 1300℃ for 3 h to form a metallurgical bond between the activated powder and the surface of the hard particles. The mixture was then reduced using an ammonia-hydrogen mixed gas (volume ratio of 3:1) at 700℃ for 1 h to obtain surface-metallized hard particles.

[0094] Hard particles with surface metallization, metal matrix powder (600~800 mesh) and binder are ball-milled and mixed at a mass ratio of 7:4:1 for 4 h. The mixture is then placed in a steel mold and pressed at 200 MPa to obtain a metal-ceramic layer with the same dimensions as the high-temperature alloy layer and a thickness of 20 mm.

[0095] (3) The nickel-chromium alloy layer is cast using lost foam casting, and has the same dimensions as the high-temperature alloy layer, with a thickness of 30 mm;

[0096] (4) The high-temperature alloy layer, the metal ceramic layer and the nickel-chromium alloy layer are stacked in sequence in an alumina mold and sintered at 1350°C for 6 h in an argon atmosphere to obtain the composite heat-resistant slider for the heating furnace walking beam.

[0097] Example 3

[0098] This embodiment provides a method for preparing a composite heat-resistant slider for a walking beam in a heating furnace, including:

[0099] (1) The high-temperature alloy layer is made by lost foam casting, with a size of 150 mm × 50 mm and a thickness of 30 mm;

[0100] (2) Mix 2 parts by mass of silicon dioxide powder, 2 parts by mass of ferric oxide powder, 5 parts by mass of manganese oxide powder and 1 part by mass of calcium oxide powder in a ball mill for 12 h. The powder mesh size is 1000~1200 mesh to obtain activated powder.

[0101] The activated powder and hard alumina particles were ball-milled at a mass ratio of 1:5, with a particle diameter of 3-5 mm. A small amount of binder was added and mixed for 6 h to coat the surface of the hard particles with the activated powder. The mixture was then sintered at 1350℃ for 1 h to form a metallurgical bond between the activated powder and the surface of the hard particles. The mixture was then reduced using an ammonia-hydrogen mixed gas (volume ratio of 3:1) at 1000℃ for 0.5 h to obtain surface-metallized hard particles.

[0102] Hard particles with surface metallization, metal matrix powder (500~800 mesh) and binder are ball-milled and mixed at a mass ratio of 5:2:1 for 4 h. The mixture is then placed in a steel mold and pressed at 400 MPa to obtain a metal-ceramic layer with the same dimensions as the high-temperature alloy layer and a thickness of 30 mm.

[0103] (3) The nickel-chromium alloy layer is cast using lost foam casting, and has the same dimensions as the high-temperature alloy layer, with a thickness of 60 mm;

[0104] (4) The high-temperature alloy layer, the metal ceramic layer and the nickel-chromium alloy layer are stacked in sequence in an alumina mold and sintered at 1380°C for 5 h in an argon atmosphere to obtain the composite heat-resistant slider for the heating furnace walking beam.

[0105] Example 4

[0106] In this embodiment, except for step (2), mixing 1 part by mass of silicon dioxide powder, 3 parts by mass of ferric oxide powder, 4 parts by mass of manganese oxide powder and 1.5 parts by mass of calcium oxide powder in a ball mill for 10 h to obtain activated powder with a powder mesh size of 800~1000 mesh; and mixing the activated powder with ZTA ceramic particles in a mass ratio of 1:4 by ball milling, all other conditions are the same as in Example 1.

[0107] Example 5

[0108] In this embodiment, except for step (2), mixing 3 parts by weight of silicon dioxide powder, 1 part by weight of ferric oxide powder, 6 parts by weight of manganese oxide powder and 0.5 parts by weight of calcium oxide powder in a ball mill for 10 h to obtain activated powder with a powder mesh size of 800~1000 mesh; and mixing the activated powder with WC hard particles in a ball mill at a mass ratio of 1:4, all other conditions are the same as in Example 1.

[0109] Comparative Example 1

[0110] This comparative example is made of a single-component high-temperature alloy, and its specific composition is the same as the first high-temperature alloy layer in Example 1.

[0111] Comparative Example 2

[0112] This comparative example is made of a single-component high-temperature alloy, and its specific composition is the same as the first high-temperature alloy layer in Example 2.

[0113] Comparative Example 3

[0114] This comparative example is made of a single-component nickel-chromium alloy, and its specific composition is the same as the third nickel-chromium alloy layer in Example 2.

[0115] Comparative Example 4

[0116] This comparative example is made of a single-component nickel-chromium alloy, and its specific composition is the same as the third nickel-chromium alloy layer in Example 3.

[0117] The mass fraction (%) of each element in the high-temperature alloy layer in Examples 1-3 is shown in Table 1.

[0118] Table 1

[0119]

[0120] The mass fraction (%) of each element in the nickel-chromium alloy layer in Examples 1-3 is shown in Table 2.

[0121] Table 2

[0122]

[0123] The mass fraction (%) of each element in the metal matrix powder of the metal ceramic layer in Examples 1-3 is shown in Table 3.

[0124] Table 3

[0125]

[0126] The compressive strength of the composite heat-resistant sliders for the walking beams of the heating furnace provided in Examples 1-5 and Comparative Examples 1-4 was tested. The sliders were welded to the walking beams and the welding quality was tested. The welded walking beam sliders were brought into contact with the steel billets of the production line for a period of time to observe whether black marks were produced. The results are shown in Table 4.

[0127] Because the composite slider in this patent embodiment is mainly composed of a high-temperature alloy layer, a metal-ceramic layer, and a nickel-chromium alloy layer sintered together sequentially, it needs to be tested layer by layer. In contrast, the slider in the comparative example is composed of only a single metal, so only one layer needs to be tested.

[0128] The compressive strength was tested using a universal testing machine equipped with a high-temperature furnace, and the testing method was the standard method for high-temperature compression testing of metallic materials, ASTM E209-18.

[0129] 1) Example of a composite slider: Samples of the first high-temperature alloy layer and the second metal-ceramic layer of the composite slider were taken and heated to 1250℃ (the actual operating temperature of the walking beam furnace), held at that temperature for 1 hour, and then tested immediately. Samples of the third layer were taken and heated to 800℃ (the third layer is close to the water beam, and the temperature is lower in actual operating conditions), held at that temperature for 1 hour, and then tested immediately.

[0130] 2) Comparative single metal slider: Samples were heated to 1250℃ (actual operating temperature of the walking beam furnace), held for 1 hour, and then tested immediately.

[0131] The welding quality is tested by visual inspection with a magnifying glass (20x) and by inspection using weld gauges and calipers.

[0132] The testing method for black marks is the color chart comparison method (gray-black / deep black), using the Pantone color chart or grayscale meter for detection.

[0133] Table 4

[0134]

[0135] The physical and schematic diagrams of the composite heat-resistant slider for the walking beam of the heating furnace prepared in Example 3 are shown below. Figure 1 and Figure 4 As shown, SEM and XRD tests were performed on its internal tissue structure, and the results are as follows. Figure 2 and Figure 3 As shown. Figure 2 The composite interface between ceramic particles and the metal matrix in the second metal-ceramic layer was characterized by scanning electron microscopy (SEM), which revealed a metallurgically bonded transition layer between the ceramic ZTA and the matrix interface. XRD analysis near this transition layer showed (…). Figure 3 The interface layer mainly consists of composite oxides of Mn, Si, Al, and Zr. During the sintering process, the powder in the metal-based ceramic composite layer also forms a metallurgically bonded sintering interface with the high-temperature alloy layer (layer 1) and the nickel-chromium alloy layer (layer 3), causing the interfaces of the three layers to fuse and sinter into the finished slider.

[0136] The applicant declares that the detailed structural features of the present invention are illustrated through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components selected in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0137] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0138] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0139] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A composite heat-resistant slider for a walking beam in a heating furnace, characterized in that, The composite heat-resistant slider for the heating furnace walking beam includes a metal-based ceramic layer and a nickel-chromium alloy layer connected in sequence by a high-temperature alloy layer. The method for preparing the metal-based ceramic layer includes: The activated powder is mixed with hard particles so that the activated powder coats the surface of the hard particles. The mixture is then subjected to sintering and reduction treatments to obtain surface-metallized hard particles. The hard particles are mixed with the metal matrix powder and pressed to obtain the metal-based ceramic layer; The activated powder comprises, by weight, 1-3 parts silicon dioxide powder, 1-3 parts ferric oxide powder, 4-6 parts manganese oxide powder and 0.5-1.5 parts calcium oxide powder; The hard particles include any one or a combination of at least two of Al2O3, ZrO2, WC, Cr3C2, SiC ceramics or ZTA ceramics; The metal matrix powder comprises, by mass fraction, 0-50% Co, 10-50% Cr, 5-60% Ni, 0-10% Mo, 0-40% W, 0-1% Si, 0.1-1% C, 0-6% Mn, with the balance being Fe; The mass ratio of the metal matrix powder to the surface-metallized hard particles is 5~7:4~2; The pressing pressure is 200~400 MPa.

2. The composite heat-resistant slider for the walking beam of the heating furnace according to claim 1, characterized in that, The mass ratio of the activated powder to the hard particles is 1:3~5.

3. The composite heat-resistant slider for the walking beam of the heating furnace according to claim 1, characterized in that, The sintering temperature of the surface-metallized hard particles is 1300~1400℃, and the time is 1~3 h; The reduction treatment of the surface-metallized hard particles is carried out in a reducing atmosphere, and the temperature of the reduction treatment is 700~1000℃, and the time is 0.5~1 h. The reducing atmosphere includes a hydrogen-containing atmosphere or a carbon-containing atmosphere.

4. The composite heat-resistant slider for the walking beam of the heating furnace according to claim 1, characterized in that, The high-temperature alloy layer comprises, by mass fraction: C≤0.25%, Co 0~60%, Mo≤2.5%, Ni 2~50%, Mn≤1.5%, Si 1~15%, Al 0~5%, Cr 20~80%, with the balance being Fe.

5. The composite heat-resistant slider for the walking beam of the heating furnace according to claim 1, characterized in that, The nickel-chromium alloy layer comprises, by mass fraction: C≤0.15%, Ni 10~50%, Mo 1~3%, Nb≤1.5%, Mn≤1.5%, Si≤1.5%, Cr 10~40%, with the balance being Fe.

6. A method for preparing a composite heat-resistant slider for a walking beam in a heating furnace according to any one of claims 1 to 5, characterized in that, The preparation method includes: The composite heat-resistant slider for the heating furnace walking beam is obtained by sequentially stacking a high-temperature alloy layer, a metal ceramic layer, and a nickel-chromium alloy layer in a mold and sintering it under a protective atmosphere.

7. The preparation method according to claim 6, characterized in that, The sintering temperature is 1350~1450℃, and the time is 2~6 h.

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