Hot coating and melting method for chamfered crystallizer copper plate

Abstract

The invention provides a hot coating and melting method for a chamfered crystallizer copper plate, and belongs to the field of metal surface treatment. The method comprises the steps that the surface of a chamfering crystallizer copper plate base body is pretreated; according to a set spraying sequence, spraying treatment is conducted on the surface of the pretreated chamfered crystallizer copper plate base body, gas cooling is conducted in the spraying treatment process, a coating is formed on the surface of the chamfered crystallizer copper plate base body, and a chamfered copper plate semi-finished product is obtained; assembling the chamfered copper plate semi-finished product and an anti-deformation tool; and under the inert gas atmosphere, coating fusion welding treatment is conducted on the chamfered copper plate semi-finished product assembled with the anti-deformation tool, then cooling and correction are conducted, and the chamfered crystallizer copper plate is obtained. The gradient coating of the copper plate is designed, the spraying sequence is reasonably designed, and gas cooling and assembly of a chamfered copper plate semi-finished product and an anti-deformation tool are carried out simultaneously in the spraying process, so that deformation of a chamfered part is reduced in the thermal spraying process of the chamfered crystallizer copper plate.

Description

Technical Field

[0001] The present application relates to the technical field of metal surface treatment, and in particular to a hot-melt coating method for a chamfered crystallizer copper plate. Background Art

[0002] The crystallizer is the core component of continuous casting. The crystallizer copper plate is an important heat-conducting component for continuous casting from liquid steel to solidified solid billet shell. Its quality directly affects the surface quality of the billet, the casting speed of the continuous casting machine and other indicators. At present, the copper plates of the domestic continuous casting medium and thick slab crystallizer are divided into wide copper plates and narrow copper plates, and the narrow copper plates are further divided into right-angle and chamfered narrow copper plates. The right-angle narrow copper plate has always been a structural copper plate widely used in domestic continuous casting crystallizers. In recent years, with the development of the continuous casting industry towards high speed, large-scale and fine, the introduction of high-end steel products such as silicon steel and high-strength steel automotive plates has put higher and higher requirements on the quality of the billet. In order to solve problems such as transverse cracks in the billet, many steel mills choose to use chamfered narrow copper plates. The application of chamfered crystallizer copper plates has effectively improved the problem of transverse cracks in the billet and improved the quality of the billet. The number of online applications of chamfered crystallizer copper plates is increasing.

[0003] Up to now, the surface treatment method of chamfered narrow copper plates has always adopted the traditional electroplating repair method, but its life span can hardly meet the requirements of long life and high efficiency of modern steel, and the level of online over-steel use is low. Therefore, laser cladding technology, spray welding, and spraying technology are gradually applied to crystallizer copper plates. Among them, thermal spraying technology is more widely used, but thermal spraying technology is currently limited to right-angle copper plates. The difference between the chamfered crystallizer copper plate and the traditional right-angle copper plate is that the crystallizer copper plate is designed with blunt chamfers on both sides, and in order to achieve the online cooling effect of the ingot, a cooling water tank is designed at the blunt chamfer of the copper plate. The thermal spraying process will include two key processes: thermal spraying and heat treatment. During the thermal spraying and heat treatment process, the copper plate is subjected to high temperature and rapid cooling, which can easily cause internal stress in the chamfered copper plate and cause deformation, so that the size of the blunt chamfer of the chamfered copper plate cannot meet the original structural design requirements, and cannot form a qualified product. Summary of the invention

[0004] The present application provides a thermal coating method for a chamfered crystallizer copper plate to solve the following technical problem: how to reduce the deformation of the chamfered portion during the thermal spraying process of the chamfered crystallizer copper plate.

[0005] The present application provides a method for hot-melting a chamfered crystallizer copper plate, the method comprising:

[0006] Pre-treating the surface of the chamfered crystallizer copper plate substrate;

[0007] According to the set spraying sequence, the pre-treated surface of the chamfered crystallizer copper plate substrate is sprayed, and gas cooling is performed during the spraying process to form a coating on the surface of the chamfered crystallizer copper plate substrate to obtain a chamfered copper plate semi-finished product;

[0008] Assembling the chamfered copper plate semi-finished product with the anti-deformation tooling; and

[0009] In an inert gas atmosphere, the chamfered copper plate semi-finished product after assembling the anti-deformation tooling is subjected to coating melting welding treatment, and then cooled and corrected to obtain a chamfered crystallizer copper plate; wherein the upper coating thickness of the chamfered crystallizer copper plate is less than the lower coating thickness.

[0010] Optionally, the thickness of the upper coating is 0.3 mm to 0.5 mm, and the thickness of the lower coating is 1.0 mm to 1.3 mm.

[0011] Optionally, the spraying sequence is: first spray the bottom surface of the chamfered crystallizer copper plate substrate, wait for the chamfered crystallizer copper plate substrate to cool to a set temperature, and then spray the chamfered surfaces on both sides of the chamfered crystallizer copper plate substrate respectively; the set temperature is 60°C to 70°C.

[0012] Optionally, the gas cooling uses a cooling tool to make the overall temperature of the chamfered crystallizer copper plate substrate be 100°C to 150°C.

[0013] Optionally, during the spraying process, the spraying angle of the spraying process is perpendicular to the bottom surface and the chamfered surfaces on both sides of the chamfered crystallizer copper plate substrate.

[0014] Optionally, the anti-deformation tooling includes: a horizontal plate, a first vertical plate and a second vertical plate, the tops of the first vertical plate and the second vertical plate are connected via the horizontal plate; and the chamfered copper plate semi-finished product is clamped between the first vertical plate and the second vertical plate.

[0015] Optionally, the temperature of the coating fusion welding treatment is 600° C. to 900° C., and the insulation time of the coating fusion welding treatment is 60 min to 90 min.

[0016] Optionally, the flatness of the chamfered crystallizer copper plate is 0.3 mm / m to 0.5 mm / m.

[0017] Optionally, the pretreatment of the surface of the chamfered crystallizer copper plate substrate includes:

[0018] The surface of the chamfered crystallizer copper plate substrate is pre-processed, cleaned and sandblasted for pretreatment.

[0019] Optionally, the surface roughness Ra of the chamfered crystallizer copper plate substrate after pretreatment is 10 μm to 20 μm.

[0020] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0021] The present application provides a method for hot coating and melting of a chamfered crystallizer copper plate, the method comprising: pre-treating the surface of a chamfered crystallizer copper plate substrate; spraying the pre-treated surface of the chamfered crystallizer copper plate substrate according to a set spraying sequence, and performing gas cooling during the spraying process to form a coating on the surface of the chamfered crystallizer copper plate substrate to obtain a chamfered copper plate semi-finished product; assembling the chamfered copper plate semi-finished product with an anti-deformation tooling; and in an inert gas atmosphere, coating and melting welding the chamfered copper plate semi-finished product after assembling the anti-deformation tooling, followed by cooling and correction to obtain a chamfered crystallizer copper plate; wherein the upper coating thickness of the chamfered crystallizer copper plate is less than the lower coating thickness. First, by designing the gradient coating of the copper plate, the requirements for online use with fast heat transfer of the upper coating and excellent wear resistance of the lower coating are achieved; secondly, according to the structural form of the chamfered copper plate, the spraying sequence is reasonably designed to ensure uniform coating and reduce local stress concentration; thirdly, gas cooling is performed during the spraying process to prevent the copper plate from overheating, ensure coating performance and prevent copper plate deformation; finally, the chamfered copper plate semi-finished product is assembled with the anti-deformation tooling to prevent excessive deformation of the copper plate and ensure the shape and position dimensions of the chamfered copper plate at the blunt chamfer. Thus, the deformation of the chamfered part is reduced during the thermal spraying process of the chamfered crystallizer copper plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0024] Figure 1 A flow chart of a hot-melt coating method for a chamfered crystallizer copper plate provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of a chamfered crystallizer copper plate provided in an embodiment of the present application;

[0026] Figure 3 A schematic diagram of the structure of the cooling tooling provided in the embodiment of the present application;

[0027] Figure 4 Schematic diagram of fusion welding of chamfered crystallizer copper plates provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0030] In addition, in the description of the specification of the present application, the terms "including", "comprising", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this article, "at least one" means one or more, and "plurality" means two or more. "At least one", "the following at least one item (items)" or similar expressions refer to any combination of these items, including any combination of single items (items) or plural items (items). For example, "at least one of a, b, or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e. a and b), ac, bc or abc, where a, b, c can be single or plural, respectively.

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0032] Figure 1 A schematic flow chart of a hot coating method for a chamfered crystallizer copper plate provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of the chamfered crystallizer copper plate provided in an embodiment of the present application.

[0033] See also Figure 1 and Figure 2 The present application provides a method for hot-melting a chamfered crystallizer copper plate, the method comprising:

[0034] S1, pre-treating the surface of the chamfered crystallizer copper plate substrate;

[0035] Pretreatment ensures that the surface of the copper plate substrate is clean and free of impurities, providing a good adhesion basis for subsequent spraying treatment.

[0036] In some embodiments, the pretreatment of the surface of the chamfered crystallizer copper plate substrate comprises:

[0037] The surface of the chamfered crystallizer copper plate substrate is pre-processed, cleaned and sandblasted for pretreatment.

[0038] In some embodiments, the surface roughness Ra of the chamfered crystallizer copper plate substrate after pretreatment is 10 μm to 20 μm.

[0039] Combined with the copper plate gradient coating design, machining equipment is used to process the copper plate matrix. For repairing the copper plate, the original repair layer needs to be removed; use acetone or xylene and other organic solvents to clean the copper plate surface to be sprayed to ensure that the copper plate surface to be sprayed is clean, so as to ensure the bonding performance between the copper plate matrix and the coating; then use cast steel sand to sandblast the copper plate surface to be sprayed to remove the oxide layer on the copper plate surface and improve the surface roughness to ensure the bonding performance between the copper plate matrix and the coating. Exemplarily, the surface roughness Ra of the chamfered crystallizer copper plate substrate after pretreatment can be 10μm, 12μm, 14μm, 16μm, 18μm, 19μm, 20μm, etc.

[0040] S2, spraying the pretreated surface of the chamfered crystallizer copper plate substrate according to a set spraying sequence, and performing gas cooling during the spraying process to form a coating on the surface of the chamfered crystallizer copper plate substrate to obtain a chamfered copper plate semi-finished product;

[0041] Through spraying and gas cooling, a uniform and dense coating is formed on the surface of the copper plate substrate to improve the wear resistance and corrosion resistance of the copper plate. Spraying materials can be selected according to specific needs, such as nickel-based alloy powder or WC 12 Co powder materials, etc.

[0042] In some embodiments, the spraying material of the spraying treatment is 50% to 70% Ni, 12% to 20% Cr, 10% to 15% Cu, 1% to 10% B, 1% to 5% Si and 2% to 6% Mo by mass fraction.

[0043] In some embodiments, the spraying process uses a robot and a high velocity flame spraying device.

[0044] The present invention uses advanced programming software to program detailed spraying paths and parameters for the spraying robot. This includes the movement trajectory, speed, spraying thickness, etc. of the spray gun. At the same time, the built-in sensors of the robot system can monitor the spraying process and coating quality in real time to ensure that each spraying achieves the preset effect. During the spraying process, the robot uses its precise mechanical structure and advanced control system to ensure that the spray gun can accurately aim at the chamfered part of the copper plate for spraying. The supersonic flame spraying equipment uses supersonic high-temperature flame flow to heat and accelerate the spraying material, so that it is quickly deposited on the surface of the copper plate to form a high-quality coating.

[0045] In some embodiments, the spraying sequence is: first spray the bottom surface of the chamfered crystallizer copper plate substrate, wait for the chamfered crystallizer copper plate substrate to cool to a set temperature, and then spray the chamfered surfaces on both sides of the chamfered crystallizer copper plate substrate respectively; the set temperature is 60°C to 70°C.

[0046] The present invention reasonably designs the spraying sequence according to the structure of the chamfered copper plate, and first sprays the bottom surface. As an important part of the substrate, the coating quality of the bottom surface directly affects the wear resistance, corrosion resistance and heat conduction efficiency of the entire copper plate. Spraying the bottom surface first can ensure that the bottom surface coating has enough time to solidify and cool in the subsequent treatment, reduce the stress change caused by temperature change, help to ensure the integrity and adhesion of the bottom surface coating, and provide a stable foundation for subsequent operations. The coating needs a certain time to solidify and cool after spraying to achieve ideal physical and chemical properties. Cooling the substrate to a set temperature (60°C to 70°C) is conducive to the stable solidification of the coating, while avoiding internal stress concentration or deformation of the coating caused by excessive temperature. Then spray the chamfered surfaces on both sides. As a special part in the copper plate structure, the chamfered surface has a complex shape and is easily affected by stress concentration. After the bottom surface coating is stable, spraying the chamfered surface can ensure that the coating can also achieve good coverage and uniformity on complex shapes. Thereby improving the overall quality and durability of the coating, reducing the risk of cracking or peeling of the coating due to local stress concentration. Thus, the spraying sequence of the present invention effectively ensures the uniformity, adhesion and stability of the overall structure of the coating, and reduces local stress concentration. Exemplarily, the set temperature can be 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, etc.

[0047] Figure 3 A schematic diagram of the structure of the cooling tooling provided in an embodiment of the present application.

[0048] See also Figure 3 In some embodiments, the gas cooling uses a cooling tool to make the overall temperature of the chamfered crystallizer copper plate substrate be 100°C to 150°C.

[0049] The cooling tooling is mainly designed with 2 to 4 rows of cooling pipes according to the size of the chamfered copper plate, and 5 to 10 3-8 mm air outlet holes are left on each row of cooling pipes. At the same time, all cooling pipes are collected into the air inlet pipe and connected to the air inlet.

[0050] During the spraying process, a cooling fixture is used, and cooling gas is introduced into the cooling fixture to prevent the copper plate from overheating, reduce local stress concentration, ensure coating performance and prevent deformation of the copper plate. For example, the overall temperature of the copper plate substrate of the chamfered crystallizer is 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.

[0051] In some embodiments, during the spraying process, the spraying angle of the spraying process is perpendicular to the bottom surface and the chamfered surfaces on both sides of the chamfered crystallizer copper plate substrate.

[0052] S3, assembling the chamfered copper plate semi-finished product with the anti-deformation tooling; and

[0053] By assembling the chamfered copper plate semi-finished product with the anti-deformation tooling, the shape of the copper plate can be kept stable during subsequent processing to prevent deformation due to thermal stress and other reasons.

[0054] Figure 4 Schematic diagram of fusion welding of chamfered crystallizer copper plates provided in an embodiment of the present application.

[0055] See also Figure 4 In some embodiments, the anti-deformation tooling includes: a horizontal plate, a first vertical plate and a second vertical plate, the tops of the first vertical plate and the second vertical plate are connected by the horizontal plate; the chamfered copper plate semi-finished product is clamped between the first vertical plate and the second vertical plate.

[0056] The connection can be made by screw connection, clamp connection and other commonly used connection methods in this field. For the hot melt welding and cooling process, due to high temperature heat treatment and rapid cooling, the copper plate coating and the copper plate base material generate stress, which causes the copper plate to deform, especially the blunt chamfered part of the chamfered copper plate. The deformation of the copper plate can reach 2mm~5mm. Therefore, the copper plate is assembled with anti-deformation tooling to prevent excessive deformation and ensure the shape and position dimensions of the blunt chamfered part of the chamfered copper plate. After the anti-deformation tooling is installed, the overall deformation of the chamfered copper plate is 0.5mm~0.7mm.

[0057] S4. Under an inert gas atmosphere, the chamfered copper plate semi-finished product after the anti-deformation tooling is assembled is subjected to coating fusion welding treatment, and then cooled and corrected to obtain a chamfered crystallizer copper plate; wherein the upper coating thickness of the chamfered crystallizer copper plate is less than the lower coating thickness.

[0058] The fusion welding process forms a metallurgical bond between the coating and the substrate, further improving the bonding strength and performance stability of the coating; and the final product is obtained through cooling and correction steps.

[0059] In some embodiments, the thickness of the upper coating is 0.3 mm to 0.5 mm, and the thickness of the lower coating is 1.0 mm to 1.3 mm.

[0060] During the continuous casting process, the upper coating is in direct contact with the ingot, and its main function is to ensure that heat can be quickly and evenly transferred to the cooling medium, thereby maintaining the cooling rate and temperature distribution of the ingot. A thinner coating thickness helps to reduce thermal resistance and improve heat transfer efficiency. During the continuous casting process, the lower coating not only has to withstand the friction and wear of the ingot, but also has to resist the scouring and corrosion of the molten metal. Therefore, a thicker coating thickness can provide higher wear resistance and corrosion resistance, and extend the service life of the copper plate. Therefore, the present invention can ensure efficient heat transfer of the upper mouth and meet the strong wear resistance requirements of the lower mouth through a gradient design of thin upper and thick lower mouth, thereby achieving optimized performance under multiple working conditions. At the same time, the thicker coating at the lower mouth effectively resists wear and corrosion, reduces the failure of the copper plate caused by excessive wear of the coating, and thus extends the overall service life. Exemplarily, the thickness of the upper coating can be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, etc., and the thickness of the lower coating is 1.0 mm, 1.05 mm, 1.1 mm, 1.15 mm, 1.2 mm, 1.25 mm, 1.3 mm, etc.

[0061] In some embodiments, the temperature of the coating fusion welding treatment is 600° C. to 900° C., and the insulation time of the coating fusion welding treatment is 60 min to 90 min.

[0062] The temperature of the coating fusion welding treatment is limited to 600°C to 900°C, and the holding time is 60min to 90min. The coating material can be fully softened and form a good metallurgical bond with the substrate, thereby improving the bonding strength between the coating and the substrate. Exemplarily, the temperature of the coating fusion welding treatment can be 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, etc., and the holding time is 60min, 65min, 70min, 75min, 80min, 85min, 90min, etc.

[0063] In some embodiments, the flatness of the chamfered crystallizer copper plate is 0.3 mm / m to 0.5 mm / m.

[0064] Because the chamfered copper plate still has a certain deformation after heat treatment, a leveling machine is used to correct the copper plate to a flatness of 0.3mm / m to 0.5mm / m, and then the spray coating machining allowance can be removed to meet the chamfered copper plate size design requirements. For example, the flatness of the chamfered crystallizer copper plate can be 0.3mm / m, 0.32mm / m, 0.35mm / m, 0.38mm / m, 0.4mm / m, 0.45mm / m, 0.48mm / m, 0.5mm / m, etc.

[0065] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to industry standards. If there is no corresponding industry standard, then the conditions recommended by the manufacturer are followed.

[0066] Example 1

[0067] This embodiment provides a method for hot-melting a chamfered crystallizer copper plate, which comprises the following steps:

[0068] (1) Design a gradient coating with an upper coating thickness of 0.3 mm and a lower coating thickness of 1.0 mm;

[0069] (2) Copper plate pre-processing: According to the requirements of the drawings, the chamfered crystallizer copper plate substrate is pre-processed, and the surface roughness after processing is Ra ≤ 3.2 μm;

[0070] (3) Cleaning: Use acetone to clean the surface to be sprayed on the chamfered crystallizer copper plate substrate;

[0071] (4) Sandblasting: Use cast steel sand to sandblast the surface to be blasted of the chamfered crystallizer copper plate substrate, and the roughness Ra after sandblasting is 20 μm;

[0072] (5) Design of coating spraying sequence: According to the structural form of the chamfered crystallizer copper plate, the bottom surface is sprayed first. After the copper plate is cooled to 70°C, the chamfered parts on both sides are sprayed respectively to ensure that the overall temperature of the copper plate is within the range of 100°C to 150°C; in terms of mass fraction, the spraying material is 60% Ni, 16% Cr, 12% Cu, 5% B, 3% Si, and 4% Mo.

[0073] (6) Robot hot coating melting + cooling: Turn on the cooling gas of the cooling tooling, and use the robot and supersonic flame spraying equipment to spray the chamfered crystallizer copper plate substrate according to the designed coating spraying sequence, ensuring that the overall temperature of the copper plate is within the range of 100°C to 150°C, the upper coating spray layer thickness is 0.6mm, the lower coating layer thickness is 1.3mm, and a certain processing allowance is sprayed to ensure the designed coating thickness, and the chamfered copper plate semi-finished product is obtained;

[0074] (7) Hot melt welding + cooling: Assemble the anti-deformation tooling on the chamfered copper plate semi-finished product, and perform coating hot melt welding on the chamfered copper plate semi-finished product under argon protection, and then cool it down. The coating heat treatment temperature is 900℃ and the time is 60min;

[0075] (8) Correction: Use a leveling device to correct the chamfered copper plate. After correction, the flatness of the copper plate is 0.5 mm / m;

[0076] (9) Post-processing of the copper plate: According to the finished product drawing, the spray coating processing allowance is removed to meet the size design requirements of the chamfered crystallizer copper plate, and the finished chamfered crystallizer copper plate is obtained, the upper coating thickness is 0.3 mm, and the lower coating thickness is 1.0 mm, which meets the use requirements. The chamfered crystallizer copper plate obtained in Example 1 is actually used in a steelmaking continuous casting production line in a domestic steel plant, and the amount of steel used online is 135,000 tons, which is 2-3 times the amount of steel used by the traditional electroplating process to repair the copper plate (30,000-50,000 tons), and the actual application effect is good.

[0077] Example 2

[0078] This embodiment provides a method for hot-melting a chamfered crystallizer copper plate, which comprises the following steps:

[0079] (1) Design a gradient coating with an upper coating thickness of 0.4 mm and a lower coating thickness of 1.1 mm;

[0080] (2) Copper plate pre-processing: According to the requirements of the drawings, the chamfered crystallizer copper plate substrate is pre-processed, and the surface roughness after processing is Ra ≤ 3.2 μm;

[0081] (3) Cleaning: Use acetone to clean the surface to be sprayed on the chamfered crystallizer copper plate substrate;

[0082] (4) Sandblasting: Use cast steel sand to sandblast the surface to be blasted of the chamfered crystallizer copper plate substrate, and the roughness Ra after sandblasting is 10 μm;

[0083] (5) Design of coating spraying sequence: According to the structural form of the chamfered crystallizer copper plate, the bottom surface is sprayed first. After the copper plate is cooled to 60°C, the chamfered parts on both sides are sprayed respectively to ensure that the overall temperature of the copper plate is within the range of 100°C to 150°C; in terms of mass fraction, the spraying material is 60% Ni, 16% Cr, 12% Cu, 5% B, 3% Si, and 4% Mo.

[0084] (6) Robot hot coating melting + cooling: Turn on the cooling gas of the cooling tooling, and use the robot and supersonic flame spraying equipment to spray the chamfered crystallizer copper plate substrate according to the designed coating spraying sequence, ensuring that the overall temperature of the copper plate is within the range of 100°C to 150°C, the upper coating spray layer thickness is 0.7mm, the lower coating layer thickness is 1.4mm, and a certain processing allowance is sprayed to ensure the designed coating thickness, and the chamfered copper plate semi-finished product is obtained;

[0085] (7) Hot melt welding + cooling: Assemble the anti-deformation tooling on the chamfered copper plate semi-finished product, and perform coating hot melt welding on the chamfered copper plate semi-finished product under argon protection, and then cool it down. The coating heat treatment temperature is 600℃ and the time is 90min;

[0086] (8) Correction: Use a leveling device to correct the chamfered copper plate. After correction, the flatness of the copper plate is 0.3 mm / m;

[0087] (9) Post-processing of copper plate: According to the finished product drawing, the spray coating processing allowance is removed to meet the size design requirements of the chamfered crystallizer copper plate, and the finished chamfered crystallizer copper plate is obtained, the upper coating thickness is 0.4 mm, and the lower coating thickness is 1.1 mm, which meets the use requirements. The chamfered crystallizer copper plate obtained in Example 2 is actually used in a steelmaking continuous casting production line in a domestic steel plant, and the amount of steel used online is 142,000 tons, which is 2-3 times the amount of steel used by the traditional electroplating process to repair the copper plate (30,000-50,000 tons), and the actual application effect is good.

[0088] Example 3

[0089] This embodiment provides a method for hot-melting a chamfered crystallizer copper plate, which comprises the following steps:

[0090] (1) Design a gradient coating with an upper coating thickness of 0.5 mm and a lower coating thickness of 1.3 mm;

[0091] (2) Copper plate pre-processing: According to the requirements of the drawings, the chamfered crystallizer copper plate substrate is pre-processed, and the surface roughness after processing is Ra ≤ 3.2 μm;

[0092] (3) Cleaning: Use acetone to clean the surface to be sprayed on the chamfered crystallizer copper plate substrate;

[0093] (4) Sandblasting: Use cast steel sand to sandblast the surface to be blasted of the chamfered crystallizer copper plate substrate, and the roughness Ra after sandblasting is 20 μm;

[0094] (5) Design of coating spraying sequence: According to the structural form of the chamfered crystallizer copper plate, the bottom surface is sprayed first. After the copper plate is cooled to 65°C, the chamfered parts on both sides are sprayed respectively to ensure that the overall temperature of the copper plate is within the range of 100°C to 150°C; in terms of mass fraction, the spraying material is 60% Ni, 16% Cr, 12% Cu, 5% B, 3% Si, and 4% Mo.

[0095] (6) Robot hot coating melting + cooling: Turn on the cooling gas of the cooling tooling, and use the robot and supersonic flame spraying equipment to spray the chamfered crystallizer copper plate substrate according to the designed coating spraying sequence, ensuring that the overall temperature of the copper plate is within the range of 100°C to 150°C, the upper coating spray layer thickness is 0.8mm, the lower coating layer thickness is 1.6mm, and a certain processing allowance is sprayed to ensure the designed coating thickness, and the chamfered copper plate semi-finished product is obtained;

[0096] (7) Hot melt welding + cooling: Assemble the anti-deformation tooling on the chamfered copper plate semi-finished product, and perform coating hot melt welding on the chamfered copper plate semi-finished product under argon protection, and then cool it down. The coating heat treatment temperature is 700℃ and the time is 70min;

[0097] (8) Correction: Use a leveling device to correct the chamfered copper plate. After correction, the flatness of the copper plate is 0.4 mm / m;

[0098] (9) Post-processing of copper plate: According to the finished product drawing, the spray coating processing allowance is removed to meet the size design requirements of the chamfered crystallizer copper plate, and the finished chamfered crystallizer copper plate is obtained, the upper coating thickness is 0.5 mm, and the lower coating thickness is 1.3 mm, which meets the use requirements. The chamfered crystallizer copper plate obtained in Example 3 is actually used in a steelmaking continuous casting production line in a domestic steel plant, and the amount of steel used online is 148,000 tons, which is 2-3 times the amount of steel used by the traditional electroplating process to repair the copper plate (30,000-50,000 tons), and the actual application effect is good.

[0099] The properties of the surface coatings of the chamfered mold copper plates obtained in Examples 1 to 3 were measured, and the results are shown in Table 1.

[0100] Table 1 Performance of the surface coating of the chamfered crystallizer copper plate obtained in Examples 1 to 3

[0101] Group Porosity (%) Binding strength(Mpa) Microhardness (HV0.3) Example 1 0.03％ ＞80 730 Example 2 0.02％ ＞80 750 Example 3 0.02％ ＞80 780

[0102] In addition, one or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0103] In the embodiment of the present invention, a robot coating process is invented for chamfered narrow copper plates. A high hardness and high wear resistance coating is obtained on the surface of the chamfered narrow copper plates, replacing the traditional electroplating process method, so that the online service life is more than doubled.

[0104] In the embodiment of the present invention, by designing a reasonable coating structure, designing a robot walking trajectory, designing cooling tooling and anti-deformation tooling, the problem of excessive deformation of the chamfered crystallizer copper plate is effectively solved, and through subsequent corrective treatment and machining, the chamfered copper plate reaches the design size requirements and meets the requirements for online use.

[0105] In the embodiment of the present invention, a robotic melting process for the chamfered crystallizer copper plate is implemented to replace the original traditional electroplating process. The coating has excellent thermal conductivity and wear resistance, which increases the service life of the chamfered crystallizer copper plate, effectively stabilizes the online use cycle of the crystallizer, and helps to improve the continuous casting operation rate level.

[0106] In the embodiment of the present invention, a robot-assisted melting process for chamfering a copper plate of a crystallizer is realized, which also lays a foundation for realizing the melting process for copper plates of other special-shaped crystallizers and provides a valuable reference basis.

[0107] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A hot melt coating method for chamfering a crystallizer copper plate, characterized in that: The method comprises: Pre-treating the surface of the chamfered crystallizer copper plate substrate; According to the set spraying sequence, the pre-treated surface of the chamfered crystallizer copper plate substrate is sprayed, and gas cooling is performed during the spraying process to form a coating on the surface of the chamfered crystallizer copper plate substrate to obtain a chamfered copper plate semi-finished product; Assembling the chamfered copper plate semi-finished product with the anti-deformation tooling; and In an inert gas atmosphere, the chamfered copper plate semi-finished product after assembling the anti-deformation tooling is subjected to coating melting welding treatment, and then cooled and corrected to obtain a chamfered crystallizer copper plate; wherein the upper coating thickness of the chamfered crystallizer copper plate is less than the lower coating thickness.

2. The method according to claim 1, characterized in that The thickness of the upper coating is 0.3 mm to 0.5 mm, and the thickness of the lower coating is 1.0 mm to 1.3 mm.

3. The method according to claim 1, characterized in that The spraying sequence is: first spray the bottom surface of the chamfered crystallizer copper plate substrate, wait for the chamfered crystallizer copper plate substrate to cool to a set temperature, and then spray the chamfered surfaces on both sides of the chamfered crystallizer copper plate substrate respectively; the set temperature is 60°C to 70°C.

4. The method according to claim 1, characterized in that: The gas cooling uses a cooling tool to make the overall temperature of the chamfered crystallizer copper plate substrate be 100°C to 150°C.

5. The method according to claim 1, characterized in that During the spraying process, the spraying angle of the spraying process is perpendicular to the bottom surface and the chamfered surfaces on both sides of the chamfered crystallizer copper plate substrate.

6. The method according to claim 1, characterized in that The anti-deformation tooling includes: a horizontal plate, a first vertical plate and a second vertical plate, the tops of the first vertical plate and the second vertical plate are connected via the horizontal plate; the chamfered copper plate semi-finished product is clamped between the first vertical plate and the second vertical plate.

7. The method according to claim 1, characterized in that The temperature of the coating fusion welding treatment is 600° C. to 900° C., and the insulation time of the coating fusion welding treatment is 60 min to 90 min.

8. The method according to claim 1, characterized in that The flatness of the chamfered crystallizer copper plate is 0.3 mm / m to 0.5 mm / m.

9. The method according to claim 1, characterized in that: The method of pre-treating the surface of the chamfered crystallizer copper plate substrate comprises: The surface of the chamfered crystallizer copper plate substrate is pre-processed, cleaned and sandblasted for pretreatment.

10. The method according to claim 9, characterized in that The surface roughness Ra of the chamfered crystallizer copper plate substrate after pretreatment is 10 μm to 20 μm.

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