A method for preparing a high-precision cold-weld wear-resistant coating on an inner cylindrical surface of a combustion chamber shell

Abstract

The present application relates to a kind of preparation methods of high-precision cold welding wear-resistant coating in combustion chamber shell cylinder, comprising the following steps: S1 carries out pretreatment to cold welding matrix 0Cr17Ni4Cu4Nb stainless steel: after solid solution strengthening and aging strengthening to cold welding matrix 0Cr17Ni4Cu4Nb stainless steel, in turn, machining treatment, cleaning, drying are carried out, the matrix after treatment is obtained;S2 cold welding machine cold welding preparation work: first, the position correction of combustion chamber is carried out;Then, light point is checked;Adjust the spacing of welding wire and workpiece, and the spacing of tungsten electrode and welding wire;Finally, check whether gas cylinder, cooling water is opened, check whether the parameters of high-precision cold welding machine and its displacement machine parameters and the speed of robot are matched;S3 high-precision cold welding machine is automatically sent wire, and high-precision cold welding wear-resistant coating is obtained.The present application is stable in operation, process parameter is matched, the obtained coating can significantly improve the tribological properties of substrate, and the bonding strength with matrix is high.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell. Background Technology

[0002] The combustion chamber is a closed space where fuel and oxidizer mix and burn violently, converting chemical energy into high-temperature and high-pressure gas. However, the working environment of the combustion chamber is extremely harsh. Tiny gaps between the inner shell and the inner lining of the combustion chamber cause leakage of high-temperature and high-pressure gas, resulting in continuous high-temperature ablation and high-speed erosion of the metal wall. In addition, the high-frequency vibration during engine operation causes fretting wear between the inner shell and the inner lining, eventually forming annular ablation grooves.

[0003] High-precision cold welding technology has advantages such as low heat input, short pulse time, fast cooling rate, high bonding strength, and controllable performance, and can be used for additive manufacturing of various metals. However, high-precision cold welding technology relies on the operator's experience, and consistency in manual operation is difficult to guarantee; moreover, the process parameters are sensitive, requiring precise matching of parameters such as base current, wire feed speed, precision current, and welding time, otherwise the prepared coating will have defects such as pores and cracks, affecting the coating performance.

[0004] Patent CN 115488019 A discloses a process for preparing a heat-insulating coating for the inner wall of a solid rocket engine combustion chamber. The method involves first sandblasting the inner wall of the combustion chamber, followed by surface treatment with high-temperature manganese-based phosphating. Then, GT-401 organosilicon anti-ablation coating is used as the coating raw material, and the viscosity is controlled to 16-24 s by adding anhydrous ethanol. A centrifugal spraying process is then used to coat the inner wall with the heat-insulating layer. Finally, the combustion chamber with the heat-insulating layer is added using a gradient heating method to allow the heat-insulating layer to cure. This invention achieves a heat-insulating layer thickness of over 0.5 mm without peeling or cracking, improving the thermal protection performance of the combustion chamber. However, it does not solve the problem of the coating's wear resistance.

[0005] Patent CN 120138621 A discloses a powder, method, and coating for cold spraying of internal combustion engine combustion chamber components. The powder described in this patent is composed of stainless steel powder, ceramic powder, and elemental metal powder. The powder provided by this invention, when cold sprayed, produces a coating with good corrosion resistance. The bonding strength between the coating and the cast iron internal combustion engine combustion chamber components is above 30 MPa. However, the wear resistance of the coating is still not resolved.

[0006] Patent CN 113294261 A discloses a cylinder head, a coating preparation apparatus, and a coating preparation method. A porous alumina layer is formed on a first and second region of the cylinder head body, and a heat-insulating coating is formed on the surface of the porous alumina layer facing the combustion chamber. While the heat-insulating coating can prevent heat loss from the combustion chamber, it does not solve the problem of whether the coating is wear-resistant. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of the combustion chamber shell with stable operation and matching process parameters.

[0008] To address the above problems, the present invention provides a method for preparing a high-precision cold-welded anti-wear coating on the inner cylindrical surface of a combustion chamber shell, comprising the following steps: S1 performs pretreatment on the cold-welding substrate 0Cr17Ni4Cu4Nb stainless steel: First, the cold-welded base 0Cr17Ni4Cu4Nb stainless steel is subjected to solution strengthening and aging strengthening. Then, the surface of the welded base is subjected to machining treatment, anhydrous ethanol cleaning and drying in sequence to obtain the treated base. Preparation for cold welding with S2 cold welding machine: First, use a level to calibrate the position of the combustion chamber; then select the cold welding program to be used and calibrate the starting point; next, adjust the distance between the welding wire and the workpiece, as well as the distance between the tungsten electrode and the welding wire; finally, check whether the gas cylinder is open, whether the cooling water is open, and check whether the parameters of the high-precision cold welding machine, its positioner parameters, and the robot speed are matched. S3 uses a high-precision cold welding machine to automatically feed wire, simultaneously melting the nickel-chromium-molybdenum-niobium-based alloy welding wire on the treated substrate surface, and then cooling it at room temperature to obtain a high-precision cold welding anti-wear coating.

[0009] The solution treatment step in step S1 is as follows: the temperature is raised from room temperature to 800°C within 80 minutes, then raised from 800°C to 1200°C within 60 minutes, held at that temperature for 40 minutes, and then air-cooled.

[0010] The aging process in step S1 is as follows: the temperature is raised from room temperature to 400°C within 40 minutes, held for 40 minutes, and then air-cooled.

[0011] In step S2, the distance between the welding wire and the workpiece is 0~2mm, and the distance between the welding wire and the tungsten electrode is 0.5~2mm.

[0012] In step S3, the nickel-chromium-molybdenum-niobium-based alloy welding wire is composed of ≥58% Ni, 20~23% Cr, 8.0~10.0% Mo, 3.15~4.15% Nb, and ≤5% Fe, and its diameter is 0.9~1.2 mm.

[0013] In step S3, the high-precision cold welding machine uses a base current of 5~15A, a gas delay of 5~15s, a wire feeding speed of 10~35r / min, a precision current of 100~200A, a welding time of 50~100ms, an arc-stop delay of 1~3s, an interval time of 50~200ms, an overlap of 1~3mm, an argon flow rate of 10~30L / min, a robot speed of 100~200mm / min, and a positioner speed of 0.2~0.5r / min.

[0014] Compared with the prior art, the present invention has the following advantages: 1. This invention uses 0Cr17Ni4Cu4Nb stainless steel as the cold welding substrate and wear-resistant nickel-chromium-molybdenum-niobium based alloy welding wire as the cold welding material. An automatic wire feeding system and a high-precision cold welding machine are used to prepare an wear-resistant coating on the substrate surface. The resulting coating forms a dense metallurgical bond with the substrate, exhibiting high bonding strength and resisting detachment under long-term operating conditions. Furthermore, due to the high content of nickel, chromium, and molybdenum in the prepared coating, the wear rate of the wear-resistant coating material is an order of magnitude lower than that of the 0Cr17Ni4Cu4Nb substrate. This demonstrates that the wear-resistant coating material possesses excellent wear resistance and can significantly improve the tribological properties of the substrate.

[0015] 2. This invention uses robot program control, which avoids the consistency problem of manual operation. By matching the various process parameters, it effectively solves the problem of defects such as pores and cracks in the welded coating, making the surface of the welded layer smooth and thus improving the wear resistance of the coating. Attached Figure Description

[0016] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0017] Figure 1 The right view shows a cross-sectional view of the high-precision cold-welded wear-resistant coating on the cylindrical surface of the combustion chamber (left) shell described in this invention.

[0018] Figure 2 The friction coefficient of the high-precision cold-welded substrate described in this invention changes with time when the substrate and TC4 alloy are rubbed together at different temperatures.

[0019] Figure 3 The friction coefficient of the high-precision cold-welded wear-resistant coating described in this invention changes over time when the substrate and TC4 alloy are rubbed together at different temperatures.

[0020] Figure 4 The average coefficient of friction of the substrate and the high-precision cold-welded wear-resistant coating of this invention when rubbed against TC4 alloy at different temperatures.

[0021] Figure 5The wear rates of the substrate and the high-precision cold-welded wear-resistant coating of this invention when rubbed against TC4 alloy at different temperatures are shown. Detailed Implementation

[0022] A method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell includes the following steps: S1 performs pretreatment on the cold-welding substrate 0Cr17Ni4Cu4Nb stainless steel: First, the cold-welded base material, 0Cr17Ni4Cu4Nb stainless steel, undergoes solution strengthening and aging strengthening. The solution treatment steps are: heating from room temperature to 800℃ over 80 minutes, then heating from 800℃ to 1200℃ over 60 minutes, holding at that temperature for 40 minutes, and then air cooling. The aging treatment steps are: heating from room temperature to 400℃ over 40 minutes, holding at that temperature for 40 minutes, and then air cooling.

[0023] Then, the surface of the welding substrate is machined to remove the excess oxide layer; next, the machined welding substrate is cleaned with anhydrous ethanol and dried with a hair dryer to obtain the treated substrate.

[0024] Preparation for cold welding with S2 cold welding machine: First, use a spirit level to adjust the position of the combustion chamber (e.g.) Figure 1 (As shown in the left figure); then select the cold welding program to use and calibrate the starting point; next, adjust the distance between the welding wire and the workpiece, and the distance between the tungsten electrode and the welding wire; the distance between the welding wire and the workpiece is 0~2mm, and the distance between the welding wire and the tungsten electrode is 0.5~2mm. Finally, check whether the gas cylinder is open, whether the cooling water is turned on, and check whether the parameters of the high-precision cold welding machine, its positioner parameters, and the robot speed are matched.

[0025] S3 uses a high-precision cold welding machine with automatic wire feeding to simultaneously melt the nickel-chromium-molybdenum-niobium-based alloy welding wire on the treated substrate surface. After cooling at room temperature, a high-precision cold-welded wear-resistant coating is obtained (e.g., ...). Figure 1 (As shown in the right figure).

[0026] Among them, the nickel-chromium-molybdenum-niobium-based alloy welding wire is composed of ≥58% Ni, 20~23% Cr, 8.0~10.0% Mo, 3.15~4.15% Nb and ≤5% Fe, and its diameter is 0.9~1.2mm.

[0027] The high-precision cold welding machine uses a base current of 5~15A, a gas delay of 5~15s, a wire feed speed of 10~35r / min, a precision current of 100~200A, a welding time of 50~100ms, an arc stop delay of 1~3s, an interval time of 50~200ms, an overlap of 1~3mm, an argon flow rate of 10~30L / min, a robot speed of 100~200mm / min, and a positioner speed of 0.2~0.5r / min.

[0028] The high-precision cold welding machine can be the HRWS-3250B high-precision cold welding machine produced by Shanghai Langxian Electromechanical Equipment Co., Ltd.

[0029] The positioner can be the TSK400 tiltable positioner manufactured by Shenzhen Yankong Automation Technology Co., Ltd.

[0030] The robot can be a KUKA welding machine or a KR 10 R 1420 robot manufactured by KUKA Robotics Ltd.

[0031] Example 1 A method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell includes the following steps: S1 performs pretreatment on the cold-welding substrate 0Cr17Ni4Cu4Nb stainless steel: First, the cold-welded base material, 0Cr17Ni4Cu4Nb stainless steel, was subjected to solution strengthening and aging strengthening. The solution strengthening steps were as follows: the temperature was increased from room temperature to 800℃ within 80 minutes, then increased from 800℃ to 1200℃ within 60 minutes, held at that temperature for 40 minutes, and then air-cooled. The aging strengthening steps were as follows: the temperature was increased from room temperature to 400℃ within 40 minutes, held at that temperature for 40 minutes, and then air-cooled.

[0032] Next, the surface of the welding substrate is machined to remove excess oxide layer; then the machined welding substrate is cleaned with anhydrous ethanol and dried with a hair dryer to obtain the treated substrate.

[0033] Preparation for cold welding with S2 cold welding machine: First, use a level to calibrate the position of the combustion chamber; then select the cold welding program to be used and calibrate the starting point; next, adjust the distance between the welding wire and the workpiece to 1mm and the distance between the welding wire and the tungsten electrode to 2mm; finally, check whether the gas cylinder is open, whether the cooling water is open, and check whether the parameters of the high-precision cold welding machine, its positioner parameters, and the robot speed are matched.

[0034] S3 uses a high-precision cold welding machine to automatically feed wire, simultaneously melting the nickel-chromium-molybdenum-niobium-based alloy welding wire on the treated substrate surface, and then rapidly cooling it at room temperature to form an alloy coating, thus obtaining a high-precision cold welding anti-wear coating.

[0035] The high-precision cold welding machine uses a base current of 15A, a gas delay of 10s, a wire feeding speed of 35r / min, a precision current of 160A, a welding time of 100ms, an arc-stop delay of 1.5s, an interval time of 100ms, an overlap of 3mm, an argon flow rate of 10L / min, a robot speed of 100mm / min, and a positioner speed of 0.2r / min.

[0036] Figure 2 and Figure 3 The graph shows the variation of the friction coefficients of 0Cr17Ni4Cu4Nb and the anti-wear coating material with TC4 at different temperatures over time. As can be seen from the graph, the friction coefficients of both materials with TC4 remain relatively stable over time. However, the friction coefficients of 0Cr17Ni4Cu4Nb and the anti-wear coating material show some differences with increasing temperature. With increasing temperature, the friction coefficient of 0Cr17Ni4Cu4Nb exhibits a trend of first increasing, then decreasing, then increasing again, and then decreasing again, reaching its maximum value at 200℃. In contrast, the friction coefficient of the anti-wear coating material generally shows a trend of first increasing and then decreasing with increasing temperature, reaching its maximum value at 400℃, while maintaining relatively low values ​​at 800℃ and 1000℃. Figure 4 The variation in average friction coefficient shows that, except at 400℃, the average friction coefficient of the anti-wear coating material is generally lower than that of the 0Cr17Ni4Cu4Nb substrate from room temperature to 1000℃. At 600℃, the average friction coefficients are relatively close. The higher average friction coefficient of the anti-wear coating material at 400℃ may be related to the high-temperature softening of the material and the incomplete formation of the lubricating film.

[0037] Comparison of wear rates of 0Cr17Ni4Cu4Nb substrate and wear-resistant coating material at different test temperatures ( Figure 5 It can be seen that the wear rate of the 0Cr17Ni4Cu4Nb substrate is 10 at room temperature and 10 at 200℃. -4 mm 3 / (N·m) and 10 -5 mm 3 The wear rate is on the order of N·m, and is generally higher than that of other temperature ranges. The wear rate of the wear-resistant coating material reaches its maximum value of 10 at room temperature. -5 mm 3 The wear rate of both materials remained at 10 N·m, on the order of N·m, within the range of 400℃ to 1000℃. -6 mm 3The wear rate is on the order of N·m. Comparing the wear rates of the two materials, it can be seen that, except at 400℃, the wear rate of the anti-wear coating material is lower than that of the 0Cr17Ni4Cu4Nb substrate in all other temperature ranges. Specifically, at room temperature and 200℃, the wear rate of the anti-wear coating material is an order of magnitude lower than that of the 0Cr17Ni4Cu4Nb substrate. This indicates that the anti-wear coating material has excellent wear resistance, and the anti-wear coating material prepared on the surface of the 0Cr17Ni4Cu4Nb substrate can significantly improve the tribological properties of the substrate.

[0038] In summary, the coating prepared by the method of the present invention can achieve good metallurgical bonding with the substrate, with no obvious defects along the coating surface and a low wear rate. Therefore, the method of the present invention can achieve metallurgical bonding between a high-performance surface layer and the substrate material while ensuring the wear resistance of the weld layer.

Claims

1. A method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell, comprising the following steps: S1 performs pretreatment on the cold-welding substrate 0Cr17Ni4Cu4Nb stainless steel: First, the cold-welded base 0Cr17Ni4Cu4Nb stainless steel is subjected to solution strengthening and aging strengthening. Then, the surface of the welded base is subjected to machining treatment, anhydrous ethanol cleaning and drying in sequence to obtain the treated base. Preparation for cold welding with S2 cold welding machine: First, use a level to calibrate the position of the combustion chamber; then select the cold welding program to be used and calibrate the starting point; next, adjust the distance between the welding wire and the workpiece, as well as the distance between the tungsten electrode and the welding wire; finally, check whether the gas cylinder is open, whether the cooling water is open, and check whether the parameters of the high-precision cold welding machine, its positioner parameters, and the robot speed are matched. S3 uses a high-precision cold welding machine to automatically feed wire, simultaneously melting the nickel-chromium-molybdenum-niobium-based alloy welding wire on the treated substrate surface, and then cooling it at room temperature to obtain a high-precision cold welding anti-wear coating.

2. The method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell as described in claim 1, characterized in that: The solution treatment step in step S1 is as follows: the temperature is raised from room temperature to 800°C within 80 minutes, then raised from 800°C to 1200°C within 60 minutes, held at that temperature for 40 minutes, and then air-cooled.

3. The method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell as described in claim 1, characterized in that: The aging process in step S1 is as follows: the temperature is raised from room temperature to 400°C within 40 minutes, held for 40 minutes, and then air-cooled.

4. The method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell as described in claim 1, characterized in that: In step S2, the distance between the welding wire and the workpiece is 0~2mm, and the distance between the welding wire and the tungsten electrode is 0.5~2mm.

5. The method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell as described in claim 1, characterized in that: In step S3, the nickel-chromium-molybdenum-niobium-based alloy welding wire is composed of ≥58% Ni, 20~23% Cr, 8.0~10.0% Mo, 3.15~4.15% Nb, and ≤5% Fe, and its diameter is 0.9~1.2 mm.

6. The method for preparing a high-precision cold-welded wear-resistant coating on the inner cylindrical surface of a combustion chamber shell as described in claim 1, characterized in that: In step S3, the high-precision cold welding machine uses a base current of 5~15A, a gas delay of 5~15s, a wire feeding speed of 10~35r / min, a precision current of 100~200A, a welding time of 50~100ms, an arc-stop delay of 1~3s, an interval time of 50~200ms, an overlap of 1~3mm, an argon flow rate of 10~30L / min, a robot speed of 100~200mm / min, and a positioner speed of 0.2~0.5r / min.

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