Sliding bearing surface coating forming method

Abstract

The invention relates to the technical field of rotary body machining, and provides a sliding bearing surface coating forming method which comprises the steps that a sliding bearing is installed on a clamping device; the diameter of the sliding bearing ranges from 58 mm to 220 mm. Cladding the welding wire on the outer wall surface of the sliding bearing by adopting a cladding device to form a cladding layer; the rollers and the sliding bearings are driven to rotate, and the multiple rollers are matched to roll the cladding layer; the sliding bearing is driven to move in the stepping direction; machining is conducted in a cladding-rolling-moving circulation mode, and every two adjacent cladding layers are in lap joint till the outer wall face of the sliding bearing is provided with the cladding layer in a cladding-rolling mode; and carrying out heat treatment on the sliding bearing after cladding-rolling to form the target sliding bearing. The surface coating of the sliding bearing is prepared in a mode of combining cladding and rolling, residual tensile stress formed in a cladding layer through rapid cooling after cladding can be adjusted into pressure stress, the mechanical property of the sliding bearing is improved, and the service life of the sliding bearing is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of rotating body processing, and in particular to a method for forming a surface coating of a sliding bearing. Background Art

[0002] In the field of renewable energy, wind power, with its unique advantages of cleanliness and renewable energy, has become an important part of the global energy structure transformation. As a core component of wind turbines, the performance of bearings has a crucial impact on the reliability and efficiency of the entire wind power system. Bearings not only need to withstand the harsh working conditions of wind power equipment in complex and changeable natural environments, such as extreme temperatures, strong winds, salt spray corrosion, etc., but also need to meet the stringent use requirements of long life and high reliability to ensure the continuous and stable operation of wind power systems.

[0003] In order to improve the wear resistance, corrosion resistance and load-bearing capacity of bearings, laser / arc cladding technology is widely used in the prior art. This technology forms a copper-based cladding layer on the surface of the bearing, thereby enhancing the surface hardness and wear resistance of the bearing, thereby increasing its service life. However, the rapid heating and cooling characteristics of the laser / arc cladding process make it easy for residual tensile stress to be generated inside the bearing cladding layer. Residual tensile stress will not only reduce the strength of the steel-copper bonding interface, causing the cladding layer to easily fall off, but also affect the corrosion resistance and fatigue performance of the cladding layer, thereby reducing the load-bearing capacity and overall service life of the parts.

[0004] The presence of residual tensile stress will make the cladding layer more prone to cracks and peeling when subjected to external forces, thereby accelerating the wear and failure of the bearing. At the same time, residual tensile stress will also reduce the corrosion resistance of the cladding layer, making it more susceptible to corrosion and erosion in harsh environments. In addition, residual tensile stress will also affect the fatigue performance of the cladding layer, making the bearing more prone to failure modes such as fatigue fracture during long-term use. Summary of the invention

[0005] The invention provides a sliding bearing surface coating forming method, which is used to solve the problem that the sliding bearing prepared by the sliding bearing surface coating forming method in the prior art has poor mechanical properties and affects the service life of the sliding bearing.

[0006] The present invention provides a method for forming a surface coating of a sliding bearing. The equipment for preparing the surface coating of a sliding bearing is used to prepare a coating of the sliding bearing, and comprises: a clamping device, a cladding device and a rolling device. The clamping device is used to clamp the sliding bearing, and the sliding bearing can rotate around its own axis and can move in a stepping direction; the cladding device is used to clad the welding wire to the outer wall surface of the sliding bearing; the rolling device comprises a plurality of rollers, and the plurality of rollers are separately arranged on the outer periphery of the sliding bearing; the method for forming the surface coating of the sliding bearing comprises: installing the sliding bearing on the clamping device; holding device; the diameter of the sliding bearing is 58-220mm; a cladding device is used to clad the welding wire on the outer wall surface of the sliding bearing to form a cladding layer; the roller and the sliding bearing are driven to rotate, and a plurality of the rollers cooperate to roll the cladding layer; the sliding bearing is driven to move along the stepping direction; the cladding-rolling-moving cycle is used for processing, and two adjacent cladding layers are overlapped until the outer wall surface of the sliding bearing is clad-rolled with a cladding layer; the sliding bearing after cladding-rolling is heat treated to form a target sliding bearing.

[0007] According to a method for forming a surface coating of a sliding bearing provided by the present invention, a cladding device is used to clad a welding wire on the outer wall surface of the sliding bearing to form a cladding layer; the method comprises: placing the end of the welding wire on the outer wall surface of the sliding bearing, or placing the end of the welding wire at a position 0-1mm away from the outer wall surface of the sliding bearing; and using an arc cladding device to clad the welding wire on the outer wall surface of the sliding bearing.

[0008] According to a sliding bearing surface coating forming method provided by the present invention, an arc cladding device is used to clad the welding wire on the outer wall surface of the sliding bearing, including: controlling the distance between the cladding end of the arc cladding device and the outer wall surface of the sliding bearing to be 4-6mm for cladding; controlling the arc cladding device to perform cladding at a welding current of 100-140A; controlling the arc cladding device to perform cladding at a welding rate of 200-360mm / min; controlling the rate of feeding the welding wire to be 125-175mm / min; and controlling the overlap rate of the cladding layer to be 18-20%.

[0009] According to a method for forming a surface coating of a sliding bearing provided by the present invention, the roller and the sliding bearing are driven to rotate, and a plurality of the rollers cooperate to roll the cladding layer; the method comprises: controlling the arc distance between the axis of the roller and the cladding end of the cladding device to be 10-30 mm; and controlling the rolling device to roll with a rolling force of 10-30 KN.

[0010] According to a sliding bearing surface coating forming method provided by the present invention, the sliding bearing after cladding-rolling is heat treated to form a target sliding bearing; the method comprises: using an electromagnetic induction heater to heat treat the sliding bearing after cladding-rolling, and the frequency of the electromagnetic induction heater is 1KHz-20KHz.

[0011] According to a method for forming a surface coating of a sliding bearing provided by the present invention, an electromagnetic induction heater is used to heat treat the sliding bearing after cladding and rolling, and the frequency of the electromagnetic induction heater is 1KHz-20KHz; comprising: controlling the temperature of the electromagnetic induction heater to 550-650°C and controlling the insulation time to 60-120min.

[0012] According to a sliding bearing surface coating forming method provided by the present invention, the sliding bearing surface coating preparation equipment also includes a drying device; a cladding device is used to clad the welding wire on the outer wall surface of the sliding bearing to form a cladding layer; and the method also includes: using a drying device to dry the welding wire.

[0013] According to a method for forming a surface coating of a sliding bearing provided by the present invention, a drying device is used to dry the welding wire, which includes: controlling the drying temperature of the drying device to 150-200° C. and the drying time to 60-120 minutes.

[0014] According to a method for forming a surface coating of a sliding bearing provided by the present invention, the surface coating preparation equipment of the sliding bearing also includes a cleaning device; a cladding device is used to clad the welding wire on the outer wall surface of the sliding bearing to form a cladding layer; and before that, it also includes: cleaning the sliding bearing.

[0015] According to a method for forming a surface coating of a sliding bearing provided by the present invention, the welding wire is a tin bronze wire; and the diameter of the welding wire is 0.8-1.2 mm.

[0016] The sliding bearing surface coating forming method provided by the present invention adopts a combination of cladding and rolling to prepare the sliding bearing surface coating, and the residual tensile stress formed in the cladding layer by rapid cooling after cladding can be adjusted to compressive stress, thereby improving the fatigue performance and corrosion resistance of the sliding bearing; after rolling, the cladding-rolled sliding bearing is heat treated to balance the strength of the junction between the cladding layer and the sliding bearing, thereby improving the service life of the sliding bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic flow chart of the method for forming a surface coating of a sliding bearing provided by the present invention; Figure 2 It is a structural schematic diagram of a device for preparing a sliding bearing coating provided by the present invention; Figure 3 is a metallographic structure diagram of the first embodiment provided by the present invention; Figure 4 is a hardness variation trend diagram of Example 1 provided by the present invention; Figure 5 is a metallographic structure diagram of the fourth embodiment provided by the present invention; Figure 6 is a hardness variation trend diagram of the fourth embodiment provided by the present invention; Figure 7 is a metallographic structure diagram of the fifth embodiment provided by the present invention; Reference numerals: 1. Sliding bearing; 11. Cladding layer; 2. Cladding device; 3. Welding wire; 4. Roller. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0024] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0025] Combine the following Figure 1-Figure 7 The method for forming a surface coating of a sliding bearing according to the present invention is described.

[0026] The equipment for preparing the surface coating of sliding bearings is used for preparing the coating of sliding bearings. The sliding bearings include bearings. Figure 2The equipment for preparing the surface coating of the sliding bearing includes a clamping device, a cladding device 2 and a rolling device. The clamping device is used to clamp the sliding bearing 1, and the sliding bearing 1 can rotate around its own axis. The clamping device is also connected to a driving member, and the driving member drives the sliding bearing 1 to move in a stepping direction, and the stepping direction is consistent with the axis of the sliding bearing 1. The cladding device 2 is used to clad the welding wire 3 to the outer wall surface of the sliding bearing 1, and the outer wall surface of the sliding bearing 1 forms a cladding layer 11. During the cladding process, the sliding bearing is driven to rotate, and a cladding layer can be clad along the circumference of the sliding bearing.

[0027] The cladding device 2 includes a laser cladding device and an arc cladding device. Rapid cooling of laser cladding and arc cladding can easily form residual tensile stress in the cladding layer, which seriously affects the strength of the steel-copper interface, the corrosion resistance and fatigue performance of the cladding layer, and reduces the bearing capacity and service life of the sliding bearing. Based on this, the embodiment of the present invention proposes to use a rolling device for rolling to adjust the residual tensile stress to compressive stress. Specifically, the rolling device includes a plurality of rollers 4, and the plurality of rollers 4 are arranged on the periphery of the sliding bearing. During the processing, the sliding bearing 1 rotates, and the cladding device 2 is used to clad the welding wire 3 on the periphery of the sliding bearing 1; at the same time, the plurality of rollers 4 are driven to rotate at the same time, and the plurality of rollers 4 are matched with each other to roll the formed cladding layer 11. After the rolling is completed, the sliding bearing 1 is driven to move along the stepping direction to clad the next cladding layer 11, and the two adjacent cladding layers 11 are overlapped.

[0028] The surface coating preparation device for the sliding bearing also includes a cleaning device, which is used to clean the oil stains, rust spots, etc. on the outer wall of the sliding bearing 1 before the cladding device is used for cladding. The cleaning device includes a laser surface cleaning machine.

[0029] The equipment for preparing the surface coating of the sliding bearing also includes a drying device, which is used to dry the welding wire, thereby facilitating the welding wire 3 to be clad on the outer wall surface of the sliding bearing 1 .

[0030] refer to Figure 1 The surface coating forming method of a sliding bearing provided by an embodiment of the present invention comprises: step 100, installing the sliding bearing on a clamping device, wherein the sliding bearing can rotate around its own axis and can move in a stepping direction to adjust the position of the sliding bearing. The diameter of the sliding bearing is 58-220 mm, and optionally, the diameter of the sliding bearing can be 58 mm, 80 mm, 92 mm, 100 mm, 110 mm, 125 mm, 140 mm, 155 mm, 170 mm, 188 mm, 200 mm, 213 mm, 220 mm, etc.

[0031] After clamping is completed, a cleaning device is used to clean the outer wall surface of the sliding bearing to remove oil stains, rust spots, etc. on the surface of the sliding bearing to ensure the cleanliness of the outer wall surface of the sliding bearing. The cleaning equipment includes a laser surface cleaning machine.

[0032] The welding wire is dried by a drying device, and the outer wall of the welding wire is dried. The temperature of the drying device is controlled to be 150-200°C, and 150°C, 160°C, 175°C, 182°C, 190°C, 198°C, 200°C, etc. are optional; the drying time is controlled to be 60-120min, and 60min, 75min, 82min, 90min, 105min, 113min, 120min, etc. are optional.

[0033] It should be noted that when the cleaning device is used to pre-treat the sliding bearing, the sliding bearing can be stably fixed on the clamping device, and the sliding bearing can also be driven to rotate to improve efficiency.

[0034] Step 200, using a cladding device to clad the welding wire on the outer wall of the sliding bearing to form a cladding layer. The welding wire is made of tin bronze wire as raw material, including: CuSn12Ni2, Cu9Ni6Sn, CuSn10, etc. and alloy components improved and optimized on this basis. The diameter of the welding wire is 0.8-1.2mm, and optionally, the diameter of the welding wire is 0.8mm, 0.9mm, 0.95mm, 1.0mm, 1.1mm, 1.2mm, etc. The end of the welding wire is placed on the outer wall of the sliding bearing, or the end of the welding wire is placed at a distance of 0-1mm from the outer wall of the sliding bearing, and optionally, 0.2mm, 0.5mm, 0.8mm, 1mm, etc.

[0035] The cladding device includes a laser cladding device and an arc cladding device. The following are the process parameters of the arc cladding device when the arc cladding device is used for cladding, wherein the cladding end of the arc cladding device can be clad with a tungsten needle, the tungsten needle includes a body and a tungsten needle tip, the angle of the tungsten needle tip is 30-45°, and the cone angle formed by the tungsten needle tip and the body is optional, 30°, 40°, 45°, etc. The distance between the cladding end of the arc cladding device and the outer wall surface of the sliding bearing is controlled to be 4-6mm, optionally 4mm, 4.2mm, 5mm, 5.5mm, 5.8mm, 6mm, etc. The distance between the cladding end of the arc cladding device and the outer wall surface of the sliding bearing can be adjusted according to the diameter of the welding wire. The arc cladding device is controlled to perform cladding at a welding current of 100-140A, and optionally, the welding current is 100A, 103A, 110A, 112A, 120A, 125A, 130A, 138A, 140A, etc. The arc cladding device is controlled to perform cladding at a welding rate of 200-360mm / min, and optionally, 200mm / min, 220mm / min, 280mm / min, 300mm / min, 340mm / min, 360mm / min, etc. The wire feeding rate is matched with the welding rate, and the wire feeding rate is controlled to be 125-175 mm / min. Optionally, the wire feeding rate is 125 mm / min, 130 mm / min, 132 mm / min, 140 mm / min, 148 mm / min, 150 mm / min, 156 mm / min, 160 mm / min, 167 mm / min, 170 mm / min, 175 mm / min, etc. Cladding is performed with the above process parameters to form a cladding layer on the outer wall surface of the sliding bearing.

[0036] Step 300, driving the rollers and the sliding bearing to rotate, and multiple rollers cooperate to roll the formed cladding layer, adjusting the residual tensile stress formed by the rapid heating and cooling of the cladding to compressive stress, effectively improving the fatigue strength and stress corrosion resistance of the bimetallic sliding bearing, and significantly extending the service life of the parts. It should be noted that the cladding and rolling are carried out simultaneously, and the rolling can be carried out within the hot rolling temperature range of the welding wire to reduce the porosity defects in the cladding layer.

[0037] The arc distance between the axis of the roller and the cladding end of the cladding device can be adjusted according to the rotation speed of the sliding bearing and the temperature of the cladding layer, so that the cladding layer can be rolled within a certain temperature range. The distance between the axis of the roller and the cladding end of the cladding device is controlled to be 10-30mm, optionally 10mm, 12mm, 16mm, 20mm, 25mm, 28mm, 30mm, etc. The rolling device is controlled to roll with a rolling force of 10-30KN, optionally, the rolling force is 10KN, 13KN, 16KN, 20KN, 23KN, 28KN, 30KN, etc. It should be noted that rolling can be carried out simultaneously with cladding, or rolling can be carried out at a preset time interval after the cladding is completed.

[0038] Step 400, driving the sliding bearing to move along the stepping direction. That is, after the rolling of the first cladding layer is completed, the sliding bearing is moved to the position of the next cladding layer to prepare the next cladding layer.

[0039] Step 500, processing is performed in a cladding-rolling-moving cycle, with two adjacent cladding layers overlapping until the outer wall surface of the sliding bearing is clad-rolled with a cladding layer. The lap rate of the cladding layer is controlled to be 18-20%, and optionally, the lap rate is 18%, 18.5%, 19%, 19.3%, 20%, etc. It should be noted that the distance the sliding bearing moves along the stepping direction is calculated based on the size of the sliding bearing, the parameters of the welding wire and the lap rate. The embodiment of the present invention adopts a single-pass cladding-in-situ rolling-multiple-pass overlap method to form a tin bronze cladding layer with a thickness of about 1-1.5 mm, and optionally, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, etc.

[0040] Step 600, heat-treating the sliding bearing after cladding-rolling to form a target sliding bearing. In the prior art, cyclic heat input is used in the process of laser cladding or arc additive forming to form a heat-affected zone at a certain depth on the surface of the steel shaft. The structure of this area undergoes a solid phase transformation to form quenched martensite, and the grains are significantly refined, resulting in a sharp increase in the hardness at the copper / steel interface. The mismatch in hardness at the interface may lead to stress concentration and accelerate material fatigue fracture. The embodiment of the present invention can effectively balance the hardness change trend at the interface between the copper cladding zone and the steel heat-affected zone by heat-treating the sliding bearing after cladding-rolling, so that the interface bonding strength reaches more than 500MPa.

[0041] Specifically, an electromagnetic induction heater is used to heat treat the sliding bearing after cladding and rolling, and the frequency of the electromagnetic induction heater is 1KHz-20KHz, and optionally, 1KHz, 8KHz, 10KHz, 15KHz, 18KHz, 20KHz, etc. The temperature of the electromagnetic induction heater is controlled to be 550-650℃, and optionally, 550℃, 560℃, 575℃, 580℃, 595℃, 600℃, etc.; the insulation time is 60-120min, and optionally, 60min, 63min, 70min, 75min, 80min, 82min, 90min, 98min, 105min, 113min, 120min, etc.

[0042] The sliding bearing in the embodiment of the present invention can be a steel shaft, a 42CrMo shaft with a diameter of 128 mm, and a laser cleaning machine is used to quickly clean the oil and rust spots on the surface of the shaft before cladding.

[0043] In Example 1, the welding wire is a CuSn12Ni2 wire with a diameter of 1.2 mm, and its alloy composition is as follows: Sn11.0-13.0%, Ni1.5-2.5%, Si0.01%, P0.05-0.4%, Zn<0.4%, Pb<0.3%, Mn<0.2% by mass percentage. Before arc cladding, it is dried in a drying oven at a drying temperature of 150°C and a drying time of 120 minutes.

[0044] The process parameters of arc cladding are as follows: the tungsten needle is sharpened to a 45° angle with a tungsten needle sharpener before arc cladding; the distance between the tungsten needle electrode and the 42CrMo shaft surface is 5 mm; the welding current is 140A; the welding rate is 240mm / min; the wire feeding rate is 175mm / min; the overlap rate is 18.5%. The process parameters of in-situ rolling are as follows: the distance between the roller and the outer wall of the shaft is 10mm; the rolling force is 25KN.

[0045] Arc cladding-rolling composite forming a layer of CuSn12Ni2 tin bronze cladding layer with a thickness of about 1.2mm. After forming, a medium frequency (1KHz-20KHz) electromagnetic induction heater is used to anneal the cladding layer and the substrate. The heat treatment temperature is 650℃ and the holding time is 120min.

[0046] Figure 3 This is a schematic diagram of the metallographic structure of a 42CrMo-CuSn12Ni2 bimetallic sliding bearing formed by arc cladding-rolling composite forming. There are no pore defects in the cladding layer. Figure 4 This is the hardness change trend diagram of the arc cladding-rolling composite formed 42CrMo-CuSn12Ni2 bimetallic sliding bearing. The interface bonding strength between CuSn12Ni2 and 42CrMo reaches 596MPa.

[0047] In Example 2, the welding wire is a 1.2 mm Cu9Ni6Sn wire, and its alloy composition is as follows: Sn5.5-6.5%, Ni8.5-9.5%, Zn<0.5%, Pb<0.02%, Mn0.05-0.3%, Zn<0.5%, Mg<0.15%. Before arc cladding, it is dried in a drying oven at a drying temperature of 180°C and a drying time of 120 minutes.

[0048] The process parameters of arc cladding are as follows: the tungsten needle is sharpened to a 45° angle using a tungsten needle sharpener before arc cladding; the distance between the tungsten needle electrode and the 42CrMo shaft surface is 4mm; the welding current is 120A; the welding rate is 220mm / min; the wire feeding rate is 150mm / min; the overlap rate is 20%. The process parameters of in-situ rolling are as follows: the distance between the roller and the outer wall of the shaft is 12mm; the rolling force is 20KN.

[0049] Arc cladding-rolling composite forming a layer of Cu9Ni6Sn tin bronze cladding layer with a thickness of about 1.0mm. After forming, the cladding layer and the substrate are annealed by a medium frequency (1KHz-20KHz) electromagnetic induction heater at a heat treatment temperature of 600℃ and a holding time of 120min.

[0050] The interface bonding strength of 42CrMo-Cu9Ni6Sn bimetallic sliding bearing formed by arc cladding-rolling composite forming is 530MPa.

[0051] In the third embodiment, the welding wire is a CuSn10 wire with a diameter of 1.2 mm, and its alloy composition is as follows: Sn9.0-12.0%, Pb<0.1%, P<0.3% by mass percentage. Before arc cladding, it is dried in a drying oven at a drying temperature of 200° C. and a drying time of 120 min.

[0052] The process parameters of arc cladding are as follows: the tungsten needle is sharpened to a 45° angle with a tungsten needle sharpener before arc cladding; the distance between the tungsten needle electrode and the 42CrMo shaft surface is 6 mm; the welding current is 100A; the welding rate is 360mm / min; the wire feeding rate is 175mm / min; the overlap rate is 18%. The process parameters of in-situ rolling are as follows: the distance between the roller and the outer wall of the shaft is 15mm; the rolling force is 20KN.

[0053] Arc cladding-rolling composite forming a CuSn10 tin bronze cladding layer with a thickness of about 1.5mm. After forming, a medium frequency (1KHz-20KHz) electromagnetic induction heater is used to anneal the cladding layer and the substrate at a heat treatment temperature of 550℃ and a holding time of 120min.

[0054] The interface bonding strength of 42CrMo-CuSn10 bimetallic sliding bearing formed by arc cladding-rolling composite forming is 510MPa.

[0055] In the fourth embodiment, the welding wire is a CuSn10 wire with a diameter of 1.2 mm, and its alloy composition is as follows: Sn9.0-12.0%, Pb<0.1%, P<0.3% by mass percentage. Before arc cladding, it is dried in a drying oven, the drying temperature is 180°C, and the drying time is 120 minutes.

[0056] Before arc cladding, the tungsten needle was ground into a 45° angle using a tungsten needle sharpener; the distance between the tungsten needle electrode and the 42CrMo shaft surface was 5 mm; the welding current was 140 A; the welding rate was 240 mm / min; the wire feeding rate was 125 mm / min; and the overlap rate was 18%.

[0057] Embodiment 4 Compared with Embodiments 1 to 3, only arc cladding is used without rolling. Porosity defects will be formed in the cladding layer, affecting the mechanical properties and service life of the parts. Figure 5 and Figure 6 shown.

[0058] In Example 5, the welding wire is a CuSn12Ni2 wire with a diameter of 1.2 mm, and its alloy composition is as follows: Sn11.0-13.0%, Ni1.5-2.5%, Si0.01%, P0.05-0.4%, Zn<0.4%, Pb<0.3%, Mn<0.2% by mass percentage. A drying oven is used to dry the wire before arc addition, and the drying temperature is 200°C and the drying time is 120 minutes.

[0059] The process parameters of arc cladding are as follows: the tungsten needle is sharpened to a 30° angle with a tungsten needle sharpener before arc cladding; the distance between the tungsten needle electrode and the 42CrMo shaft surface is 2 mm; the welding current is 200A; the welding rate is 360mm / min; the wire feeding rate is 175mm / min; the overlap rate is 10%. The process parameters of in-situ rolling are as follows: the distance between the roller and the outer wall of the shaft is 15mm; the rolling force is 25KN.

[0060] Arc cladding-rolling composite forming a layer of CuSn12Ni2 tin bronze cladding layer with a thickness of about 1.8mm. After forming, the cladding layer and the substrate are annealed by a medium frequency (1KHz-20KHz) electromagnetic induction heater. The heat treatment process parameters are 650℃ and the temperature is kept for 120min.

[0061] Embodiment 5, compared with Embodiments 1 to 3 in the present application, has different arc cladding process parameters, and infiltration cracks appear at the interface between the cladding layer and the outer wall of the sliding bearing, such as Figure 7 shown.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for forming a sliding bearing surface coating, and a sliding bearing surface coating preparation device for preparing a sliding bearing coating, comprising: A clamping device, a cladding device and a rolling device, wherein the clamping device is used to clamp a sliding bearing, and the sliding bearing can rotate around its own axis and can move along the stepping direction; the cladding device is used to clad the welding wire to the outer wall surface of the sliding bearing; the rolling device includes a plurality of rollers, and the plurality of rollers are separately arranged on the outer periphery of the sliding bearing; Characterized in that the sliding bearing surface coating forming method comprises: Install the sliding bearing on the clamping device; the diameter of the sliding bearing is 58-220mm; Using a cladding device to clad the welding wire on the outer wall surface of the sliding bearing to form a cladding layer; Driving the roller and the sliding bearing to rotate, and the plurality of rollers cooperate to roll the cladding layer; driving the sliding bearing to move along the stepping direction; The processing is performed by a cladding-rolling-moving cycle, and two adjacent cladding layers are overlapped until the outer wall surface of the sliding bearing is clad-rolled with a cladding layer; The sliding bearing after cladding and rolling is heat treated to form a target sliding bearing.

2. The method for forming a surface coating of a sliding bearing according to claim 1, characterized in that: The welding wire is clad on the outer wall surface of the sliding bearing by using a cladding device to form a cladding layer; comprising: Placing the end of the welding wire on the outer wall surface of the sliding bearing, or placing the end of the welding wire at a position 0-1 mm away from the outer wall surface of the sliding bearing; The welding wire is clad on the outer wall surface of the sliding bearing by using an arc cladding device.

3. The method for forming a surface coating of a sliding bearing according to claim 2, characterized in that: The arc cladding device is used to clad the welding wire on the outer wall surface of the sliding bearing, comprising: Controlling the distance between the cladding end of the arc cladding device and the outer wall surface of the sliding bearing to be 4-6 mm for cladding; Controlling the arc cladding device to perform cladding with a welding current of 100-140A; Controlling the arc cladding device to perform cladding at a welding rate of 200-360 mm / min; Control the wire feeding rate to 125-175mm / min; The overlap rate of the cladding layer is controlled to be 18-20%.

4. The method for forming a surface coating of a sliding bearing according to claim 1, characterized in that: The roller and the sliding bearing are driven to rotate, and a plurality of the rollers cooperate to roll the cladding layer; comprising: Controlling the arc distance between the axis of the roller and the cladding end of the cladding device to be 10-30 mm; The rolling device is controlled to perform rolling at a rolling force of 10-30KN.

5. The method for forming a surface coating of a sliding bearing according to claim 1, characterized in that: Heat treatment is performed on the sliding bearing after cladding-rolling to form a target sliding bearing; including: The electromagnetic induction heater is used to heat treat the sliding bearing after cladding and rolling, and the frequency of the electromagnetic induction heater is 1KHz-20KHz.

6. The method for forming a surface coating of a sliding bearing according to claim 5, characterized in that: The electromagnetic induction heater is used to heat treat the sliding bearing after cladding and rolling, and the frequency of the electromagnetic induction heater is 1KHz-20KHz; including: The temperature of the electromagnetic induction heater is controlled to be 550-650° C., and the insulation time is controlled to be 60-120 min.

7. The method for forming a surface coating of a sliding bearing according to claim 1, characterized in that: The sliding bearing surface coating preparation equipment also includes a drying device; a cladding device is used to clad the welding wire on the outer wall surface of the sliding bearing to form a cladding layer; and the following also includes: The welding wire is dried by using a drying device.

8. The method for forming a surface coating of a sliding bearing according to claim 7, characterized in that: The welding wire is dried using a drying device, comprising: The drying device is controlled to have a drying temperature of 150-200° C. and a drying time of 60-120 min.

9. The method for forming a surface coating of a sliding bearing according to claim 1, characterized in that: The sliding bearing surface coating preparation equipment also includes a cleaning device; A welding wire is clad on the outer wall surface of the sliding bearing by using a cladding device to form a cladding layer; before that, the method further includes: cleaning the sliding bearing.

10. The method for forming a surface coating of a sliding bearing according to claim 1, characterized in that: The welding wire is tin bronze wire; the diameter of the welding wire is 0.8-1.2 mm.

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