Mark milling method for reserved area of adapter

Abstract

The invention relates to the technical field of machining and metal structural part identification, in particular to an adapter reserved area identification milling method which comprises the steps that an adapter is cleaned and polished, three-dimensional size data of a reserved area on the adapter are obtained, and the reserved area is marked to form positioning information; according to the three-dimensional size data and the positioning information, the adapter is clamped on a numerical control milling machine to be milled to form character grooves; cleaning and degreasing the font groove; filling materials are added in a welding mode to form concave-convex characters, stress relief annealing is conducted on the adapter, and surface finishing is conducted; and carrying out bonding strength detection on the adapter until a detection result reaches a preset threshold value (otherwise, returning to the previous step), and completing identification processing of the adapter. According to the method, through full-process control of'precise positioning and milling, standardized welding combination, destressing treatment and strength detection ', the reliability and long-term stability of the adapter identification are remarkably improved while the machining precision is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of machining and metal structural component marking technology, and in particular to a method for milling markings in the reserved area of ​​a load-bearing saddle. Background Technology

[0002] A load-bearing saddle is a load-bearing and fixing component widely used in large equipment, primarily for locomotive and rolling stock support, pipeline support, and precision mechanical devices. Its surface typically requires markings to identify its location, model, parameters, and other information during subsequent assembly, maintenance, and operation. Common marking methods include mechanical engraving, chemical etching, spraying, and labeling.

[0003] In existing technologies, the most common process is to use CNC engraving machines or manual engraving to create markings on the surface of the load-bearing saddle. This method is relatively simple, but because it involves direct cutting of the material, stress concentration can easily occur in the processing area, resulting in micro-cracks and burrs on the groove walls, which in turn affects the overall strength and service life of the load-bearing saddle. At the same time, it is difficult to maintain consistent processing accuracy with ordinary engraving processes, especially on curved or complex surfaces like load-bearing saddles, where deviations in processing depth and groove width can lead to insufficient marking clarity.

[0004] Furthermore, while traditional spraying or pasting labeling methods are simple, they have poor durability and are susceptible to peeling off due to high temperatures, humidity, wear, or corrosion during long-term operation, making it difficult to meet the requirements for long-term reliable labeling. Chemical etching processes require the use of acidic or alkaline etching solutions, which not only pose environmental pollution problems during operation but also make it difficult to control the etching depth, resulting in poor consistency and stability of the labels.

[0005] In recent years, some studies have attempted to use welding or laser cladding techniques to create raised or recessed lettering on the surface of load-bearing saddles, but the related process paths lack systematic design. For example, there are no complete process flows for workpiece pretreatment, groove shape control, cleaning and surface roughening, welding parameter control, and post-weld treatment, resulting in insufficient consistency and reliability of the markings.

[0006] In summary, the existing methods for processing bearing saddle markings have the following problems:

[0007] Mechanical engraving processes are prone to micro-cracks and stress concentration, resulting in insufficient processing accuracy and durability.

[0008] Spraying and labeling methods result in poor adhesion, making the labels easy to fall off.

[0009] Chemical etching processes have problems such as environmental pollution and difficulty in controlling the depth of corrosion.

[0010] The lack of standardized supporting processes for welding or cladding methods makes it difficult to guarantee the forming quality and bonding strength of the markings.

[0011] Therefore, a new marking processing method for the reserved area of ​​the bearing saddle is still needed, which can achieve systematic control in the process steps and improve the reliability and long-term stability of the marking while ensuring processing accuracy. Summary of the Invention

[0012] To overcome the above-mentioned technical defects, the present invention aims to provide a milling method for marking the reserved area of ​​the bearing saddle. Through the whole process control of "precise positioning and milling, standardized welding combination, stress relief treatment and strength testing", the reliability and long-term stability of the bearing saddle marking are significantly improved while ensuring the machining accuracy.

[0013] This invention discloses a method for milling markings in a reserved area of ​​a bearing saddle, comprising the following steps:

[0014] Step S100: Surface pretreatment and positioning of the bearing saddle. The bearing saddle is cleaned and polished. The three-dimensional dimension data of the reserved area on the bearing saddle is obtained using high-precision measuring equipment. The reserved area is marked according to the design requirements to form positioning information for subsequent processing.

[0015] Step S200: Milling the groove. Based on the three-dimensional dimension data and positioning information obtained in step S100, the bearing saddle is clamped on a CNC milling machine, and a milling tool with a diameter of 0.8 times or less than the minimum width of the reserved area is selected to mill the reserved area to form a font groove with a machining accuracy of ±0.05mm.

[0016] Step S300: Cleaning and sandblasting of the font groove. The font groove formed in step S200 is cleaned and degreased, and then sandblasted to make the surface roughness of the font groove Ra3.2~Ra6.3μm.

[0017] Step S400: Adding raised and recessed fonts. In the font groove processed in step S300, filler material is added by welding to form raised and recessed fonts. The welding parameters are controlled by formula according to the size of the font groove and the diameter of the filler material.

[0018] Step S500: Stress-relief annealing and finishing. The bearing saddle after adding the raised lettering in step S400 is subjected to stress-relief annealing and surface finishing.

[0019] Step S600: Combined with strength testing, the bearing saddle processed in step S500 is subjected to a bonding strength test. If the test result does not reach the preset threshold, step S400 is executed, the welding parameters are adjusted and the process is repeated until the test result reaches the preset threshold, and the marking of the bearing saddle is completed.

[0020] Preferably, when cleaning the surface of the bearing saddle in step S100, a weakly alkaline water-based cleaning agent is used for cleaning, the cleaning temperature is 40~50℃, and the cleaning time is 10~15min; when polishing, sandpaper with a grit size of 200~400 is used, and the polishing direction is consistent with the long axis direction of the reserved area.

[0021] Preferably, the milling tool in step S200 is a carbide-coated tool with a cutting edge radius of less than 0.02 mm; water-based cutting fluid is used as the cooling and lubrication medium during the milling process, with a concentration of 5% to 8% and a flow rate of 20 to 30 L / min.

[0022] Preferably, anhydrous ethanol or acetone is used for cleaning the font groove in step S300; the degreasing time is 1~3 minutes, so that the surface of the font groove is clean before the sandblasting process is performed.

[0023] Preferably, the sand used in the sandblasting process in step S300 is brown fused alumina sand with a particle size of 40-60 mesh; the sandblasting pressure is 0.4-0.6 MPa and the sandblasting time is 3-5 min.

[0024] Preferably, in step S400, the welding is performed by overlay welding to add raised and recessed lettering, and the parameters of the overlay welding include:

[0025] The relationship between the welding current I and the diameter d of the filler material is: I = (10~15) × d, where I is in amperes (A) and d is in millimeters (mm); the welding voltage is 20~30V and the welding speed is 10~20mm / min.

[0026] Preferably, in step S400, laser welding is used to add raised and recessed lettering, and the parameters of the laser welding include:

[0027] The relationship between laser power P and the depth h of the font groove is P = (500~1000) × h; where P is in watts (W) and h is in millimeters (mm).

[0028] The width of the laser pulse is 0.5~2ms, and the frequency of the laser pulse is 10~50Hz;

[0029] The welding speed is 5~15mm / s;

[0030] Argon gas is used as the shielding gas in the welding area, with a flow rate of 10~15L / min.

[0031] Preferably, in step S400, laser cladding is used to add raised and recessed lettering, and the cladding material is an alloy powder that matches the substrate of the bearing saddle, with a particle size of 150-300 mesh.

[0032] The relationship between the laser power P and the cladding layer thickness δ in laser cladding is P = (1000~2000) × δ, where the unit of P is watts (W) and the unit of δ is millimeters (mm); the scanning speed is 5~15mm / s and the powder feeding rate is 5~10g / min.

[0033] Preferably, the stress-relief annealing process conditions in step S500 include:

[0034] The heating temperature is 550~650℃, the holding time is 2~3h, the heating rate is 50~100℃ / h, and the cooling rate is 30~50℃ / h.

[0035] Preferably, before step S200, the accuracy of the CNC milling machine is further verified, wherein the positioning accuracy of the CNC milling machine is ±0.02mm and the repeatability is ±0.01mm.

[0036] Compared with existing technologies, the above technical solution has the following advantages:

[0037] 1. This invention significantly improves the reliability and long-term stability of the bearing saddle markings while ensuring machining accuracy through full-process control of "precise positioning and milling, standardized welding, stress relief treatment and strength testing";

[0038] 2. In existing technology (ordinary engraving process), the size error of the font groove is usually within ±0.15 to 0.20 mm, resulting in unclear markings or even deformation; the present invention adopts high-precision measurement and positioning and CNC milling process to control it within ±0.05 mm, and the optimal error can reach ±0.02 mm, thereby ensuring the clarity and consistency of the marking edges;

[0039] 3. In the existing technology, the ordinary engraving process is only mechanical cutting, and the relationship between the font and the supporting saddle is a physical groove, with a bonding strength generally lower than 60MPa; the present invention forms a metallurgical bond by welding or cladding in the font groove, and the bonding strength can reach 100-135MPa (an increase of about 2-3 times), which greatly reduces the risk of font peeling or falling off;

[0040] 4. In existing engraving processes without sandblasting, the surface roughness of the groove bottom is approximately Ra12.5μm, resulting in insufficient adhesion. This invention controls the groove bottom roughness to Ra3.2~6.3μm through sandblasting, which is more conducive to the metallurgical bonding of the filling material and improves the reliability of the interface.

[0041] 5. Comparative tests show that the lifespan of ordinary engraved markings under ±150MPa alternating load is approximately... Cracks or peeling will appear immediately; this invention indicates a lifespan of up to [percentage missing] under the same load. The improvement is approximately 4 to 6 times, and the long-term stability is significantly enhanced.

[0042] 6. Traditional engraving processes in the current technology are highly dependent on the processing personnel, and there are differences in operation, resulting in poor consistency; the present invention controls the welding and cladding parameters in a formulaic way, so that the process parameters match the font groove size, ensuring the consistency and traceability between different batches of parts.

[0043] 7. In the prior art, existing engraved markings are prone to blurring or failure in high temperature, vibration, and corrosive environments; the present invention, through stress-relief annealing and finishing treatment, ensures that the markings are firmly bonded to the substrate, significantly improves high temperature resistance and environmental interference resistance, and meets the requirements for long-term service. Attached Figure Description

[0044] Figure 1 This is a schematic diagram illustrating the steps of a milling process for marking the reserved area of ​​a bearing saddle according to the present invention. Detailed Implementation

[0045] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0046] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0047] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0048] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0049] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0051] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0052] See Figure 1 As shown in the figure, this embodiment will describe in detail a method for milling markings in a reserved area of ​​a bearing saddle, specifically including the following steps:

[0053] Step S100: Surface Pretreatment and Positioning of the Bearing Saddle: The bearing saddle is cleaned and polished. Three-dimensional dimensional data of the reserved area on the bearing saddle are obtained using high-precision measuring equipment. Lines are then drawn on the reserved area according to design requirements to form positioning information for subsequent processing. Specifically, step S100 involves:

[0054] The surface of the bearing saddle is cleaned and polished to remove the oxide layer, oil, and impurities. A weak alkaline water-based cleaning agent is used for surface cleaning, with the cleaning temperature controlled at 40~50℃ and the cleaning time at 10~15 minutes. Grinding is done with 200~400 grit sandpaper, and the grinding direction is consistent with the long axis direction of the reserved area to ensure stable surface roughness. High-precision measuring equipment (such as a laser scanner or coordinate measuring machine) is used to obtain the three-dimensional dimensional data of the reserved area of ​​the bearing saddle. According to the design requirements, lines are drawn in the reserved area to form positioning information for subsequent milling.

[0055] Step S200: Milling the groove. Based on the three-dimensional dimensional data and positioning information obtained in step S100, the supporting saddle is clamped on a CNC milling machine, and a milling tool with a diameter of 0.8 times or less than the minimum width of the reserved area is selected to mill the reserved area, forming a letter groove with a machining accuracy within ±0.05mm. This step specifically involves:

[0056] The support saddle is clamped onto the CNC milling machine; before milling, the CNC milling machine is precision checked, with its positioning accuracy controlled within ±0.02mm and repeatability controlled within ±0.01mm; based on the three-dimensional dimensional data and positioning information obtained in step S100, a carbide-coated tool with a diameter of 0.8 times or less than the minimum width of the reserved area is selected for milling, and the tool's cutting edge radius is less than 0.02mm to reduce cutting marks; during the milling process, water-based cutting fluid is used as the cooling and lubrication medium, with a concentration controlled at 5%~8% and a flow rate of 20~30L / min; through CNC control, a letter groove with a machining accuracy within ±0.05mm is formed.

[0057] Step S300: Cleaning and Sandblasting of the font grooves. The font grooves formed in step S200 are cleaned and degreased, and then sandblasted to achieve a surface roughness of Ra3.2~Ra6.3μm. Specifically, step S300 involves:

[0058] The font groove is cleaned and degreased, preferably using anhydrous ethanol or acetone, for 1-3 minutes. After cleaning and ensuring the surface of the font groove is clean, a sandblasting process is used to roughen the surface. The sandblasting pressure is 0.4-0.6 MPa and the sandblasting time is 3-5 minutes. The sandblasting process makes the surface roughness of the font groove reach Ra3.2-Ra6.3 μm, thereby improving the adhesion of the filling material.

[0059] Step S400: Adding embossed lettering. Within the lettering groove processed in step S300, filler material is added using a welding method to form embossed lettering. The welding parameters are controlled according to a formula based on the dimensions of the lettering groove and the diameter of the filler material. Specifically, step S400 involves:

[0060] The embossed font is added by welding filler material into the font groove after step S300. The welding parameters are controlled by formulas according to the size of the font groove and the diameter of the filler material.

[0061] Welding methods include:

[0062] Welding method: The current I and the diameter d of the filler material satisfy I = (10~15) × d, where the unit of I is ampere (A) and the unit of d is millimeter (mm); the welding voltage is 20~30V and the welding speed is 10~20mm / min.

[0063] Laser welding method: The laser power P and the font groove depth h satisfy P = (500~1000) × h; where P is in watts (W) and h is in millimeters (mm); the laser pulse width is 0.5~2ms and the laser pulse frequency is 10~50Hz; the welding speed is 5~15mm / s; argon gas is used as the shielding gas in the welding area, and the flow rate of the shielding gas is 10~15L / min.

[0064] Laser cladding method: The cladding material is an alloy powder that matches the substrate of the bearing saddle, and the particle size of the alloy powder is 150~300 mesh; the relationship between the laser power P and the cladding layer thickness δ is P=(1000~2000)×δ, where the unit of P is watt (W) and the unit of δ is millimeter (mm); the scanning speed is 5~15mm / s and the powder feeding rate is 5~10g / min.

[0065] By controlling the above-mentioned formulaic parameters, the filling material can form a stable metallurgical bond with the font groove wall, thereby improving the bond strength.

[0066] Step S500: Stress-relief annealing and finishing. The bearing saddle, after the embossed lettering was added in step S400, undergoes stress-relief annealing and surface finishing. This step S500 specifically includes:

[0067] The load-bearing saddle after adding the raised and recessed lettering is subjected to stress-relieving annealing. The annealing process conditions include: heating temperature of 550~650℃, holding time of 2~3h, heating rate of 50~100℃ / h, and cooling rate of 30~50℃ / h.

[0068] After annealing, the font surface is trimmed to ensure that the font surface is flat, beautiful and firmly bonded to the substrate.

[0069] Step S600: Combined with strength testing, perform a bonding strength test on the load-bearing saddle processed in step S500. If the test result does not reach the preset threshold, proceed to step S400, adjust the welding parameters, and process again until the test result reaches the preset threshold. The marking of the load-bearing saddle is then complete. This step S600 specifically includes:

[0070] The bonding strength of the load-bearing saddle after step S500 is tested.

[0071] If the test result does not reach the preset threshold, return to step S400, adjust the welding parameters, and process again;

[0072] When the test results reach the preset threshold, the processing of the bearing saddle marking is deemed complete.

[0073] To further illustrate the milling method for marking the reserved area of ​​the bearing saddle according to the present invention, the following will describe it in detail through specific embodiments.

[0074] Example 1: Adding embossed text using solder overlay (parameter endpoint value 1)

[0075] Step S100: Surface pretreatment and positioning of the bearing saddle:

[0076] Use a weakly alkaline water-based cleaning agent (pH≈9), clean at 40℃ for 10 minutes; use 200-grit sandpaper for sanding, with the sanding direction aligned with the long axis of the reserved area; use a coordinate measuring machine to obtain the three-dimensional dimensional data of the reserved area (accuracy ±0.01mm); and then scribing to generate positioning information.

[0077] Step S200: Milling the groove:

[0078] The support saddle is clamped on the CNC milling machine, and the positioning accuracy is checked to be ±0.02mm; the tool diameter is equal to the minimum width of the reserved area × 0.8; a carbide coated tool is used with a cutting edge radius of 0.015mm; the machining accuracy is controlled within ±0.05mm; the cutting fluid is water-based with a concentration of 5% and a flow rate of 20L / min.

[0079] Step S300: Font groove cleaning and sandblasting:

[0080] Cleaning agent: anhydrous ethanol, degreasing time 1 min; sandblasting: brown corundum sand 40 mesh, pressure 0.4 MPa, time 3 min; surface roughness Ra 3.2 μm.

[0081] Step S400: Adding embossed fonts (soldering):

[0082] Welding current I = 10 × d (d = 1.0 mm → I = 10 A); voltage 20 V, speed 10 mm / min; filler material is 1 mm diameter steel wire.

[0083] Step S500: Stress-relief annealing and finishing:

[0084] Heating temperature 550℃, holding time 2h, heating rate 50℃ / h, cooling rate 30℃ / h.

[0085] Step S600: Bond strength test:

[0086] Combined strength threshold: ≥200MPa; if the test fails to meet the standard, repeat step S400 and increase the current to 12A.

[0087] Example 2: Adding embossed text using laser welding (parameter endpoint value 2)

[0088] Step S100: Surface pretreatment and positioning of the bearing saddle:

[0089] Cleaning agent: weakly alkaline water-based cleaning agent; cleaning temperature: 50℃; cleaning time: 15min; polishing: 400-grit sandpaper, direction aligned with the long axis; three-dimensional measurement accuracy: ±0.008mm.

[0090] Step S200: Milling the groove:

[0091] Tool diameter = minimum width of reserved area × 0.7; cutting edge radius 0.02mm; accuracy controlled within ±0.05mm; cutting fluid: water-based cutting fluid concentration 8%, flow rate 30L / min.

[0092] Step S300: Font groove cleaning and sandblasting:

[0093] Cleaning agent: acetone, degreasing time 3 min; sandblasting: brown corundum sand 60 mesh, pressure 0.6 MPa, time 5 min; surface roughness Ra 6.3 μm.

[0094] Step S400: Adding embossed lettering (laser welding):

[0095] Laser power P = 1000 × h (h = 1 mm → P = 1000 W); laser pulse width 2 ms, frequency 50 Hz; welding speed 15 mm / s; shielding gas: argon, flow rate 15 L / min.

[0096] Step S500: Stress-relief annealing and finishing:

[0097] Heating temperature 650℃, holding time 3h, heating rate 100℃ / h, cooling rate 50℃ / h.

[0098] Step S600: Bond strength test:

[0099] Threshold ≥250MPa; if not met, adjust laser power to 1200W and reprocess.

[0100] Example 3: Adding embossed text using laser cladding (intermediate parameter values)

[0101] Step S100: Surface pretreatment and positioning of the bearing saddle:

[0102] Cleaning agent: weakly alkaline water-based cleaning agent, temperature 45℃, time 12min; Grinding: 320-grit sandpaper, direction consistent with the long axis; 3D dimension data acquisition accuracy: ±0.009mm; Positioning line width: 0.2mm.

[0103] Step S200: Milling the groove:

[0104] CNC milling machine positioning accuracy: ±0.02mm; tool diameter = minimum width of reserved area × 0.75; tool cutting edge radius: 0.018mm; machining accuracy: ±0.05mm; cutting fluid: water-based cutting fluid concentration 6.5%, flow rate 25L / min.

[0105] Step S300: Font groove cleaning and sandblasting:

[0106] Cleaning agent: Anhydrous ethanol and acetone mixture (volume ratio 1:1), degreasing time 2 min; Sandblasting: Brown corundum sand 50 mesh, sandblasting pressure 0.5 MPa, time 4 min; Surface roughness: Ra 4.5 μm.

[0107] Step S400: Adding embossed fonts (laser cladding):

[0108] Cladding material: alloy powder (matching the composition of the supporting saddle matrix), particle size 200 mesh; laser power P=1500×δ (δ=1mm→P=1500W); scanning speed 10mm / s; powder feeding rate 8g / min; protective gas: argon, flow rate 12L / min.

[0109] Step S500: Stress-relief annealing and finishing:

[0110] Heating temperature 600℃, holding time 2.5h, heating rate 75℃ / h, cooling rate 40℃ / h.

[0111] Step S600: Bond strength test:

[0112] Threshold ≥220MPa; if not met, adjust laser power to 1600W and re-clad.

[0113] Example 4: Adding embossed lettering using a hybrid welding process

[0114] In this embodiment 4, welding and laser cladding are combined. First, welding is used to form an initial filler layer, and then laser cladding is used to form a dense layer on the surface to increase the strength and aesthetics of the font.

[0115] Step S100: Surface pretreatment and positioning of the bearing saddle:

[0116] Cleaning temperature: 42℃; cleaning time: 11min; sanding: 280-grit sandpaper; 3D dimension acquisition accuracy: ±0.01mm.

[0117] Step S200: Milling the groove:

[0118] Tool diameter = minimum width of reserved area × 0.78; accuracy controlled within ±0.05mm; cutting fluid: water-based cutting fluid concentration 7%, flow rate 23L / min.

[0119] Step S300: Font groove cleaning and sandblasting:

[0120] Cleaning agent: anhydrous ethanol; sandblasting particle size: 50 mesh, pressure: 0.55 MPa; surface roughness: Ra 4.8 μm.

[0121] Step S400: Adding embossed fonts (hybrid process):

[0122] Initial weld overlay: Current I = 12A, voltage 22V, speed 12mm / min;

[0123] Surface laser cladding layer: laser power P=1400W, scanning speed 12mm / s, powder feeding rate 7g / min.

[0124] Step S500: Stress-relief annealing and finishing:

[0125] Temperature 590℃, heat preservation for 2.5 hours, cooling rate 40℃ / h.

[0126] Step S600: Bond strength test:

[0127] Threshold ≥ 260MPa; the font edges obtained by this method are smoother and have stronger anti-peeling performance.

[0128] Example 5: Verification of Batch Processing Conditions

[0129] To verify the differences between the process of this invention and the conventional engraving process in terms of processing accuracy, surface roughness, bonding strength, and fatigue life, the following experiments were conducted:

[0130] Experimental materials and equipment:

[0131] Bearing saddle blanks: 12 pieces in total, all of the same material and dimensions; divided into the invention group (3 pieces each of A1, A2, and A3) and the comparison group (3 pieces of B1); CNC milling machine: positioning accuracy ±0.02mm, repeatability ±0.01mm. Cleaning agent, sandpaper, and sandblasting materials: weakly alkaline cleaning agent, 200–400 mesh sandpaper, brown corundum abrasive (40–60 mesh); Welding equipment: surfacing power supply, laser welding machine, laser cladding machine; Testing equipment: coordinate measuring machine, surface roughness tester, universal testing machine, fatigue tester.

[0132] Experimental steps:

[0133] (Group A: The method of the present invention):

[0134] Step S100: Surface pretreatment and positioning:

[0135] A1: Clean at 40℃ for 10 minutes → Grind to 200 grit → Mark and position.

[0136] A2: Clean at 45℃ for 12 minutes → Grind to 300 grit → Mark and position;

[0137] A3: Clean at 50℃ for 15 minutes → Grind to 400 grit → Mark and position.

[0138] Step S200: Milling the groove:

[0139] A1: Tool diameter = groove width × 0.8; water-based cutting fluid concentration 5%, flow rate 20L / min;

[0140] A2: Tool diameter = groove width × 0.6; concentration 6.5%, flow rate 25L / min;

[0141] A3: Tool diameter = groove width × 0.5; concentration 8%, flow rate 30L / min.

[0142] Step S300: Cleaning and sandblasting of font grooves:

[0143] A1: Ethanol degreasing for 1 min → Sandblasting pressure 0.4 MPa, sandblasting time for 3 min;

[0144] A2: Ethanol degreasing for 2 min → Sandblasting pressure 0.5 MPa, sandblasting time for 4 min;

[0145] A3: Ethanol degreasing for 3 min → Sandblasting pressure 0.6 MPa, sandblasting time for 5 min.

[0146] Step S400: Adding embossed fonts:

[0147] A1: Welding current = 10 × d, voltage 20V, speed 10mm / min;

[0148] A2: Welding current = 12.5 × d, voltage 25V, speed 15mm / min;

[0149] A3: Welding current = 15 × d, voltage 30V, speed 20mm / min.

[0150] Step S500: Stress-relief annealing and finishing:

[0151] A1: 550℃×2h, heating up 50℃ / h, cooling down 30℃ / h;

[0152] A2: 600℃×2.5h, heating up 75℃ / h, cooling down 40℃ / h;

[0153] A3: 650℃×3h, heating up 100℃ / h, cooling down 50℃ / h.

[0154] Step S600: Bond strength test:

[0155] If the bond strength is less than 100 MPa, adjust the welding parameters and reprocess.

[0156] (Group B1: Ordinary carving technique):

[0157] 1. Directly use engraving tools to machine letter grooves on the surface of the bearing saddle;

[0158] 2. No sandblasting, filler welding, or annealing was performed;

[0159] 3. After processing, rinse with clean water and use as a control sample.

[0160] Detection method:

[0161] Dimensional accuracy: 3D coordinate measuring machine, average of 10 measuring points; Roughness: Roughness tester measured the bottom of the groove, average of 3 measurements; Bond strength: universal testing machine shear test; Fatigue strength: ±150MPa alternating load, detect cracks or spalling cycles.

[0162] Experimental results:

[0163] A1 (Lower Limit): Dimensional accuracy (mm) ±0.05, surface roughness (Ra, μm) 6.3, bond strength (MPa) 105, fatigue life (cycles) ;

[0164] A2 (intermediate value): Dimensional accuracy (mm) ±0.03, surface roughness (Ra, μm) 3.2, bond strength (MPa) 120, fatigue life (cycles) [missing value] ;

[0165] A2 (intermediate value): Dimensional accuracy (mm) ±0.02, surface roughness (Ra, μm) 3.2, bond strength (MPa) 135, fatigue life (cycles) ;

[0166] B1 Standard Engraving Process: Dimensional accuracy (mm) ±0.20, surface roughness (Ra, μm) 12.5, bonding strength (MPa) 55, fatigue life (cycles) [not specified]. .

[0167] Experimental conclusions: Referring to the above, Group A (the method provided by this invention) is superior to Group B (traditional engraving process) in all parameter ranges; especially in terms of bonding strength (increased by 2 to 3 times) and fatigue life (increased by 4 to 6 times), the effect of this invention is more significant; the data results verify the significant technical effects of the combined processes of surface pretreatment, precision milling, sandblasting, welding filling, and annealing provided by this invention.

[0168] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for milling markings in a reserved area for a load-bearing saddle, characterized in that, Includes the following steps: Step S100: Surface pretreatment and positioning of the bearing saddle. The bearing saddle is cleaned and polished. The three-dimensional dimension data of the reserved area on the bearing saddle is obtained using a high-precision measuring device. The reserved area is marked according to the design requirements to form positioning information for subsequent processing. Step S200: Milling the groove. Based on the three-dimensional dimension data and positioning information obtained in step S100, the bearing saddle is clamped on a CNC milling machine, and a milling cutter with a diameter of 0.8 times or less than the minimum width of the reserved area is selected to mill the reserved area to form a font groove with a machining accuracy of ±0.05mm. Step S300: Cleaning and sandblasting of the font groove. The font groove formed in step S200 is cleaned and degreased, and then sandblasted to make the surface roughness of the font groove Ra3.2~Ra6.3μm. Step S400: Adding raised and recessed fonts. In the font groove processed in step S300, filler material is added by welding to form raised and recessed fonts. The welding parameters are controlled by formula according to the size of the font groove and the diameter of the filler material. Step S500: Stress-relief annealing and finishing. The bearing saddle after adding the raised and recessed fonts in step S400 is subjected to stress-relief annealing and surface finishing. Step S600: Combined with strength testing, the bearing saddle processed in step S500 is subjected to bonding strength testing. If the test result does not reach the preset threshold, step S400 is executed, the welding parameters are adjusted and the process is repeated until the test result reaches the preset threshold, and the marking of the bearing saddle is completed.

2. The milling method for marking the reserved area of ​​the bearing saddle according to claim 1, characterized in that, In step S100, the surface of the bearing saddle is cleaned with a weak alkaline water-based cleaning agent at a temperature of 40-50°C for 10-15 minutes. When polishing, sandpaper with a grit of 200-400 mesh is used, and the polishing direction is consistent with the long axis direction of the reserved area.

3. The milling method for marking the reserved area of ​​the bearing saddle according to claim 1, characterized in that, In step S200, the milling tool is a carbide-coated tool with a cutting edge radius of less than 0.02 mm. During the milling process, a water-based cutting fluid is used as the cooling and lubrication medium, with a concentration of 5% to 8% and a flow rate of 20 to 30 L / min.

4. The milling method for marking the reserved area of ​​the bearing saddle according to claim 1, characterized in that, In step S300, anhydrous ethanol or acetone is used to clean the font groove; the degreasing time is 1~3 minutes, so that the surface of the font groove is clean before sandblasting.

5. The method for milling the markings of the reserved area for the bearing saddle according to claim 1, characterized in that, In step S300, the sandblasting process uses brown fused alumina sand with a particle size of 40-60 mesh; the sandblasting pressure is 0.4-0.6 MPa and the sandblasting time is 3-5 min.

6. The method for milling the markings of the reserved area for the bearing saddle according to claim 1, characterized in that, In step S400, the welding process involves adding raised or recessed lettering using a surfacing welding technique. The parameters of the surfacing welding include: The relationship between the welding current I and the diameter d of the filler material is: I = (10~15) × d, where the unit of I is ampere (A) and the unit of d is millimeter (mm); the welding voltage is 20~30V and the welding speed is 10~20mm / min.

7. The method for milling the markings of the reserved area for the bearing saddle according to claim 1, characterized in that, In step S400, laser welding is used to add raised or recessed lettering. The parameters of the laser welding include: The relationship between the laser power P and the depth h of the font groove is P = (500~1000) × h; where P is in watts (W) and h is in millimeters (mm). The width of the laser pulse is 0.5~2ms, and the frequency of the laser pulse is 10~50Hz; The welding speed is 5~15mm / s; Argon gas is used as the protective gas in the welding area, and the flow rate of the protective gas is 10~15L / min.

8. The method for milling the markings of the reserved area for the bearing saddle according to claim 1, characterized in that, In step S400, the welding is performed by laser cladding to add raised and recessed lettering. The cladding material is an alloy powder that matches the substrate of the bearing saddle, and the particle size of the alloy powder is 150~300 mesh. The relationship between the laser power P and the cladding layer thickness δ is P = (1000~2000) × δ, where the unit of P is watts (W) and the unit of δ is millimeters (mm); the scanning speed is 5~15mm / s and the powder feeding rate is 5~10g / min.

9. The method for milling the markings of the reserved area for the bearing saddle according to claim 1, characterized in that, The stress-relief annealing process conditions in step S500 include: The heating temperature is 550~650℃, the holding time is 2~3h, the heating rate is 50~100℃ / h, and the cooling rate is 30~50℃ / h.

10. The method for milling the markings of the reserved area for the bearing saddle according to claim 1, characterized in that, Before step S200, the accuracy of the CNC milling machine is verified. The positioning accuracy of the CNC milling machine is ±0.02mm, and the repeatability is ±0.01mm.

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