A device and method for treating a severely corroded and contaminated failure fracture

Abstract

The present invention relates to the technical field of failure fracture analysis, and discloses a device and method for processing a failure fracture with severe corrosion and contamination. The processing device utilizes laser to irradiate the fracture surface, so that pollutants, rust, etc. on the fracture surface absorb the laser energy and are instantly peeled off or evaporated, and are eventually efficiently removed from the fracture surface. After the fracture is laser cleaned, the camera is used in high-magnification inspection mode, and the depth of field synthesis technology is used to observe the cleaning inside the fracture. It is possible to find the parts inside the fracture that are not cleaned clean, and clean these parts again. Since the damage threshold of the matrix material is determined by adjusting the laser pulse parameters + observing the fracture morphology with a high-magnification electron microscope, and pulsed flat-top light is used, the light beam is softer and does not damage the substrate. During laser cleaning, nitrogen is used for purging at the same time, which ultimately achieves the effective, rapid, and environmentally friendly removal of attachments on the surface of the severely corroded (contaminated) fracture without damaging the macroscopic and microscopic morphological characteristics of the fracture.

Description

Technical Field

[0001] The present invention relates to the technical field of failure fracture analysis, and in particular to a device and method for processing a failure fracture caused by severe corrosion and pollution. Background Art

[0002] The failure fracture records the initiation, expansion and fracture information of the component under load and service conditions. Therefore, the observation and analysis of the fracture is the most important part of the failure analysis work. Fracture analysis requires technicians to carefully observe the morphology, color, roughness, crack propagation and other characteristics of the fracture at both macro and micro levels. However, in actual engineering, due to the complexity and harshness of the service environment, the failure fracture is often covered by a thick layer of corrosion products or oil stains, which makes it very difficult for technicians to observe the original traces of the failure fracture. Therefore, it is necessary to adopt effective methods to remove attachments on the surface of the heavily corroded (contaminated) fracture without damaging the macro and micro morphological characteristics of the fracture.

[0003] At present, the common fracture treatment technologies are: (1) Organic solvent method: soak the fracture surface with solvents such as anhydrous ethanol, acetone, and gasoline, and use ultrasonic cleaning. This method is only suitable for cleaning fracture surfaces with mild corrosion (pollution). When the fracture surface is severely corroded (polluted), the treatment effect of this method is very poor; (2) Mechanical stripping method: Use AC paper (cellulose acetate) or a colloidal liquid of "cellulose acetate + acetone" (see Chinese patent CN101750243A) to clean the fracture surface. This method is only suitable for cleaning fracture surfaces with moderate corrosion (pollution). It cannot effectively remove the interior of the fracture surface (such as small holes, etc.) and corrosive (pollution) substances with strong adhesion. In addition, cellulose acetate can easily remain on the rough surface of the fracture surface, affecting the observation quality of the fracture surface. In addition, this method is difficult to complete the treatment in one go. Generally, it takes 2-3 days to treat a fracture surface with moderate corrosion (pollution), which is a long time; (3) Chemical reagent method: Use corrosive chemical reagents for cleaning, such as dilute hydrochloric acid or hydrochloric acid + corrosion inhibitor for cleaning. This method can be used for treating fracture surfaces with severe corrosion (pollution). Since the chemical reagents used are somewhat corrosive, improper operation can easily damage the fracture details, affecting the subsequent morphological analysis of the fracture microscopic details. (4) Cathodic electrolysis: The principle is to release hydrogen bubbles to mechanically remove deposits, so the fracture will not be damaged by chemical corrosion. Since the mechanical stripping force of the released hydrogen bubbles is relatively low, it is suitable for cleaning fractures with mild to moderate corrosion (contamination).

[0004] In order to solve the above problems, various solutions have been proposed in the prior art, as shown below:

[0005] Chinese patents (publication numbers CN109433665A and CN110512221A) disclose devices and methods for cleaning failed fracture surfaces. Publication number CN109433665A provides an automatic fracture cleaning device. This cleaner, without the need for direct operator operation, can automatically spray and brush clean failed fracture surfaces. Publication number CN110512221A provides a fracture cleaning system that can fix the sample to be cleaned and then clean it with a brush, or add a cleaning solution and clean it under heated conditions, reducing the risk of personal injury to technicians caused by cleaning agents and improving cleaning efficiency. While these two technical solutions reduce labor intensity, they are essentially based on an organic solvent method combined with a chemical reagent method, performing a "spray and brush" treatment on the fracture surface. Therefore, they are only effective for treating fracture surfaces with mild or moderate corrosion (contamination), and their effectiveness for treating fracture surfaces with severe corrosion (contamination) is very limited. Furthermore, improper chemical reagent concentration or operation can easily damage fracture details.

[0006] Chinese patents (publication numbers CN109778203A and CN108796514A) disclose solutions and methods for cleaning failed fracture surfaces. The technical solution provided by publication number CN109778203A employs a chemical cleaning method based on hydrochloric acid and hexamethylenetetramine; the technical solution provided by publication number 108796514A combines an organic solvent method with a liquid mechanical stripping method for cellulose acetate binding and a chemical cleaning method based on hydrochloric acid and hexamethylenetetramine. While these two technical solutions offer some improvement over traditional treatment methods, the shortcomings of traditional fracture treatment solutions persist in both solutions.

[0007] A Chinese patent (publication number 202111265839.4) discloses a method for removing the rust layer on the fracture of a metal material. This method mainly uses phenolic resin embedding powder to embed the fracture, then embeds the fracture under a certain temperature and pressure, and finally peels off the rust layer on the fracture. Although this technical solution is an upgrade of the mechanical stripping method, this method has the following shortcomings: (1) The hot embedding process requires the use of a metallographic hot embedding machine. Due to the size limitation of the equipment, only smaller fractures can be processed; (2) After hot embedding, the phenolic resin has a strong bonding force with the fracture, and mechanically stripping the phenolic resin from the fracture surface is time-consuming and labor-intensive. If the stripping process is not careful, the fracture surface can be easily damaged.

[0008] Both the Chinese patent (publication number CN114119535A) and the literature [Laser cleaning detection method for steel rust surface based on machine vision. Applied Laser, 2021, 41(6):6.] disclose a laser cleaning method based on visual detection. This technology is based on visual recognition and laser cleaning technology, which realizes the rapid cleaning of the rust layer on the surface of the workpiece. However, the above two technologies, as well as the existing laser cleaning technology solutions, are only applicable to relatively flat workpiece surfaces and the cleaning of rust layers with relatively uniform thickness. In addition, the actual failure fracture surface is often undulating and uneven; and the thickness of the corrosion products (pollutants) is uneven, and corrosion products are also hidden inside the fracture (such as small holes), making it difficult to clean. More importantly, after the failure fracture is processed, it is generally necessary to observe the microscopic features of the fracture under an optical microscope or a scanning electron microscope. If the operation is improper, it is easy to damage the microstructure of the matrix, forming melt traces or dendritic papillary structures, resulting in the inability to accurately analyze the micromorphology of the fracture. Summary of the Invention

[0009] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a device and method for processing severely corroded and contaminated failed fractures, so as to solve the technical problem in the prior art that it is impossible to effectively and quickly remove surface attachments of severely corroded (contaminated) fractures without damaging the macro and micro morphological characteristics of the fracture.

[0010] The present invention is achieved through the following technical solutions:

[0011] A device for processing a failure fracture caused by severe corrosion and contamination, comprising a motion frame base, a laser cleaning unit, a photographic lighting assembly, a control unit and a gas protection unit; the motion frame base comprises a chassis, a stage, a support frame, a cantilever frame and two sets of DC servo motors; the stage is horizontally mounted on the top of the chassis for placing a fracture sample, the support frame is vertically fixed to the chassis, and a guide rail is provided on the support frame; the guide rail is arranged along the vertical direction of the support frame, one end of the cantilever frame is mounted on the guide rail, and the other end is movably connected to a flip head; the two sets of DC servo motors are respectively mounted in the stage and the support frame; The laser cleaning unit includes a laser generator and a laser cleaning head; the laser generator is assembled in the chassis, the laser cleaning head is assembled on the flip head and is set toward the stage, and the laser cleaning head is connected to the output end of the laser cleaning unit; the photographic lighting assembly is assembled on the flip head and is set toward the stage; the control end of the control unit is respectively connected to the laser cleaning unit, the photographic lighting assembly and two sets of DC servo motors, and the gas protection unit includes a nitrogen bottle and a pressure regulating nozzle, the pressure regulating nozzle is assembled on the flip head and is set toward the stage, and the pressure regulating nozzle is connected to the output end of the nitrogen bottle.

[0012] Preferably, a controller is provided in the control unit, the input end of the controller is connected to the image receiving module, and the output end of the controller is respectively connected to the image processing module, the motion control module, the cleaning control module and the lighting drive module; the input end of the image receiving module is connected to the photographing lighting assembly; the output end of the lighting drive module is connected to the photographing lighting assembly; the motion control module is respectively connected to two groups of DC servo motors and the flipping drive end of the flip head; the output end of the cleaning control module is connected to the drive end of the laser generator.

[0013] Furthermore, the output end of the controller is also connected to the human-computer interaction module, and the input end of the human-computer interaction module is connected to the image processing module for displaying image processing information.

[0014] Preferably, the pressure regulating nozzle and the laser cleaning head are both arranged on one side of the flip head, and the photographing lighting assembly is arranged on the other side of the flip head.

[0015] Preferably, the photographing lighting assembly includes a camera and an annular coaxial light lighting system; the camera is mounted on the flip head, and the annular coaxial light lighting system is mounted on the camera.

[0016] Preferably, the cantilever frame is vertically arranged to the support frame, and the cantilever frame is raised and lowered horizontally by a guide rail.

[0017] Preferably, the output end of the laser generator is connected to the laser cleaning head via an optical fiber.

[0018] Preferably, the output end of the nitrogen bottle is connected to the pressure regulating nozzle through a hose, and an electric control valve is provided on the output end of the nitrogen bottle.

[0019] Preferably, rollers are provided at the bottom of the sports frame base.

[0020] A method for treating a severely corroded and contaminated failure fracture, based on the aforementioned device for treating a severely corroded and contaminated failure fracture, comprises the following steps:

[0021] Step 1: Place the fracture sample on the stage with the fracture surface facing both sides; the laser cleaning unit performs local laser cleaning on a portion of the substrate adjacent to the fracture surface until a fresh metal surface is exposed in the substrate.

[0022] Step 2: Observe the microscopic morphology of the substrate in a certain area after local laser cleaning to analyze whether there are traces of melting or dendritic papillary structures;

[0023] If it exists, return to step 1, reduce the cleaning power, and perform local laser cleaning on another area of ​​the substrate again until no obvious damage is found in the substrate microstructure. The micro damage threshold of the substrate can be determined and step 3 can be performed.

[0024] Step 3: The camera captures a fresh metal image of the substrate after partial laser cleaning, and transmits the image to the control unit to calculate and obtain average grayscale value information of the fresh metal image;

[0025] Step 4: Place the fracture sample on the stage with the fracture surface facing upward; use a camera to capture a macroscopic image of the entire fracture surface, determine the fracture source area, expansion area, and instantaneous fracture area of ​​the fracture, and mark the areas in the control unit;

[0026] Step 5: Set the cleaning power, scanning speed, pulse frequency, pulse width and other parameters so that the laser energy density is no greater than the substrate micro-damage threshold. The control unit analyzes the entire fracture morphology and contour characteristics, sends a laser cleaning path, and the laser cleaning unit begins to perform comprehensive laser cleaning on the fracture surface. At the same time, the gas protection unit is turned on to achieve cooling, protection and dust removal of the fracture surface.

[0027] Step 6: The camera scans the fracture source area and extension area of ​​the fracture surface. When encountering areas with large fluctuations, the depth of field synthesis mode is used to obtain a clearer fracture image at a lower position. The control unit calculates the average grayscale value information of the cleaned image, and then grids and numbers the position of the cleaned fracture image, and compares it with the average grayscale value information of the fresh fracture image.

[0028] When it is found that there is a fracture position that is not cleaned, the image number of the part that is not cleaned is marked; at the same time, the control unit issues a position number instruction for the part that is not cleaned, and executes step 7;

[0029] When all the positions of the fracture surface are found to be clean, the fracture surface sample processing is completed;

[0030] Step 7: For the parts of the fracture that are not cleaned, the laser cleaning unit performs local laser cleaning; at the same time, the gas protection unit cools, protects and removes dust from the fracture; after cleaning, the camera performs another comparison inspection on the parts that are not cleaned;

[0031] When it is found that the fracture sample has been cleaned, the fracture sample processing is completed; otherwise, repeat step 7.

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

[0033] The present invention provides a device for processing a failure fracture caused by severe corrosion and contamination. The device comprises a stage arranged on a chassis for placing a fracture sample. A support frame is vertically fixed to the chassis, a guide rail is provided on the support frame, a cantilever frame is assembled on the guide rail, and a DC servo motor drives the guide rail to drive the cantilever frame to move in the vertical direction, thereby adjusting the height and focal length of the workbench. A DC servo motor is arranged in the stage, and the stage is driven to move in the horizontal direction by the DC servo motor. A flip head is assembled at the other end of the cantilever frame, and a photographic lighting component, a pressure regulating nozzle and a laser cleaning head are assembled respectively. On the flip head, the photographic lighting assembly is used to scan and shoot low-magnification and high-magnification fracture images, while ensuring that the fracture images taken by the camera are clear and shadow-free; the pressure regulating nozzle cools, protects and removes dust from the fracture, and the laser cleaning head can clean the fracture; the control end of the control unit in the present invention is respectively connected to the laser cleaning unit, the photographic lighting assembly and two sets of DC servo motors, which greatly improves the intelligent control of the processing device, and at the same time can effectively and quickly remove severely corroded (polluted) fracture surface attachments without damaging the macro and micro morphological characteristics of the fracture.

[0034] The present invention provides a method for treating a failed fracture caused by severe corrosion and contamination. The treatment device utilizes laser to irradiate the fracture surface, so that pollutants, rust, etc. on the fracture surface absorb the laser energy and are instantly peeled off or evaporated, and are eventually efficiently removed from the fracture surface. After the fracture is laser cleaned, the high-magnification inspection mode of the camera is used, and the depth of field synthesis technology is used to observe the cleaning inside the fracture. It is possible to find the parts inside the fracture that are not cleaned clean, and clean these parts again. Since the damage threshold of the matrix material is determined by adjusting the laser pulse parameters + observing the fracture morphology with a high-magnification electron microscope, and pulsed flat-top light is used, the light beam is softer and does not damage the substrate. In addition, during laser cleaning, nitrogen is used for purging at the same time to protect the fracture surface from oxidation. Ultimately, it is achieved that the surface attachments of the severely corroded (contaminated) fracture can be effectively, quickly, and environmentally friendly without damaging the macroscopic and microscopic morphological characteristics of the fracture, providing strong evidence for the subsequent failure analysis of mechanical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the structure of the device for treating a failure fracture caused by severe corrosion pollution according to the present invention;

[0036] Figure 2 This is a flow chart of the method for treating a failure fracture caused by severe corrosion and contamination according to the present invention;

[0037] Figure 3 This is the macroscopic morphology of the severely contaminated failure fracture surface of the TS-90 coiled tubing failure sample in Example 1 of the present invention;

[0038] Figure 4The macroscopic morphology of the failure fracture finally obtained after the treatment in Example 1 of the present invention;

[0039] Figure 5 The scanning electron microscope high-magnification morphology of the failure fracture finally obtained after the treatment in Example 1 of the present invention;

[0040] Figure 6 This is the macroscopic morphology of the impact fracture of the L360 induction heating elbow sample in Example 2 of the present invention;

[0041] Figure 7 This is the macroscopic morphology of the fracture surface finally obtained after treatment using Example 2 of the present invention;

[0042] Figure 8 This is the scanning electron microscope high-magnification morphology of the fracture finally obtained after the treatment using Example 2 of the present invention.

[0043] In the figure: 1 is the base of the motion frame; 1-1 is the chassis; 1-2 is the loading platform; 1-3 is the support frame; 1-4 is the cantilever frame; 1-5 is the DC servo motor; 1-6 is the roller; 1-3-1 is the guide rail; 1-4-1 is the flip head; 2 is the laser cleaning unit; 2-1 is the laser generator; 2-2 is the optical fiber; 2-3 is the laser cleaning head; 3 is the shooting lighting component; 3-1 is the camera; 3-2 is the annular coaxial light lighting system; 4 is the control unit; 5 is the gas protection unit; 5-1 is the nitrogen bottle; 5-2 is the electric control valve; 5-3 is the hose; 5-4 is the pressure regulating nozzle. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only 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 making creative efforts should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] The present invention is described in further detail below with reference to the accompanying drawings:

[0047] See also Figure 1 In one embodiment of the present invention, a device for treating a severely corroded and contaminated failure fracture is provided, comprising a moving frame base 1, a laser cleaning unit 2, a photographic lighting assembly 3, a control unit 4, and a gas protection unit 5;

[0048] The motion frame base 1 includes a chassis 1-1, a loading platform 1-2, a support frame 1-3, a cantilever frame 1-4 and two sets of DC servo motors 1-5; the loading platform 1-2 is horizontally mounted on the top of the chassis 1-1 for placing fracture samples, the support frame 1-3 is vertically fixed to the chassis 1-1, and a guide rail 1-3-1 is provided on the support frame 1-3; the guide rail 1-3-1 is arranged along the vertical direction of the support frame 1-3, one end of the cantilever frame 1-4 is mounted on the guide rail 1-3-1, and the other end is movably connected to the flip head 1-4-1; the two sets of DC servo motors 1-5 are respectively mounted in the loading platform 1-2 and the support frame 1-3;

[0049] The stage 1-2 enables the movement and precise positioning of fracture samples. The Z-axis movement of the cantilever 1-4 allows for adjustment of the worktable's height and focal length. A flip head 1-4-1 is provided at one end of the cantilever 1-4, enabling switching between "laser cleaning" and "video and photography" functions.

[0050] Specifically, the laser cleaning unit 2 includes a laser generator 2-1, an optical fiber 2-2 and a laser cleaning head 2-3.

[0051] The laser generator 2-1 is placed inside the chassis 1-1. Specifically, the laser generator 2-1 is a pulsed flat-top laser with an average output power of 100-200W, a maximum pulse energy of 1.0-2.0mJ, a pulse frequency range of 1-4500kHz, a pulse width of 1-500ns, and a beam diameter of 6-9mm. The optical fiber 2-2 is 3m to 6m long and primarily connects the laser emitter 2-1 to the laser cleaning head 2-3. The laser cleaning head 2-3 is mounted on the flip head 1-4-1 at the end of the cantilever.

[0052] The imaging and lighting unit 3 includes a camera 3-1 and an annular coaxial light illumination system 3-2. The camera 3-1 is mounted on the tilting head 1-4-1 at the end of the cantilever and is not located on the same working surface as the laser cleaning head 2-3. The camera 3-1 has autofocus and an optical zoom of 0.6x to 10.0x, and is used to scan and capture low- and high-magnification images of the fracture. The annular coaxial light illumination system 3-2 provides illumination, ensuring that the fracture images captured by the camera 3-1 are clear and shadow-free.

[0053] A controller is provided in the control unit 4, the input end of the controller is connected to the image receiving module, and the output end of the controller is respectively connected to the image processing module, the motion control module, the cleaning control module and the lighting drive module; the input end of the image receiving module is connected to the photographing lighting component 3; the output end of the lighting drive module is connected to the photographing lighting component 3; the motion control module is respectively connected to two groups of DC servo motors 1-5 and the flipping drive end of the flip head 1-4-1; the output end of the cleaning control module is connected to the drive end of the laser generator 2-1.

[0054] Specifically, the motion control module primarily receives commands and sends pulse signals to the DC servo motor 1-5. The DC servo motor then controls the precise horizontal movement of the stage 1-2 and the vertical movement of the cantilever 1-4. The precise Z-direction movement of the cantilever 1-4 adjusts the focal length of the laser cleaning head 2-3 and the camera 3-1. Furthermore, the motion control module controls the flip head 1-4-1 to switch between "laser cleaning" and "video recording" modes.

[0055] The image processing module primarily analyzes the fracture surface images captured by camera 3-1 and issues a laser cleaning path to motion control module 4-1. This module grids and numbers the fracture surface images at different locations, compares them with images of clean fracture surfaces, and identifies the image numbers of areas that were not cleaned. Simultaneously, it quickly issues positional instructions to the motion control module to identify the locations of the remaining areas.

[0056] The image processing module can also perform depth-of-field synthesis on images of uneven fracture surfaces. Specifically, when encountering a fracture with significant height fluctuations, the image processing module sends a command to the motion control module to drive the camera 3-1 in the vertical direction and continuously capture multiple fracture images with different depths of field for analysis and superposition, forming a full-depth fracture image with clear areas.

[0057] The cleaning control module primarily inputs parameters such as cleaning power, scanning speed, pulse frequency, and pulse width. It controls laser cleaning unit 2 to clean the fracture surface. There are two main cleaning methods: one is "full" laser cleaning of the entire fracture surface; the other is "localized" laser cleaning of remaining areas by receiving commands and adjusting the laser head's focal length.

[0058] The output end of the controller is also connected to the human-computer interaction module, and the input end of the human-computer interaction module is connected to the image processing module for displaying image processing information.

[0059] Specifically, the output end of the nitrogen bottle 5-1 is connected to the pressure regulating nozzle 5-4 through a hose 5-3, and an electric control valve 5-1 is provided on the output end of the nitrogen bottle 5-1; the electric control valve 5-2 controls the nitrogen bottle 5-1 to realize the opening and closing of the gas source; the pressure regulating nozzle 5-4 can manually adjust the pressure and the purge position, thereby realizing cooling, protection and dust removal of the fracture.

[0060] Specifically, rollers 1-6 are provided at the bottom of the motion frame base 1, and the rollers 1-6 are equipped with brake devices and are installed at the bottom of the chassis 1-1 to facilitate overall movement and fixation.

[0061] The present invention also provides a method for treating a severely corroded failure fracture, based on the above-mentioned device for treating a severely corroded failure fracture, characterized in that it comprises the following steps:

[0062] Step 1, sample pretreatment: soak the fracture sample in anhydrous ethanol liquid and perform ultrasonic cleaning for 30 to 60 minutes to remove mud and oil on the sample surface and loosen the pollutants and rust on the fracture surface.

[0063] The fractured specimen is then placed on stage 1-2, with the fracture surface facing both sides. Parameters such as cleaning power, scan speed, pulse frequency, and pulse width are input into the cleaning control module. Laser cleaning unit 2 performs a "localized" laser cleaning of a small area of ​​the substrate adjacent to the fracture surface, until the fresh metal surface is exposed in this area.

[0064] Step 2: Determine the microscopic damage threshold of the substrate: Use a scanning electron microscope to observe the microscopic morphology of the pre-cleaned area at 100x to 500x magnification to analyze whether there are traces of melting or dendritic papillary structures.

[0065] If so, proceed to step 1, reducing the cleaning power by 5-20% and re-pre-cleaning the substrate in a different area (not the fractured area). If no significant damage is observed in the substrate's microstructure, the substrate's micro-damage threshold can be determined and proceed to step 3.

[0066] Step 3: Acquire fresh metal image information: Camera 3-1 uses high magnification mode (no less than 5 times) to capture the image of the pre-cleaned fresh metal. The image processing module calculates the average grayscale value information of the fresh metal image.

[0067] Step 4, Fracture Imagery and Analysis: Place the fractured specimen on a base with the fracture surface facing upward. Camera 3-1 uses low magnification (no greater than 1x) to capture a macroscopic image of the entire fracture surface. Through fracture observation and background data analysis, technicians identify the fracture source, expansion, and transient fracture zones, and label these zones using the image processing module.

[0068] Step 5: Comprehensive Fracture Cleaning: Parameters such as cleaning power, scanning speed, pulse frequency, and pulse width are set so that the laser energy density does not exceed the substrate's microscopic damage threshold. The image processing module analyzes the entire fracture surface's morphology and contours, and sends a laser cleaning path to the motion control module. Laser cleaning unit 2 begins comprehensive laser cleaning of the fracture surface. Simultaneously, gas shield unit 5 is activated to cool, protect, and remove dust from the fracture surface.

[0069] Step 6, Fracture Inspection: Camera 3-1 uses high magnification (no less than 5x) to scan the fracture source and extension areas of the fracture surface. When encountering areas with significant height fluctuations, depth of field synthesis mode is used to obtain clearer fracture images at lower locations. The image processing module calculates the average grayscale value of the cleaned image. The image processing module grids and numbers the locations of the cleaned fracture image, comparing it with the average grayscale value of the fresh fracture image.

[0070] After comparison, if the image processing module finds that there is a fracture position that is not cleaned, it marks the image number of the part that is not cleaned, and quickly sends the position number instruction of the part that is not cleaned to the motion control module, and executes step 7.

[0071] After comparison, the image processing module finds that all positions of the fracture have been cleaned, indicating that the fracture processing is completed.

[0072] Step 7, Localized Fracture Cleaning and Inspection: Laser cleaning unit 2 performs "localized" laser cleaning on any remaining areas of the fracture. Simultaneously, gas shield unit 5 cools, protects, and removes dust from the fracture. After cleaning, camera 3-1 uses high magnification (no less than 5x) to perform a comparison inspection of any remaining areas.

[0073] When the image processing module finds that the fracture has been cleaned after comparison, it indicates that the fracture processing is completed; when the image processing module finds that the fracture has not been cleaned after comparison, step 7 is repeated.

[0074] In order to prevent the microscopic morphology of the substrate from being damaged, the laser cleaning unit 2 stops cleaning when the number of local cleaning times of the fracture surface exceeds 5. The technicians take further cleaning measures according to the actual cleaning effect of the fracture surface and the need for fracture surface observation.

[0075] Example 1:

[0076] A TS-90 coiled tubing with a specification of Φ31.8×3.2mm suddenly broke while in service. Due to the harsh working conditions on site, the fracture was severely contaminated. Figure 3 The present invention is used to clean the fracture surface, see Figure 2 , the specific steps are:

[0077] 1. Sample pretreatment: Immerse the fracture sample in anhydrous ethanol liquid and perform ultrasonic cleaning for 60 minutes to remove mud and oil on the surface of the sample and loosen the pollutants and rust on the fracture surface.

[0078] The fractured specimen was then placed on stage 1-2, with the fracture surface facing both sides. The cleaning control module was configured with a cleaning power of 150W, a scanning speed of 3000mm, a pulse frequency of 100kHz, and a pulse width of 200ns. Laser cleaning unit 2 then performed a "localized" laser cleaning of a small area of ​​the substrate adjacent to the fracture surface for 1-2 seconds, until the fresh metal surface was exposed in this area.

[0079] 2. Determine the substrate micro damage threshold:

[0080] Using a scanning electron microscope, the micromorphology of the pre-cleaned position was observed at 300 times magnification, and it was found that there were dendritic papillary structures in the micromorphology, indicating that the micromorphology was damaged.

[0081] Adjust the cleaning power to 130W, keeping all other parameters unchanged. Pre-clean the substrate again in a different area (not the fractured area) for approximately 2 seconds. Scanning electron microscopy at 300x magnification revealed no microstructural damage, thus determining the substrate's microdamage threshold.

[0082] 3. Acquiring fresh metal image information: Camera 3-1, with a magnification of 5x, captures an image of the pre-cleaned fresh metal. The image processing module calculates the average grayscale value of the fresh metal image.

[0083] 4. Fracture Photography and Analysis: Place the fractured specimen on a base with the fracture surface facing upward. Camera 3-1 captures a macroscopic image of the entire fracture surface at a magnification of 0.6x. Technicians mark the fracture origin, extension, and transient fracture zones on the image processing module.

[0084] 5. Comprehensive Fracture Cleaning: The cleaning control module inputs a cleaning power of 130W, a scanning speed of 3000mm, a pulse frequency of 100kHz, and a pulse width of 200ns. The image processing module analyzes the entire fracture surface's topography and contour features and sends a laser cleaning path to the motion control module. Laser cleaning unit 2 begins comprehensive laser cleaning of the fracture surface. Simultaneously, gas shield unit 5 is activated to cool, protect, and remove dust from the fracture surface.

[0085] 6. Fracture Inspection: Camera 3-1, at a magnification of 5x, scans the fracture source and extension areas of the fracture surface. When encountering areas with significant height fluctuations, depth-of-field synthesis mode is used to obtain clearer fracture images at lower locations. The image processing module calculates the average grayscale value of the cleaned image. The cleaned fracture image is gridded and numbered, and then compared with the average grayscale value of the fresh fracture image.

[0086] The image processing module compares and finds two locations on the fracture that haven't been cleaned properly. It marks these locations with the image numbers QX-109 and QX-301. It also quickly sends the location number instructions to the motion control module to perform local cleaning of the fracture.

[0087] 7. Local cleaning and inspection of the fracture: The laser cleaning unit 2 performs "local" laser cleaning on the uncleaned parts (numbers QX-109 and QX-301) for 1 to 2 seconds. At the same time, the gas protection unit 5 cools, protects and removes dust from the fracture. After cleaning, the fracture is inspected. When the image processing module finds that the two locations have been cleaned after comparison, it indicates that the fracture processing is completed. Figure 4 shown.

[0088] The fracture source region morphology was observed under a scanning electron microscope at 300 times magnification, showing typical cleavage fracture characteristics. Figure 5 shown.

[0089] Example 2:

[0090] The specification of the induction heating elbow is D273 PN63 R=6D L360. Due to the unqualified impact toughness of the material during service, the Charpy impact fracture specimen was analyzed. Figure 6 The present invention is used to clean the fracture surface, see Figure 2 , the specific steps are:

[0091] 1. Sample pretreatment: Immerse the fracture sample in anhydrous ethanol liquid and perform ultrasonic cleaning for 40 minutes to remove mud and oil on the surface of the sample and loosen the pollutants and rust on the fracture surface.

[0092] The fractured specimen was then placed on stage 1-2, with the fracture surface facing both sides. The cleaning control module was configured with a cleaning power of 130W, a scanning speed of 2500mm, a pulse frequency of 100kHz, and a pulse width of 200ns. Laser cleaning unit 2 then performed a "localized" laser cleaning of a small area of ​​the substrate adjacent to the fracture surface for 1-2 seconds, until the fresh metal surface was exposed in this area.

[0093] 2. Determine the substrate micro-damage threshold:

[0094] Using a scanning electron microscope, the micromorphology of the pre-cleaned position was observed at 500 times magnification, and it was found that there were dendritic papillary structures in the micromorphology, indicating that the micromorphology was damaged.

[0095] The cleaning power was adjusted to 120W, while other parameters remained unchanged. The substrate was pre-cleaned again in a different area (not the fractured area) for approximately 2 seconds. Subsequent scanning electron microscopy at 500x magnification still revealed fine dendritic papillary structures.

[0096] The cleaning power was adjusted to 110W, while other parameters remained unchanged. The substrate was pre-cleaned again in a different area (not the fractured area) for approximately 2 seconds. No microstructural damage was observed under a scanning electron microscope at 500x magnification. This allowed the determination of the substrate's microdamage threshold.

[0097] 3. Acquiring fresh metal image information: Camera 3-1, with a magnification of 5x, captures an image of the pre-cleaned fresh metal. The image processing module calculates the average grayscale value of the fresh metal image.

[0098] 4. Fracture Photography and Analysis: Place the fractured specimen on a base with the fracture surface facing upward. Camera 3-1 captures a macroscopic image of the entire fracture surface at a magnification of 0.6x. Technicians mark the fracture origin, extension, and transient fracture zones on the image processing module.

[0099] 5. Comprehensive Fracture Cleaning: The cleaning control module inputs a cleaning power of 110W, a scanning speed of 2500mm, a pulse frequency of 100kHz, and a pulse width of 200ns. The image processing module analyzes the entire fracture surface's topography and contour features and sends a laser cleaning path to the motion control module. Laser cleaning unit 2 begins comprehensive laser cleaning of the fracture surface. Simultaneously, gas shield unit 5 is activated to cool, protect, and remove dust from the fracture surface.

[0100] 6. Fracture Inspection: Camera 3-1, at a magnification of 5x, scans the fracture source and extension areas of the fracture surface. When encountering areas with significant height fluctuations, depth-of-field synthesis mode is used to obtain clearer fracture images at lower locations. The image processing module calculates the average grayscale value of the cleaned image. The cleaned fracture image is gridded and numbered, and then compared with the average grayscale value of the fresh fracture image.

[0101] The image processing module compares and finds a cracked part that has not been cleaned, marking the part with the image number QX-207. At the same time, it quickly sends the position number instruction of the part that has not been cleaned to the motion control module to carry out local cleaning of the cracked part.

[0102] 7. Local cleaning and inspection of the fracture: The laser cleaning unit 2 performs "local" laser cleaning on the uncleaned part (number QX-207) for 1 to 2 seconds. At the same time, the gas protection unit 5 cools, protects and removes dust on the fracture. After cleaning, the fracture is inspected. The image processing module finds that the part has been cleaned after comparison, indicating that the fracture processing is completed. Figure 7 shown.

[0103] The morphology of the fracture source region was observed under a scanning electron microscope at 800 times, showing typical intergranular fracture characteristics, such as Figure 8 shown.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for treating a failure fracture caused by severe corrosion pollution, wherein the method is implemented by a device for treating a failure fracture caused by severe corrosion pollution, the device comprising a motion frame base (1), a laser cleaning unit (2), a photographic lighting component (3), a control unit (4) and a gas protection unit (5); the motion frame base (1) comprises a chassis (1-1), a stage (1-2), a support frame (1-3), a cantilever frame (1-4) and two sets of DC servo motors (1-5); the photographic lighting component (3) comprises a camera (3-1) and an annular coaxial light illumination system (3-2); a support frame (1-3) is vertically fixed on the chassis (1-1), and a guide rail (1-3-1) is provided on the support frame (1-3); the guide rail (1-3-1) is arranged along the vertical direction of the support frame (1-3), one end of the cantilever frame (1-4) is assembled on the guide rail (1-3-1), and the other end is movably connected to the flip head (1-4-1), and the flip head (1-4-1) is used to realize the switching between the two functions of laser cleaning and video recording, and is characterized in that, The steps include: Step 1: placing the fracture sample on the stage (1-2) with the fracture surface facing both sides; the laser cleaning unit (2) performs local laser cleaning on a portion of the substrate adjacent to the fracture surface until a fresh metal surface is exposed in the substrate in the portion; Step 2: Observe the microscopic morphology of the substrate in a certain area after local laser cleaning to analyze whether there are traces of melting or dendritic papillary structures; If it exists, return to step 1, reduce the cleaning power, and perform local laser cleaning on another area of ​​the substrate again until no obvious damage is found in the substrate microstructure. The micro damage threshold of the substrate can be determined and step 3 can be performed. Step 3, the camera (3-1) captures a fresh metal image of the substrate after partial laser cleaning, and transmits the image to the control unit (4) to calculate and obtain average grayscale value information of the fresh metal image; Step 4, placing the fracture sample on the stage (1-2) with the fracture surface facing upward; the camera (3-1) captures a macroscopic image of the entire fracture surface, determines the fracture source area, expansion area and instantaneous fracture area of ​​the fracture, and marks the area in the control unit (4); Step 5, setting the cleaning power, scanning speed, pulse frequency, and pulse width parameters so that the laser energy density is not greater than the substrate micro-damage threshold, the control unit (4) analyzes the entire fracture morphology and contour characteristics, and sends a laser cleaning path to the laser cleaning unit (2), and the laser cleaning unit (2) starts to perform comprehensive laser cleaning on the fracture surface; at the same time, the gas protection unit (5) is turned on to achieve cooling, protection, and dust removal of the fracture; Step 6: The camera (3-1) scans the fracture source area and the extension area of ​​the fracture surface. When encountering an area with large fluctuations, the depth of field synthesis mode is used to obtain a clearer fracture image at a lower position. The control unit (4) obtains the average gray value information of the cleaned image by calculation; and the cleaned fracture image is grid-divided and numbered, and compared with the average gray value information of the fresh fracture image. When it is found that there is a fracture position that has not been cleaned, the image number of the part that has not been cleaned is marked; at the same time, the control unit (4) issues a position number instruction for the part that has not been cleaned, and executes step 7; When all the positions of the fracture surface are found to be clean, the fracture surface sample processing is completed; Step 7: The laser cleaning unit (2) performs local laser cleaning on the fracture surface that is not cleaned; at the same time, the gas protection unit (5) cools, protects and removes dust on the fracture surface; after cleaning, the camera (3-1) performs a comparison inspection on the uncleaned part again; When it is found that the fracture sample has been cleaned, the fracture sample processing is completed; otherwise, repeat step 7.

2. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: The stage (1-2) is horizontally mounted on the top of the chassis (1-1) for placing fracture samples; two sets of DC servo motors (1-5) are respectively mounted in the stage (1-2) and the support frame (1-3); the laser cleaning unit (2) includes a laser generator (2-1) and a laser cleaning head (2-3); the laser generator (2-1) is mounted in the chassis (1-1), the laser cleaning head (2-3) is mounted on the flip head (1-4-1) and is arranged toward the stage (1-2), and the laser cleaning head (2-3) is connected to the output end of the laser cleaning unit (2). The photographic lighting assembly (3) is mounted on the flip head (1-4-1) and is disposed toward the stage (1-2). The control end of the control unit (4) is respectively connected to the laser cleaning unit (2), the photographic lighting assembly (3) and the two sets of DC servo motors (1-5). The gas protection unit (5) includes a nitrogen bottle (5-1) and a pressure regulating nozzle (5-4). The pressure regulating nozzle (5-4) is mounted on the flip head (1-4-1) and is disposed toward the stage (1-2). The pressure regulating nozzle (5-4) is connected to the output end of the nitrogen bottle (5-1).

3. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: A controller is provided in the control unit (4), wherein the input end of the controller is connected to the image receiving module, and the output end of the controller is respectively connected to the image processing module, the motion control module, the cleaning control module and the lighting drive module; the input end of the image receiving module is connected to the photographing lighting assembly (3); the output end of the lighting drive module is connected to the photographing lighting assembly (3); the motion control module is respectively connected to two groups of DC servo motors (1-5) and the flipping drive end of the flip head (1-4-1); and the output end of the cleaning control module is connected to the drive end of the laser generator (2-1).

4. The method for treating a severely corroded failure fracture according to claim 3, characterized in that: The output end of the controller is also connected to the human-computer interaction module, and the input end of the human-computer interaction module is connected to the image processing module for displaying image processing information.

5. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: The pressure regulating nozzle (5-4) and the laser cleaning head (2-3) are both arranged on one side of the flip head (1-4-1), and the photographic lighting assembly (3) is arranged on the other side of the flip head (1-4-1).

6. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: The camera (3-1) is assembled on the flip head (1-4-1), and the annular coaxial light illumination system (3-2) is assembled on the camera (3-1).

7. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: The cantilever frame (1-4) and the support frame (1-3) are vertically arranged, and the cantilever frame (1-4) is lifted and lowered horizontally via the guide rail (1-3-1).

8. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: The output end of the laser generator (2-1) is connected to the laser cleaning head (2-3) via an optical fiber (2-2).

9. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: The output end of the nitrogen bottle (5-1) is connected to the pressure regulating nozzle (5-4) via a hose (5-3), and an electric control valve (5-2) is provided on the output end of the nitrogen bottle (5-1).

10. The method for treating a severely corroded and contaminated failure fracture according to claim 1, characterized in that: The bottom of the sports frame base (1) is provided with rollers (1-6).

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