A laser cladding surface wear-resistant strengthening method of non-magnetic drill collar

Abstract

The present application relates to the technical field of metal surface treatment, and specifically provides a laser cladding surface wear-resistant strengthening method for non-magnetic drill collars, comprising the following steps: S1, cleaning treatment of the surface of the non-magnetic drill collar to be strengthened; S2, clamping the non-magnetic drill collar by a positioner chuck to adjust the concentricity, and teaching the linkage program of a robot and the positioner to perform laser cladding processing on the non-magnetic drill collar; S3, laser cladding of a nickel-based non-magnetic or weak-magnetic base cladding layer on the surface of the non-magnetic drill collar to be strengthened; S4, laser cladding of a high-hardness nickel-based wear-resistant cladding layer on the surface of the base cladding layer of the non-magnetic drill collar; and S5, magnetic and hardness detection of the surface of the non-magnetic drill collar. The present application effectively reduces the risk of cracking and porosity of high-hardness wear-resistant materials. The double-layer thickness can reach 2-2.5 mm, and no block shedding phenomenon occurs, the cladding layer surface is smooth, and there is no protrusion at both ends, and the appearance is beautiful.

Description

Technical Field

[0001] This invention belongs to the field of metal surface treatment technology, specifically relating to a method for strengthening the wear resistance of a non-magnetic drill collar surface by laser cladding. Background Technology

[0002] Non-magnetic drill collars are crucial components in downhole exploration and drilling. They are made of low-carbon, high-chromium-manganese alloy steel and possess excellent mechanical properties, including low magnetic permeability and high strength. Due to the complex and harsh operating environment of non-magnetic drill collars, such as vibration and tension, and primarily severe wear, they are subject to significant challenges. Furthermore, since downhole measuring instruments must operate in a non-magnetic environment, the reinforcing materials on the drill collar surface must not only have sufficient wear resistance but also meet the requirement of low magnetic permeability. Laser cladding offers advantages such as strong additive surface bonding, low dilution rate, small heat-affected zone, and a wide range of powder materials that can be selected.

[0003] However, existing laser cladding methods use offline programming software to generate a large number of laser points through technologies such as 3D scanning. After importing the laser points into the laser cladding robot, the robot performs laser irradiation according to the laser points. However, offline programming software needs to be purchased, which is costly, and the computational load is large, requiring high hardware specifications. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method for strengthening the wear resistance of laser cladding surface of non-magnetic drill collars to solve the above-mentioned technical problems.

[0005] This invention provides a method for strengthening the wear resistance of a laser cladding surface of a non-magnetic drill collar, comprising: S1. Clean the areas on the surface of the non-magnetic drill collar that need to be strengthened; S2. The positioner chuck clamps the non-magnetic drill collar and adjusts its concentricity. The robot and positioner work together to teach the program to perform laser cladding on the non-magnetic drill collar. S3. Laser cladding of a nickel-based non-magnetic or weakly magnetic undercoating layer onto the surface of the non-magnetic drill collar to be strengthened; S4. On the surface of the base cladding layer of the non-magnetic drill collar, a high-hardness nickel-based wear-resistant cladding layer is laser-clad. S5. Perform magnetic and hardness tests on the surface of the non-magnetic drill collar.

[0006] Furthermore, in step S1, the cleaning treatment method for the part of the non-magnetic drill collar to be strengthened includes the following steps: S11. Grinding and polishing removes oxide scale and rust from the surface of the non-magnetic drill collar; S12. Wipe the surface of the area to be strengthened with industrial detergent or industrial alcohol.

[0007] Specifically, manual polishing is used to remove surface rust and other impurities from the area to be strengthened on the non-magnetic drill collar. The surface of the area to be strengthened is then wiped with industrial detergent or industrial alcohol to minimize its impact on the cladding quality.

[0008] Furthermore, in step S2, the positioner is linked to teach the robot's position, and the trajectory posture presents a strip-shaped plane with the curvature following the shape of the drill collar's wear-resistant strip. The robot is set to turn on and off in advance at both ends of the trajectory to reduce the protrusion of the cladding layer at both ends, thus completing the program logic editing.

[0009] Furthermore, in step S3, the material selected is a nickel-based alloy powder, which includes the following chemical composition by weight percentage: Cr 20.82%, Ni 63.93%, Fe 2.86%, Mo 8.67%, Nb 3.72%, with the balance being unavoidable impurities.

[0010] Furthermore, the nickel-based alloy powder has a particle size of 270-400 mesh and an average hardness of 25-30 HRC.

[0011] Furthermore, in step S3, the laser cladding parameters for the base cladding layer include: laser power of 3000W, spot size of 3.5mm, robot running fitting speed of 52cm / min, protective gas of Ar, gas flow rate of 8-9L / min, program running trajectory of clockwise linkage rotation along the circumference of the non-magnetic drill collar, laser head at a 75° angle to the surface of the non-magnetic drill collar, powder feeding rate of 1.5-2r / min, and cladding layer thickness of 60 mils on one side.

[0012] Furthermore, in step S4, the material selected is nickel-based wear-resistant alloy powder, which includes the following chemical composition by weight percentage: Cr 15.12%, Ni 60.37%, Fe 4.01%, W 19.93%, with the balance being unavoidable impurities.

[0013] Furthermore, the nickel-based wear-resistant alloy powder has a particle size of 270-400 mesh and an average hardness of 58-60 HRC.

[0014] Furthermore, in step S4, the laser cladding parameters for the wear-resistant cladding layer include: laser power of 4000W, spot size of 4mm, robot running fitting speed of 45cm / min, protective gas of Ar, gas flow rate of 8-9L / min, program running trajectory of clockwise linkage rotation along the circumference of the non-magnetic drill collar, laser head at a 75° angle to the surface of the non-magnetic drill collar, powder feeding rate of 2.5-3r / min, and single-sided thickness of the cladding layer of 1.5-1.8mm.

[0015] Furthermore, in step S5, the surface of the non-magnetic drill collar is tested for magnetism and hardness. The magnetic permeability of the drill collar is 1.009, and the reference value is 1, which meets the non-magnetic or weakly magnetic standard. The surface hardness of the wear-resistant band is 58HRC, and there are no obvious pores or cracks on the surface.

[0016] The beneficial effects of this invention are as follows: The laser cladding surface wear-resistant strengthening method for non-magnetic drill collars provided by this invention applies an underlayer and a wear-resistant layer to the area to be strengthened on the non-magnetic drill collar, effectively reducing the risk of cracking and porosity in high-hardness wear-resistant materials. The double-layer thickness can reach 2-2.5mm without any chipping or detachment. The cladding surface is smooth, with no protrusions at both ends, resulting in an aesthetically pleasing appearance. Secondly, during the cladding process of the non-magnetic drill collar, the generation of the processing trajectory or motion does not require scanning instruments or offline programming software. By using a robot-spindle linkage method, only one point needs to be taught. The rotation angle and overlap data of the wear-resistant strip of the drill collar are calculated, and the shape processing of the wear-resistant strip can be achieved through a logical loop. Finally, in the powder selection for the non-magnetic drill collar strengthening method, this invention uses nickel-based alloy materials with added wear-resistant components. The strengthened cladding layer not only has high hardness and wear resistance but also does not affect the magnetic permeability of the non-magnetic drill collar, meeting the requirements for drill collar downhole operations.

[0017] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart of a method according to an embodiment of the present invention.

[0020] Figure 2 This is a rendering of the effect of a method according to an embodiment of the present invention. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0023] To facilitate understanding of the present invention, the following description, based on the principle of the laser cladding surface wear-resistant strengthening method for non-magnetic drill collars of the present invention and in conjunction with embodiments, will further describe the laser cladding surface wear-resistant strengthening method for non-magnetic drill collars provided by the present invention.

[0024] For details, please refer to Figure 1 The method for strengthening the wear resistance of the laser cladding surface of the non-magnetic drill collar includes: Step 1: Cleaning the area to be strengthened on the surface of the non-magnetic drill collar: Manually grind and polish to remove rust and other contaminants from the surface of the non-magnetic drill collar, and wipe the surface of the area to be strengthened with industrial detergent or industrial alcohol. The purpose of this process is to reduce the negative impact that impurities and stains on the substrate surface may have on the cladding layer.

[0025] Step 2: Robot and Positioner Linkage Program Teaching: The positioner chuck clamps the non-magnetic drill collar and adjusts its concentricity. Through the linkage with the positioner, the robot's position is taught, and its trajectory and posture present a strip-shaped plane. The curvature follows the shape of the wear-resistant strip on the drill collar. The ends are pre-activated and pre-activated to reduce cladding protrusions at both ends. Based on the wear-resistant strip data from the drawings, the rotation angle and cladding overlap of the wear-resistant strip are calculated, and the program logic is edited to achieve cyclic processing of the wear-resistant strip.

[0026] (1) Methods for setting the trajectory of the underlying layer include: Set the standard linear velocity of the cladding head. Calculate the standard time for the non-magnetic drill collar to rotate one revolution based on the standard linear velocity, the circumference of the non-magnetic drill collar, and a preset circumference error. Set the quotient of 360° divided by the standard time as the rotational angular velocity of the positioner. Set the standard time as the time it takes for the positioner to drive the non-magnetic drill collar to rotate one revolution. Obtain the diameter of the laser spot and set this diameter as the width of the cladding strip.

[0027] The cladding head starts feeding powder at the first starting point and turns on the laser at a specified distance from the first starting point; the first ending point of the cladding head is set, and the laser is turned off and powder feeding is stopped at a specified distance from the first end point; the specified distance is the radius of the laser spot.

[0028] To further simplify the control of the cladding head, distance can be converted to time, specifically: The cladding head is set to start feeding powder at the first starting point, and the laser is turned on when the running time reaches the specified duration; the total time from the first starting point to the first ending point is calculated, and the time difference between the total time and the specified duration is set as the ending time; the laser is turned off when the running time reaches the specified ending time.

[0029] The trajectory of the first cladding layer is a complete spiral. Laser control is performed at the beginning and end of the trajectory to prevent the cladding layer at the beginning and end from lifting due to excessive laser irradiation.

[0030] (2) Methods for setting the wear-resistant layer trajectory include: A three-dimensional model of a non-magnetic drill collar is constructed, and the wear-resistant layer area is marked on the three-dimensional model. A spiral trajectory is generated on the three-dimensional model of the non-magnetic drill collar based on the rotation speed and the travel speed. The spiral trajectory within the wear-resistant layer area is marked as a valid trajectory, and the spiral trajectory outside the wear-resistant layer area is marked as an invalid trajectory. According to the standard linear velocity of the cladding head, the effective trajectory length, and the wireless trajectory length, the start time of the cladding head from the second starting point to the start point of the effective trajectory and the end time of the cladding head to the end point of the effective trajectory are calculated. The start time and end time of the effective trajectory are set as the cladding time period of the cladding head.

[0031] The calculation of the start time and end time of the effective trajectory's starting point is as follows: For example, select a segment of effective trajectory as the target effective trajectory. Calculate the length of the spiral trajectory between the starting point and the second starting point, and set the quotient of this length and the standard linear velocity as the start time of the target effective trajectory. Calculate the length of the spiral trajectory between the end point and the second starting point, and set the quotient of this length and the standard linear velocity as the end time of the target effective trajectory. Calculate the start and end times of all effective trajectories in this way. Arrange all start and end times in order and save them to a time list.

[0032] Powder feeding and laser irradiation are turned on at the start time and turned off at the end time.

[0033] In addition, to prevent the cladding layer from lifting at the endpoint of the cladding trajectory, the laser irradiation time can be adjusted. The adjustment methods include: setting the cladding head to start feeding powder at the start time, and turning on the laser when the difference between the running time and the start time reaches a specific duration (the duration obtained by dividing the spot radius by the standard linear velocity of the cladding head); calculating the time from the first starting point to the end point of the cladding head, and setting the time difference between this time and the specific duration as the end time; and turning off the laser when the running time reaches the end time, i.e., turning off the laser in advance.

[0034] Step 3: Laser cladding of nickel-based non-magnetic (weakly magnetic) base cladding layer: The material selected is nickel-based alloy powder, which includes the following chemical composition by weight percentage: Cr 20.82%, Ni 63.93%, Fe 2.86%, Mo 8.67%, Nb 3.72%, with the balance being unavoidable impurities; the particle size of the nickel-based alloy powder is 270~400 mesh, and the average hardness is 25-30HRC.

[0035] The parameters for the laser cladding method for the bottom layer are as follows: laser power is 3000W, spot size is 3.5mm, robot running fitting speed is 52cm / min, protective gas is Ar, gas flow rate is 8-9L / min, program running trajectory is clockwise linkage rotation along the circumference of the non-magnetic drill collar, the laser head is at a 75° angle with the surface of the non-magnetic drill collar, powder feeding rate is 1.5-2r / min, and the single-sided thickness of the cladding layer is 60 mils.

[0036] Step 4: Laser cladding a high-hardness nickel-based wear-resistant cladding layer onto the surface of the non-magnetic drill collar. The material selected is nickel-based wear-resistant alloy powder, which includes the following chemical composition by weight percentage: Cr 15.12%, Ni 60.37%, Fe 4.01%, W 19.93%, with the balance being unavoidable impurities. The particle size of the nickel-based wear-resistant alloy powder is 270~400 mesh, and the average hardness is 58-60 HRC.

[0037] The laser cladding method parameters for the wear-resistant layer are as follows: laser power 4000W, spot size 4mm, robot running fitting speed 45cm / min, protective gas Ar, gas flow rate 8-9L / min, program running trajectory clockwise rotation along the circumference of the non-magnetic drill collar, laser head at a 75° angle to the surface of the non-magnetic drill collar, powder feeding rate 2.5-3r / min, and cladding layer thickness on one side 1.5-1.8mm. Figure 2 The image shown is a physical diagram of the reinforced wear-resistant belt cladding layer according to a specific embodiment of the present invention.

[0038] Step 5: Surface magnetism and hardness test of non-magnetic drill collar: The magnetic permeability test data of the drill collar is 1.009 (the reference value is 1), which meets the non-magnetic (weak magnetic) standard. The surface hardness of the wear-resistant band is about 58HRC, and there are no obvious pores and cracks on the surface.

[0039] The final non-magnetic drill collar cladding effect is as follows: Figure 2 As shown.

[0040] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A method for strengthening the wear resistance of a non-magnetic drill collar surface by laser cladding, characterized in that, Includes the following steps: S1. Clean the areas on the surface of the non-magnetic drill collar that need to be strengthened; S2. The positioner chuck clamps the non-magnetic drill collar and adjusts its concentricity. The robot and positioner work together to teach the program to perform laser cladding on the non-magnetic drill collar. S3. Laser cladding of a nickel-based non-magnetic or weakly magnetic undercoating layer onto the surface of the non-magnetic drill collar to be strengthened; S4. On the surface of the base cladding layer of the non-magnetic drill collar, a high-hardness nickel-based wear-resistant cladding layer is laser-clad. S5. Perform magnetic and hardness tests on the surface of the non-magnetic drill collar; In step S2, the positioner is linked to the teaching robot's position, and the trajectory posture presents a strip-shaped plane with the curvature following the shape of the drill collar's wear-resistant strip. The robot's pre-lighting and pre-lighting are set at both ends of the trajectory to reduce the protrusion of the cladding layer at both ends, thus completing the program logic editing. In step S3, the material selected is nickel-based alloy powder, which includes the following chemical composition by weight percentage: Cr 20.82%, Ni 63.93%, Fe 2.86%, Mo 8.67%, Nb 3.72%, with the balance being unavoidable impurities; The particle size of the nickel-based alloy powder is 270~400 mesh, and the average hardness is 25-30 HRC; In step S3, the laser cladding parameters for the base cladding layer include: laser power of 3000W, spot size of 3.5mm, robot running fitting speed of 52cm / min, protective gas of Ar, gas flow rate of 8-9L / min, program running trajectory of clockwise linkage rotation along the circumference of the non-magnetic drill collar, laser head at a 75° angle to the surface of the non-magnetic drill collar, powder feeding rate of 1.5-2r / min, and cladding layer thickness of 60 mils on one side; (1) Methods for setting the trajectory of the undercoating layer include: Set the standard linear velocity of the cladding head, calculate the standard time for the non-magnetic drill collar to rotate one revolution based on the standard linear velocity, the circumference of the non-magnetic drill collar, and a preset circumference error; set the quotient of 360° divided by the standard time as the rotational angular velocity of the positioner; set the standard time as the time for the positioner to drive the non-magnetic drill collar to rotate one revolution; obtain the diameter of the laser spot, and set the diameter as the width of the cladding strip; The cladding head starts feeding powder at a first starting point and turns on the laser at a specified distance from the first starting point; a first ending point is set for the cladding head, and the laser is turned off and powder feeding stops at a specified distance from the first ending point; the specified distance is the radius of the laser spot; The steps to convert distance to time include: The cladding head is set to start feeding powder at a first starting point, and the laser is turned on when the running time reaches the specified duration; the total time from the first starting point to the first ending point is calculated, and the time difference between the total time and the specified duration is set as the ending time; the laser is turned off when the running time reaches the ending time. The trajectory of the first cladding layer is a complete spiral shape. Laser control is performed at the beginning and end of the trajectory to prevent the cladding layer at the beginning and end from lifting due to excessive laser irradiation. (2) Methods for setting the wear-resistant cladding trajectory include: A three-dimensional model of a non-magnetic drill collar is constructed, and the wear-resistant layer area is marked on the three-dimensional model. A spiral trajectory is generated on the three-dimensional model of the non-magnetic drill collar based on the rotation speed and travel speed. The spiral trajectory within the wear-resistant layer area is marked as a valid trajectory, and the spiral trajectory outside the wear-resistant layer area is marked as an invalid trajectory. According to the standard linear velocity of the cladding head, the effective trajectory length, and the wireless trajectory length, the start time of the cladding head from the second starting point to the start point of the effective trajectory and the end time of the cladding head to the end point of the effective trajectory are calculated. The start time and end time of the effective trajectory are set as the cladding time period of the cladding head. The calculation of the start time of the effective trajectory and the end time of the effective trajectory includes: selecting a segment of effective trajectory as the target effective trajectory; calculating the length of the spiral trajectory between the start point and the second starting point of the effective trajectory, and setting the quotient of this length and the standard linear velocity as the start time of the target effective trajectory; calculating the length of the spiral trajectory between the end point of the effective trajectory and the second starting point, and setting the quotient of this length and the standard linear velocity as the end time of the target effective trajectory; and so on to calculate the start time and end time of all effective trajectories; arranging all start times and end times in order and saving them to a time list; Powder feeding and laser irradiation are turned on at the start time and turned off at the end time. The laser irradiation time is adjusted by means of: setting the cladding head to start feeding powder at the start time, and turning on the laser when the difference between the running time and the start time reaches a specific duration; calculating the time from the first starting point to the end point of the cladding head, and setting the time difference between this time and the specific duration as the end time; and turning off the laser when the running time reaches the end time, i.e., turning off the laser in advance.

2. The method for strengthening the wear resistance of a non-magnetic drill collar surface by laser cladding as described in claim 1, characterized in that, In step S1, the cleaning process for the area to be strengthened in the non-magnetic drill collar includes the following steps: S11. Grinding and polishing removes oxide scale and rust from the surface of the non-magnetic drill collar; S12. Wipe the surface of the area to be strengthened with industrial detergent or industrial alcohol.

3. The method for strengthening the wear resistance of a non-magnetic drill collar surface by laser cladding as described in claim 1, characterized in that, In step S4, the material selected is nickel-based wear-resistant alloy powder, which includes the following chemical composition by weight percentage: Cr 15.12%, Ni 60.37%, Fe 4.01%, W 19.93%, with the balance being unavoidable impurities.

4. The method for strengthening the wear resistance of a non-magnetic drill collar surface by laser cladding as described in claim 3, characterized in that, The particle size of the nickel-based wear-resistant alloy powder is 270~400 mesh, and the average hardness is 58-60 HRC.

5. The method for wear-resistant strengthening of the laser cladding surface of a non-magnetic drill collar as described in claim 1, characterized in that, In step S4, the laser cladding parameters for the wear-resistant cladding layer include: laser power of 4000W, spot size of 4mm, robot running fitting speed of 45cm / min, protective gas of Ar, gas flow rate of 8-9L / min, program running trajectory of clockwise linkage rotation along the circumference of the non-magnetic drill collar, laser head at a 75° angle to the surface of the non-magnetic drill collar, powder feeding rate of 2.5-3r / min, and single-sided thickness of cladding layer of 1.5-1.8mm.

6. The method for strengthening the wear resistance of a non-magnetic drill collar surface by laser cladding as described in claim 1, characterized in that, In step S5, the surface of the non-magnetic drill collar is tested for magnetism and hardness. The magnetic permeability of the drill collar is 1.009, and the reference value is 1, which meets the non-magnetic or weakly magnetic standard. The surface hardness of the wear-resistant band is 58HRC, and there are no obvious pores or cracks on the surface.

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