A laser straightening method and device for high-carbon and high-hardness slender shaft parts

Abstract

The present invention belongs to the technical field of metal part shaping, and particularly relates to a laser shaping method and apparatus for high-carbon, high-hardness, slender shaft-like components. The present invention provides a metal component for slender shaft-like components (aspect ratio > 20) made of die steel, high-speed steel, or other materials with a maximum curvature of less than 2mm, a carbon content of 0.5%-4.0%, and a hardness of 50-65HRC, such as die steel or high-speed steel. Furthermore, a laser shaping method for slender shaft-like components (aspect ratio > 20) manufactured by laser cladding composite manufacturing of die steel or high-speed steel with a maximum curvature of less than 2mm, a carbon content of 0.5%-4.0%, and a hardness of 50-65HRC, such as die steel or high-speed steel, is provided. This method solves the problem of scrapping slender shaft-like components made of high-hardness, wear-resistant materials such as die steel or high-speed steel after bending and deformation, saving material costs, processing costs, and labor costs, and achieving significant economic benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal part shaping, and in particular relates to a laser shaping method and device for high-carbon and high-hardness slender shaft parts. Background Art

[0002] Laser shape correction technology uses a laser beam of a certain intensity to scan along a specific path across the workpiece to be corrected, targeting areas of internal stress concentration corresponding to forming errors. The laser's thermal effect reduces the yield strength of the material in that area and enhances its plastic deformation capacity, encouraging elastic internal energy to work, correcting forming errors and improving the workpiece's shape accuracy. This non-contact, heat-effect-accumulating shape correction technology utilizes amorphous molds and requires no external forces, resulting in short cycle times, high flexibility, and high precision.

[0003] While laser shaping technology has been studied for aluminum and titanium alloy parts, its application on steel parts is limited. This is primarily due to factors such as the high yield strength of steel parts, the difficulty in developing the process, anisotropy, and cost-effectiveness. Conventional hydraulic shaping technology is difficult and has a very low success rate for high-value-added steels such as high-carbon, high-hardness mold steel and high-speed steel. Conventional flame shaping is prone to macrocracks and does not meet application requirements.

[0004] Slender shaft-like metal components with an aspect ratio greater than 20, particularly those made of high-carbon, high-hardness materials such as mold steel and high-speed steel, can bend and deform during high-speed machining, failing to meet shape accuracy requirements. During laser cladding of high-carbon, high-hardness mold steel and high-speed steel, the continuous heat input can cause the roller surface to deflect, resulting in insufficient machining capacity, scrapped workpieces, and significant losses. This invention aims to address the laser shape correction process for high-carbon, high-hardness, wear-resistant materials. Ultimately, this approach restores machining accuracy, reduces losses, and achieves significant economic benefits.

[0005] This technical solution is not limited by the processing environment or workpiece size. It uses a 3D laser tracker to detect the degree of workpiece deformation, determine deformation data, and define the laser scanning path. By optimizing laser processing parameters and precisely releasing the elastic potential energy in the stress concentration areas of the workpiece to be reshaped, the magnitude and distribution of the stress state are changed. Furthermore, a stress detector is used to monitor the workpiece surface, thereby improving the shape accuracy of the formed part. This technology offers significant advantages, including high processing flexibility, precise controllability, excellent post-molding material properties, and zero pollution, while also delivering improved economic benefits. Summary of the Invention

[0006] In response to the problems existing in the prior art, the present invention provides a laser correction method and device for high-carbon and high-hardness slender shaft parts; provides metal material components of slender shaft parts (aspect ratio > 20) made of mold steel, high-speed steel, etc. with a maximum curvature of less than 2mm, a carbon content of 0.5%-4.0%, and a hardness of 50-65HRC, as well as a laser correction method for slender shaft parts (aspect ratio > 20) manufactured by laser cladding composite manufacturing of mold steel and high-speed steel with a maximum curvature of less than 2mm, a carbon content of 0.5%-4.0%, and a hardness of 50-65HRC.

[0007] In order to solve the above technical problems, the present invention specifically provides the following technical solutions.

[0008] A laser correction method for high-carbon and high-hardness slender shaft parts specifically includes the following steps:

[0009] Step 1: Use a three-dimensional laser tracker to accurately measure the deformation of the deformed shaft, measure the axial runout value of the entire slender roller surface, determine the maximum deformation position, and record the deformation value.

[0010] Step 2: According to the deformation value, mark two points where the deformation ranges from 0.5 mm to the maximum value, and determine the laser action area. The length is from the deformation range of 0.5 mm to the maximum deformation area, and the width is 10% of the calibration diameter.

[0011] Step 3: The entire roller surface is preheated evenly. When the roller surface temperature is greater than 200°C, the requirement is met.

[0012] Step 4: Use a zigzag path and certain laser processing parameters to irradiate the roller surface.

[0013] Step 5: Each time the laser correction process is completed, a three-dimensional laser tracker is used to detect the deformation after correction, and a stress detector is used to monitor the stress change area. Steps 2-5 are repeated until the maximum deformation is less than 0.3 mm.

[0014] Furthermore, the laser processing parameters used in step 4 are 400-1000W, the laser action mode adopts a programmed pulse laser action mode, the pulse frequency is 13-18HZ, the action time is 40-60s, the scanning speed is 2000-3000mm / min, the spot size is 5mm, and the overlap amount is 0mm.

[0015] Furthermore, in step 4, an atmosphere protection cover needs to be used during the laser correction process, and the oxygen content in the local atmosphere protection space is controlled to be below 100 ppm to prevent oxidation pores from forming on the roller surface under laser irradiation.

[0016] Furthermore, in step 4, the power of the second and subsequent laser corrections must be smaller than that of the previous one, to ensure that the depth of each laser action on the substrate is smaller than that of the first time.

[0017] Compared with the prior art, the present invention has the following beneficial effects.

[0018] 1. For high-hardness materials such as mold steel and high-speed steel, due to their high strength, traditional straightening methods are either ineffective or use large-pressure hydraulic straightening to cause serious cracking. The present invention solves the problem of scrapping workpieces after bending and deformation of slender shaft parts made of high-hardness and wear-resistant materials such as mold steel and high-speed steel, saving material costs, processing costs, and labor costs, and can achieve great economic benefits.

[0019] 2. By assembling existing equipment, we have established a highly efficient and flexible laser alignment platform, including a 3D laser tracker, laser processing machine, stress detection device, and other complete equipment. This platform enables the selection of different laser alignment processes based on the degree of workpiece deformation. A corresponding laser process database has been established, enabling efficient alignment of workpieces with varying degrees of deformation.

[0020] 3. The present invention has no effect on the metal component material or the metallographic structure of the high-hardness wear-resistant coating after laser cladding. The depth is 0.02-0.2 mm, the active area is shallow, and can be removed by subsequent machining.

[0021] 4. The present invention adopts a laser shaping process, and the laser output mode adopts a programmable pulse action mode to adjust the time between the parts and the laser, so that the laser action time is shortened, which has a significant effect on the cracking sensitivity of high-hardness materials under continuous laser impact.

[0022] 5. After laser shaping, a certain residual compressive stress can be generated, which is beneficial to improving the fatigue resistance of materials and coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the working platform of the present invention.

[0024] Figure 2 Schematic diagram of the workpiece after flaw detection in Example 2 of the present invention. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings of the embodiments.

[0026] A laser correction method for high-carbon and high-hardness slender shaft parts specifically includes the following steps:

[0027] Step 1: Use a three-dimensional laser tracker to accurately measure the deformation of the deformed shaft, measure the axial runout value of the entire slender roller surface, determine the maximum deformation position, and record the deformation value.

[0028] Step 2: According to the deformation value, mark two points where the deformation ranges from 0.5 mm to the maximum value, and determine the laser action area. The length is from the deformation range of 0.5 mm to the maximum deformation area, and the width is 10% of the calibration diameter.

[0029] Step 3: The entire roller surface is preheated evenly. When the roller surface temperature is greater than 200°C, the requirement is met.

[0030] Step 4: Use a zigzag path and certain laser processing parameters to irradiate the roller surface.

[0031] Step 5: Each time the laser correction process is completed, a three-dimensional laser tracker is used to detect the deformation after correction, and a stress detector is used to monitor the stress change area. Steps 2-5 are repeated until the maximum deformation is less than 0.3 mm.

[0032] Furthermore, the laser processing parameters used in step 4 are 400-1000W, the laser action mode adopts a programmed pulse laser action mode, the pulse frequency is 13-18HZ, the action time is 40-60s, the scanning speed is 2000-3000mm / min, the spot size is 5mm, and the overlap amount is 0mm.

[0033] Furthermore, in step 4, an atmosphere protection cover needs to be used during the laser correction process, and the oxygen content in the local atmosphere protection space is controlled to be below 100 ppm to prevent oxidation pores from forming on the roller surface under laser irradiation.

[0034] Furthermore, in step 4, the power of the second and subsequent laser corrections must be smaller than that of the previous one, to ensure that the depth of each laser action on the substrate is smaller than that of the first time.

[0035] Implementation case 1.

[0036] Laser alignment of the air-cooled roller at the outlet of a steel plant's high-speed wire laying machine after laser cladding:

[0037] After cladding, the roller body is 1800mm long and 125mm in diameter

[0038] Step 1: Use a three-dimensional laser tracker to accurately measure the deformation of the deformed shaft and record the deformation value. The maximum deformation is 1.5 mm.

[0039] Step 2: Scan the laser action path according to the deformation value, and mark the area with deformation from 0.5mm to the maximum value, with a length of 800mm and a width of 12mm;

[0040] Step 3: Preheat the entire roller surface evenly and ensure the roller surface temperature is 220°C before laser correction;

[0041] Step 4: Using a zigzag path, the roller surface is irradiated with certain laser processing parameters, the laser processing parameters are 700W, scanning speed 2000mm / min, pulse frequency 13HZ, action time 60s, spot size 5mm, and overlap amount 0mm;

[0042] Step 5: After laser correction, a three-dimensional laser tracker is used to detect the deformation of 0.5 mm after correction;

[0043] Step 6: Continue to use the zigzag path and irradiate the roller surface with certain laser processing parameters. The laser processing parameters are 500W, scanning speed 2000mm / min, pulse frequency 13HZ, action time 60s, spot size 5mm, and overlap amount 0mm.

[0044] After laser correction, the deformation of the roller was corrected from 1.5mm to 0.2mm. After correction, no cracks were found during flaw detection. The roller was restored to good condition, turning waste into useful products.

[0045] Implementation case 2.

[0046] Laser correction of pickling and straightening rollers in a steel plant:

[0047] After cladding, the roller body is 2000mm long and 80mm in diameter

[0048] Step 1: Use a three-dimensional laser tracker to accurately measure the deformation of the deformed shaft and record the deformation value. The maximum deformation is 1.2 mm.

[0049] Step 2: Scan the laser action path according to the deformation value, and mark the area with deformation from 0.5mm to the maximum value, with a length of 900mm and a width of 8mm;

[0050] Step 3: Preheat the entire roller surface evenly and ensure the roller surface temperature is 220°C before laser correction;

[0051] Step 4: Using a zigzag path, the roller surface is irradiated with certain laser processing parameters, the laser processing parameters are 700W, scanning speed 3000mm / min, pulse frequency 18HZ, action time 40s, spot size 5mm, overlap amount 0mm;

[0052] Step 5: After laser correction, a three-dimensional laser tracker is used to detect the deformation amount after correction, which is 0.4 mm.

[0053] Step 6: Continue to use the zigzag path and irradiate the roller surface with certain laser processing parameters. The laser processing parameters are 500W, scanning speed 3000mm / min, pulse frequency 18HZ, action time 40s, spot size 5mm, and overlap amount 0mm.

[0054] After laser correction, the deformation of the roller was corrected from 1.2mm to 0.2mm. After correction, no cracks were found during flaw detection. The roller was restored to good condition, turning waste into useful products.

Claims

1. A laser correction method for high-carbon and high-hardness slender shaft parts, characterized in that: The specific steps include: Step 1: Use a three-dimensional laser tracker to accurately measure the deformation of the deformed shaft, measure the axial runout value of the entire slender roller surface, determine the maximum deformation position, and record the deformation value; Step 2: According to the deformation value, mark two points where the deformation ranges from 0.5mm to the maximum value, and determine the laser action area. The length is from the deformation range of 0.5mm to the maximum deformation area, and the width is 10% of the calibration diameter. Step 3: The entire roller surface is preheated evenly. When the roller surface temperature is greater than 200°C, it meets the requirements. Step 4: Using a zigzag path, the roller surface is irradiated with certain laser processing parameters; the laser processing parameters are 400-1000W, the laser action mode adopts a programmed pulse laser action mode, the pulse frequency is 13-18HZ, the action time is 40-60s, the scanning speed is 2000-3000mm / min, the spot size is 5mm, and the overlap amount is 0mm; an atmosphere protection cover is used during the laser correction process, and the oxygen content of the local atmosphere protection space is controlled to be below 100ppm; Step 5: Each time the laser correction process is completed, a three-dimensional laser tracker is used to detect the deformation after correction, and a stress detector is used to monitor the stress change area. Steps 2-5 are repeated until the maximum deformation is less than 0.3 mm.

2. The laser correction method for high-carbon and high-hardness slender shaft parts according to claim 1, characterized in that: In step 4, the power of the second and subsequent laser corrections must be less than the previous one to ensure that the depth of each laser action on the substrate is less than the first depth.

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