High-precision narrow-slit laser pipe cutting machining method for GCr15 bearing steel sleeve

Abstract

The invention discloses a high-precision narrow-slit laser pipe cutting machining method for a GCr15 bearing steel sleeve. A 3,000 W or 6,000 W optical fiber laser pipe cutting machine is adopted for cutting the GCr15 bearing steel pipe with the outer diameter being 22.5 mm-63 mm and the wall thickness being 2.0 mm-6. 0 mm, the laser output power is 1,500 W-6,000 W, the cutting speed is 4.5 m / min-11 m / min, the diameter of a laser nozzle is 0.15 mm-0. 30 mm, the width of a cutting seam is 0.15 mm-0. 40 mm (the typical value is 0.2 mm), and the ratio of the width of the cutting seam to the diameter of the nozzle is controlled within the range of 1.0 mm-1. 3. The cutting seam is extremely narrow and is far smaller than that of traditional saw cutting (2-3mm) and blade cutting, the material loss is remarkably reduced, and the yield of each ton of raw materials can be increased by about 15%; alloy blades are not needed, so that the cost is greatly reduced; and the efficiency is improved by 200%, finished products are free of burrs, precision is high, and the device is suitable for large-scale production of bearing accessories.

Description

Technical Field

[0001] This invention relates to the field of laser cutting technology, and specifically to a narrow-slit laser tube cutting method for GCr15 bearing steel sleeves. Background Technology

[0002] GCr15 bearing steel raceways are core components of rolling bearings. Traditional machining methods often involve sawing or blade cutting, which has the following drawbacks. question: 1. Kerf width: The kerf width of a saw is usually 2~3mm, and the kerf width of a blade is also 1.5~2.5mm, resulting in large material loss; 2. Low efficiency: Traditional processing requires multiple steps, resulting in low production efficiency; 3. Poor quality: The cut is prone to burrs and deformation, requiring secondary processing; 4. High cost: Alloy cutting tools are consumed quickly, resulting in high processing costs.

[0003] The number of finished rings produced from each ton of raw materials is limited, making it difficult for enterprises to improve their economic benefits. Summary of the Invention

[0004] This invention provides a high-precision narrow-slit laser tube cutting method for GCr15 bearing steel sleeves, aiming to solve the problems of wide slits, low material utilization, and poor processing quality in the prior art. Technical solution

[0005] A method for fiber laser cutting of GCr15 bearing steel sleeves, characterized by comprising the following steps: A 3000W or 6000W fiber laser tube cutter is used to cut GCr15 bearing steel tubes with an outer diameter of 22.5mm~63mm and a wall thickness of 2.0mm~6.0mm, with a finished product length of 5mm~25mm. Compressed air or high-purity nitrogen is used for cutting, with a gas pressure of 12.0 bar to 28.0 bar. The laser output power is 1500W~6000W, and the cutting speed is 4.5m / min~11m / min; The laser nozzle diameter is 0.15mm~0.30mm, and the kerf width is 0.15mm~0.40mm; The focal point is set at the outer wall of the pipe as the zero point, and the adjustment range is -2.0mm to +2.0mm. The chuck speed is 10r / min to 250r / min, and the cut-off delay is 0.05s to 2.0s. Technical solution

[0006] • When the cutting gas is high-purity nitrogen: nitrogen pressure 15.0 bar ~ 25.0 bar, focal point position +0.3 mm ~ +2.0 mm.

[0007] When the cutting gas is compressed air: air pressure 12.0 bar ~ 28.0 bar, focal point position -2.0 mm ~ -0.5 mm. • The preferred laser nozzle diameter is 0.20mm~0.25mm, and the kerf width is 0.18mm~0.28mm.

[0008] • The preferred wall thickness range is 2.0mm to 5.0mm.

[0009] Process Parameter Matching Instructions In this invention, parameters such as laser power, cutting speed, gas pressure, and focal point position are determined based on the pipe wall thickness and the type of cutting gas. The matching process is as follows: For nitrogen-assisted cutting (non-oxidizing, high precision): • When the wall thickness is 2.0~2.5mm, the laser power should be 1500~2500W, the cutting speed should be 8.0~11.0m / min, the gas pressure should be 15~20bar, and the focal position should be +1.0~+2.0mm. • When the wall thickness is 2.5~3.5mm, the laser power should be 2000~3500W, the cutting speed should be 6.0~8.5m / min, the gas pressure should be 15~22bar, and the focal position should be +0.8~+1.8mm. • When the wall thickness is 3.5~4.5mm, the laser power should be 3000~4500W, the cutting speed should be 5.0~7.0m / min, the gas pressure should be 18~25bar, and the focal position should be +0.5~+1.5mm. • When the wall thickness is 4.5~6.0mm, the laser power should be 4000~6000W, the cutting speed should be 4.5~6.0m / min, the gas pressure should be 20~28bar, and the focal position should be +0.3~+1.2mm.

[0010] For air-assisted cutting (low cost, allows for slight oxidation): • When the wall thickness is 2.0~2.5mm, the laser power should be 1500~2500W, the cutting speed should be 7.0~10.0m / min, the gas pressure should be 12~18bar, and the focal position should be -1.2~-2.0mm. • When the wall thickness is 2.5~3.5mm, the laser power should be 2000~3500W, the cutting speed should be 5.5~7.5m / min, the gas pressure should be 12~20bar, and the focal position should be -1.0~-1.8mm. • When the wall thickness is 3.5~4.5mm, the laser power should be 3000~4500W, the cutting speed should be 4.5~6.5m / min, the gas pressure should be 15~22bar, and the focal position should be -0.8~-1.5mm. • When the wall thickness is 4.5~6.0mm, the laser power should be 4000~6000W, the cutting speed should be 4.5~5.5m / min, the gas pressure should be 18~25bar, and the focal position should be -0.5~-1.2mm.

[0011] The matching relationship between nozzle diameter and kerf width: • When the nozzle diameter is 0.15~0.18mm, the kerf width is 0.15~0.22mm; • When the nozzle diameter is 0.18~0.22mm, the kerf width is 0.18~0.26mm; • When the nozzle diameter is 0.22~0.26mm, the kerf width is 0.22~0.32mm; • When the nozzle diameter is 0.26~0.30mm, the kerf width is 0.26~0.40mm.

[0012] In the above matching relationship, the kerf width is slightly larger than the nozzle diameter, and their ratio is controlled within the range of 1.0 to 1.3, which is in line with laser cutting. Physical laws.

[0013] The above parameter matching relationship can be determined through conventional experiments. Based on the teachings of this invention, those skilled in the art can select the optimal parameter combination according to different wall thicknesses, power, and gas types to achieve high-precision and high-efficiency laser cutting. Beneficial effects

[0014] 1. Extremely narrow kerf, extremely high material utilization: The kerf is only 0.2mm (typical value), which is much smaller than traditional sawing (2~3mm) and blade cutting (1.5~2.5mm). Material loss is significantly reduced, and the output of each ton of GCr15 bearing steel pipe can be increased by about 15%, resulting in a significant improvement in economic benefits. 2. No consumables required: Eliminates the need for alloy blades, significantly reducing production costs; 3. Dual-mode cutting: Can use compressed air or nitrogen to adapt to different precision and surface quality requirements; 4. Significantly improved efficiency: Taking the same specifications of pipe (outer diameter 36mm, wall thickness 2.0mm, cutting height 11.0mm) as an example, traditionally one person with three machines can produce about 40,000 pieces in 10 hours, while this invention can produce up to 120,000 pieces, improving efficiency by 200%. 5. Excellent finished product quality: smooth cut without burrs or oxidation (nitrogen mode), dimensional accuracy ±0.1mm, no secondary processing required; 6. Equipped with a dedicated high-pressure gas supply system, ensuring stable and clean gas for more reliable cutting quality; 7. Strong process adaptability: Wide parameter range, adaptable to different specifications of pipes and equipment, and highly versatile. Detailed Implementation

[0015] The following specific implementation methods are all based on the process parameters modified in this application. Among them, the slit width can be adjusted within the range of 0.15mm to 0.40mm according to the nozzle diameter, and the ratio of the slit width to the nozzle diameter is controlled within the range of 1.0 to 1.3.

[0016] Those skilled in the art will understand that the process parameters of the present invention are well adaptable to pipes with wall thicknesses in the range of 2.0 mm to 6.0 mm; for pipes with wall thicknesses slightly less than 2.0 mm, the laser power can be appropriately reduced or the cutting speed increased based on the parameters of this patent, and the same excellent cutting quality can still be obtained.

[0017] In a preferred embodiment of the present invention, the chuck rotation speed is 10~250 r / min, and the cutting delay is 0.05~2.0 s. The chuck rotation speed is determined by the cutting speed and the outer diameter of the tube: n = v / (πD), where n is the chuck rotation speed (r / min), v is the cutting speed (m / min), and D is the outer diameter of the tube (m). The cutting delay is set according to the wall thickness and gas type: 0.05~0.30 s for thin walls (2.0~3.0 mm), 0.20~0.80 s for medium walls (3.0~4.5 mm), and 0.80~1.50 s for thick walls (4.5~6.0 mm). The delay can be appropriately shortened when using high-pressure gas and appropriately extended when using low-pressure gas. The above settings of the chuck rotation speed and cutting delay parameters ensure that the radial feed of the laser head is synchronized with the rotation of the tube, and that the cuts are completely separated without adhesion.

[0018] I. Example of Nitrogen-Assisted Cutting Example 1 (thin-walled, outer diameter 25mm, wall thickness 2.0mm) A 2000W fiber laser tube cutter was used, with a cutting speed of 10.0 m / min, a nitrogen pressure of 18 bar, a focal point of +1.5 mm, a nozzle diameter of 0.20 mm, and a kerf width of 0.20 mm.

[0019] Results: The cut is free of oxidation and burrs, with a dimensional accuracy of ±0.05mm.

[0020] Example 2 (thin-walled, outer diameter 36mm, wall thickness 2.0mm, 10 rings cut in one feeding) A 2000W fiber laser tube cutter was used, with a cutting speed of 9.0m / min, a nitrogen pressure of 16bar, a focal position of +1.2mm, a nozzle diameter of 0.20mm, and a kerf width of 0.20mm.

[0021] Results: A single feed can continuously cut 10 finished rings (each 11.0mm high), with smooth cuts, no burrs, no oxidation, and dimensional accuracy of ±0.05mm, significantly improving production efficiency.

[0022] Example 3 (middle wall, outer diameter 45mm, wall thickness 3.5mm) A 3500W fiber laser tube cutter was used, with a cutting speed of 7.0m / min, a nitrogen pressure of 20bar, a focal point of +1.2mm, a nozzle diameter of 0.22mm, and a kerf width of 0.22mm.

[0023] Results: The end face is flat and smooth, with no slag residue, and the processing time for a single piece is reduced by 40%.

[0024] Example 4 (thick-walled, outer diameter 60mm, wall thickness 5.5mm) A 5500W fiber laser tube cutter was used, with a cutting speed of 5.0m / min, a nitrogen pressure of 25bar, a focal point of +0.8mm, a nozzle diameter of 0.26mm, and a kerf width of 0.28mm.

[0025] Results: Cut perpendicularity ≤0.08mm, no deformation in the heat-affected zone.

[0026] II. Examples of Air-Assisted Cutting Example 5 (thin-walled, outer diameter 25mm, wall thickness 2.0mm) A 2000W fiber laser tube cutter was used, with a cutting speed of 9.0m / min, an air pressure of 15bar, a focal point of -1.5mm, a nozzle diameter of 0.20mm, and a kerf width of 0.22mm.

[0027] Results: Smooth cut, slight oxide layer, and 30% cost reduction.

[0028] Example 6 (middle wall, outer diameter 45mm, wall thickness 3.5mm) A 3500W fiber laser tube cutter was used, with a cutting speed of 6.5m / min, an air pressure of 18bar, a focal point of -1.2mm, a nozzle diameter of 0.22mm, and a kerf width of 0.24mm.

[0029] Results: No burrs, slight oxide layer, overall efficiency improved by 50%.

[0030] Example 7 (thick-walled, outer diameter 60mm, wall thickness 5.5mm) A 5500W fiber laser tube cutter was used, with a cutting speed of 4.5m / min, an air pressure of 22bar, a focal point of -0.8mm, a nozzle diameter of 0.26mm, and a kerf width of 0.30mm.

[0031] Results: Excellent cut quality, no deformation, and significantly increased number of rings per ton of raw material. Attached Figure Description

[0032] Figure 1 is a schematic diagram comparing the kerf of conventional cutting with the laser cutting of this invention. The left side shows conventional cutting with a kerf width of approximately 2 mm; the right side shows laser cutting of this invention with a kerf width of only approximately 0.2 mm, significantly reducing material loss.

[0033] Figure 2 shows a cross-sectional photograph of a bearing steel raceway cut with a traditional cutter. The end face is rough with obvious burrs, requiring secondary processing and resulting in low material utilization.

[0034] Figure 3 shows a photograph of a bearing steel raceway sample prepared by the air-assisted cutting process of this invention. Compressed air is used as the assist gas, resulting in a narrow kerf (approximately 0.2 mm), a smooth end face, no burrs, and only an extremely thin oxide layer on the cut surface. This method is low-cost and highly efficient, suitable for machining non-critical surfaces where surface oxidation requirements are not high.

[0035] Figure 4 shows a photograph of a bearing steel raceway sample prepared by the nitrogen-assisted cutting process of this invention. High-purity nitrogen is used as the assist gas, resulting in an extremely narrow kerf (approximately 0.2 mm), a mirror-like smooth end face, and no oxidation or burrs, with a dimensional accuracy of ±0.05 mm. This method is suitable for machining critical components requiring high precision and no oxidation.

Claims

1. A GCr15 bearing steel laser cutting process, characterized in that, Includes the following steps: Using a 3000W or 6000W fiber laser tube cutter, for outer diameters of 22.5mm to 63mm and wall thicknesses... GCr15 bearing steel pipes with a diameter of 2.0mm to 6.0mm are cut to a finished length of 5mm to 25mm. Compressed air or high-purity nitrogen is used for cutting, with a gas pressure of 12.0 bar to 28.0 bar. The laser output power is 1500W~6000W, and the cutting speed is 4.5m / min~11m / min; The laser nozzle diameter is 0.15mm~0.30mm, and the kerf width is 0.15mm~0.40mm; The focal point is set at the outer wall of the pipe as the zero point, and the adjustment range is -2.0mm to +2.0mm. The chuck speed is 10r / min to 250r / min, and the cut-off delay is 0.05s to 2.0s.

2. The GCr15 bearing steel laser cutting process according to claim 1, wherein, When cut When the cutting gas is high-purity nitrogen: Nitrogen pressure is 15.0 bar to 25.0 bar; The focus position adjustment range is +0.3mm to +2.0mm.

3. The GCr15 bearing steel laser cutting process according to claim 1, wherein, When cut When the cutting gas is compressed air: The air pressure is 12.0 bar to 28.0 bar. The focus position adjustment range is -2.0mm to -0.5mm.

4. The GCr15 bearing steel laser cutting process of claim 1, wherein, The The laser nozzle diameter is 0.20mm~0.25mm, and the kerf width is 0.18mm~0.28mm.

5. The GCr15 bearing steel laser cutting process of claim 1, wherein, The The ratio of the kerf width to the laser nozzle diameter is 1.0 to 1.

3.

6. The GCr15 bearing steel laser cutting process of claim 1, wherein, The The wall thickness ranges from 2.0mm to 5.0mm.

7. The laser cutting process for GCr15 bearing steel according to claim 1, characterized in that, The The length tolerance of the cut finished product is ±0.1mm, and the surface roughness of the cut surface Ra≤3.2μm.

8. A GCr15 bearing steel ring prepared using the process described in any one of claims 1 to 7, characterized in that... The characteristic is that the ferrule is directly cut from the tubing, with no burrs or heat-affected zone deformation on the end face, and precise dimensions. Degree ±0.1mm.

9. The GCr15 bearing steel ring of claim 8, wherein, When nitrogen gas cutting is used When cutting, there is no oxide layer on the cut surface; when air cutting is used, there is only a slight oxide layer on the cut surface.

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