An S3 double hexagon bit and its preparation method

Abstract

The present invention relates to the technical field of the preparation of double hexagon bits, and particularly to a method for preparing an S3 double hexagon bit, including: performing cold drawing treatment on the surface-treated S3 wire rod through a wire drawing machine to obtain a semi-finished wire; performing spheroidizing annealing treatment on the wire through a pit type annealing furnace to obtain a granular pearlite structure; determining the qualification of the annealing treatment according to the uniformity index of the granular pearlite; performing pickling and phosphating treatment on the annealed qualified wire and then performing hexagonal drawing through a wire drawing machine to obtain a hexagonal wire; obtaining an S3 double hexagon bit by performing shearing, shaping, and rod shrinking on the drawn qualified hexagonal wire through a cold heading machine; determining the qualification of a single S3 double hexagon bit according to the comprehensive performance characteristic value and determining the qualification of the preparation of the S3 double hexagon bit according to the proportion of the qualified S3 double hexagon bits in the sampling inspection. The present invention improves the performance stability and preparation efficiency of the double hexagon bit.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of double hexagon bits, and particularly to a method for preparing an S3 double hexagon bit. Background Art

[0002] S3 is a medium-carbon alloy tool material with high silicon. The added Si significantly improves the hardness and strength of ferrite and austenite, increases the elastic limit, yield strength and yield ratio of the steel, and improves the fatigue strength. The traditional process for S3 double hexagon bits is that the hot-rolled wire rods from the steel mill are pickled and drawn into hexagonal wire coils. The wire coils are then cut into sections by a blanking machine and then formed into small-headed hexagons by turning. However, this technical route has a large metal loss during the turning and milling processes, low efficiency, and the machining accuracy is greatly affected by tool wear. Therefore, it is necessary to develop a spheroidizing cold heading forming process.

[0003] Chinese Patent Application Publication No.: CN106862475A discloses a cold heading production process for an internal hexagon double-headed stud blank, which is characterized by including the following steps: blanking; shaping; backward extrusion and stretching; upsetting; backward extrusion and stretching; internal hexagon forming; extrusion of a through hole. The present invention centrally uses a variety of technologies such as strong stretching, internal hexagon forming, and extrusion perforation to form a complete processing technology for machining this internal hexagon double-headed stud on a multi-station cold heading machine.

[0004] However, the following problems exist in the prior art: The lack of intelligent detection and adjustment during the processing in the prior art results in poor product quality consistency and low production efficiency. Summary of the Invention

[0005] Therefore, the present invention provides a method for preparing an S3 double hexagon bit to overcome the problems in the prior art that the lack of intelligent detection and adjustment during the processing leads to unqualified product quality and low production efficiency.

[0006] To achieve the above object, the present invention provides a method for preparing an S3 double hexagon bit, including:

[0007] Performing cold drawing treatment on the surface-treated S3 wire rods through a wire drawing machine to obtain semi-finished wire rods;

[0008] Performing spheroidizing annealing treatment on the wire rods through a pit type annealing furnace to obtain a granular pearlite structure;

[0009] Judging the qualification of the annealing treatment according to the uniformity index of the granular pearlite. Based on the condition that the annealing treatment is unqualified, increasing the annealing holding time, or, when the annealing treatment is judged to be unqualified by obtaining the fracture morphology characteristic values of the wire rods through a torsion test combined with a scanning electron microscope and according to the fracture morphology characteristic values, increasing the annealing temperature;

[0010] Performing pickling and phosphating treatment on the wire rods qualified in the annealing treatment and then performing hexagonal drawing through a wire drawing machine to obtain hexagonal wires;

[0011] Determine the surface defect index through the surface morphology analysis of the hexagonal wire obtained by a metallurgical microscope and judge the qualification of the hexagonal drawing based on the surface defect index. Reduce the drawing speed based on the unqualified conditions or determine the maximum drawing length according to the surface roughness.

[0012] The qualified hexagonal wire is sheared, shaped, and necked down by a cold heading machine to obtain an S3 double hexagonal bit.

[0013] Sample and test the torque bearing capacity and surface quality of the S3 double hexagonal bit and determine the comprehensive performance characteristic value of a single S3 double hexagonal bit.

[0014] Judge the qualification of a single S3 double hexagonal bit based on the comprehensive performance characteristic value and judge the qualification of the preparation of the S3 double hexagonal bit according to the proportion of qualified S3 double hexagonal bits in the sampling inspection. Based on the unqualified preparation conditions, determine the reason for the unqualified preparation according to the difference between the preset proportion and the proportion and increase the shaping pressure or reduce the stamping speed.

[0015] Furthermore, judge the qualification of the annealing treatment according to the uniformity index of the granular pearlite. Among them, if the uniformity index is less than the first preset uniformity index, it is judged that the annealing treatment is qualified, and the wire rod is subjected to pickling and phosphating treatment.

[0016] If the uniformity index is greater than or equal to the first preset uniformity index and less than the second preset uniformity index, it is judged that the annealing treatment is unqualified, and the qualification of the annealing treatment is judged again according to the fracture morphology characteristic value.

[0017] If the uniformity index is greater than or equal to the second preset uniformity index, it is judged that the annealing treatment is unqualified, and the annealing holding time is increased according to the difference between the uniformity index and the second preset uniformity index.

[0018] Furthermore, the uniformity index is jointly determined by the size uniformity and distribution uniformity of the granular pearlite.

[0019] Furthermore, based on the condition that the fracture morphology characteristic value is less than the preset morphology characteristic value, it is judged again that the annealing treatment is unqualified, and the annealing temperature is increased according to the difference between the preset morphology characteristic value and the fracture morphology characteristic value.

[0020] Based on the condition that the fracture morphology characteristic value is greater than or equal to the preset morphology characteristic value, it is judged again that the annealing treatment is qualified, and the wire rod is subjected to pickling and phosphating treatment.

[0021] Furthermore, the fracture morphology characteristic value is jointly determined by the fracture shrinkage rate and the fracture roughness.

[0022] Further, the qualification of hexagonal drawing is determined according to the surface defect index. Among them, if the surface defect index is less than the first preset surface defect index, it is determined that the hexagonal drawing is qualified, and the hexagonal wire is cold-headed to obtain an S3 double hexagonal bit;

[0023] If the surface defect index is greater than or equal to the first preset surface defect index and less than the second preset surface defect index, it is determined that the hexagonal drawing is unqualified, and the drawing speed is reduced according to the difference between the second preset surface defect index and the surface defect index;

[0024] If the surface defect index is greater than or equal to the second preset surface defect index, it is determined that the hexagonal drawing is unqualified, and the maximum drawing length is reduced according to the surface roughness of the hexagonal wire.

[0025] Further, based on the condition that the comprehensive performance characteristic value is less than the preset comprehensive performance characteristic value, it is determined that a single S3 double hexagonal bit is unqualified, and the unqualified S3 double hexagonal bit is marked; based on the condition that the comprehensive performance characteristic value is greater than or equal to the preset comprehensive performance characteristic value, it is determined that a single S3 double hexagonal bit is qualified, and the qualification of the remaining S3 double hexagonal bits is continuously detected and determined.

[0026] Further, the qualification of the preparation of the S3 double hexagonal bit is determined according to the proportion of qualified S3 double hexagonal bits in the sampling inspection. Among them, if the proportion is less than the preset proportion, it is determined that the preparation of the S3 double hexagonal bit is unqualified, and the reason for the unqualified preparation is determined according to the difference between the preset proportion and the proportion;

[0027] If the proportion is greater than or equal to the preset proportion, it is determined that the preparation of the S3 double hexagonal bit is qualified, and the preparation is completed according to the current preparation parameters.

[0028] Further, the reason for the unqualified preparation is determined according to the proportion difference. Among them, if the proportion difference is less than the preset proportion difference, it is determined that the reason for the unqualified preparation is that the shaping pressure in the cold-heading process does not meet the standard, and the shaping pressure is increased according to the opposite side tolerance value of the unqualified S3 double hexagonal bit;

[0029] If the proportion difference is greater than or equal to the preset proportion difference, it is determined that the reason for the unqualified preparation is that the stamping speed in the cold-heading process does not meet the standard, and the stamping speed is reduced according to the deformation rate of the unqualified S3 double hexagonal bit;

[0030] The proportion difference is the difference between the preset proportion and the proportion.

[0031] The present invention also provides an S3 double hexagonal bit, and the ratio of the opposite side lengths of the two end faces of the S3 double hexagonal bit is 3:4.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows. By optimizing the process flow, the present invention significantly improves the product quality and production efficiency. Through the processes of cold drawing, annealing, pickling, hexagonal drawing, and cold heading, the problem of material waste in traditional turning and milling processing is avoided. Additionally, through the optimized heat treatment and forming processes, the bit has a more uniform organizational structure and higher dimensional accuracy, while also improving the production efficiency.

[0033] Furthermore, the present invention introduces a uniformity index to determine the qualification of the annealing treatment. When the annealing treatment is determined to be unqualified, the qualification of the annealing treatment is re-determined based on the fracture morphology characteristic values, or the annealing holding time is increased. The uniformity index is determined jointly by the size uniformity and distribution uniformity of the particles, improving the accuracy of the determination. At the same time, through intelligent hierarchical determination and precise parameter adjustment, the problems of lagging quality control and rough adjustment in the traditional annealing process are effectively solved, realizing the refined management of the spheroidizing annealing process of S3 steel balls.

[0034] Furthermore, the present invention determines the qualification of the hexagonal drawing based on the surface defect index. Based on the unqualified conditions, the drawing speed or the maximum drawing length is reduced. Through the real-time regulation of the drawing process, a better quality wire rod foundation is provided for the subsequent cold heading process.

[0035] Furthermore, the present invention determines the qualification of the preparation of S3 double hexagonal bits based on the proportion of qualified S3 double hexagonal bits in the sampling inspection. Based on the unqualified conditions, the reasons for the unqualified preparation are determined and the parameters of the cold heading are adjusted. By promptly giving the process adjustment plan, the preparation efficiency is improved, and at the same time, the product quality is ensured.

[0036] Furthermore, the present invention selects S3 wire rod as the raw material, improving the elastic limit, yield strength, and fatigue strength of the product. Description of the Drawings

[0037] Figure 1 It is a flowchart of the preparation method of the S3 double hexagonal bit according to the embodiment of the present invention;

[0038] Figure 2 It is a flowchart of determining the qualification of the annealing treatment according to the embodiment of the present invention;

[0039] Figure 3 It is a flowchart of determining the qualification of the preparation of the S3 double hexagonal bit according to the embodiment of the present invention;

[0040] Figure 4 It is a flowchart of determining the reasons for the unqualified preparation of the S3 double hexagonal bit according to the embodiment of the present invention. Detailed Embodiments

[0041] To make the objectives and advantages of the present invention more clear and understandable, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0043] It should be noted that the data in this embodiment are all obtained through comprehensive analysis and evaluation of the historical test data and corresponding historical test results of the present invention in the three months before this test. Those skilled in the art can understand that the determination method of the above single parameter by the present invention can be to select the value with the highest proportion according to the data distribution as the preset standard parameter, use weighted summation to obtain the value as the preset standard parameter, substitute each historical data into a specific formula and use the value obtained by this formula as the preset standard parameter or other selection methods, as long as it satisfies that the present invention can clearly define different specific situations in the single determination process through the obtained values.

[0044] Please refer to Figures 1 to 4 as shown, which are respectively the flowchart of the preparation method of the S3 double hexagon bit in the embodiment of the present invention; the flowchart of determining the qualification of the annealing treatment in the embodiment of the present invention; the flowchart of determining the qualification of the preparation of the S3 double hexagon bit in the embodiment of the present invention; the flowchart of determining the reasons for the unqualified preparation of the S3 double hexagon bit in the embodiment of the present invention.

[0045] The preparation method of the S3 double hexagon bit in the embodiment of the present invention includes:

[0046] Step S1, cold drawing the surface-treated S3 wire rod through a wire drawing machine to obtain semi-finished wire;

[0047] Step S2, subjecting the wire to spheroidizing annealing treatment in a pit-type annealing furnace to obtain a granular pearlite structure;

[0048] Step S3, determining the qualification of the annealing treatment according to the uniformity index of the granular pearlite. Based on the unqualified conditions of the annealing treatment, increase the annealing holding time, or obtain the fracture morphology characteristic values of the wire through a torsion test combined with a scanning electron microscope and increase the annealing temperature when the annealing treatment is determined to be unqualified according to the fracture morphology characteristic values;

[0049] Step S4, subjecting the wire with qualified annealing treatment to pickling and phosphating treatment and then performing hexagonal drawing through a wire drawing machine to obtain hexagonal wire;

[0050] Step S5: Determine the surface defect index through the surface morphology analysis of the hexagonal wire obtained by a metallographic microscope, and judge the qualification of the hexagonal drawing based on the surface defect index. Based on the unqualified conditions, reduce the drawing speed or determine the maximum drawing length according to the surface roughness;

[0051] Step S6: Pass the qualified hexagonal wire through a cold heading machine for shearing, shaping, and necking to obtain an S3 double hexagonal bit;

[0052] Step S7: Sample and test the torque bearing capacity and surface quality of the S3 double hexagonal bits and determine the comprehensive performance characteristic values of individual S3 double hexagonal bits;

[0053] Step S8: Judge the qualification of individual S3 double hexagonal bits based on the comprehensive performance characteristic values and judge the qualification of the preparation of S3 double hexagonal bits according to the proportion of qualified S3 double hexagonal bits in the sampling inspection. Based on the unqualified preparation conditions, determine the reasons for the unqualified preparation according to the difference between the preset proportion and the proportion, and increase the shaping pressure or reduce the stamping speed.

[0054] Specifically, the surface treatment of the S3 wire rod includes rust removal, pickling, water washing, phosphating, and saponification treatment. Through the surface treatment of the S3 wire rod, the scale on the surface of the wire rod is removed and a phosphate lubricating layer is formed to make it suitable for drawing treatment.

[0055] In the embodiment of the present invention, the initial annealing temperature of the spheroidizing annealing treatment is set to 760°C, and the initial holding time is set to 8 hours. However, the above values are not limited to this, and those skilled in the art can adjust these values according to actual needs.

[0056] Specifically, the processing process of step S6 includes: feeding the drawn hexagonal wire into a cold heading machine. The cold heading machine first shears the fed wire, and then in the second process, the first shaping of the cut end face is carried out. Then in the third process, it is flipped to shape the other shearing surface. In the fourth process, necking is carried out, first necking into a round shape, and in the fifth station, it is translated and the round rod is necked into a small hexagon to obtain the final S3 double hexagonal bit product.

[0057] Specifically, judge the qualification of the annealing treatment according to the uniformity index of the granular pearlite. Among them, if the uniformity index is less than the first preset uniformity index of 0.75, it is judged that the annealing treatment is qualified, and the wire is subjected to pickling and phosphating treatment;

[0058] If the uniformity index is greater than or equal to the first preset uniformity index and less than the second preset uniformity index of 0.90, it is judged that the annealing treatment is unqualified, and the qualification of the annealing treatment is judged again according to the fracture morphology characteristic values;

[0059] If the uniformity index is greater than or equal to the second preset uniformity index, it is determined that the annealing treatment is unqualified, and the annealing holding time is increased according to the difference between the uniformity index and the second preset uniformity index.

[0060] In the embodiments of the present invention, the value of the first preset uniformity index is 0.75, and the value of the second preset uniformity index is 0.90. However, the above values are not limited thereto, and those skilled in the art can adjust the values according to actual needs.

[0061] Specifically, the uniformity index is jointly determined by the size uniformity and distribution uniformity of granular pearlite, and is calculated by the following formula. In the formula, is the uniformity index. is the size uniformity weight coefficient, and it is set that = 0.55. is the size uniformity. is the distribution uniformity weight coefficient, and it is set that = 0.42. is the distribution uniformity.

[0062] Specifically, the uniformity index of granular pearlite is obtained by combining a metallographic microscope with an image processing algorithm. Five points are randomly selected on the wire rod to take metallographic images, and then the size uniformity and distribution uniformity of the granular pearlite in each image are determined through the image processing algorithm. Then, the average value of the uniformity indices obtained from each image is taken as the uniformity index of the granular pearlite. Among them, the size uniformity represents the degree of dispersion of the pearlite particle area and is used to quantify the size consistency of the carbide particles in the pearlite; the distribution uniformity is used to evaluate the spatial distribution uniformity of the pearlite particles in the matrix and avoid local aggregation or sparseness.

[0063] Specifically, the annealing holding time is increased according to the difference between the uniformity index and the second preset uniformity index. Among them, if the difference in the uniformity index is less than the first preset difference in the uniformity index of 0.05, the annealing holding time is increased to the corresponding value using the first time adjustment coefficient of 1.05.

[0064] If the difference in the uniformity index is greater than or equal to the first preset difference in the uniformity index and less than the second preset difference in the uniformity index of 0.12, the annealing holding time is increased to the corresponding value using the second time adjustment coefficient of 1.13.

[0065] If the difference in the uniformity index is greater than or equal to the second preset difference in the uniformity index, the annealing holding time is increased to the corresponding value using the third time adjustment coefficient of 1.25.

[0066] The uniformity index difference is the difference between the uniformity index and the second preset uniformity index.

[0067] In the embodiment of the present invention, the first preset uniformity index difference is taken as 0.05, and the second preset uniformity index difference is taken as 0.12. However, the above values are not limited thereto, and those skilled in the art can adjust this value according to actual needs.

[0068] Specifically, in step S3, a torsion test is performed by a microcomputer-controlled torsion testing machine, and the torsion speed is set to 3 r / min. Through the torsion test, not only the maximum torque and shear modulus of the wire rod can be obtained, but also the morphology of the wire rod fracture can be obtained. Then, the fracture morphology characteristic value is obtained by observing the fracture morphology with a scanning electron microscope.

[0069] Specifically, based on the condition that the fracture morphology characteristic value is less than the preset morphology characteristic value of 0.7, it is secondarily determined that the annealing treatment is unqualified, and the annealing temperature is increased according to the difference between the preset morphology characteristic value and the fracture morphology characteristic value;

[0070] Based on the condition that the fracture morphology characteristic value is greater than or equal to the preset morphology characteristic value, it is secondarily determined that the annealing treatment is qualified, and the wire rod is subjected to pickling and phosphating treatment.

[0071] Specifically, the fracture morphology characteristic value is jointly determined by the fracture shrinkage rate and the fracture roughness, and is calculated by the following formula. , in the formula, is the fracture morphology characteristic value, is the shrinkage rate weight coefficient, set = 0.52, is the shrinkage rate threshold, set = 10%, is the fracture shrinkage rate, is the roughness weight coefficient, set = 0.45, is the roughness threshold, set = 15 μm, is the fracture roughness.

[0072] Specifically, the fracture shrinkage rate and the fracture roughness are obtained by image analysis software, such as ImageJ, MATLAB, etc., and are not specifically limited.

[0073] Specifically, the annealing temperature is positively correlated with the fracture morphology difference. Among them, the fracture morphology difference is the difference between the preset morphology characteristic value and the fracture morphology characteristic value. In this embodiment, the adjustment range of the annealing temperature is 760 °C to 780 °C.

[0074] Specifically, the qualification of hexagonal drawing is determined according to the surface defect index. Among them, if the surface defect index is less than 3% of the first preset surface defect index, the hexagonal drawing is determined to be qualified, and the hexagonal wire is cold-headed to obtain an S3 double hexagonal bit;

[0075] If the surface defect index is greater than or equal to the first preset surface defect index and less than 5% of the second preset surface defect index, it is determined that the hexagonal drawing is unqualified, and the drawing speed is reduced according to the difference between the second preset surface defect index and the surface defect index;

[0076] If the surface defect index is greater than or equal to the second preset surface defect index, it is determined that the hexagonal drawing is unqualified, and the maximum drawing length is reduced according to the surface roughness of the hexagonal wire.

[0077] In the embodiment of the present invention, the value of the first preset surface defect index is 3%, and the value of the second preset surface defect index is 5%. However, the above values are not limited to this, and those skilled in the art can adjust this value according to actual needs.

[0078] Specifically, the surface defect index is the ratio of the defect area in the acquisition area of the hexagonal wire to the acquisition area. The calculation method is to randomly select 5 points on the surface of the hexagonal wire, take surface images through a metallographic microscope, obtain the defect area through image analysis software and calculate the surface defect index of a single image, and then take the average value of the surface defect indices of these 5 points to obtain the surface defect index of the hexagonal wire. Among them, the defects include surface cracks, scratches, pits, etc., and are not specifically limited.

[0079] Specifically, in the step S7, the sampling ratio is 5%, the surface quality is characterized by the surface defect value, and the process of jointly determining the comprehensive performance characteristic value by the torque bearing capacity and the surface defect value of the S3 double hexagonal bit is as follows: Take the square root of the ratio of the torque bearing capacity to the torque bearing capacity threshold and multiply it by the first weight coefficient to obtain the torque bearing capacity evaluation value. Among them, the torque bearing capacity threshold is set to 15, and the first weight coefficient is set to 0.6; Take the square root of the ratio of the surface defect value to the surface defect threshold and multiply it by the second weight coefficient to obtain the surface defect evaluation value. Among them, the surface defect threshold is set to 5%, and the second weight coefficient is set to 0.4; Add the torque bearing capacity evaluation value and the surface defect evaluation value to obtain the comprehensive performance characteristic value.

[0080] Specifically, the surface defect value is the ratio of the defect area of the S3 double hexagonal bit to the overall area, and is obtained by analyzing and calculating the images collected from multiple perspectives of the S3 double hexagonal bit.

[0081] Specifically, based on the condition that the comprehensive performance characteristic value is less than 0.92 of the preset comprehensive performance characteristic value, it is determined that a single S3 double hexagon bit is unqualified, and the unqualified S3 double hexagon bit is marked; based on the condition that the comprehensive performance characteristic value is greater than or equal to the preset comprehensive performance characteristic value, it is determined that a single S3 double hexagon bit is qualified, and the qualification of the remaining S3 double hexagon bits is continuously detected and determined.

[0082] In the embodiment of the present invention, the preset comprehensive performance characteristic value is taken as 0.92, but the above value is not limited thereto, and those skilled in the art can adjust this value according to actual needs.

[0083] Specifically, the qualification of the S3 double hexagon bit preparation is determined according to the proportion of qualified S3 double hexagon bits in the sampling inspection. Among them, if the proportion is less than the preset proportion of 95%, it is determined that the S3 double hexagon bit preparation is unqualified, and the reason for the unqualified preparation is determined according to the difference between the preset proportion and the proportion;

[0084] If the proportion is greater than or equal to the preset proportion, it is determined that the S3 double hexagon bit preparation is qualified, and the preparation is completed according to the current preparation parameters.

[0085] Specifically, the reason for the unqualified preparation is determined according to the proportion difference. Among them, if the proportion difference is less than the preset proportion difference of 2%, it is determined that the reason for the unqualified preparation is that the shaping pressure in the cold heading process does not meet the standard, and the shaping pressure is increased according to the opposite side tolerance value of the unqualified S3 double hexagon bit;

[0086] If the proportion difference is greater than or equal to the preset proportion difference, it is determined that the reason for the unqualified preparation is that the stamping speed in the cold heading process does not meet the standard, and the stamping speed is reduced according to the deformation rate of the unqualified S3 double hexagon bit;

[0087] The proportion difference is the difference between the preset proportion and the proportion.

[0088] In the embodiment of the present invention, the preset proportion is taken as 95%, and the preset proportion difference is taken as 2%, but the above values are not limited thereto, and those skilled in the art can adjust this value according to actual needs.

[0089] Specifically, the shaping pressure is increased according to the opposite side tolerance value of the unqualified S3 double hexagon bit. Among them, if the opposite side tolerance value is less than the first preset tolerance value of 0.08 mm, the shaping pressure is increased to the corresponding value using the first pressure adjustment coefficient of 1.1;

[0090] If the opposite side tolerance value is greater than or equal to the first preset tolerance value and less than the second preset tolerance value of 0.15 mm, the shaping pressure is increased to the corresponding value using the second pressure adjustment coefficient of 1.3;

[0091] If the opposite side tolerance value is greater than or equal to the second preset tolerance value, the shaping pressure is increased to the corresponding value using the third pressure adjustment coefficient of 1.5.

[0092] In the embodiment of the present invention, the initial shaping pressure is set to 200 MPa, the first preset tolerance value is taken as 0.08 mm, and the second preset tolerance value is taken as 0.15 mm. However, the above values are not limited thereto, and those skilled in the art can adjust these values according to actual needs.

[0093] Specifically, the opposite side tolerance value of the unqualified S3 double hexagon bit is measured by an on-line laser measuring instrument.

[0094] Specifically, the stamping speed is reduced according to the deformation rate of the unqualified S3 double hexagon bit. Among them, if the deformation rate is less than the first preset deformation rate of 1.5%, the stamping speed is reduced to the corresponding value using the first speed adjustment coefficient of 0.92;

[0095] If the deformation rate is greater than or equal to the first preset deformation rate and less than the second preset deformation rate of 3.0%, the stamping speed is reduced to the corresponding value using the second speed adjustment coefficient of 0.83;

[0096] If the deformation rate is greater than or equal to the second preset deformation rate, the stamping speed is reduced to the corresponding value using the third speed adjustment coefficient of 0.75.

[0097] In the embodiment of the present invention, the initial stamping speed is set to 70 mm / s, the first preset deformation rate is taken as 1.5%, and the second preset deformation rate is taken as 3.0%. However, the above values are not limited thereto, and those skilled in the art can adjust these values according to actual needs.

[0098] Specifically, the deformation rate of the unqualified S3 double hexagon bit is measured by a laser scanner.

[0099] In the embodiment of the present invention for the S3 double hexagon bit, the ratio of the opposite side lengths of the two end faces of the S3 double hexagon bit is 3:4, and the length is not specifically limited.

[0100] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

[0101] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention; for those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of an S3 double hexagon bit, characterized in that, Including: Cold-drawing the surface-treated S3 wire rod through a wire-drawing machine to obtain semi-finished wire; Performing spheroidizing annealing treatment on the wire through a pit-type annealing furnace to obtain a granular pearlite structure; Judging the qualification of the annealing treatment according to the uniformity index of the granular pearlite. Based on the unqualified condition of the annealing treatment, increase the annealing holding time, or obtain the fracture morphology characteristic value of the wire through a torsion test combined with a scanning electron microscope and increase the annealing temperature when the annealing treatment is judged unqualified according to the fracture morphology characteristic value; Performing pickling and phosphating treatment on the wire with qualified annealing treatment and then performing hexagonal drawing through a wire-drawing machine to obtain hexagonal wire; Obtaining the surface morphology of the hexagonal wire through a metallographic microscope to analyze and determine the surface defect index and judging the qualification of the hexagonal drawing according to the surface defect index. Based on the unqualified condition, reduce the drawing speed or determine the maximum drawing length according to the surface roughness; Performing shearing, shaping, and rod shrinking on the qualified hexagonal wire through a cold heading machine to obtain an S3 double hexagonal bit; Sampling and testing the torque bearing capacity and surface quality of the S3 double hexagonal bit and determining the comprehensive performance characteristic value of a single S3 double hexagonal bit; Judging the qualification of a single S3 double hexagonal bit according to the comprehensive performance characteristic value and judging the qualification of the preparation of the S3 double hexagonal bit according to the proportion of qualified S3 double hexagonal bits in the sampling inspection. Based on the unqualified preparation condition, determine the reason for the unqualified preparation according to the difference between the preset proportion and the proportion and increase the shaping pressure or reduce the stamping speed; Judging the qualification of the annealing treatment according to the uniformity index of the granular pearlite. Among them, if the uniformity index is less than the first preset uniformity index, it is judged that the annealing treatment is qualified, and the wire is subjected to pickling and phosphating treatment; If the uniformity index is greater than or equal to the first preset uniformity index and less than the second preset uniformity index, it is judged that the annealing treatment is unqualified, and the qualification of the annealing treatment is judged again according to the fracture morphology characteristic value; If the uniformity index is greater than or equal to the second preset uniformity index, it is judged that the annealing treatment is unqualified, and the annealing holding time is increased according to the difference between the uniformity index and the second preset uniformity index; Based on the condition that the fracture morphology characteristic value is less than the preset morphology characteristic value, it is judged again that the annealing treatment is unqualified, and the annealing temperature is increased according to the difference between the preset morphology characteristic value and the fracture morphology characteristic value; Based on the condition that the fracture morphology characteristic value is greater than or equal to the preset morphology characteristic value, it is judged again that the annealing treatment is qualified, and the wire is subjected to pickling and phosphating treatment.

2. The preparation method of the S3 double hexagon bit according to claim 1, characterized in that, The uniformity index is jointly determined by the size uniformity and distribution uniformity of the granular pearlite.

3. The preparation method of the S3 double hexagon bit according to claim 2, characterized in that, The fracture morphology characteristic value is jointly determined by the fracture shrinkage rate and the fracture roughness.

4. The preparation method of the S3 double hexagon bit according to claim 3, characterized in that, Judging the qualification of the hexagonal drawing according to the surface defect index. Among them, if the surface defect index is less than the first preset surface defect index, it is judged that the hexagonal drawing is qualified, and the hexagonal wire is cold-headed to obtain an S3 double hexagonal bit; If the surface defect index is greater than or equal to the first preset surface defect index and less than the second preset surface defect index, it is determined that the hexagonal drawing is unqualified, and the drawing speed is reduced according to the difference between the second preset surface defect index and the surface defect index; If the surface defect index is greater than or equal to the second preset surface defect index, it is determined that the hexagonal drawing is unqualified, and the maximum drawing length is reduced according to the surface roughness of the hexagonal wire.

5. The preparation method of the S3 double hexagon bit according to claim 4, characterized in that, Based on the condition that the comprehensive performance characteristic value is less than the preset comprehensive performance characteristic value, it is determined that a single S3 double hexagonal bit is unqualified, and the unqualified S3 double hexagonal bit is marked; Based on the condition that the comprehensive performance characteristic value is greater than or equal to the preset comprehensive performance characteristic value, it is determined that a single S3 double hexagonal bit is qualified, and the qualification of the remaining S3 double hexagonal bits is continuously detected and determined.

6. The preparation method of the S3 double hexagonal bit according to claim 5, wherein, The qualification of the preparation of the S3 double hexagonal bit is determined according to the proportion of the qualified S3 double hexagonal bits in the sampling inspection. Among them, if the proportion is less than the preset proportion, it is determined that the preparation of the S3 double hexagonal bit is unqualified, and the reason for the unqualified preparation is determined according to the difference between the preset proportion and the proportion; If the proportion is greater than or equal to the preset proportion, it is determined that the preparation of the S3 double hexagonal bit is qualified, and the preparation is completed according to the current preparation parameters.

7. The preparation method of the S3 double hexagon bit according to claim 6, characterized in that, The reason for the unqualified preparation is determined according to the proportion difference. Among them, if the proportion difference is less than the preset proportion difference, it is determined that the reason for the unqualified preparation is that the shaping pressure in the cold heading process does not meet the standard, and the shaping pressure is increased according to the opposite side tolerance value of the unqualified S3 double hexagonal bit; If the proportion difference is greater than or equal to the preset proportion difference, it is determined that the reason for the unqualified preparation is that the stamping speed in the cold heading process does not meet the standard, and the stamping speed is reduced according to the deformation rate of the unqualified S3 double hexagonal bit; The proportion difference is the difference between the preset proportion and the proportion.

8. An S3 double hexagonal bit obtained by the preparation method according to any one of claims 1-7, characterized in that, The ratio of the opposite side lengths of the two end faces of the S3 double hexagonal bit is 3:4.

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