A method for eliminating the bending of round steel shear head

Abstract

The invention discloses a method for eliminating the bending of a round steel shearing head. Step 1: Control the incoming material temperature: control the shearing temperature of round steel with a finished product diameter of less than φ19 mm at 110-130°C; control the shearing temperature of round steel with a diameter of more than φ20 mm at 120-140°C; Step 2: Control the feeding speed to match the shearing speed: the speed of the magnetic chain and the pre-shear transmission roller of the φ13-φ28 mm round steel is 1.8-2.0 m / s, and the speed of the round steel with a diameter of more than φ28 mm is 1.5-1.8 m / s; Step 3: Control the uniform distribution of the finished product: the round steel is transported in sections and intervals on the steel transfer chain, and the interval is controlled at 8-10 mm. The front pressure roller is improved to be a grooved pressure roller to ensure that the pressure roller is fully in contact with the round steel to prevent shearing bounce; Step 4: Adjust the round steel shearing process: control the shear blade gap value within the range of 0.07-0.15mm, use 20-groove shear blades when shearing round steel with a diameter of less than φ22mm, and the newly improved shear blade has a designed contact angle of 0° behind the shear blade. At the same time, the shear groove arc angle is reduced from 60° to 34°.

Description

Technical Field

[0001] The invention relates to a method for eliminating the bending of a round steel shearing head. Background Art

[0002] The small-scale unit of Bagang mainly produces high-quality steel, and the product specifications are φ13-φ60mm. When producing round steel, after a series of processes such as rolling-cutting-cooling on a cooling bed-cutting to fixed length, the finished product is cut into fixed length, and the shear end face is uneven and horseshoe-shaped and inclined. A relatively serious head bending is prone to occur at about 60mm from the end of the round steel, and the bending degree exceeds 0.7%, especially the small specifications of φ13-φ32. At this time, the bent head of the round steel needs to be manually sawed and ground before it can be sold, which not only affects production efficiency but also increases labor costs. According to a large number of on-site sampling and data investigation, it was found that the above defects were caused by the fixed-length cutting process. The small-scale unit of Bagang adopts the fixed-length shearing method of groove shears. Its shearing temperature, the matching of the magnetic chain and the speed of the transmission roller before shearing with the shearing speed, and the height difference between the center of the swing shear blade and the center of the round steel will affect the quality of the sheared end face and the head bending. The rear contact angle of the shear blade of traditional groove shears is generally designed to be -5° to -9°. Since the shear blade is in line contact with the round steel, one end of the round steel will be lifted due to lack of support during shearing, causing the shearing bevel and the head of the round steel to bend at about 60mm.

[0003] Retrieved literature: (1) Yang Rongqing and Li Baoming - Discussion on improving the quality of sheared round steel ends "Shandong Metallurgy" October 1998, Issue 5, Volume 20 (2) Zheng Xiaoning - Analysis of causes of round steel shearing defects and improvement measures "Shandong Industrial Technology" 2019 Issue 09 (3) Li Fangchun, Yang Rongqing, Li Ritong - "Angang Technology" August 1997, Issue 8 Research on further improving the quality of sheared round steel ends (4) Ma Qihong, Yin Zhixiang, Chen Huaqiang Improve shearing process and improve shearing quality "Egang Science and Technology" 2007 Issue 4 (5) Xia Zhenyao and Xia Zhenwei A round steel cold shear blade with smooth end shearing Patent announcement number: CN202021495404.X.

[0004] From the above searched literature, it can be seen that the current control of the bending of the head when the finished round steel is sheared in the production of small-sized products is still focused on controlling the shearing temperature and using a single control method such as a grooved shear blade with a rear contact angle of -5 to -9°. There is no systematic method to comprehensively consider the method of eliminating the bending of the head when the finished round steel is sheared by adjusting the shearing temperature of the incoming material, controlling the matching of the incoming material speed and the shearing speed, eliminating the rear contact angle of the shear blade, reducing the groove arc angle, adjusting the pressure of the pressure roller and the center height of the shear blade, etc. Summary of the invention

[0005] The purpose of the present invention is to provide a method for eliminating the bending of the shear head of round steel, which can achieve the purpose of eliminating the shear bending and improving the quality of the shear end face by controlling the shearing temperature of the incoming material and improving the contact area between the shear blade and the round steel during the shearing process.

[0006] A method for eliminating the bending of the shear head of round steel, the method is implemented in steps;

[0007] Step 1 Control the incoming material temperature: Leave one step between the multiple lengths of the upper cooling bed of the round steel, increase the residence time, ensure that the steel temperature of the lower bed of the multiple length is ≤200℃, increase the residence time of the steel transfer chain, and further reduce the steel temperature, so that the shearing temperature of the finished round steel with a diameter of less than φ19mm is controlled at 110-130℃; the shearing temperature of the round steel with a diameter of more than φ20mm is controlled at 120-140℃;

[0008] Step 2: Control the feeding speed to match the shearing speed: the speed of the magnetic chain and the transmission roller before shearing for round steel of φ13-φ28mm is 1.8-2.0 m / s, and the speed of round steel of φ28mm or above is 1.5-1.8 m / s;

[0009] Step 3: Control the uniform distribution of finished products: The round steel is transported in sections on the steel transfer chain, and the interval is controlled at 8-10mm. It is transported to the lower grooved shear blade guide hole through the magnetic chain. An air storage tank and a pneumatic booster pump are added to the air path of the cylinder driving the pre-shear pressure roller to meet the adjustment of the pre-shear pressure roller pneumatic pressure of 4.5-6bar. The front pressure roller is improved to a grooved pressure roller to ensure that the pressure roller is fully in contact with the round steel to prevent shearing bounce;

[0010] Step 4 Adjust the round steel shearing process: 1.1 Control the shear blade gap value within the range of 0.07-0.15mm, so that the shear torque acts on the round steel at the maximum, effectively controlling the inclination angle of the shear section and inhibiting the bending and collapse of the shear section; 1.2 Use a 20-slot shear blade when shearing round steel with a diameter of less than φ22mm. The newly improved shear blade is designed with a contact angle of 0° behind the shear blade. During shearing, the entire shear blade slot hole provides "support" for the round steel, sharing part of the shear resistance T3, reducing the upward force F2 of the round steel, effectively reducing the extrusion deformation, and at the same time reducing the shear groove arc angle from 60° to 34°, increasing the contact area between the shear blade and the round steel, and the round steel is tightly locked during shearing and will not warp. At the same time, the height difference between the center of the swing shear blade and the center of the round steel is increased to 7mm, which makes the round steel lifted by the shear blade to form a reverse bow during shearing, offsetting part of the downward pressure of the shear blade during shearing to produce plastic bending and collapse.

[0011] Compared with the original technology, the improved swing shear groove shear blade of the present invention is conducive to the uniform diffusion of shear extrusion stress during shearing, reduces the shearing backward movement of the finished material, and effectively suppresses the shearing dislocation. At the same time, through the comprehensive adjustment of the system's shearing material temperature, shearing speed, finished product conveying speed, shear blade contact angle, shear blade gap, front and rear roller compaction force and other parameters, multiple technical means are used to effectively eliminate the bending of the head of the finished round steel during shearing, improve the shear end surface quality, and meet the original design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a three-dimensional layout diagram of the newly improved shear blades in the present invention;

[0013] Figure 2 It is a front view of the grooved shear blade of the present invention;

[0014] Figure 3 for Figure 2 AA section view in;

[0015] Figure 4 for Figure 2 CC profile in ;

[0016] Figure 5 for Figure 2 Enlarged view of point D in . DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings:

[0018] A method to eliminate the bending of the round steel shear head, such as Figure 1 , 2 , 3, 4, and 5, the method is implemented in steps;

[0019] Step 1 Control the incoming material temperature: Leave one step between the multiple lengths of the upper cooling bed of the round steel, increase the residence time, ensure that the steel temperature of the lower bed of the multiple length is ≤200℃, increase the residence time of the steel transfer chain, and further reduce the steel temperature, so that the shearing temperature of the finished round steel with a diameter of less than φ19mm is controlled at 110-130℃; the shearing temperature of the round steel with a diameter of more than φ20mm is controlled at 120-140℃;

[0020] Step 2: Control the feeding speed to match the shearing speed: the speed of the magnetic chain and the transmission roller before shearing for round steel of φ13-φ28mm is 1.8-2.0 m / s, and the speed of round steel of φ28mm or above is 1.5-1.8 m / s;

[0021] Step 3: Control the uniform distribution of finished products: The round steel is transported in sections on the steel transfer chain, and the interval is controlled at 8-10mm. It is transported to the lower grooved shear blade guide hole through the magnetic chain. An air storage tank and a pneumatic booster pump are added to the air path of the cylinder driving the pre-shear pressure roller to meet the adjustment of the pre-shear pressure roller pneumatic pressure of 4.5-6bar. The front pressure roller is improved to a grooved pressure roller to ensure that the pressure roller is fully in contact with the round steel to prevent shearing bounce;

[0022] Step 4 Adjust the round steel shearing process: 1.1 Control the shear blade gap value within the range of 0.07-0.15mm, so that the shear torque acts on the round steel at the maximum, effectively controlling the inclination angle of the shear section and inhibiting the bending and collapse of the shear section; 1.2 Use a 20-slot shear blade when shearing round steel with a diameter of less than φ22mm. The newly improved shear blade is designed with a contact angle of 0° behind the shear blade. During shearing, the entire shear blade slot hole provides "support" for the round steel, sharing part of the shear resistance T3, reducing the upward force F2 of the round steel, effectively reducing the extrusion deformation, and at the same time reducing the shear groove arc angle from 60° to 34°, increasing the contact area between the shear blade and the round steel, and the round steel is tightly locked during shearing and will not warp. At the same time, the height difference between the center of the swing shear blade and the center of the round steel is increased to 7mm, which makes the round steel lifted by the shear blade to form a reverse bow during shearing, offsetting part of the downward pressure of the shear blade during shearing to produce plastic bending and collapse.

[0023] Example 1

[0024] φ28 sucker rod steel production, steel grade 20Cr2Mo;

[0025] Step 1: Control the incoming material temperature: Leave one step between the multiples of the upper cooling bed of φ28 round steel, stay on the cooling bed for 25 minutes, and control the shear incoming material temperature at 130-140℃.

[0026] Step 2: Feeding: The speed of the magnetic chain and the transmission roller before shearing of the finished steel φ28 is 1.8 m / s. According to the multiple length, the whole multiple of the fixed length is taken plus the head and tail cutting amount. The finished fixed length is 9.44 m, and the multiple length is set to 85.5 m.

[0027] Step 3: Material division: φ28 steel is transported in sections on the steel transfer chain, the interval between round steels is controlled at 15mm, a 12-groove comb-type guide groove is used before shearing, and the pneumatic pressure of the pressure roller before shearing is adjusted to 5.5bar.

[0028] Step 4 Steel shearing: The shear blade clearance value is 0.07-0.15mm; use the improved 12-groove shear blade with a rear contact angle of 0°, a groove arc angle of 36°, and a height difference of 6mm between the center of the swing shear blade and the center of the round steel.

[0029] Example 2

[0030] φ22 sucker rod steel production, steel grade 20Cr2Mo;

[0031] Step 1 Incoming material temperature: There is one space between the multiples of the upper cooling bed for φ22 steel, the bed residence time is 31 minutes, and the shear incoming material temperature is 120-130℃.

[0032] Step 2: Feeding: The speed of the magnetic chain and the transmission roller before shearing of the finished steel φ22 is 1.9 m / s. According to the multiple length, the whole multiple of the fixed length is taken plus the head and tail cutting amount. The finished fixed length is 9.41 m, and the multiple length is set to 85.3 m.

[0033] Step 3: Material division: φ22 steel is transported in sections on the steel transfer chain, the interval between round steels is controlled at 12mm, a 20-groove comb-type guide groove is used before shearing, and the pneumatic pressure of the pressure roller before shearing is adjusted to 5.5bar.

[0034] Step 4 Steel shearing: The shear blade clearance value is 0.07-0.15mm; use the improved 20-groove shear blade with a rear contact angle of 0°, a groove arc angle of 33°, and a height difference of 7mm between the center of the swing shear blade and the center of the round steel.

[0035] The setting of the bending adjustment parameters of the shear head of various specifications of round steel is summarized as shown in Table 1

[0036]

[0037] This method is applicable to enterprises that continuously produce high-quality steel, and has a very high demonstration effect on the production of high-quality steel in China. The above schematically describes the present invention and its implementation methods, which are not restrictive. What is shown in the accompanying drawings is only one of the implementation methods of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it, without departing from the purpose of the invention, they can creatively design structural methods and embodiments similar to the technical solution, which should all fall within the scope of protection of the present invention.

Claims

1. A method for eliminating the bending of round steel shear head, characterized in that The method is implemented in steps; Step 1 Control the incoming material temperature: Leave one step between the multiple lengths of the upper cooling bed of the round steel, increase the residence time, ensure that the steel temperature of the lower bed of the multiple length is ≤200℃, increase the residence time of the steel transfer chain, and further reduce the steel temperature, so that the shearing temperature of the finished round steel with a diameter of less than φ19mm is controlled at 110-130℃; the shearing temperature of the round steel with a diameter of more than φ20mm is controlled at 120-140℃; Step 2: Control the feeding speed to match the shearing speed: the speed of the magnetic chain and the transmission roller before shearing for round steel of φ13-φ28mm is 1.8-2.0 m / s, and the speed of round steel of φ28mm or above is 1.5-1.8 m / s; Step 3: Control the uniform distribution of finished products: The round steel is transported in sections on the steel transfer chain, and the interval is controlled at 8-10mm. It is transported to the lower grooved shear blade guide hole through the magnetic chain. An air storage tank and a pneumatic booster pump are added to the air path of the cylinder driving the pre-shear pressure roller to meet the adjustment of the pre-shear pressure roller pneumatic pressure of 4.5-6bar. The front pressure roller is improved to a grooved pressure roller to ensure that the pressure roller is fully in contact with the round steel to prevent shearing bounce; Step 4 Adjust the round steel shearing process: 1.1 Control the shear blade gap value within the range of 0.07-0.15mm, so that the shear torque acts on the round steel at the maximum, control the inclination angle of the shear section, and inhibit the bending and collapse of the shear section; 1.2 Use a 20-groove shear blade when shearing round steel with a diameter of less than φ22mm. The newly improved shear blade is designed with a contact angle of 0° behind the shear blade to reduce extrusion deformation. At the same time, the shear groove arc angle is reduced from 60° to 34° to increase the contact area between the shear blade and the round steel. At the same time, the height difference between the center of the swing shear blade and the center of the round steel is increased to 7mm to offset part of the plastic bending and collapse caused by the downward pressure during shearing.

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