A method for rolling a bar to a size beyond a set of precision

Abstract

The application discloses a kind of bar size super group precision rolling method, it is related to rolling technical field.The bar size super group precision rolling method includes the following specific steps, S1 prepares before rolling, S2 checks electrical system, S3 is checked to the hydraulic system of rolling mill, S4 raw material preparation, S5 is carried out surface cleaning to billet, S6 is heated to billet, S7 rough rolling stage, S8 medium rolling stage, S9 finish rolling stage, S10 cooling treatment, S11 straightening treatment, S12 detection and adjustment, the scheme can significantly improve the precision of bar size, by accurately controlling the rolling parameter and process of four-roll round rolling mill, the size precision of bar can be improved to super group precision level, meet the high-precision requirement of high-end application field to bar, effectively control bar ovality, adopt reasonable rolling process and roll adjusting method, the ovality of bar can be controlled within 0.1, make the cross-sectional shape of bar more regular, improve the consistency and stability of product.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rolling technology, in particular to a method for rolling a bar with a size precision exceeding a group. BACKGROUND

[0002] In the field of bar production, the requirement for size precision is increasing. Traditional rolling methods and equipment often have difficulty achieving high-precision bar rolling, especially achieving the requirement of exceeding a group, due to various constraints in the production process, such as rolling mill structure, rolling process parameter control, and raw material quality.

[0003] When using ordinary rolling mills for rolling, problems such as large size fluctuations of the rolled piece, poor ovality control, and surface quality defects often occur. These problems not only affect the quality and performance of the product, but also limit its application in high-end fields. In addition, the parameter adjustment in the traditional rolling process is not accurate and timely enough, and cannot be quickly optimized according to the real-time state of the rolled piece, resulting in low production efficiency and high scrap rate.

[0004] With the continuous development of the industrial field, higher requirements are placed on the size precision, surface quality, and mechanical properties of bars. In particular, in some precision machinery manufacturing, automobile industry, aerospace, and other fields, bars with a size precision exceeding a group are required to meet the high performance and high quality requirements of products. Therefore, it is of great practical significance to develop a method for rolling a bar with a size precision exceeding a group using a four-high round rolling mill. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a method for rolling a bar with a size precision exceeding a group, which can solve the above problems.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: a method for rolling a bar with a size precision exceeding a group, comprising the following specific steps: S1 preparation before rolling, equipment inspection and debugging, comprehensively checking the mechanical parts of the four-high round rolling mill, including the roll, roll bearing, roll adjustment mechanism, transmission system, etc., to ensure that each part is free of damage, wear and loosening phenomenon;

[0007] S2 check the electrical system, including motor, control system, sensor, etc., to ensure that the electrical connection is good, the control system parameters are accurate and correct, and each sensor is working properly;

[0008] S3 check the hydraulic system of the rolling mill, to ensure that the hydraulic pump, hydraulic cylinder, hydraulic valve, etc. are free of leakage, the hydraulic oil level and oil temperature are normal, and the pressure is stable; debug the roll gap adjustment mechanism of the rolling mill to ensure that the roll gap adjustment precision meets the requirement of exceeding a group;

[0009] S4 raw material preparation, select high quality billet as rolling raw material, the chemical composition of billet should be uniform and stable, meet the product requirements;

[0010] S5 surface cleaning of billet, remove the scale, rust and other impurities, ensure the billet surface clean;

[0011] S6 billet heating, heating temperature should be according to the steel grade and rolling process requirements of accurate control, heating uniformity error should be controlled in a small range;

[0012] S7 rough rolling stage, the heated billet is sent to four roller round rolling mill for rough rolling, in the rough rolling stage, the larger reduction is adopted, the pass reduction is controlled between 10-20mm;

[0013] S8 medium rolling stage, the rolled piece after rough rolling enters the medium rolling stage, in the medium rolling stage, the reduction is gradually reduced, the pass reduction is controlled between 5-10mm;

[0014] S9 finishing rolling stage, the rolled piece after medium rolling enters the finishing rolling stage, in the finishing rolling stage, the smaller reduction is adopted, the pass reduction is controlled between 1-3mm;

[0015] S10 cooling treatment, the rod after rolling adopts the cooling mode of combination of rapid cooling and slow cooling, in the rapid cooling stage, water cooling or air cooling mode is adopted to make the rod temperature drop rapidly, inhibit the grain growth, in the slow cooling stage, natural cooling or heat preservation cooling mode is adopted to make the internal stress of the rod fully released, avoid the crack and deformation;

[0016] S11 straightening treatment, the rod after cooling enters the straightening machine for straightening treatment, eliminate the bending and distortion deformation generated in the rolling process, adjust the reduction and straightening speed of the straightening machine, ensure that the straightness of the rod reaches the super group precision requirements;

[0017] S12 detection and adjustment, in the rolling process, the diameter and ovality of the rod are detected in real time by the on-line laser diameter measuring instrument, according to the detection results, the rolling process parameters and straightening process parameters are adjusted in time, ensure that the ovality of the rod is always controlled within 0.1.

[0018] Preferably, the electrical control adopts the drawing steel rolling, the excess deformation is digested by the change of speed, because the deformation is very small, the steel normally slips between the rolling mills, so the drawing state does not affect the fullness condition.

[0019] Preferably, the current short stress line rolling mill is used as the mother rack, the round rolling mill is installed behind the short stress line, the round rolling mill roller is at 90 degrees with the short stress line rolling mill, the sub rolling mill is installed in front of the mother rack, the distance from the mother rack roller is about 3-5cm, the sub rolling mill is not powered, after biting, the sub rolling mill is equivalent to a drawing pass.

[0020] Preferably, in the rough rolling process, the rolling speed, rolling force and roll gap are adjusted in time according to the deformation and size change of the billet to ensure the stability of the rolling process and the regular shape of the rolled piece.

[0021] Preferably, the rolling speed and rolling force of the roll are adjusted to further refine the grain of the rolled piece in the intermediate rolling process, improve the organizational performance, and improve the dimensional accuracy.

[0022] Preferably, the roll gap and rolling force of the roll are accurately adjusted to make the dimensional accuracy of the rolled piece reach the super-group precision requirement, and the ovality of the rolled piece is controlled within 0.1.

[0023] Preferably, in the finishing rolling process, the size change of the rolled piece is monitored in real time by using an online size detection system, and the rolling parameters are adjusted in time according to the detection data to ensure the stability and consistency of the size of the rolled piece.

[0024] Compared with the prior art, the beneficial effects of the present application are:

[0025] 1. The rod size super-group precision rolling method can significantly improve the dimensional accuracy of the rod. By accurately controlling the rolling parameters and process of the four-roll round rolling mill, the dimensional accuracy of the rod can be improved to the super-group precision level, meeting the high-precision requirements of the rod in high-end application fields, effectively controlling the ovality of the rod, and using reasonable rolling process and roll adjustment method to control the ovality of the rod within 0.1, making the cross-sectional shape of the rod more regular, and improving the consistency and stability of the product.

[0026] 2. The rod size super-group precision rolling method can improve the surface quality of the rod. In the rolling process, by optimizing the rolling parameters and cooling method, the defects and cracks on the surface of the rolled piece are reduced, the surface quality of the rod is improved, the production efficiency is improved, the accurate rolling parameter control and the application of online detection system reduce the generation of waste products and the adjustment time in the rolling process, improve the production efficiency, and reduce the production cost. BRIEF DESCRIPTION OF DRAWINGS

[0027] The present application will be further described below in conjunction with the drawings and examples:

[0028] Figure 1 The present application is a round principle schematic diagram. DETAILED DESCRIPTION

[0029] This part will describe the specific embodiments of the present application in detail. The preferred embodiments of the present application are shown in the drawings, and the drawings serve to supplement the description in the text part of the specification, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application. However, it cannot be understood as a limitation on the protection scope of the present application.

[0030] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by the upper, lower, front, rear, left, right and the like, is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0031] In the description of the present application, greater than, less than, more than, etc. are understood as not including the number, and above, below, within, etc. are understood as including the number. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0032] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0033] The present application provides a technical solution: a method for rolling a bar with a size exceeding a set of precision, comprising the following specific steps: S1, preparation before rolling, equipment inspection and debugging, comprehensively checking the mechanical parts of the four-roll roundness rolling mill, including the roll, the roll bearing, the roll adjusting mechanism, the transmission system, etc., to ensure that each part is free of damage, wear and loosening phenomenon;

[0034] S2, checking the electrical system, including the motor, the control system, the sensor, etc., to ensure that the electrical connection is good, the control system parameters are accurate and correct, and each sensor is working normally;

[0035] S3, checking the hydraulic system of the rolling mill to ensure that the hydraulic pump, the hydraulic cylinder, the hydraulic valve and other components are free of leakage, the hydraulic oil level and the oil temperature are normal, and the pressure is stable; debugging the roll gap adjusting mechanism of the rolling mill to ensure that the roll gap adjusting precision meets the super set precision requirement;

[0036] S4, raw material preparation, selecting high-quality billets as the rolling raw material, the chemical composition of the billet should be uniform and stable, meeting the product requirements;

[0037] S5, surface cleaning of the billet to remove the scale, rust and other impurities, ensuring the cleanliness of the billet surface;

[0038] S6, heating of the billet, the heating temperature should be accurately controlled according to the steel grade and the rolling process requirements, and the heating uniformity error should be controlled within a small range;

[0039] S7 rough rolling stage, the heated billet is sent to the four-roll round rolling mill for rough rolling, in the rough rolling stage, a larger reduction is adopted, and the pass reduction is controlled between 10-20mm;

[0040] In the rough rolling process, the rolling speed, rolling force and roll gap are adjusted in time according to the deformation and size change of the billet, so as to ensure the stability of the rolling process and the regular shape of the rolled piece;

[0041] S8 medium rolling stage, the rolled piece after rough rolling enters the medium rolling stage, in the medium rolling stage, the reduction is gradually reduced, and the pass reduction is controlled between 5-10mm;

[0042] In the medium rolling process, the rolling speed and rolling force of the roll are adjusted to further refine the grain of the rolled piece, improve the organizational performance, and improve the size accuracy,

[0043] S9 finishing rolling stage, the rolled piece after medium rolling enters the finishing rolling stage, in the finishing rolling stage, a smaller reduction is adopted, and the pass reduction is controlled between 1-3mm;

[0044] In which, the roll gap and rolling force of the roll are accurately adjusted to make the size accuracy of the rolled piece reach the super-group precision requirement, and the ovality of the rolled piece is controlled within 0.1;

[0045] In the finishing rolling process, the size change of the rolled piece is monitored in real time by using an online size detection system, and the rolling parameters are adjusted in time according to the detection data to ensure the stability and consistency of the size of the rolled piece;

[0046] S10 cooling treatment, the rolled bar is cooled by combining rapid cooling and slow cooling, in the rapid cooling stage, water cooling or air cooling is adopted to rapidly cool the bar to inhibit grain growth, in the slow cooling stage, natural cooling or heat preservation cooling is adopted to fully release the internal stress of the bar to avoid cracks and deformation;

[0047] S11 straightening treatment, the cooled bar enters the straightening machine for straightening treatment to eliminate the bending and twisting deformation generated in the rolling process, the reduction and straightening speed of the straightening machine are adjusted to ensure that the straightness of the bar reaches the super-group precision requirement;

[0048] S12 detection and adjustment, in the rolling process, the diameter and ovality of the bar are detected in real time by using an online laser diameter gauge, and the rolling process parameters and straightening process parameters are adjusted in time according to the detection results to ensure that the ovality of the bar is always controlled within 0.1;

[0049] In which, the electrical control adopts steel drawing, and the excess deformation is digested by changing the speed, since the deformation is very small, the steel normally slips between the rolling mills, so the drawing state does not affect the fullness condition;

[0050] The process involves using a short stress line mill as the main frame, installing a circular mill after the short stress line, with the rolls of the circular mill forming a 90-degree angle with the short stress line mill, and installing a sub-mill in front of the main frame, approximately 3-5 cm away from the rolls of the main frame. The sub-mill is unpowered, and after biting in, it is equivalent to a drawing die.

[0051] Please see Figure 1 Composed of two identical circular holes, this system sets a relatively large steel pulling condition. The larger part can be pulled down through the circular holes. Due to the principle of equal flow rate per second and the rotation speed being greater than the rolling speed, the steel slips in the holes, thus preventing the steel from widening. The two orthogonal holes pull the relatively larger surface of each face to the required size. The two holes have a 30-degree intersection angle, so this hole system has very low equipment requirements. Slight misalignment and cross-movement have little impact on its ellipticity and will not produce unsightly indentations or other defects on the finished product surface. At the same time, the amount of misalignment will be automatically corrected by the holes, and the amount of misalignment will be eliminated by the arc surface, thus achieving a circular shape.

[0052] By adopting this die system, the expansion angle of the finished die can be further increased, thereby eliminating the formation of ears during the trial rolling process. Theoretically, this die should not produce ears. As long as the minimum size of the incoming material is larger than the die size, perfect roundness can be achieved.

[0053] Furthermore, this solution can significantly improve the dimensional accuracy of bars. By precisely controlling the rolling parameters and processes of the four-roll gauge mill, the dimensional accuracy of bars can be improved to a level exceeding the first set of accuracy, meeting the high precision requirements of high-end applications. It can also effectively control the ellipticity of bars. By adopting reasonable rolling processes and roll adjustment methods, the ellipticity of bars can be controlled within 0.1, making the cross-sectional shape of the bars more regular and improving the consistency and stability of the products.

[0054] Furthermore, this solution can improve the surface quality of the bar stock. During the rolling process, by optimizing rolling parameters and cooling methods, it reduces the generation of defects and cracks on the surface of the rolled product, thereby improving the surface quality of the bar stock and increasing production efficiency. The application of precise rolling parameter control and online detection system reduces the generation of scrap and the adjustment time during the rolling process, thereby improving production efficiency and reducing production costs.

[0055] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method of rolling a bar to a size outside a set of gauges, characterized by: The method comprises the following specific steps: S1, preparation before rolling, equipment inspection and debugging, checking the mechanical parts of the four-roll roundness rolling mill, including the roll, roll bearing, roll adjusting mechanism and transmission system, to ensure that each part is free of damage, wear and looseness; S2, checking the electrical system, including the motor, control system and sensor, to ensure that the electrical connection is good, the control system parameters are accurate and the sensors are working properly; S3, checking the hydraulic system of the rolling mill to ensure that the hydraulic pump, hydraulic cylinder and hydraulic valve parts have no leakage, the hydraulic oil level and oil temperature are normal and the pressure is stable; adjusting the roll gap adjusting mechanism of the rolling mill to ensure that the roll gap adjusting precision meets the super-group precision requirement; S4, raw material preparation, selecting high-quality billets as the rolling raw material, the chemical composition of the billet should be uniform and stable, meeting the product requirements; S5, surface cleaning of the billet to remove scale, rust and other impurities, ensuring the cleanliness of the billet surface; S6, heating the billet, the heating temperature should be accurately controlled according to the steel grade and rolling process requirements, and the heating uniformity error should be controlled within a small range; S7, rough rolling stage, the heated billet is sent to the four-roll roundness rolling mill for rough rolling, in the rough rolling stage, a larger reduction is adopted, and the pass reduction is controlled between 10-20mm; S8, intermediate rolling stage, the rolled piece after rough rolling enters the intermediate rolling stage, in the intermediate rolling stage, the reduction is gradually reduced, and the pass reduction is controlled between 5-10mm; S9, finish rolling stage, the rolled piece after intermediate rolling enters the finish rolling stage, in the finish rolling stage, a smaller reduction is adopted, and the pass reduction is controlled between 1-3mm; S10, cooling treatment, the rolled bar is cooled by combining fast cooling and slow cooling, in the fast cooling stage, water cooling or air cooling is adopted to rapidly cool the bar to inhibit grain growth, in the slow cooling stage, natural cooling or heat preservation cooling is adopted to fully release the internal stress of the bar to avoid cracks and deformation; S11, straightening treatment, the cooled bar enters the straightening machine for straightening treatment to eliminate the bending and twisting deformation generated in the rolling process, the reduction and straightening speed of the straightening machine are adjusted to ensure that the straightness of the bar meets the super-group precision requirement; S12, detection and adjustment, the diameter and ovality of the bar are detected in real time by using an online laser diameter detector during the rolling process, the rolling process parameters and straightening process parameters are adjusted in a timely manner according to the detection results to ensure that the ovality of the bar is always controlled within 0.

1.

2. A method of rolling bar stock to a set of tolerances beyond the normal size range, as claimed in claim 1, wherein: In the aspect of electrical control, the steel is rolled in the drawing state, and the excess deformation is eliminated by changing the speed, since the deformation is very small, the steel normally slips between the rolling mills, so the drawing state does not affect the fullness of the steel.

3. A method of rolling bar stock to a set of tolerances beyond the normal size range, as claimed in claim 1, wherein: The current short stress line rolling mill is used as the mother rack, and the roundness rolling mill is installed after the short stress line, the roll of the roundness rolling mill is at a 90-degree angle with the short stress line rolling mill, the sub-rolling mill is installed in front of the mother rack, and the distance between the sub-rolling mill and the roll of the mother rack is 3-5cm, the sub-rolling mill is not powered, and after biting, the sub-rolling mill is equivalent to a drawing hole.

4. A method of rolling bar stock to a set of tolerances beyond the normal size range as claimed in claim 1, wherein: In the rough rolling process, the roll speed, rolling force and roll gap are adjusted in a timely manner according to the deformation and size change of the billet to ensure the stability of the rolling process and the regular shape of the rolled piece.

5. A method of rolling bar stock to a set of tolerances beyond the normal size range as claimed in claim 1, wherein: Adjust the speed of the roll and the rolling force, so that the rolling piece is further refined in the process of medium rolling, the organization performance is improved, and the size accuracy is improved.

6. A method of rolling bar stock to a set of tolerances beyond the normal size range as claimed in claim 1, wherein: Adjust the roll gap and rolling force of the roll accurately, so that the size accuracy of the rolling piece reaches the super-group precision requirement, and the ovality of the rolling piece is controlled within 0.

1.

7. A method of rolling bar stock to a set of tolerances beyond the normal size range as claimed in claim 1, wherein: In the finishing process, the size change of the rolling piece is monitored in real time by using an online size detection system, the rolling parameters are adjusted in time according to the detection data, and the stability and consistency of the size of the rolling piece are ensured.

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