Rolling method for enabling size of bar to exceed one set of precision

Abstract

The invention discloses a rolling method for enabling the size of a bar to exceed one set of precision, and relates to the technical field of rolling. The rolling method for the bar with the size exceeding one set of precision comprises the following specific steps of S1, preparation before rolling, S2, inspection of an electrical system, S3, inspection of a hydraulic system of a rolling mill, S4, raw material preparation, S5, surface cleaning of a steel billet, S6, heating of the steel billet, S7, a rough rolling stage, S8, a medium rolling stage, S9, a finish rolling stage, S10, cooling treatment, S11, straightening treatment and S12, detection and adjustment. According to the scheme, the size precision of the bar can be remarkably improved, the size precision of the bar can be improved to be higher than one set of precision level by accurately controlling the rolling parameters and technology of the four-roller rounding rolling mill, the requirement of the high-end application field for the high precision of the bar is met, the bar ovality is effectively controlled, and the reasonable rolling technology and the reasonable roller adjusting method are adopted; and the ovality of the bar can be controlled within 0.1, so that the section shape of the bar is more regular, and the consistency and stability of a product are improved.

Description

Technical Field

[0001] The invention relates to the technical field of rolling, and in particular to a method for rolling a bar with a size exceeding a set of precision. Background Art

[0002] In the field of bar production, the requirements for dimensional accuracy are increasing day by day. Traditional rolling methods and equipment are often difficult to achieve high-precision bar rolling, especially to meet the requirements of super-precision, due to the constraints of various factors such as rolling mill structure, rolling process parameter control, and raw material quality during the production process.

[0003] When rolling with ordinary rolling mills, problems such as large fluctuations in rolled piece size, 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 traditional rolling process does not adjust parameters accurately and timely during the rolling process, and cannot be quickly optimized according to the real-time status 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 put forward for the dimensional accuracy, surface quality, mechanical properties and other aspects of bars. Especially in some fields such as precision machinery manufacturing, automobile industry, aerospace, etc., bars with super-precision are needed to meet the high performance and high quality requirements of products. Therefore, it is of great practical significance to develop a method for rolling bars with super-precision size using a four-roller gauge round rolling mill. Summary of the invention

[0005] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a method for rolling a bar with a size exceeding one set of precision, which can solve the above-mentioned problem.

[0006] To achieve the above object, the present invention provides the following 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, comprehensive inspection of the mechanical parts of the four-roller round rolling mill, including the rolls, roll bearings, roll adjustment mechanisms, transmission systems, etc., to ensure that each part is free of damage, wear and looseness;

[0007] S2 Check the electrical system, including the motor, control system, sensors, etc., to ensure that the electrical connections are good, the control system parameters are accurate, and all sensors are working properly;

[0008] S3 Check the hydraulic system of the rolling mill to ensure that there is no leakage in the hydraulic pump, hydraulic cylinder, hydraulic valve and other components, 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 accuracy meets the requirements of the first group;

[0009] S4 Raw material preparation: select high-quality steel billets as rolling raw materials. The chemical composition of the steel billets should be uniform and stable and meet product requirements.

[0010] S5 cleans the surface of the steel billet to remove scale, rust and other impurities to ensure the surface of the steel billet is clean;

[0011] S6 heats the steel billet. The heating temperature should be precisely controlled according to the steel type and rolling process requirements, and the heating uniformity error should be controlled within a small range.

[0012] In the rough rolling stage S7, the heated billet is sent to a four-roller round rolling mill for rough rolling. In the rough rolling stage, a larger reduction is used, and the reduction per pass is controlled between 10-20 mm.

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

[0014] S9 finishing rolling stage, after the intermediate rolling, the rolled piece enters the finishing rolling stage. In the finishing rolling stage, a smaller reduction is adopted, and the reduction per pass is controlled between 1-3mm;

[0015] S10 cooling treatment: the rolled bar adopts a cooling method combining rapid cooling and slow cooling. In the rapid cooling stage, water cooling or air cooling is used to quickly cool the bar and inhibit grain growth. In the slow cooling stage, natural cooling or heat preservation cooling is used to fully release the stress inside the bar and avoid cracks and deformation.

[0016] S11 straightening treatment: the cooled bar enters the straightening machine for straightening treatment to eliminate the bending and twisting deformation caused by the rolling process, adjust the pressure reduction and straightening speed of the straightening machine to ensure that the straightness of the bar meets the precision requirements of a group;

[0017] S12 detection and adjustment: During the rolling process, an online laser diameter gauge is used to perform real-time detection of the diameter and ovality of the bar. According to the detection results, the rolling process parameters and straightening process parameters are adjusted in time to ensure that the ovality of the bar is always controlled within 0.1.

[0018] Preferably, the electrical control adopts steel drawing rolling, and the excess deformation is absorbed by the overspeed change. Since the deformation is very small, the steel normally slips between the rolling mills, so the steel drawing state has no effect on its fullness condition.

[0019] Preferably, the current short stress line rolling mill is used as the mother frame, and a gauge rolling mill is installed behind the segment stress line. The rollers of the gauge rolling mill form a 90-degree angle with the short stress line rolling mill. The sub-rolling mill is installed in front of the mother frame, about 3-5 cm away from the rollers of the mother frame. The sub-rolling mill is unpowered, and after biting in, it is equivalent to a drawing hole.

[0020] Preferably, during the rough rolling process, the roller speed, rolling force and roll gap are adjusted in a timely manner according to the deformation and size change of the steel billet to ensure a stable rolling process and a regular shape of the rolled piece.

[0021] Preferably, the rotation speed and rolling force of the rolling rollers are adjusted so that the grains of the rolled piece are further refined during the intermediate rolling process, the structural properties are improved, and the dimensional accuracy is increased.

[0022] Preferably, the roll gap and rolling force of the rollers are precisely adjusted so that the dimensional accuracy of the rolled piece exceeds a set of accuracy requirements, while the ovality of the rolled piece is controlled within 0.1.

[0023] Preferably, during the finish rolling process, an online size detection system is used to monitor the size change of the rolled piece in real time, 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 present invention has the following beneficial effects:

[0025] 1. The bar size exceeds a group of precision rolling methods. This solution can significantly improve the bar size accuracy. By accurately controlling the rolling parameters and processes of the four-roller round rolling mill, the size accuracy of the bar can be improved to a level exceeding a group of precision, meeting the high-precision requirements of high-end application fields for bars, and effectively controlling the ovality of the bar. By adopting a reasonable rolling process and roller adjustment method, the ovality of the bar can be controlled within 0.1, making the cross-sectional shape of the bar more regular and improving the consistency and stability of the product.

[0026] 2. The bar size exceeds a set of precision rolling methods. This solution can improve the surface quality of the bar. During the rolling process, by optimizing the rolling parameters and cooling methods, the defects and cracks on the surface of the rolled piece are reduced, the surface quality of the bar is improved, and the production efficiency is improved. The application of precise rolling parameter control and online detection system reduces the generation of scrap and the adjustment time during the rolling process, improves production efficiency and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0028] Figure 1 It is a schematic diagram of the circle rubbing principle of the present invention. DETAILED DESCRIPTION

[0029] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In the description of the present invention, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0032] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0033] The present invention 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, comprehensive inspection of mechanical parts of a four-roller round rolling mill, including rolls, roll bearings, roll adjustment mechanisms, transmission systems, etc., to ensure that each part is free of damage, wear and looseness;

[0034] S2 Check the electrical system, including the motor, control system, sensors, etc., to ensure that the electrical connections are good, the control system parameters are accurate, and all sensors are working properly;

[0035] S3 Check the hydraulic system of the rolling mill to ensure that there is no leakage in the hydraulic pump, hydraulic cylinder, hydraulic valve and other components, 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 accuracy meets the requirements of the first group;

[0036] S4 Raw material preparation: select high-quality steel billets as rolling raw materials. The chemical composition of the steel billets should be uniform and stable and meet product requirements.

[0037] S5 cleans the surface of the steel billet to remove scale, rust and other impurities to ensure the surface of the steel billet is clean;

[0038] S6 heats the steel billet. The heating temperature should be precisely controlled according to the steel type and rolling process requirements, and the heating uniformity error should be controlled within a small range.

[0039] In the rough rolling stage S7, the heated billet is sent to a four-roller round rolling mill for rough rolling. In the rough rolling stage, a larger reduction is used, and the reduction per pass is controlled between 10-20 mm.

[0040] During the rough rolling process, the roll speed, rolling force and roll gap are adjusted in time according to the deformation and size change of the steel billet to ensure a stable rolling process and a regular shape of the rolled piece.

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

[0042] Among them, the speed and rolling force of the rolls are adjusted to further refine the grains of the rolled piece during the intermediate rolling process, improve the organizational properties, and at the same time improve the dimensional accuracy.

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

[0044] Among them, the roll gap and rolling force of the rolls are precisely adjusted to make the dimensional accuracy of the rolled piece reach a higher than one set of accuracy requirements, while controlling the ovality of the rolled piece within 0.1;

[0045] During the finishing rolling process, the online dimension detection system is used to monitor the dimension changes of the rolled piece in real time, and the rolling parameters are adjusted in time according to the detection data to ensure the stability and consistency of the dimension of the rolled piece.

[0046] S10 cooling treatment: the rolled bar adopts a cooling method combining rapid cooling and slow cooling. In the rapid cooling stage, water cooling or air cooling is used to quickly cool the bar and inhibit grain growth. In the slow cooling stage, natural cooling or heat preservation cooling is used to fully release the stress inside the bar and 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 caused by the rolling process, adjust the pressure reduction and straightening speed of the straightening machine to ensure that the straightness of the bar meets the precision requirements of a group;

[0048] S12 detection and adjustment: During the rolling process, an online laser diameter gauge is used to detect the diameter and ovality of the bar in real time. According to the detection results, the rolling process parameters and straightening process parameters are adjusted in time to ensure that the ovality of the bar is always controlled within 0.1.

[0049] Among them, the electrical control adopts steel drawing rolling, and the excess deformation is absorbed by the change of overspeed. Since the deformation is very small, the steel normally slips between the rolling mills, so the steel drawing state has no effect on its fullness.

[0050] Among them, the current short stress line rolling mill is used as the mother frame, and the gauge rolling mill is installed behind the section stress line. The roller of the gauge rolling mill forms a 90-degree angle with the short stress line rolling mill. The sub-rolling mill is installed in front of the mother frame, about 3-5 cm away from the roller of the mother frame. The sub-rolling mill has no power, and after biting in, the sub-rolling mill is equivalent to a drawing hole type;

[0051] See also Figure 1 , composed of two identical circular holes, a relatively large steel drawing condition is set, and the large part can be pulled down through the round hole type. Due to the principle of equal flow rate per second, the rotation speed is greater than the rolling speed, and the steel slips in the hole type, so that the steel does not expand. Through two orthogonal hole types, the relatively large surface of each surface is pulled to the required size. The two hole types have an intersection angle of 30 degrees, so the hole type system has very low requirements for equipment. Slight misalignment and stringing will not have much effect on its ovality, and will not produce ugly indentations and other defects on the surface of the finished product. At the same time, the amount of misalignment will be automatically aligned through the hole type, and the misalignment will be eliminated through the arc surface, thereby achieving roundness;

[0052] By adopting this hole system, the expansion angle of the finished product hole can be further relaxed, thereby preventing the generation of ears during the trial rolling process. Theoretically, this hole will not produce ears. As long as the minimum size of the incoming material is larger than the hole 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-roller round rolling mill, the dimensional accuracy of bars can be improved to a level beyond a group of precision, meeting the high-precision requirements of bars in high-end application fields, and effectively controlling the ovality of bars. By adopting a reasonable rolling process and roll adjustment method, the ovality 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 product.

[0054] Furthermore, this solution can improve the surface quality of the bar. During the rolling process, by optimizing the rolling parameters and cooling methods, the defects and cracks on the surface of the rolled piece are reduced, the surface quality of the bar is improved, and the production efficiency is improved. The application of precise rolling parameter control and online detection system reduces the generation of scrap and the adjustment time during the rolling process, improves production efficiency and reduces production costs.

[0055] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A method for rolling a bar with a size exceeding one group of precision, characterized in that: It includes the following specific steps: S1. Preparation before rolling, equipment inspection and commissioning, comprehensive inspection of the mechanical parts of the four-roller round rolling mill, including rolls, roll bearings, roll adjustment mechanisms, transmission systems, etc., to ensure that all parts are free of damage, wear and looseness; S2 Check the electrical system, including the motor, control system, sensors, etc., to ensure that the electrical connections are good, the control system parameters are accurate, and all sensors are working properly; S3 Check the hydraulic system of the rolling mill to ensure that there is no leakage in the hydraulic pump, hydraulic cylinder, hydraulic valve and other components, 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 accuracy meets the requirements of the first group; S4 Raw material preparation: select high-quality steel billets as rolling raw materials. The chemical composition of the steel billets should be uniform and stable and meet product requirements. S5 cleans the surface of the steel billet to remove scale, rust and other impurities to ensure the surface of the steel billet is clean; S6 heats the steel billet. The heating temperature should be precisely controlled according to the steel type and rolling process requirements, and the heating uniformity error should be controlled within a small range. In the rough rolling stage S7, the heated billet is sent to a four-roller round rolling mill for rough rolling. In the rough rolling stage, a larger reduction is used, and the reduction per pass is controlled between 10-20 mm. S8 intermediate rolling stage, after rough rolling, the rolled piece enters the intermediate rolling stage, in which the reduction is gradually reduced, and the reduction per pass is controlled between 5-10mm; S9 finishing rolling stage, after the intermediate rolling, the rolled piece enters the finishing rolling stage. In the finishing rolling stage, a smaller reduction is adopted, and the reduction per pass is controlled between 1-3mm; S10 cooling treatment: the rolled bar adopts a cooling method combining rapid cooling and slow cooling. In the rapid cooling stage, water cooling or air cooling is used to quickly cool the bar and inhibit grain growth. In the slow cooling stage, natural cooling or heat preservation cooling is used to fully release the stress inside the bar and avoid cracks and deformation. S11 straightening treatment: the cooled bar enters the straightening machine for straightening treatment to eliminate the bending and twisting deformation caused by the rolling process, adjust the pressure reduction and straightening speed of the straightening machine to ensure that the straightness of the bar meets the precision requirements of a group; S12 detection and adjustment: During the rolling process, an online laser diameter gauge is used to perform real-time detection of the diameter and ovality of the bar. According to the detection results, the rolling process parameters and straightening process parameters are adjusted in time to ensure that the ovality of the bar is always controlled within 0.

1.

2. A method for rolling a bar with a size exceeding one group of precision according to claim 1, characterized in that: In terms of electrical control, steel drawing rolling is adopted, and the excess deformation is absorbed by the over-speed change. Since the deformation is very small, the steel normally slips between the rolling mills, so the steel drawing state has no effect on its fullness condition.

3. A method for rolling a bar with a size exceeding one group of precision according to claim 1, characterized in that: The current short stress line rolling mill is used as the mother frame, and a gauge rolling mill is installed behind the section stress line. The rollers of the gauge rolling mill form a 90-degree angle with the short stress line rolling mill. The sub-rolling mill is installed in front of the mother frame, about 3-5 cm away from the rollers of the mother frame. The sub-rolling mill has no power, and after biting in, it is equivalent to a drawing hole.

4. A method for rolling a bar with a size exceeding one group of precision according to claim 1, characterized in that: During the rough rolling process, the roller speed, rolling force and roller gap are adjusted in a timely manner according to the deformation and size change of the steel billet to ensure a stable rolling process and a regular shape of the rolled piece.

5. A method for rolling a bar with a size exceeding one group precision according to claim 1, characterized in that: Adjust the speed and rolling force of the rolls to further refine the grains of the rolled piece during the intermediate rolling process, improve the organizational properties, and at the same time increase the dimensional accuracy.

6. A method for rolling a bar with a size exceeding one group of precision according to claim 1, characterized in that: Accurately adjust the roll gap and rolling force of the rollers to ensure that the dimensional accuracy of the rolled piece exceeds a set of accuracy requirements, while controlling the ovality of the rolled piece within 0.

1.

7. A method for rolling a bar with a size exceeding one group precision according to claim 1, characterized in that: During the finishing rolling process, an online size detection system is used to monitor the size change of the rolled piece in real time, 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.

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