A method for improving the application effect of a bearing for a continuous casting segment

Abstract

The present application relates to continuous casting steelmaking technical field, specifically to a kind of method for improving the application effect of bearing for continuous casting fan-shaped section, comprising: bearing selects GCr15 bearing steel;Bearing inner and outer ring and roller adopt logarithmic surface contact;Bearing roller hardness is greater than the hardness of sleeve ring, and the plasticity of bearing sleeve ring is greater than the plasticity of roller;The clearance of bearing sleeve ring and roller is determined according to the load, speed, slab surface temperature of continuous casting fan-shaped section;Continuous casting fan-shaped section continuous casting roll surface is cooled;Continuous casting fan-shaped section continuous casting roll and bearing are assembled with clearance fit;Reduce the load of continuous casting machine.The present application uses high-quality bearing steel, uses reasonable contact surface design, clearance control and other design methods, cooperates bearing seat, water cooling, reduces load and other continuous casting field applications, guarantees the service life of bearing in high humidity, high temperature, high salt, high dust environment, improves the precision when bearing is applied.

Description

Technical Field

[0001] This invention relates to the field of continuous casting steelmaking technology, and specifically to a method for improving the application effect of bearings used in continuous casting sector sections. Background Technology

[0002] Continuous casting technology, due to its advantages such as high efficiency and low loss, has become the mainstream process in iron and steel metallurgy, with the proportion of continuous casting reaching over 95%. In recent years, continuous casting technology has developed rapidly, making significant progress in many fields such as high-efficiency continuous casting, thin slab continuous casting, and casting machine design and manufacturing.

[0003] The sector section is one of the important pieces of equipment in the continuous casting process, serving to guide and support the billet. Its functions include suppressing the bulging deformation of the billet caused by the static pressure of molten steel, guiding and clamping the dummy bar, and ensuring that the billet shell moves along a predetermined trajectory. The sector section consists of support rollers, a frame, a clamping device, a drive roller pressing device, and atomizing nozzles.

[0004] Bearings are crucial components in the assembly of the support rollers for the sector section. Their quality directly affects the accuracy of the sector section opening and the amount of friction force the cast billet can withstand. The sector section bearings operate in extremely harsh environments with high temperatures, high humidity, and high dust levels, and are subjected to high loads and radial axial forces, demanding exceptionally high bearing quality. Currently, the sector section bearings in continuous casting machines, as basic spare parts, are almost entirely imported. While some domestically produced bearings are used as substitutes, they suffer from issues such as low precision and short service life, directly impacting production safety, steel quality, and the working environment, necessitating urgent solutions. Summary of the Invention

[0005] To address the problem of poor performance of existing bearing technologies, this invention provides a method to improve the performance of bearings used in continuous casting sector sections, which can improve the problems of low precision and short service life of bearings used in continuous casting sector sections.

[0006] This invention provides a method for improving the application effect of bearings used in continuous casting sector sections, comprising:

[0007] The bearings are made of GCr15 bearing steel.

[0008] The bearing inner and outer rings and rollers use logarithmic curved surface contact. In the plane of the axis, the outer surface of the bearing uses basic cylindrical or conical rollers with continuous or discontinuous slightly convex arc design, which are called convex rollers and profiled rollers. Logarithmic curve rollers are also convex rollers. Their convexity generatrix is ​​composed of two mutually symmetrical logarithmic curves, that is, slightly convex in the middle, and the curve profile gradually decreases towards both ends, with the ends smoothly transitioning to the two chamfered arcs. Correspondingly, the inner and outer rings of the bearing are also machined with a relatively symmetrical logarithmic curve design. The contact form between the inner and outer rings of the bearing designed in this way and the rollers is logarithmic curved surface contact. The purpose is to prevent stress concentration at the end of the contact between the roller and the raceway.

[0009] The bearing rollers have a higher hardness than the bearing races, and the bearing races have a higher plasticity than the rollers. By using differentiated friction pairs between the races and rollers, the damage rate of the races and rollers can be reduced.

[0010] The clearance between the bearing rings and rollers is determined based on the load, speed, and surface temperature of the billet in the continuous casting sector.

[0011] The surface of the continuous casting roll in the sector section is cooled to ensure the cooling effect, reduce radial movement, and ensure that the positioning clearance of the free end bearing can meet the thermal expansion space requirements of the continuous casting roll.

[0012] The continuous casting sector section continuous casting roll and bearing are assembled with clearance fit. Cold assembly is used during assembly to avoid the need for hot assembly due to interference fit caused by non-standard machining of the shaft head outer diameter.

[0013] To reduce the load on the continuous casting machine, the following methods are employed: adjusting the light reduction parameters, optimizing the tail billet output mode, and activating the soft clamping function. These measures effectively reduce the occurrence of instantaneous overload on the continuous casting machine, thereby reducing the total tensile force in the sector section during the production process and minimizing bearing damage caused by overload.

[0014] Furthermore, GCr15 bearing steel has the following technical requirements: oxygen content ≤ 6 ppm, titanium content ≤ 10 ppm; carbon segregation controlled within 0.01% to 0.02% in the same cross-section; inclusion Ds ≤ 0.5 grade, micro-inclusions are fine and uniform, and the ultrasonic detection volume of macro-inclusions is 5.0 dm. 3 The total cleanliness index is ≤5mm / dm. 3 The maximum length of a single inclusion should be ≤2mm.

[0015] Furthermore, the bearing roller hardness is ≥65HRC, and the bearing ring hardness is ≥63.5HRC.

[0016] Furthermore, the method for determining the clearance between the bearing rings and rollers is as follows: the cross-sectional dimensions of the continuously cast slab are 200mm×1700mm, the fan-shaped section of the continuous casting machine is two-section, the speed is 1.2~1.4m / min, the surface temperature of the cast slab is 1150~1180℃, and the clearance between the bearing rings and rollers is 160~300μm.

[0017] Furthermore, the method for determining the clearance between the bearing rings and rollers is as follows: the cross-sectional dimensions of the continuously cast slab are 200mm×1400mm, the continuous casting machine has seven fan-shaped sections, the speed is 1.2~1.4m / min, the surface temperature of the cast slab is 950~980℃, and the clearance between the bearing rings and rollers is 120~230μm.

[0018] Furthermore, the surface temperature of the continuous casting roll in the sector section is cooled to ≤150℃.

[0019] Furthermore, the lubricating oil supply for the continuous casting sector adopts an automatic oil supply mode, and the dry oil pump and dry oil distributor adopt an intelligent lubrication system to achieve automatic oil supply and refueling; strengthen the management of the use of dry oil grease, and replace the filter element of the oil filter regularly.

[0020] The beneficial effects of this invention are that the method for improving the application effect of bearings in continuous casting sector sections provided by this invention adopts high-quality bearing steel, uses reasonable contact surface design, clearance control and other design methods, and is combined with bearing housing, water cooling, load reduction, oil film lubrication and other continuous casting field applications to ensure the service life of bearings in high humidity, high temperature, high salt and high dust environments, and improves the accuracy of bearing application. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0022] The bearings used in the following embodiments are made of GCr15 bearing steel and have the following technical requirements: oxygen content ≤ 6 ppm, titanium content ≤ 10 ppm; carbon segregation in the same cross section controlled at 0.01% to 0.02%; inclusion Ds ≤ 0.5 grade, micro-inclusions are fine and uniform, and the ultrasonic detection volume of macro-inclusions is 5.0 dm. 3 The total cleanliness index is ≤5mm / dm. 3 The maximum length of a single inclusion should be ≤2mm; the inhomogeneity of carbides should meet the relevant requirements of GB / T 38885.

[0023] In the following embodiments, the bearing inner and outer rings and rollers are in logarithmic curved surface contact, which serves to prevent stress concentration at the ends where the rollers contact the raceway.

[0024] The bearing used in the following embodiments has a hardness greater than that of the bearing race, a plasticity greater than that of the roller, and a roller hardness ≥ 65 HRC and a bearing race hardness ≥ 63.5 HRC.

[0025] The bearings and continuous casting rolls used in the following embodiments are assembled with a clearance fit. Cold assembly is used during assembly to avoid the need for hot assembly due to interference fit caused by non-standard machining of the shaft head outer diameter.

[0026] Example 1

[0027] Taking a 200mm×1700mm cross-section slab billet continuous casting machine with two fan-shaped sections as an example, the continuous casting machine speed is 1.2~1.4m / min, the billet surface temperature is 1150~1180℃, the bearing models are 24024 and 23124, and the clearance is designed to be 160~300μm. During continuous casting, the continuous casting roller surface of the continuous casting fan-shaped section is cooled down to ≤150℃, and the lubricating oil supply of the continuous casting fan-shaped section adopts an automatic oil supply mode.

[0028] This embodiment requires that the single-pass steel throughput of the sector-shaped bearing be no less than 350,000 tons and the steel throughput for bearing scrap be greater than 1 million tons. In actual operation, the single-pass steel throughput of the sector-shaped bearing can reach 420,000 tons, and the steel throughput for scrap is 1.26 million tons. After completing the 420,000-ton single-pass steel throughput, the measured raceway after the bearing goes offline is only 17.6μm, which is within the clearance control range.

[0029] Example 2

[0030] Taking a 7-segment sector of a 200mm×1400mm cross-section slab continuous casting machine in a steel plant as an example, the casting speed is 1.2-1.4m / min, the slab surface temperature is 950-980℃, the bearing clearance is designed to be 120~230μm, the continuous casting roll surface of the sector sector is cooled to ≤150℃ during continuous casting, and the lubricating oil supply of the continuous casting sector sector adopts an automatic oil supply mode.

[0031] This embodiment requires that the single-pass steel throughput of the sector-shaped bearing be no less than 500,000 tons and the steel throughput for bearing scrap be greater than 1.5 million tons. In actual operation, the single-pass steel throughput of the sector-shaped bearing can reach 570,000 tons, and the steel throughput for scrap is 1.86 million tons. Among them, after completing the single-pass steel throughput of 570,000 tons, the measured raceway after going offline is only 16.6μm, which is within the clearance control range.

[0032] This invention uses high-quality bearing steel and employs reasonable contact surface design, clearance control and other design methods, combined with bearing housing, water cooling, load reduction and oil film lubrication, to achieve continuous casting field application, ensuring the service life of the bearing in high humidity, high temperature, high salt and high dust environments, and improving the precision of bearing application.

[0033] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A method for improving the effect of application of a bearing for a continuous casting segment, characterized in that, The application relates to a bearing with a logarithmic surface contact between the inner and outer rings and the rollers. The bearing is made of GCr15 bearing steel, which has the following technical requirements: oxygen content ≤6ppm, titanium content ≤10ppm, carbon element segregation in the same section is controlled in 0.01%-0.02%, the inclusion Ds ≤0.5 level, the micro-inclusion is fine and uniform, the macro-inclusion is 5.0dm 3 , the cleanliness total index ≤5mm / dm 3 , and the maximum length of single inclusion should be ≤2mm. The hardness of the bearing rollers is greater than that of the rings, and the plasticity of the bearing rings is greater than that of the rollers. The clearance between the bearing rings and the rollers is determined by the following method: the cross-section size of the continuous casting slab is 200mm*1700mm, the continuous casting machine has two segments, the speed is 1.2-1.4m / min, the surface temperature of the casting slab is 1150-1180 DEG C, and the clearance between the bearing rings and the rollers is 160-300mu. The surface of the continuous casting segment is cooled. The continuous casting segment and the bearing are assembled in a clearance fit. The load of the continuous casting machine is reduced. The application relates to a bearing with a logarithmic surface contact between the inner and outer rings and the rollers.

2. A method of improving the effect of application of a bearing for a continuous casting segment, characterized in that, The hardness of the bearing rollers is greater than that of the rings, and the plasticity of the bearing rings is greater than that of the rollers. The bearing is made of GCr15 bearing steel, which has the following technical requirements: oxygen content ≤6ppm, titanium content ≤10ppm, carbon element segregation in the same section is controlled in 0.01%-0.02%, the inclusion Ds ≤0.5 level, the micro-inclusion is fine and uniform, the macro-inclusion is 5.0dm 3 , the cleanliness total index ≤5mm / dm 3 , and the maximum length of single inclusion should be ≤2mm. The clearance between the bearing rings and the rollers is determined by the following method: the cross-section size of the continuous casting slab is 200mm*1400mm, the continuous casting machine has seven segments, the speed is 1.2-1.4m / min, the surface temperature of the casting slab is 950-980 DEG C, and the clearance between the bearing rings and the rollers is 120-230mu. The surface of the continuous casting segment is cooled. The continuous casting segment and the bearing are assembled in a clearance fit. The load of the continuous casting machine is reduced. The hardness of the bearing rollers is greater than or equal to 65HRC, and the hardness of the bearing rings is greater than or equal to 63.5HRC. The temperature of the surface of the continuous casting segment is cooled to less than or equal to 150 DEG C.

3. The method of claim 1 or 2, wherein The continuous casting segment and the bearing are assembled in a cold fit.

4. The method for improving the application effect of the bearing for continuous casting segment according to claim 1 or 2, characterized in that, The lubricating oil supply of the continuous casting segment adopts an automatic oil supply mode.

5. The method for improving the application effect of the bearing for continuous casting segment according to claim 1 or 2, characterized in that, The method for reducing the load of the continuous casting machine is adjusting the light pressing parameters, optimizing the tail slab output mode and starting the soft clamping function.

6. The method for improving the application effect of the bearing for continuous casting segment according to claim 1 or 2, characterized in that, ​ 7. The method of improving the application effect of a bearing for a continuous casting segment according to claim 1 or 2, characterized in that, ​