Manufacturing method of roller shoulder supporting sleeve
By using 42CrMo material for the roll support sleeve, heat treatment and surface quenching, combined with stainless steel overlay welding, a high-performance support sleeve was manufactured. This solved the problems of easy wear and corrosion of the support sleeve, extended its service life, reduced maintenance costs, and ensured rolling accuracy and product quality.
Patent Information
- Application Number
- CN202610000204.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-04
- Publication Date
- 2026-02-24
AI Technical Summary
Existing roll supports are prone to premature failure due to wear and impact under high-frequency, high-load working conditions, increasing equipment maintenance costs and downtime, and corrosion affects rolling accuracy and product quality.
The sleeve blank is made of 42CrMo material, and after heat treatment and surface quenching, combined with stainless steel layer welding, reasonable wall thickness and interference fit are designed to ensure the inner and outer surface precision and wear resistance of the shoulder sleeve, and provide anti-corrosion protection layer. Through machining and precision fit, a high-performance and long-life shoulder sleeve is manufactured.
It significantly extends the service life of the shoulder sleeve, reduces equipment maintenance costs, ensures rolling accuracy and product quality, provides an efficient repair method, and reduces grinding accuracy decline and shoulder wear.
Smart Images
Figure CN121552013A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of rolling mill manufacturing technology, and in particular to a method for manufacturing a rolling mill support sleeve. Background Technology
[0002] Rolls are the core components of a rolling mill that enable continuous plastic deformation of metal, and their performance and precision directly determine the quality of the rolled products. Generally, a roll mainly consists of the roll body for direct contact with the rolled material, the roll neck for bearing support, shoulders at both ends of the roll body, and shaft ends connecting the transmission device. Among these, the shoulders serve as an important reference surface during roll grinding and operation, playing a crucial role in ensuring the roundness and cylindricity of the roll body during grinding and the stability of the rolling process.
[0003] In current widely used rolling mill roll manufacturing and application technologies, the shoulder is typically forged or cast integrally with the roll body and neck, forming an inherent structural part of the roll body. During the rolling process, to control the roll temperature, a large amount of cooling water needs to be continuously sprayed onto its surface. Because the outer surface of the shoulder is directly exposed to this humid environment and is in long-term contact with cooling water and rolling process media that may contain electrolytes, it is highly susceptible to electrochemical corrosion, leading to surface rust. Statistics show that the outer diameter of such roll shoulders commonly ranges from φ520mm to φ1220mm, generally 60-240mm smaller than the roll body diameter, and its width typically ranges from 110mm to 220mm.
[0004] This type of corrosion on the support shoulder surface, caused by structural design flaws, can trigger a series of cascading technical defects and production hazards. First, corrosion damages the geometric integrity and surface finish of the support shoulder as a precision reference surface. During subsequent grinding of the roll body, this directly leads to inaccurate grinding references, severely affecting the grinding accuracy of the roll. Second, using rolls with such damaged references in production will cause deviations in key indicators such as thickness and shape of the rolled sheet, resulting in decreased product accuracy and even batch scrap. Furthermore, the uneven surface caused by corrosion will generate abnormal friction and impact with the grinding machine's support components (such as bearings) during grinding. This not only significantly increases the transmission load and energy consumption of the grinding machine but also exacerbates abnormal wear on critical components like bearings, shortening their service life and increasing equipment maintenance costs. Therefore, effectively solving the corrosion and wear problems of the roll support shoulder has become an important technical challenge for improving roll service life, ensuring rolling accuracy, and reducing maintenance costs. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a manufacturing method for a roll support sleeve, which solves the problem that the existing support sleeve is prone to premature failure due to wear and impact under the high frequency and high load working environment of metallurgical rolling mill, thereby increasing equipment maintenance costs and downtime. Through a series of optimized materials, processes and design controls, a high-performance and long-life support sleeve product can be manufactured, which significantly reduces the operation and maintenance costs of metallurgical rolling mill.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0007] A method for manufacturing a roll support sleeve includes the following steps:
[0008] Step 1: Prepare a blank for the sleeve made of 42CrMo material;
[0009] Step 2: Perform heat treatment on the blank of the sleeve body to make its overall hardness reach HSD35-45;
[0010] Step 3: Perform surface hardening on the outer cylindrical surface of the heat-treated sleeve to achieve a surface hardness of HSD65-75.
[0011] Step 4: Machining the inner hole and end of the sleeve to meet the interference fit requirements with the roll support platform. The axial length of the inner hole mating surface matches the straight platform length of the support platform. The part of the sleeve corresponding to the roll shaft shoulder fillet is machined with a chamfer to avoid interference, and the outer circle of the sleeve is machined into a sharp corner where it meets the mating end face.
[0012] Step 5: Determine the wall thickness based on the outer diameter of the sleeve: when the outer diameter is <700mm, the wall thickness is 30-40mm; when 700mm ≤ outer diameter <900mm, the wall thickness is 40-50mm; when the outer diameter is ≥900mm, the wall thickness is greater than 50mm.
[0013] Step 6: Determine the assembly interference amount based on the diameter and axial length of the machined inner hole mating surface: when the mating surface length is ≤260mm, the interference amount is 0.85‰~1.05‰ of the mating diameter; when the mating surface length is >260mm, the interference amount is 0.75‰~0.95‰ of the mating diameter.
[0014] Step 7: Weld a stainless steel layer with a thickness of 2-5mm onto the outer circular surface of the sleeve.
[0015] A further improvement of the technical solution of the present invention is that: in step 2, the heat treatment includes: heating the blank of the sleeve to 840-860℃ for quenching, and then performing high-temperature tempering at 550-600℃.
[0016] A further improvement of the technical solution of the present invention is that: in step 3, the surface hardening of the outer cylindrical surface of the sleeve is performed by induction hardening process.
[0017] A further improvement of the technical solution of the present invention is that: in step 4, the chamfer processed on the sleeve is C2-C5 to ensure that it does not interfere with the transition fillet of R20-30 on the roll shaft.
[0018] A further improvement of the technical solution of the present invention is that, in step 4, during machining, the final machining accuracy requirements for the sleeve are as follows: the outer diameter has a allowance of 0.5 to 0.7 mm, and the length direction has a allowance of 0.2 to 0.3 mm on the assembly outer end face; the surface roughness of its inner hole mating surface is ≤ Ra1.6, and the surface roughness of the mating end face in contact with the roll shaft shoulder is ≤ Ra3.2; the cylindricity error of the inner hole is ≤ 0.05 mm, and the perpendicularity of the mating end face to the inner hole axis is ≤ 0.05 mm.
[0019] A further improvement of the technical solution of the present invention is that: in step 7, the stainless steel layer to be welded is made of martensitic stainless steel or austenitic stainless steel.
[0020] A further improvement to the technical solution of the present invention is that: after the stainless steel layer is overlaid, the overlaid layer is ground or finely processed so that its surface finish meets the requirements for use.
[0021] A further improvement of the technical solution of the present invention is that, when used to repair worn or damaged roll supports, before the step of providing the sleeve blank, the invention further includes: pre-processing the roll support area to remove the damaged layer and machining a support platform that meets the interference fit requirements.
[0022] A further improvement of the technical solution of the present invention is that: when pre-processing the roll support shoulder, the surface finish and dimensional accuracy of the processed support shoulder should be tested to ensure that its cylindricity error is less than 0.02mm and its surface roughness Ra is not greater than 1.6μm, so as to meet the assembly requirements of interference fit.
[0023] A further improvement of the technical solution of the present invention is that after all processing and welding steps are completed, the finished shoulder sleeve needs to be inspected. The inspection items include at least: uniformity of the thickness of the weld overlay layer on the outer circle surface, overall hardness of the sleeve body, tolerance of key mating dimensions, and depth of the hardened layer on the outer circle surface, wherein the depth of the hardened layer on the outer circle surface should not be less than 3mm.
[0024] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:
[0025] 1. This invention utilizes 42CrMo as the base material and combines it with a composite heat treatment process of overall tempering (HSD35-45) followed by surface hardening of the outer diameter (HSD65-75), achieving an ideal performance match of "intelligent inside and hard outside". The excellent internal toughness effectively resists assembly stress and impact loads during operation, preventing cracking; while the extremely high surface hardness of the outer diameter provides superior wear resistance, enabling it to withstand long-term friction and compression from the grinding machine bearings, thereby significantly extending the service life of the bearing sleeve and reducing replacement frequency.
[0026] 2. This invention innovatively classifies and quantifies the two key design parameters of sleeve wall thickness and interference fit. The wall thickness range is scientifically divided based on the outer diameter, ensuring the load-bearing stiffness and strength of the sleeve at different dimensions. Simultaneously, the interference fit ratio is dynamically determined based on the length of the inner hole mating surface, effectively balancing the contradiction between the assembly clamping force and the stress concentration of the sleeve. This design method ensures the structural integrity of the shoulder sleeve under enormous interference assembly force and maintains a firm connection during high-speed, heavy-load operation of the rolls, eliminating the risk of loosening.
[0027] 3. This invention deposits a 2-5mm thick stainless steel layer (such as martensitic or austenitic stainless steel) on the hardened outer circular surface of the sleeve, providing a permanent anti-corrosion protective layer for the working surface of the support shoulder. This stainless steel layer completely isolates the cooling water and corrosive media from contact with the sleeve substrate, thoroughly eliminating the problem of datum surface damage caused by rust in traditional integrated roll supports, thereby maintaining the accuracy and surface finish of the grinding datum for a long time.
[0028] 4. This invention ensures the precision and consistency of the interference fit by specifying strict form and position tolerances (e.g., cylindricity ≤ 0.05mm, perpendicularity ≤ 0.05mm) and surface roughness requirements (e.g., inner hole Ra ≤ 1.6) for key mating parts such as the inner hole and end face. Combined with dimensional inspection and grinding processes before assembly, this ensures the precision and consistency of the interference fit. After assembly and cooling, the end face gap is required to be ≤ 0.08mm. This strict control standard ensures that the shoulder sleeve is installed in place, enabling it to accurately restore and maintain the original design accuracy required by the roll drawings, laying the foundation for rolling high-precision plates.
[0029] 5. The shoulder sleeve manufactured by the method provided by this invention can not only be used in the manufacture of new rolls, but its "prefabricated sleeve body + repair processing" mode also provides an efficient and low-cost regeneration method for worn or damaged old roll shoulders. By repairing and pre-treating the old roll neck and assembling a new shoulder sleeve, the expensive roll body can be reused, avoiding overall scrapping and greatly saving equipment costs. Practical application tests have shown that this method significantly reduces the decrease in roll grinding accuracy, unplanned downtime, and bearing wear caused by shoulder problems, effectively controlling overall operation and maintenance costs, and possessing extremely high industrial application and promotion value. Attached Figure Description
[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0031] Figure 1 This is a schematic flowchart of a method for manufacturing a roll support sleeve provided by the present invention;
[0032] Figure 2 This is a schematic diagram of the structure of the roll body and the shoulder sleeve in an embodiment of the present invention;
[0033] Among them, 1. Roll body; 2. Shoulder sleeve. Detailed Implementation
[0034] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.
[0035] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:
[0036] like Figure 1 , Figure 2 As shown, the shoulder sleeve 2 is fitted onto the shoulder of the roll body 1. Regarding the manufacturing method of the shoulder sleeve 2, this invention provides a manufacturing method for a roll shoulder sleeve, specifically including the following steps:
[0037] Step 1: Prepare a blank for the sleeve made of 42CrMo material;
[0038] Step 2: Perform heat treatment on the blank of the sleeve body to make its overall hardness reach HSD35-45;
[0039] The quenching and tempering process includes: heating the blank to 840-860℃ for quenching, and then tempering at 550-600℃.
[0040] Step 3: Surface harden the outer cylindrical surface of the heat-treated sleeve to achieve a surface hardness of HSD65-75; induction hardening is used for surface hardening of the outer cylindrical surface of the sleeve.
[0041] Step 4: Machining the inner hole and end of the sleeve to meet the interference fit requirements with the roll support platform. The axial length of the inner hole mating surface matches the straight platform length of the support platform. The part of the sleeve corresponding to the roll shaft shoulder fillet is machined with a chamfer to avoid interference, and the outer circle of the sleeve is machined into a sharp corner where it meets the mating end face.
[0042] The chamfers machined on the sleeve are C2-C5 to ensure that they do not interfere with the R20-30 transition fillet on the roll shaft.
[0043] In machining,
[0044] (1) The final machining accuracy requirements for the sleeve body are as follows: the outer diameter has a margin of 0.5 to 0.7 mm, and the length direction has a margin of 0.2 to 0.3 mm on the outer end face of the assembly; the surface roughness of the inner hole mating surface is ≤ Ra1.6, the surface roughness of the mating end face that contacts the roll shaft shoulder is ≤ Ra3.2, and the other parts are Ra6.3; the cylindricity error of the inner hole is ≤ 0.05 mm, and the perpendicularity of the mating end face to the inner hole axis is ≤ 0.05 mm.
[0045] (2) Roller neck: outer diameter roughness is Ra0.8, mating end face roughness is ≤Ra1.6, and root arc is Ra1.6. The form and position tolerance of the mating surface is ≤0.03mm.
[0046] Step 5: Determine the wall thickness based on the outer diameter of the sleeve: when the outer diameter is <700mm, the wall thickness is 30-40mm; when 700mm ≤ outer diameter <900mm, the wall thickness is 40-50mm; when the outer diameter is ≥900mm, the wall thickness is greater than 50mm.
[0047] Step 6: Determine the assembly interference amount based on the diameter and axial length of the machined inner hole mating surface: when the mating surface length is ≤260mm, the interference amount is 0.85‰~1.05‰ of the mating diameter; when the mating surface length is >260mm, the interference amount is 0.75‰~0.95‰ of the mating diameter.
[0048] Step 7: Weld a stainless steel layer with a thickness of 2-5mm onto the outer circular surface of the sleeve.
[0049] The stainless steel overlay is made of martensitic or austenitic stainless steel. After the stainless steel overlay is applied, it is ground or finished to ensure that its surface finish meets the requirements for use.
[0050] Furthermore, when used to repair worn or damaged roll supports, before providing the sleeve blank step, the method further includes: pre-treating the roll support area to remove the damaged layer and machining a support platform that meets the interference fit requirements.
[0051] When pre-processing the roll support shoulder, the surface finish and dimensional accuracy of the processed support shoulder must be checked to ensure that its cylindricity error is less than 0.02mm and its surface roughness Ra is not greater than 1.6μm, so as to meet the assembly requirements of interference fit.
[0052] After all processing and welding steps are completed, the finished shoulder sleeve must be inspected. The inspection items include at least: uniformity of the weld layer thickness on the outer circle surface, overall hardness of the sleeve body, tolerance of key mating dimensions, and depth of the hardened layer on the outer circle surface, of which the depth of the hardened layer on the outer circle surface should not be less than 3mm.
[0053] Furthermore, after step 7 or step 4, there is also a finished product inspection and assembly stage, which specifically includes:
[0054] Step A, Inspection and storage of finished shoulder sleeves: Place the end face of the shoulder sleeve horizontally to inspect the inner hole size. In two axially evenly distributed sections, inspect four points evenly in the circumferential direction of each section. Record the inspection data one by one and keep it with the workpiece. The shoulder sleeves must be stored with the end face horizontal. When stacking, place wooden strips between adjacent sleeves to keep them stable.
[0055] Step B, Pre-assembly Dimensional Inspection and Grinding: Before assembling the shoulder sleeve into the roll, the inner hole size of the shoulder sleeve needs to be jointly inspected. The final interference fit is verified and determined based on the maximum inner hole size obtained from the inspection. The sleeved roll neck of the roll is then ground to the required size.
[0056] Step C, Post-assembly Acceptance: After the shoulder support is assembled into the roll and completely cooled, the gap between its mating end face and the roll shaft shoulder should be ≤0.08mm, and the machining accuracy of each part of the roll after assembly must meet the requirements of the roll drawing.
[0057] Example
[0058] A method for manufacturing a roll support sleeve is disclosed. The prepared support sleeve is suitable for roll products where the support shoulder is located in the bonding layer, resulting in uneven hardness and requiring sleeve installation. The fit between the support sleeve and the shaft is an interference fit. The length of the mating surface is the straight platform length of the support shoulder, excluding the root arc.
[0059] Assembly interference fit strength check:
[0060] Let's take a fit dimension of φ880 as an example for verification:
[0061] Fitting dimensions: φ880 (+0.03 / 0) / φ880 (+0.48 / +0.44)
[0062] Maximum interference:
[0063] Fitting diameter d=880mm; outer diameter of the sleeve , roller inner diameter ;
[0064] Modulus of elasticity of rolling mill rolls (ductile iron): Poisson's ratio ;
[0065] Forged steel shoulder sleeve elastic modulus: Poisson's ratio ;
[0066] Yield strength of forged steel shoulder sleeve:
[0067] Pressure strength at maximum interference:
[0068]
[0069] in: ;
[0070]
[0071] Verify the strength of the shoulder support sleeve:
[0072]
[0073] Under this interference fit, the strength of the shoulder sleeve is 192.9 MPa, which is less than the yield strength of 480 MPa, so it is safe.
[0074] By tracking the usage of over a thousand shoulder support covers over more than 10 years, the manufacturing method provided by this invention has shown that the shoulder support covers produced can meet the usage requirements and achieve good performance.
[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for manufacturing a roll support sleeve, characterized in that, Includes the following steps: Step 1: Prepare a blank for the sleeve made of 42CrMo material; Step 2: Perform heat treatment on the blank of the sleeve body to make its overall hardness reach HSD35-45; Step 3: Perform surface hardening on the outer cylindrical surface of the heat-treated sleeve to achieve a surface hardness of HSD65-75. Step 4: Machining the inner hole and end of the sleeve to meet the interference fit requirements with the roll support platform. The axial length of the inner hole mating surface matches the straight platform length of the support platform. The part of the sleeve corresponding to the roll shaft shoulder fillet is machined with a chamfer to avoid interference, and the outer circle of the sleeve is machined into a sharp corner where it meets the mating end face. Step 5: Determine the wall thickness based on the outer diameter of the sleeve: when the outer diameter is <700mm, the wall thickness is 30-40mm; when 700mm ≤ outer diameter <900mm, the wall thickness is 40-50mm; when the outer diameter is ≥900mm, the wall thickness is greater than 50mm. Step 6: Determine the assembly interference amount based on the diameter and axial length of the machined inner hole mating surface: when the mating surface length is ≤260mm, the interference amount is 0.85‰~1.05‰ of the mating diameter; when the mating surface length is >260mm, the interference amount is 0.75‰~0.95‰ of the mating diameter. Step 7: Weld a stainless steel layer with a thickness of 2-5mm onto the outer circular surface of the sleeve.
2. The manufacturing method according to claim 1, characterized in that, In step 2, the quenching and tempering process includes: quenching the blank at 840-860°C and then tempering it at 550-600°C.
3. The manufacturing method according to claim 1, characterized in that, In step 3, the outer cylindrical surface of the sleeve is surface hardened using an induction hardening process.
4. The manufacturing method according to claim 1, characterized in that, In step 4, the chamfer machined on the sleeve is C2-C5 to ensure that it does not interfere with the transition fillet R20-30 on the roll shaft.
5. The manufacturing method according to claim 1, characterized in that, In step 4, during machining, the final machining accuracy requirements for the sleeve are as follows: the outer diameter has a allowance of 0.5 to 0.7 mm, and the length direction has a allowance of 0.2 to 0.3 mm on the outer end face of the assembly; the surface roughness of the inner hole mating surface is ≤ Ra1.6, and the surface roughness of the mating end face in contact with the roll shoulder is ≤ Ra3.2; the cylindricity error of the inner hole is ≤ 0.05 mm, and the perpendicularity of the mating end face to the inner hole axis is ≤ 0.05 mm.
6. The manufacturing method according to claim 1, characterized in that, In step 7, the stainless steel layer to be welded is made of martensitic stainless steel or austenitic stainless steel.
7. The manufacturing method according to claim 1 or 6, characterized in that, After the stainless steel overlay layer is welded, the overlay layer is ground or precision machined to ensure that its surface finish meets the requirements for use.
8. The manufacturing method according to claim 1, characterized in that, When used to repair worn or damaged roll supports, the process includes, before providing the blank, pre-treatment of the roll support area to remove the damaged layer and machine a support platform that meets the interference fit requirements.
9. The manufacturing method according to claim 8, characterized in that, When pre-processing the roll support shoulder, the surface finish and dimensional accuracy of the processed support shoulder must be checked to ensure that its cylindricity error is less than 0.02mm and its surface roughness Ra is not greater than 1.6μm, so as to meet the assembly requirements of interference fit.
10. The manufacturing method according to claim 1, characterized in that, After all processing and welding steps are completed, the finished shoulder sleeve must be inspected. The inspection items include at least: uniformity of the weld layer thickness on the outer circle surface, overall hardness of the sleeve body, tolerance of key mating dimensions, and depth of the hardened layer on the outer circle surface, of which the depth of the hardened layer on the outer circle surface should not be less than 3mm.