A riveting and welding process for a continuous casting roll rotary joint

Abstract

The present application relates to the riveting and welding process technical field of continuous casting roller rotary joint, and discloses a riveting and welding process for continuous casting roller rotary joint, comprising the following steps: S1, the rotary joint shell is decomposed into a plurality of building block modular components;S2, the modular components are preassembled using a hot mounting process, the assembly temperature is controlled at 800-1000 DEG C, and the assembly pressure is 1.2-2.0 MPa;S3, the preassembled components are riveted and positioned;S4, argon arc welding is used to implement continuous welding on the riveted parts;S5, the weld area is subjected to stress relief annealing treatment.The riveting and welding process for continuous casting roller rotary joint replaces the casting process by hot mounting riveting and welding, eliminates internal defects, and improves the tensile strength of the shell;The modular design improves material utilization, shortens the processing cycle, the double-stage sealing system (static sealing + dynamic sealing) cooperates with the mechanical self-locking structure to ensure the sealing performance, ordinary argon arc welding machines can be used for welding, and the equipment investment is reduced.

Description

Technical Field

[0001] This invention relates to the field of riveting and welding technology for rotary joints of continuous casting rolls, specifically a riveting and welding process for rotary joints of continuous casting rolls. Background Technology

[0002] The rotary joint of the continuous casting roll is an important component in continuous casting equipment. It is responsible for transferring fluid media such as cooling water from the stationary pipeline to the rotating continuous casting roll, so as to ensure effective cooling of the roll, thereby extending its service life and improving product quality.

[0003] The housing of the continuous casting roll rotary joint is mainly formed by casting followed by machining. The casting process is prone to internal defects such as porosity and sand holes, resulting in low overall strength and poor pressure resistance of the housing. The casting blank needs to undergo multiple precision machining processes to ensure the accuracy of the sealing surface, which is costly. Therefore, there is an urgent need for a riveting and welding process for the continuous casting roll rotary joint. Summary of the Invention

[0004] The purpose of this invention is to provide a riveting and welding process for a rotary joint of a continuous casting roll, so as to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a riveting and welding process for a rotary joint of a continuous casting roll, comprising the following steps: S1, decomposes the rotary joint housing into multiple modular components; S2 uses a hot-fitting process to pre-assemble modular components, with the assembly temperature controlled at 800-1000℃ and the assembly pressure at 1.2-2.0MPa; S3, Riveting and positioning of pre-assembled components; S4, Argon arc welding is used to continuously weld the riveted parts; S5, stress-relieving annealing treatment is performed on the weld area.

[0006] Preferably, the modular component includes: Precision-machined inner diameter sleeve assembly; A housing base with L-shaped positioning holes; The end face connection flange is equipped with a 6×1mm annular groove.

[0007] The rotary joint housing is broken down into multiple modular components, including a precision-machined inner diameter sleeve assembly, a housing base with L-shaped positioning holes, and an end face connection flange with 6×1mm annular grooves. This step improves the manufacturing precision, assembly efficiency, and overall performance of the rotary joint. The modular components also facilitate maintenance and replacement, reducing operating costs.

[0008] Preferably, the heat-fitting process employs gradient temperature control: The first stage involves heating to 500℃ at a rate of ≤100℃ / h; The second stage involves heating to the operating temperature at a rate of ≤50℃ / h. The insulation time is calculated based on the maximum wall thickness of the component at 1.5 min / mm.

[0009] Preferably, the riveting positioning adopts a combined positioning structure: Two tapered bosses (height 2.5±0.1mm, cone angle 45°) are provided on the end face. Four sets of elastic steel ball locking mechanisms are arranged radially (steel ball diameter φ6mm, H9 tolerance fit).

[0010] The thermal assembly process ensures the dimensional accuracy and assembly quality of modular components during pre-assembly by precisely controlling the assembly temperature and pressure, as well as using a gradient heating method. The assembly temperature is controlled at 800-1000℃ to ensure that the components can expand to the appropriate size after being heated, which facilitates assembly. The assembly pressure is 1.2-2.0MPa to ensure that the components can fit tightly after being heated and expanded, while avoiding excessive pressure that could cause deformation or damage to the components.

[0011] Preferably, the elastic steel ball locking mechanism comprises: L-shaped guide holes machined into the outer casing substrate; φ6mm stainless steel ball; Adjusting set screw with 45° tapered tip (M8×1 fine thread); Annular elastic retaining ring (section 1×6mm, material 65Mn).

[0012] Preferably, the welding process parameters include: Tungsten electrode diameter: φ2.4mm; Welding current: 90-120A (DCEN); Protective gas flow rate: 12-15 L / min (Ar≥99.99%). Weld overlap rate: 30-40%.

[0013] Using a φ2.4mm tungsten electrode in this welding process ensures arc stability and reduces welding defects. A current range of 90-120A during welding ensures appropriate weld penetration and avoids over-melting or incomplete penetration. A flow rate range of 12-15L / min ensures adequate protection of the welding area, preventing oxidation and contamination.

[0014] Preferably, the sealing structure adopts a two-stage sealing configuration: The static sealing part uses a φ5.3mm fluororubber O-ring (pre-compression 18-22%). The dynamic sealing part uses a φ3.5mm hydrogenated nitrile rubber O-ring (pre-compression 12-15%). The surface roughness Ra of the mating surfaces is ≤0.8μm.

[0015] Preferably, the modular component includes a first-generation mechanical self-locking structure: End face boss height tolerance H7 / h6 fit; The groove has a chamfer radius of 0.5mm. Nitriding treatment of self-locking contact surfaces (layer depth 0.1-0.15mm, hardness ≥800HV).

[0016] The sealing structure adopts a two-stage sealing configuration: the static sealing part uses a φ5.3mm fluororubber O-ring (pre-compression 18-22%) to ensure that the O-ring can generate sufficient elastic deformation after assembly, thereby filling the tiny gaps in the mating surfaces and achieving a good sealing effect; the dynamic sealing part uses a φ3.5mm hydrogenated nitrile rubber O-ring (pre-compression 12-15%) because the dynamic sealing part needs to adapt to relative movement, so the pre-compression is relatively small to reduce friction and wear.

[0017] Preferably, the modular component includes a second-generation mechanical self-locking structure: The ring snap ring is formed by laser cutting (cut width ≤ 0.1mm); The steel ball mounting hole opening is spun and tapered (taper angle 30°, depth 0.3mm). The threaded portion of the set screw is coated with molybdenum disulfide solid lubricant (thickness 20-30μm).

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are: First, this invention replaces the casting process with hot-fitting riveting, eliminating internal defects and improving the tensile strength of the shell; the modular design improves material utilization and shortens the processing cycle; the dual-level sealing system (static seal + dynamic seal) combined with the mechanical self-locking structure ensures sealing performance; welding can be completed using a common argon arc welding machine, reducing equipment investment.

[0019] Secondly, this invention eliminates the casting process, reduces solid waste emissions, and significantly reduces energy consumption in the riveting and welding process, thus meeting green manufacturing standards. Attached Figure Description

[0020] Figure 1 This is a flowchart of the riveting and welding process for the rotary joint of the continuous casting roll. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention provides the following technical solutions: Example Please see Figure 1 A riveting and welding process for a rotary joint of a continuous casting roll includes the following steps: S1, decomposes the rotary joint housing into multiple modular components; Modular components include: Precision-machined inner diameter sleeve assembly; A housing base with L-shaped positioning holes; The end face connection flange is equipped with a 6×1mm annular groove.

[0023] The above technical solution decomposes the rotary joint housing into multiple modular components. These modular components include a precision-machined inner diameter sleeve assembly, an outer shell base with L-shaped positioning holes, and an end face connecting flange with a 6×1mm annular groove. This step improves the manufacturing precision, assembly efficiency, and overall performance of the rotary joint. The modular components also facilitate maintenance and replacement, reducing operating costs. The inner diameter sleeve assembly is responsible for fluid transmission, and its high-precision machining ensures smooth fluid flow and sealing performance. The L-shaped positioning holes on the outer shell base improve the accuracy and stability of assembly, reducing errors and adjustment time during assembly. The 6×1mm annular groove on the end face connecting flange enhances the sealing performance and connection strength of the flange, ensuring stable operation of the rotary joint under harsh conditions such as high pressure and high temperature.

[0024] S2 uses a hot-fitting process to pre-assemble modular components, with the assembly temperature controlled at 800-1000℃ and the assembly pressure at 1.2-2.0MPa; The hot-fitting process uses gradient temperature control: The first stage involves heating to 500℃ at a rate of ≤100℃ / h; The second stage involves heating to the operating temperature at a rate of ≤50℃ / h. The insulation time is calculated based on the maximum wall thickness of the component at 1.5 min / mm.

[0025] Through the above technical solutions, the thermal assembly process ensures the dimensional accuracy and assembly quality of modular components during pre-assembly by precisely controlling the assembly temperature and pressure, as well as using a gradient heating method. The assembly temperature is controlled at 800-1000℃ to ensure the components expand to a suitable size after heating, facilitating assembly. The assembly pressure is 1.2-2.0MPa to ensure the components fit tightly after thermal expansion, while avoiding excessive pressure that could cause deformation or damage. The gradient heating control involves two stages: first, heating at a rate of ≤100℃ / h to 500℃ to ensure uniform heating of the components and avoid thermal stress concentration caused by localized overheating; second, heating at a rate of ≤50℃ / h to the working temperature (800-1000℃) to further expand the components to a suitable size, facilitating assembly. The holding time is calculated based on the maximum wall thickness of the components at 1.5min / mm to ensure uniform temperature distribution within the components, avoiding assembly errors caused by temperature gradients, thus achieving uniform heating and precise assembly of the components.

[0026] S3, Riveting and positioning of pre-assembled components; The riveting positioning adopts a combined positioning structure: Two tapered bosses (height 2.5±0.1mm, cone angle 45°) are provided on the end face. Four sets of elastic steel ball locking mechanisms are arranged radially (steel ball diameter φ6mm, H9 tolerance fit).

[0027] The above technical solution employs a combined positioning structure for the riveting and positioning of pre-assembled components to ensure the accuracy and stability of the components during assembly. Two conical bosses with a height of 2.5±0.1mm and a cone angle of 45° are set on the end face, allowing the components to be quickly aligned during assembly. The initial positioning and fixation are achieved through the contact between the conical surface and the mating surface. Four sets of elastic steel ball locking mechanisms are arranged radially, with the steel balls having a diameter of φ6mm and an H9 tolerance fit. After the components are assembled in place, the elastic steel balls press against the mating surface under the action of springs, achieving radial locking of the components. The H9 tolerance fit ensures that the gap between the steel balls and the mating holes is moderate, neither too tight nor too loose, guaranteeing the reliability and stability of the locking. Through the synergistic effect of these two structures, high-precision positioning and secure locking of the components are achieved.

[0028] S4, Argon arc welding is used to continuously weld the riveted parts; Welding process parameters include: Tungsten electrode diameter: φ2.4mm; Welding current: 90-120A (DCEN); Protective gas flow rate: 12-15 L / min (Ar≥99.99%). Weld overlap rate: 30-40%.

[0029] Through the above technical solution, the continuous welding of the riveted parts adopts the argon arc welding process. Argon arc welding, with its high-quality and high-efficiency welding characteristics, can ensure arc stability and reduce welding defects by using a φ2.4mm tungsten electrode in this welding process. The current range of 90-120A during welding can ensure that the weld penetration is moderate and avoid over-melting or incomplete penetration. The flow rate range of 12-15L / min can ensure that the welding area is fully protected to prevent oxidation and contamination and improve the weld quality. The 30-40% overlap rate can ensure that the weld is continuous and dense, and improve the strength and sealing of the welded joint.

[0030] S5, stress-relieving annealing treatment is performed on the weld area.

[0031] Through the above technical solutions, residual stress will be generated in the weld area due to local heating and cooling during the welding process. These stresses may cause the welded joint to deform, crack or reduce fatigue strength. Stress relief annealing releases and eliminates the residual stress in the weld area by heating and slow cooling. At the same time, stress relief annealing can also improve the plasticity and toughness of the welded joint, improve its crack resistance and fatigue strength, thereby extending the service life of the welded structure.

[0032] The sealing structure adopts a two-stage sealing configuration: The static sealing part uses a φ5.3mm fluororubber O-ring (pre-compression 18-22%). The dynamic sealing part uses a φ3.5mm hydrogenated nitrile rubber O-ring (pre-compression 12-15%). The surface roughness Ra of the mating surfaces is ≤0.8μm.

[0033] Through the above technical solution, the sealing structure adopts a two-stage sealing configuration: the static sealing part uses a φ5.3mm fluororubber O-ring (pre-compression 18-22%) to ensure that the O-ring can generate sufficient elastic deformation after assembly, thereby filling the tiny gaps in the mating surfaces and achieving a good sealing effect; the dynamic sealing part uses a φ3.5mm hydrogenated nitrile rubber O-ring (pre-compression 12-15%) because the dynamic sealing part needs to adapt to relative movement, so the pre-compression is relatively small to reduce friction and wear; the roughness of the mating surfaces has an important impact on the sealing effect. Excessive roughness will lead to accelerated wear of the O-ring and reduce sealing performance. Therefore, the surface roughness Ra≤0.8μm ensures the sealing performance of the rotary joint. The two-stage sealing configuration can form multiple sealing barriers, effectively improving sealing performance. O-rings of different specifications and materials can adapt to different working conditions and media environments, ensuring the stability and reliability of the sealing effect. At the same time, as a vulnerable part, the O-ring is easy to disassemble and replace. When the sealing performance decreases or the O-ring is damaged, it can be quickly replaced to restore the performance of the sealing structure.

[0034] The modular components include a first-generation mechanical self-locking structure: End face boss height tolerance H7 / h6 fit; The groove has a chamfer radius of 0.5mm. Nitriding treatment of self-locking contact surfaces (layer depth 0.1-0.15mm, hardness ≥800HV).

[0035] The modular components include a second-generation mechanical self-locking structure: The ring snap ring is formed by laser cutting (cut width ≤ 0.1mm); The steel ball mounting hole opening is spun and tapered (taper angle 30°, depth 0.3mm). The threaded portion of the set screw is coated with molybdenum disulfide solid lubricant (thickness 20-30μm).

[0036] Through the above technical solutions, the modular components, incorporating first-generation and second-generation mechanical self-locking structures, improve the assembly accuracy and self-locking performance of the components. Specifically, the end-face boss height tolerance fits with an H7 / h6 tolerance fit, strictly controlling the height dimension of the end-face boss to ensure a moderate gap between it and the mating surface—neither too tight nor too loose. A 0.5mm chamfer is designed at the groove to make the assembly and disassembly of the components smoother, reducing damage caused by stress concentration. The self-locking contact surface undergoes nitriding treatment with a layer depth of 0.1-0.15mm and a hardness ≥800HV, ensuring the contact surface... More robust and wear-resistant, improving the stability and reliability of self-locking. Utilizing laser cutting technology, the cut width is ≤0.1mm, ensuring the forming accuracy and cut quality of the retaining spring, thus improving its strength and durability. The steel ball mounting hole is spun and closed at a 30° angle and 0.3mm depth, allowing the steel ball to be more tightly wrapped, improving its fixing effect and self-locking performance. A 20-30μm thick layer of molybdenum disulfide solid lubricant is applied to the set screw threads, making them smoother, reducing friction and wear during assembly and disassembly, and extending service life.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A riveting and welding process for a rotary joint of a continuous casting roll, characterized in that, Includes the following steps: S1, decomposes the rotary joint housing into multiple modular components; S2 uses a hot-fitting process to pre-assemble modular components, with the assembly temperature controlled at 800-1000℃ and the assembly pressure at 1.2-2.0MPa; S3, Riveting and positioning of pre-assembled components; S4, Argon arc welding is used to continuously weld the riveted parts; S5, stress-relieving annealing treatment is performed on the weld area.

2. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: The modular components include: Precision-machined inner diameter sleeve assembly; A housing base with L-shaped positioning holes; The end face connection flange is equipped with a 6×1mm annular groove.

3. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: The heat-fitting process employs gradient temperature control: The first stage involves heating to 500℃ at a rate of ≤100℃ / h; The second stage involves heating to the operating temperature at a rate of ≤50℃ / h. The insulation time is calculated based on the maximum wall thickness of the component at 1.5 min / mm.

4. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: The riveting positioning adopts a combined positioning structure: Two tapered bosses (height 2.5±0.1mm, cone angle 45°) are provided on the end face. Four sets of elastic steel ball locking mechanisms are arranged radially (steel ball diameter φ6mm, H9 tolerance fit).

5. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: The elastic steel ball locking mechanism includes: L-shaped guide holes machined into the outer casing substrate; φ6mm stainless steel ball; Adjusting set screw with 45° tapered tip (M8×1 fine thread); Annular elastic retaining ring (section 1×6mm, material 65Mn).

6. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: Welding process parameters include: Tungsten electrode diameter: φ2.4mm; Welding current: 90-120A (DCEN); Protective gas flow rate: 12-15 L / min (Ar≥99.99%). Weld overlap rate: 30-40%.

7. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: The sealing structure adopts a two-stage sealing configuration: The static sealing part uses a φ5.3mm fluororubber O-ring (pre-compression 18-22%). The dynamic sealing part uses a φ3.5mm hydrogenated nitrile rubber O-ring (preload 12-15%). The surface roughness Ra of the mating surfaces is ≤0.8μm.

8. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: The modular component includes a first-generation mechanical self-locking structure: End face boss height tolerance H7 / h6 fit; The groove has a chamfer radius of 0.5mm. Nitriding treatment of self-locking contact surfaces (layer depth 0.1-0.15mm, hardness ≥800HV).

9. The riveting and welding process for a rotary joint of a continuous casting roll according to claim 1, characterized in that: The modular component includes a second-generation mechanical self-locking structure: The ring snap ring is formed by laser cutting (cut width ≤ 0.1mm); The opening of the steel ball mounting hole is spun and tapered (taper angle 30°, depth 0.3mm). The threaded portion of the set screw is coated with molybdenum disulfide solid lubricant (thickness 20-30μm).

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