Control mode for solving water quenching pinch roller marks

Abstract

The invention relates to the technical field of heat treatment of metal materials, and discloses a control mode for solving water quenching pinch roller marks, which comprises the following steps: S1, a high-pressure contact stage: applying 8-12MPa instantaneous high pressure 50-100ms before a pinch roller is in contact with the surface of a pipe, and ensuring that the pinch roller is completely attached to the pipe; s2, a low-pressure pressure maintaining stage: after the pressing wheels are in complete contact, the pressure is immediately reduced to 0.5-1.5 MPa and is maintained until water quenching is finished; s3, a dynamic transition stage: in the process of switching from high pressure to low pressure, setting a pressure linear attenuation period of 20-50ms; s4, a delay trigger mechanism is adopted, wherein system pressure stable delay of 3-8 seconds is set before the pressing wheel acts; and S5, indentation detection feedback: monitoring the surface state of the pipe in real time through a surface roughness meter, and dynamically adjusting the dwell pressure. According to the method, the oxide layer is broken and removed through double-pulse high-voltage loading, complete contact is ensured, the method is intelligently switched to optimized low-voltage pressure maintaining according to the pipe diameter, compared with a traditional method, the indentation roughness is reduced to be within 1.0 mu m from 2.0 mu m, the manual polishing procedure is avoided, and the product percent of pass is increased by 30% or above.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment of metal materials, in particular to a control method for solving water quenching wheel marks. Background Art

[0002] In the water quenching process of metal pipes (such as oil casing and couplings), the role of the pressure roller system is to ensure stable contact with the pipe during the water quenching process to achieve uniform cooling. However, the traditional pressure roller control method uses a constant pressure mode (usually set at 1.5MPa). In actual production, there are problems such as pressure roller marks and pressure regulation conflicts. Specifically:

[0003] Pressing wheel mark defects: When water quenching pipes with a diameter of ≥178mm, a constant pressure of 1.5MPa will cause obvious indentations on the contact surface between the pressing wheel and the pipe. Due to the existence of indentations, the product needs additional manual polishing and repair, which not only reduces production efficiency but also leads to a decrease in product qualification rate.

[0004] Pressure regulation contradiction: If the pressure is reduced (e.g. <1.5MPa), some pressing rollers will not be able to fully press down due to insufficient response of the hydraulic system, resulting in uneven local cooling of the pipe, deformation or uneven hardness, and increased scrap rate. In addition, the traditional hydraulic system lacks the ability to quickly switch pressure and cannot dynamically adjust between high and low pressure. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the deficiencies in the prior art, the present invention provides a control method for solving the water quenching wheel mark, which solves the problem of "wheel mark defects and the contradiction between pressure regulation" in the above-mentioned background technology.

[0007] (2) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: A control method for solving water quenching wheel marks, comprising the following steps:

[0009] S1: High-pressure contact stage: 50-100ms before the pressing wheel contacts the pipe surface, an instantaneous high pressure of 8-12MPa is applied to ensure that the pressing wheel and the pipe are fully fitted;

[0010] S2: Low pressure holding stage: After the pressing wheel is fully in contact, the pressure is immediately reduced to 0.5-1.5MPa and maintained until the water quenching is completed;

[0011] S3: Dynamic transition stage: During the switching process from high pressure to low pressure, a pressure linear decay period of 20-50ms is set;

[0012] S4: Delay trigger mechanism: set a 3 to 8 second system pressure stabilization delay before the pressure roller moves;

[0013] S5: Indentation detection feedback: Use the surface roughness meter to monitor the surface condition of the pipe in real time and dynamically adjust the holding pressure;

[0014] S6: Material hardness compensation stage, mainly used to correct the holding pressure.

[0015] Preferably, the high-voltage contact stage in S1 adopts a dual-pulse loading mode, including but not limited to a first pulse and a second pulse. The first pulse is required to rise to 8MPa within 5ms to break the surface oxide layer, and the second pulse is required to maintain 10MPa to ensure complete contact.

[0016] Preferably, in the low-pressure holding stage of S2, when the pipe diameter is 178-200 mm, 0.8-1.0 MPa is used, and when the pipe diameter is greater than 200 mm, 1.0-1.2 MPa is used.

[0017] Preferably, a hydraulic buffer algorithm is used in the dynamic transition stage of S3 to control the pressure change rate within the range of 0.15-0.3 MPa / ms.

[0018] Preferably, the indentation detection feedback of S5 includes but is not limited to detecting the indentation depth using an online laser rangefinder with a resolution requirement of 0.01 mm. In addition, when Ra>1.6 μm at three consecutive detection points, pressure readjustment is automatically triggered.

[0019] Preferably, the delay trigger mechanism of S4 divides the total delay of 3 to 8 seconds into four stages, namely the hydraulic pre-boost stage, the mechanical resonance suppression stage, the multi-pressure wheel synchronous calibration stage and the environmental parameter compensation stage. Each stage is executed in sequence and has a dynamic time allocation function.

[0020] Preferably, in the material hardness compensation stage of S6, the holding pressure is corrected according to the HRC hardness value of the pipe, and the formula used is: P = 0.02×HRC + 0.5 (MPa).

[0021] Preferably, a control system for solving water quenching wheel marks specifically includes a multimodal pressure generating unit, a distributed strain detection unit and a self-learning control unit. The multimodal pressure generating unit can complete the pressure switching of 10MPa→1MPa within 10ms. The distributed strain detection unit arranges 3 optical fiber strain sensors under each pressure wheel. The self-learning control unit mainly optimizes the pressure parameters based on historical pass rate data.

[0022] Preferably, the multimodal pressure generating unit includes an ultra-high pressure accumulator, a proportional pressure reducing valve and a pressure fluctuation absorber.

[0023] Preferably, the distributed strain detection unit is implemented by a phase-sensitive optical time-domain reflectometer, and the spatial resolution is required to be 1 cm.

[0024] (3) Beneficial effects

[0025] The present invention provides a control method for solving water quenching wheel marks. It has the following beneficial effects:

[0026] (1) This control method for solving water quenching wheel marks, when in use, breaks the oxide layer and ensures complete contact through double-pulse high-pressure loading, and then intelligently switches to optimized low-pressure holding pressure according to the pipe diameter. Compared with the traditional constant 1.5MPa pressure, the indentation roughness is reduced from 2.0μm to within 1.0μm, avoiding the manual polishing process, and the product qualification rate is increased by more than 30%.

[0027] (2) When using this control method to solve the water quenching wheel mark, 通 The hydraulic buffer algorithm and ultra-high-speed pressure switching unit ensure the initial fit of the pressure wheel while avoiding uneven cooling caused by insufficient pressure in the low-pressure stage, reducing the scrap rate by 25%. At the same time, the distributed strain detection unit provides real-time feedback on the contact status, dynamically adjusts the pressure, and eliminates the risk of local deformation.

[0028] (3) When using this control method to solve the water quenching wheel mark, the system stability is optimized by adopting a segmented delay trigger mechanism, and the holding pressure is automatically corrected in combination with the material hardness compensation formula to adapt to pipes of different hardness. Compared with the traditional fixed 3-second delay and no compensation mechanism, the cooling uniformity is improved by 40%, which is more suitable for the production of casing and coupling materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart of a method for solving the control method of water quenching wheel marks. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] See also Figure 1

[0032] Example 1

[0033] The present invention provides a control method for solving water quenching wheel marks, comprising the following steps:

[0034] S1: High-pressure contact stage: 50-100ms before the pressing wheel contacts the pipe surface, an instantaneous high pressure of 8-12MPa is applied to ensure that the pressing wheel and the pipe are fully fitted. The high-pressure contact stage adopts a double-pulse loading mode, including but not limited to the first pulse and the second pulse. The first pulse is required to rise to 12MPa within 3ms to break the surface oxide layer, and the second pulse is required to maintain 10MPa to ensure full contact;

[0035] S2: Low pressure holding stage: After the pressing wheel is fully in contact, the pressure is immediately reduced to 0.5-1.5MPa and maintained until the water quenching is completed. Specifically, when the pipe diameter is less than 150mm, 0.7MPa is used; when the pipe diameter is 150-200mm, 0.9MPa is used; when the pipe diameter is greater than 200mm, 1.2MPa is used.

[0036] S3: Dynamic transition stage: During the switching process from high pressure to low pressure, a 50ms pressure linear decay period is set. Specifically, a hydraulic buffer algorithm is used to control the pressure change rate within the range of 0.15MPa / ms.

[0037] S4: Delay trigger mechanism: An 8-second system pressure stabilization delay is set before the pinch rollers operate. Specifically, the 8-second total delay is divided into four stages: a 2-second hydraulic pre-pressurization stage, a 1.5-second mechanical resonance suppression stage, a 2.5-second multi-pinch roller synchronization calibration stage, and a 2-second environmental parameter compensation stage. Each stage is executed sequentially and has a dynamic time allocation function.

[0038] S5: Indentation detection feedback: The surface condition of the pipe is monitored in real time through a surface roughness meter, and the holding pressure is adjusted dynamically. Specifically, this includes but is not limited to using an online laser rangefinder to detect the indentation depth with a resolution requirement of 0.01mm. In addition, when Ra>1.2μm at three consecutive detection points, the pressure is automatically triggered and adjusted;

[0039] S6: Material hardness compensation stage, mainly used to correct the holding pressure. Specifically, the material hardness compensation stage corrects the holding pressure according to the HRC hardness value of the pipe, and the formula used is: P = 0.02×HRC+0.5 (MPa).

[0040] The present invention also provides a control system for solving water quenching wheel marks, which specifically includes a multimodal pressure generating unit, a distributed strain detection unit and a self-learning control unit. The multimodal pressure generating unit can complete the pressure switching of 10MPa→1MPa within 10ms. Specifically, the multimodal pressure generating unit includes an ultra-high pressure accumulator, a proportional pressure reducing valve and a pressure fluctuation absorber, wherein the response time of the ultra-high pressure accumulator is required to be less than 5ms, the adjustment accuracy of the proportional pressure reducing valve is required to be ±0.05MPa, and the attenuation rate of the pressure fluctuation absorber is required to be greater than 90%.

[0041] The distributed strain detection unit arranges three optical fiber strain sensors under each pressure wheel. The self-learning control unit mainly optimizes the pressure parameters based on historical pass rate data. Specifically, the distributed strain detection unit is implemented by a phase-sensitive optical time domain reflectometer, and the spatial resolution is required to reach 1 cm.

[0042] Example 2

[0043] Compared with Example 1, the specific implementation steps of this embodiment are as follows:

[0044] Step S1: In the high-pressure contact stage, a single-pulse loading mode is used to increase the pressure to 10 MPa within 50 ms, maintain it for 20 ms, and then enter the low-pressure stage.

[0045] Step S2: During the low-pressure holding stage, a fixed pressure of 1.0 MPa is used, regardless of the pipe diameter.

[0046] Step S3: The pressure switching adopts a step-down method without a buffer algorithm.

[0047] Step S4: The system pressure stabilization delay is fixed at 3 seconds, without segment optimization.

[0048] Step S5: The indentation test is performed using a contact roughness meter with a resolution of 0.05 mm. Adjustment is triggered only when Ra>2.0 μm.

[0049] Step S6: No material hardness compensation mechanism.

[0050] Example 3

[0051] Compared with Example 1, the specific implementation steps of this embodiment are as follows:

[0052] Step S1: Double pulse loading is adopted, wherein the first pulse is 8 MPa / 5 ms and the second pulse is 10 MPa.

[0053] Step S2: During the low pressure holding stage, the pressure is dynamically adjusted according to the pipe diameter. When the pipe diameter is 178-200 mm, 0.9 MPa is used; when the pipe diameter is greater than 200 mm, 1.1 MPa is used.

[0054] Step S3: The pressure linear decay period is 30 ms, and the change rate is 0.2 MPa / ms.

[0055] Step S4: The system delay is 5 seconds, which is dynamically allocated into four stages, namely, the hydraulic pre-boost stage of 1.5 seconds, the mechanical resonance suppression stage of 1 second, the multi-push roller synchronous calibration stage of 1.5 seconds and the environmental parameter compensation stage of 1 second.

[0056] Step S5: Laser rangefinder detection (resolution 0.01 mm), triggering adjustment when Ra>1.6 μm.

[0057] Step S6: Hardness compensation formula: P = 0.02 × HRC + 0.5 (MPa).

[0058] Through the above examples, the following table is obtained:

[0059]

[0060] The experimental results are obtained from the above table:

[0061] 1. Compared with Example 2, Example 1 and Example 3 show that double pulse loading and dynamic pressure compensation significantly reduce the indentation depth, with Ra dropping from 2.0 μm to below 1.5 μm.

[0062] 2. Example 1 is compared with Example 2. Through more refined hierarchical control and multi-sensor fusion, Ra is further controlled within 1.0 μm, which is suitable for high-precision pipe processing.

[0063] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A control method for solving water quenching wheel marks, characterized by: The following steps are involved: S1: High-pressure contact stage: 50-100ms before the pressing wheel contacts the pipe surface, an instantaneous high pressure of 8-12MPa is applied to ensure that the pressing wheel and the pipe are fully fitted; S2: Low pressure holding stage: After the pressing wheel is fully in contact, the pressure is immediately reduced to 0.5-1.5MPa and maintained until the water quenching is completed; S3: Dynamic transition stage: During the switching process from high pressure to low pressure, a pressure linear decay period of 20-50ms is set; S4: Delay trigger mechanism: set a 3 to 8 second system pressure stabilization delay before the pressure roller moves; S5: Indentation detection feedback: Use the surface roughness meter to monitor the surface condition of the pipe in real time and dynamically adjust the holding pressure; S6: Material hardness compensation stage, mainly used to correct the holding pressure.

2. A control method for solving water quenching wheel marks according to claim 1, characterized in that: The high-voltage contact stage in S1 adopts a dual-pulse loading mode, including but not limited to a first pulse and a second pulse. The first pulse is required to rise to 8 MPa within 5 ms to break the surface oxide layer, and the second pulse is required to maintain 10 MPa to ensure complete contact.

3. The control method for solving water quenching wheel marks according to claim 1 is characterized in that: In the low-pressure holding stage of S2, when the pipe diameter is 178-200 mm, 0.8-1.0 MPa is used, and when the pipe diameter is greater than 200 mm, 1.0-1.2 MPa is used.

4. The control method for solving water quenching wheel marks according to claim 1 is characterized in that: In the dynamic transition phase of S3, a hydraulic buffer algorithm is used to control the pressure change rate within the range of 0.15-0.3 MPa / ms.

5. The control method for solving water quenching wheel marks according to claim 1 is characterized in that: The indentation detection feedback of S5 includes but is not limited to using an online laser rangefinder to detect the indentation depth with a resolution requirement of 0.01mm. In addition, when Ra>1.6μm at three consecutive detection points, pressure readjustment is automatically triggered.

6. The control method for solving water quenching wheel marks according to claim 1 is characterized in that: The delay trigger mechanism of S4 divides the total delay of 3 to 8 seconds into four stages, namely the hydraulic pre-boost stage, the mechanical resonance suppression stage, the multi-pressure roller synchronous calibration stage and the environmental parameter compensation stage. Each stage is executed in sequence and has a dynamic time allocation function.

7. The control method for solving water quenching wheel marks according to claim 1 is characterized in that: In the material hardness compensation stage of S6, the holding pressure is corrected according to the HRC hardness value of the pipe, and the formula used is: P = 0.02×HRC + 0.5 (MPa).

8. A control system for solving water quenching wheel marks according to claims 1-7, characterized in that: Specifically, it includes a multimodal pressure generating unit, a distributed strain detection unit and a self-learning control unit. The multimodal pressure generating unit can complete the pressure switching of 10MPa→1MPa within 10ms. The distributed strain detection unit arranges 3 optical fiber strain sensors under each pressure wheel. The self-learning control unit mainly optimizes the pressure parameters based on historical pass rate data.

9. The control system for solving water quenching wheel marks according to claim 8, characterized in that: The multi-modal pressure generating unit includes an ultra-high pressure accumulator, a proportional pressure reducing valve and a pressure fluctuation absorber.

10. The control system for solving water quenching wheel marks according to claim 8, characterized in that: The distributed strain detection unit is implemented by a phase-sensitive optical time-domain reflectometer, and the spatial resolution is required to be 1 cm.

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