Method and system for evaluating turning ability of pipe

Abstract

The invention discloses a method for evaluating the turning ability of a pipe, which comprises the following steps: a rolled plate for preparing the pipe is used as a tested material, the heat treatment state of the rolled plate is consistent with the heat treatment state of the pipe to be predicted, and the rolled plate is provided with a detection hole; a detection drill bit enters the detection hole at a given rotating speed and a given feeding speed, and a torsion value of the detected material is obtained; and comparing the torsion value of the tested material with the torsion value of a given standard material so as to evaluate the turning property of the tested material. In addition, the invention further discloses a system for evaluating the turning ability of the pipe. According to the invention, the quantitative test of the turning force can be completed based on the rolled plate in the development process of the oil well pipe, and then the test result is compared with the detection result of a standard product, so that the turning property of the material is evaluated, data reference is provided for batch turning processing after the material is rolled into a steel pipe, and batch turning processing scrapping can be effectively avoided.

Description

Technical Field

[0001] The present invention relates to a detection method and system, and in particular to a metal material performance detection method and system. Background Art

[0002] Oil well pipe products are essential materials for oil and gas exploration and development and subsequent transportation. Each pipe is connected into a pipe string through threads to form a mining channel. The threads of oil well pipes are currently processed by turning.

[0003] As the difficulty of oil and gas resource exploitation continues to increase, the development of oil well pipe products is gradually moving towards high alloy and high strength, which makes turning increasingly difficult. If the machinability of the developed new oil well pipe materials is not tested and evaluated in time, it is likely to cause batch scrapping of subsequent pipe processing, greatly affecting the processing efficiency and yield of the product.

[0004] However, there is a lag in the evaluation of the machinability of new materials in the development of oil well pipes. Because the weight of a single furnace used in the production of oil well pipes is relatively large, in order to avoid scrapping, new material development usually uses a small laboratory furnace to make steel, then rolls it into plates, completes mechanical and corrosion resistance research, and then conducts on-site smelting and pipe rolling trials. After the pipe material has completed heat treatment, it can be turned for trial production. At this time, a batch of pipe materials have been rolled, and the smallest single furnace is nearly 150 tons. Therefore, a large amount of material waste will be caused.

[0005] The Chinese patent document with publication number CN101412196A and publication date April 22, 2009, entitled "Turning force prediction method based on tool angle and cutting parameter changes" measures the cutting force at a certain coordinate state through a dynamometer, and then predicts the turning force after the tool angle changes through a calculation method. However, this solution is still aimed at predicting the turning force of the final shape of the product, and cannot complete the turning force prediction in the new material development stage.

[0006] A Chinese patent document with publication number CN 102490085A and publication date June 13, 2012, entitled “Device for Simultaneously Measuring Three-Axis Turning Force” proposes a solution for simultaneously measuring three-axis turning force. A device is used to integrate the turning tool and the sensor, which is then installed on a machine tool to measure the turning force. This solution is still aimed at predicting the turning force of the final shape of the product and cannot complete the turning force prediction in the new material development stage.

[0007] Based on this, it is expected to provide a method that can complete the prediction of turning force in the new material development stage. Summary of the invention

[0008] One of the purposes of the present invention is to provide a method for evaluating the machinability of a pipe. The method can be used to complete a quantitative test of the turning force based on the plate rolled during the development of oil well pipes, and then a horizontal comparison is made with the test results of existing conventional products, so as to form an evaluation of the machinability of the material, provide data reference for batch threading processing after the material is rolled into a steel pipe, thereby completing the tool and turning process preparation in a targeted manner, and effectively avoiding batch turning processing scrapping.

[0009] In order to achieve the above object, the present invention provides a method for evaluating the machinability of a pipe, which comprises the steps of:

[0010] A rolled plate used for preparing a pipe is used as a material to be tested, and its heat treatment state is consistent with the heat treatment state of the pipe to be predicted, and the rolled plate has a detection hole;

[0011] The detection drill bit enters the detection hole at a given rotation speed and feed speed, and obtains the torque value of the material being tested;

[0012] The torque value of the tested material is compared with the torque value of a given standard material to evaluate the turning performance of the tested material.

[0013] Furthermore, in the method for evaluating the machinability of a pipe according to the present invention, obtaining the torque value of the material under test comprises the steps of:

[0014] Detect and obtain the torque value curve of the rolled plate when the detection drill enters the detection hole;

[0015] Select several torque values ​​corresponding to a section of the torque value curve corresponding to the stable state;

[0016] The torque value of the measured material is obtained based on the average value of the plurality of torque values.

[0017] Furthermore, in the method for evaluating the machinability of a pipe according to the present invention, comparing the torque value of the material to be tested with the torque value of a given standard material to evaluate the machinability of the material to be tested specifically includes:

[0018] Obtain the ratio of the torque value of the material being tested to the torque value of a given standard material;

[0019] If the ratio is higher than 1, it is considered that the turning difficulty of the tested material is higher than that of the standard material, and the turning difficulty increases with the increase of the ratio.

[0020] Furthermore, in the method for evaluating the machinability of a tube according to the present invention, the rolled plate has a plurality of detection holes.

[0021] Furthermore, in the method for evaluating the machinability of a pipe according to the present invention, there is a coolant in the detection hole.

[0022] Another object of the present invention is to provide a method for evaluating the machinability of pipes. The system can be used to complete a quantitative test of the turning force based on the plates rolled during the development of oil well pipes, and then a horizontal comparison is made with the test results of existing conventional standard products, so as to form an evaluation of the machinability of the material, provide data reference for batch threading processing after the material is rolled into steel pipes, thereby completing the tool and turning process preparation in a targeted manner, and effectively avoiding batch turning processing scrapping.

[0023] Based on the above invention objectives, the present invention also provides a system for evaluating the machinability of a pipe, which is used to implement the method for evaluating the machinability of a pipe as described above, and the system comprises:

[0024] A guide rail arranged vertically;

[0025] A host, which is arranged on the guide rail; the host comprises: a drill driving assembly; a sensor, which detects a torque value;

[0026] A drill bit connected to the drill bit driving assembly so as to rotate around its own axis under the drive of the drill bit driving assembly;

[0027] The controller is connected to the host to send a control signal to the host and receive a torque value detected by a sensor.

[0028] Furthermore, in the system for evaluating the machinability of a pipe according to the present invention, the main machine further comprises: a feed drive assembly, which drives the main machine to move up and down in the height direction along the guide rail.

[0029] In some embodiments, the drill bit comprises a round thread drill bit.

[0030] In other embodiments, the drill bit comprises a trapezoidal thread drill bit.

[0031] Furthermore, in the system for evaluating the machinability of a pipe according to the present invention, the controller is configured as an electronic controller having a display screen.

[0032] In some embodiments, the controller is configured as a computer.

[0033] Furthermore, in the system for evaluating the machinability of a pipe according to the present invention, a handle is provided on the main machine.

[0034] The method and system for evaluating the machinability of a pipe according to the present invention have the following beneficial effects:

[0035] The present invention is different from the prior art in that it does not directly test the machinability of a pipe, such as an oil well pipe, but tests the torque value of a plate material for manufacturing the oil well pipe, and compares it with the torque value of a standard material, thereby achieving a quantitative evaluation of the machinability of a new material, and quickly determining the degree of difficulty in machinability of the material in subsequent batch processing after pipe rolling, thereby guiding the production unit to pre-adjust the processing tools and processes, and avoiding abnormal batch processing scrapping. The present invention has broad application prospects in the development of new materials for oil well pipes and the field of pipe body turning. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The schematic diagram of the structure of the system for evaluating the machinability of a tube according to the present invention in one embodiment is shown schematically.

[0037] Figure 2 A schematic diagram of the drill structure used in the system for evaluating the machinability of a pipe according to one embodiment of the present invention is shown.

[0038] Figure 3 A schematic diagram of a drill structure used in the system for evaluating the machinability of a pipe according to another embodiment of the present invention is shown.

[0039] Figure 4 A schematic diagram showing a material to be tested in one embodiment of the method for evaluating the machinability of a tube according to the present invention.

[0040] Figure 5 A schematic diagram showing a torque value curve obtained by the method for evaluating the machinability of a tube according to an embodiment of the present invention.

[0041] Figure 6 A bar graph showing the machinability evaluation of a tested plate in accordance with an embodiment of the method for evaluating the machinability of a tube according to the present invention. DETAILED DESCRIPTION

[0042] The system and method for evaluating the machinability of a pipe according to the present invention will be further explained and illustrated below in conjunction with the accompanying drawings and specific embodiments of the specification. However, such explanation and illustration do not constitute an improper limitation on the technical solution of the present invention.

[0043] Figure 1 The schematic diagram of the structure of the system for evaluating the machinability of a tube according to the present invention in one embodiment is shown schematically.

[0044] like Figure 1As shown, in some embodiments, the system for evaluating the machinability of a pipe includes: a vertically arranged guide rail 1, which is fixed on a base 9, and the material 8 to be tested is also placed on the base 9 during testing; a host 2, which can move up and down along the guide rail 1; a drill 7 is arranged on the host through a drill support 6; a computer 5 as a controller is connected to the host 2 through a data line 4. The host 2 includes: a drill drive assembly (not visible in the figure), which is connected to the drill 7 to drive the drill 7 to rotate around its own axis; a sensor (not visible in the figure), which detects the torque value.

[0045] During the test, the drill driving assembly in the host 2 drives the drill support 6 to rotate rapidly, thereby driving the drill 7 installed on the drill support 6 to rotate rapidly. At the same time, the host 2 moves downward along the guide rail 1, driving the drill 7 to start turning test on the material 8 to be tested. The host 2 moves upward along the guide rail 1 to drive the drill 7 away from the material 8 to be tested, and the test is ended. The data line 4 transmits the torque value detected by the sensor in the host 2 to the computer 5, and the computer 5 processes the torque value received from the data line 4 and displays it visually.

[0046] The up and down movement of the host 2 along the guide rail 1 can be performed automatically or manually. When performed manually, a handle 3 can be provided on the host. When performed automatically, the host 2 can also include a feed drive component, which drives the host 2 to move up and down along the guide rail 1 in the height direction based on a control signal sent by a controller, such as a computer 5.

[0047] Figure 2 The schematic diagram of the drill structure used in the system for evaluating the machinability of a pipe according to the present invention is shown. In this embodiment, the drill bit can be a round thread drill bit 71.

[0048] Figure 3 The schematic diagram of the drill structure used in another embodiment of the system for evaluating the machinability of a pipe according to the present invention is shown. In this embodiment, the drill can be a trapezoidal thread drill 72 .

[0049] Of course, in other embodiments, thread drill bits of other shapes may be used depending on the thread type.

[0050] In some other embodiments, the present invention also provides a method for evaluating the machinability of a pipe, which may include the steps of:

[0051] 100: A rolled plate for preparing a pipe is used as a tested material, the heat treatment state of which is consistent with the heat treatment state of the pipe to be predicted, and a detection hole is provided on the rolled plate.

[0052] Figure 4A schematic diagram showing a material to be tested in one embodiment of the method for evaluating the machinability of a tube according to the present invention.

[0053] like Figure 4 As shown, the material 8 to be tested is a rolled plate used to manufacture pipes (e.g., oil well pipes), and its heat treatment state is consistent with the final steel pipe state. There are multiple pre-processed test holes on the rolled plate, and the test holes include an introduction part 81 and a working part 82. When testing, the same type and concentration of coolant can be added into the test holes according to the actual batch processing process.

[0054] 200: The drill enters the test hole at a given rotation speed and feed speed, and obtains the torque value of the material being tested.

[0055] The surface state of the drill bit 7 is observed before each inspection to ensure that the state is basically consistent; when inspecting each process type group, the rotation speed and downward feed speed of the drill bit are set consistently to ensure that the inspection state is basically consistent.

[0056] Figure 5 A schematic diagram showing a torque value curve for a certain test hole obtained by the method for evaluating the machinability of a pipe according to an embodiment of the present invention.

[0057] like Figure 5 As shown, segment 101 is a state where the drill bit is not in contact with the plate, segment 102 is an initial detection state, and segment 103 is a stable detection state.

[0058] In a preferred embodiment, the average value of the torque value in the 103 sections of the detection hole is read as the torque value output result of the detection.

[0059] In addition, more preferably, for each process, in order to ensure the accuracy of the results, multiple tests can be performed based on multiple test holes, and for the torque value results of each test hole, the maximum and minimum values ​​are removed and the average is taken as the final torque value output result of the process.

[0060] 300: Compare the torque value of the tested material with the torque value of a given standard material to evaluate the turning performance of the tested material:

[0061] Obtain the ratio of the torque value of the material being tested to the torque value of a given standard material;

[0062] If the ratio is higher than 1, it is considered that the turning difficulty of the tested material is higher than that of the standard material, and the turning difficulty increases with the increase of the ratio.

[0063] Figure 6 A bar graph showing the machinability evaluation of a tested plate in accordance with an embodiment of the method for evaluating the machinability of a tube according to the present invention.

[0064] like Figure 6 As shown, the ordinate in the figure represents the torque value, A represents the torque value of a given standard material, and B represents the torque value of the material to be tested under the same process conditions. It can be seen that the ratio of the torque value of the material to be tested B to the torque value of the given standard material A is higher than 1, so the turning difficulty of the material to be tested is higher than that of the standard material. The bar graph can be directly displayed on the computer monitor, so it can intuitively represent the ratio of the torque value during the testing process of the material to be tested to the torque value during the testing process of the conventional material under the same process conditions, thereby quantitatively expressing the machinability of the material to be tested.

[0065] In a specific example, a conventional carbon manganese steel plate material 30Mn2 is used as a given standard material. After quenching and tempering treatment, the yield strength of the material after treatment is 800 MPa and the hardness is 26 HRC.

[0066] The high Cr hot-rolled plate is subjected to quenching and tempering treatment, and the yield strength of the treated material is 800 MPa and the hardness is 30 HRC as the test material.

[0067] The test hole of the material to be tested has a chamfer of 0.5mm×45°, the working part is a 5.0mm diameter 20mm depth round hole, and the drill bit is a trapezoidal thread drill bit with a maximum diameter of 4.2mm. During the test, 5% concentration of emulsion is uniformly added into the test hole, the drill speed is 500RPM, and the test working depth is 8-10mm.

[0068] Under the same conditions, the average torque value of the given standard material 30Mn2 is 100, and the average torque value of the high Cr steel to be tested is 150. The ratio of the two is 1.5. Therefore, if the machinability of 30Mn2 is 1.0, the machinability of the high Cr steel is only 0.5, and the machining difficulty is significantly increased.

[0069] According to the test results, the production unit can be prompted to prepare high heat-resistant and wear-resistant coated tools in advance, reduce the turning line speed by about 50%, and stabilize the batch processing process on site. The test used 30Mn2 tools and processing technology to process the high Cr steel pipe. The abnormal chipping rate of the tool increased significantly, and the turning qualified rate was less than 20%.

[0070] It can be seen that the present invention can realize quantitative evaluation of the machinability of new materials, quickly determine the difficulty of turning the material in the subsequent batch processing after pipe rolling, so as to guide the production unit to pre-adjust the processing tools and processes in advance, avoid abnormal batch processing and scrapping, and has broad application prospects in the field of new material development and pipe body turning processing of oil well pipes.

[0071] It should be noted that the prior art in the protection scope of the present invention is not limited to the embodiments given in the present application documents. All prior art that does not contradict the solutions of the present invention, including but not limited to prior patent documents, prior public publications, prior public uses, etc., can be included in the protection scope of the present invention.

[0072] In addition, the combination of the various technical features in this case is not limited to the combination described in the claims of this case or the combination described in the specific embodiments. All technical features recorded in this case can be freely combined or combined in any way unless there is a contradiction between them.

[0073] It should also be noted that the above-listed embodiments are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made therewith can be directly derived or easily associated with by those skilled in the art from the contents disclosed in the present invention, and all should belong to the protection scope of the present invention.

Claims

1. A method for evaluating the machinability of a pipe, characterized in that: Includes steps: A rolled plate used for preparing a pipe is used as a material to be tested, and its heat treatment state is consistent with the heat treatment state of the pipe to be predicted, and the rolled plate has a detection hole; The detection drill bit enters the detection hole at a given rotation speed and feed speed, and obtains the torque value of the material being tested; The torque value of the tested material is compared with the torque value of a given standard material to evaluate the turning performance of the tested material.

2. The method for evaluating the machinability of a pipe according to claim 1, characterized in that: Obtaining the torque value of the material being tested includes the following steps: Detect and obtain the torque value curve of the rolled plate when the detection drill enters the detection hole; Select several torque values ​​corresponding to a section of the torque value curve corresponding to the stable state; The torque value of the measured material is obtained based on the average value of the plurality of torque values.

3. The method for evaluating the machinability of a pipe according to claim 1, characterized in that: Compare the torque value of the material being tested with the torque value of a given standard material to evaluate the turning performance of the material being tested. Specifically include: Obtain the ratio of the torque value of the material being tested to the torque value of a given standard material; If the ratio is higher than 1, it is considered that the turning difficulty of the tested material is higher than that of the standard material, and the turning difficulty increases with the increase of the ratio.

4. The method for evaluating the machinability of a pipe according to claim 1, characterized in that: The rolled plate is provided with a plurality of detection holes.

5. The method for evaluating the machinability of a pipe according to claim 1, characterized in that: The detection hole has cooling liquid in it.

6. A system for evaluating the machinability of a pipe, characterized in that: The implementation method according to any one of claims 1 to 5, wherein the system comprises: A guide rail arranged vertically; A host, which is arranged on the guide rail; the host comprises: a drill driving assembly; a sensor, which detects a torque value; A drill bit connected to the drill bit driving assembly so as to rotate around its own axis under the drive of the drill bit driving assembly; The controller is connected to the host to send a control signal to the host and receive a torque value detected by a sensor.

7. The system for evaluating the machinability of a pipe according to claim 6, characterized in that: The drill bit includes a round thread drill bit or a trapezoidal thread drill bit.

8. The system for evaluating the machinability of a pipe according to claim 6, characterized in that: The main machine also includes: a feed drive assembly, which drives the main machine to move up and down in the height direction along the guide rail.

9. The system for evaluating the machinability of a pipe according to claim 6, characterized in that: The controller is configured as an electronic controller having a display screen.

10. The system for evaluating the machinability of a pipe according to claim 6, characterized in that: The host is provided with a handle.

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