Welding defect detection method for super-thick plate large-pipe-diameter welded pipeline

Abstract

The invention discloses a welding defect detection method for an ultra-thick plate large-diameter welded pipeline. The method comprises the following steps: cleaning the surface of a to-be-detected welded pipeline; an ultrasonic flaw detection probe and an ultrasonic diffraction time domain probe are installed on the inner side and the outer side of the welding pipeline respectively; an ultrasonic flaw detection probe is adopted for scanning the welded pipeline, and internal defects of the pipeline are detected; on the basis of the detection of the ultrasonic flaw detection probe, scanning a welded pipeline by adopting an ultrasonic diffraction time domain probe to detect the internal defects of the pipeline; detected signals are transmitted to a computer for processing, and information of positions, sizes and shapes of the defects is analyzed; according to the detected defect information, the defect is evaluated, and whether the defect affects safe operation of the pipeline or not is judged; according to the invention, the PAUT and TOFD technologies are combined, so that the detection capability of tiny defects and deep defects is improved, the detection cost is reduced, and the reliability of the detection process is improved.

Description

Technical Field

[0001] The invention relates to the technical field of welded pipeline defect detection, in particular to a welding defect detection method for an ultra-thick plate large-diameter welded pipeline. Background Art

[0002] With the rapid development of my country's economy, welded pipelines are increasingly used in the fields of petroleum, wind power, etc. The quality of welded pipelines is directly related to the safety and stable operation of the entire project. However, due to the influence of various factors during the welding process, defects such as cracks and slag inclusions are easily generated in welded pipelines, and the existence of these defects seriously threatens the safe operation of the pipeline.

[0003] At present, the defect detection methods for welded pipes mainly include X-ray detection, ultrasonic detection, magnetic particle detection, etc. Among them, ultrasonic detection has the advantages of non-destructive, fast and accurate, and is widely used in defect detection of welded pipes. However, the traditional ultrasonic detection method has certain limitations when detecting welded pipes with large plate thickness and large outer diameter.

[0004] The existing welded pipeline defect detection methods have low detection efficiency and insufficient detection accuracy for thick plates and large-diameter pipelines; the application of traditional ultrasonic detection methods in thick plates and large-diameter pipelines is limited, and it is difficult to detect tiny defects or deep-seated defects; there is a lack of a method that can efficiently and accurately detect defects in welded pipelines with a plate thickness of more than 50 mm and an outer diameter of more than 400 mm. Summary of the invention

[0005] The purpose of the present invention is to provide a welding defect detection method for ultra-thick plate large diameter welded pipes to improve detection efficiency and accuracy. By adopting the combination of PAUT (ultrasonic flaw detection) + TOFD (ultrasonic diffraction time domain) technology, the detection capability of tiny defects and deep defects is improved, while reducing the detection cost and improving the reliability of the detection process.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for detecting welding defects of ultra-thick plate large-diameter welded pipes, comprising the following steps:

[0008] Step S1, preparation stage: clean the surface of the welded pipe to be inspected to ensure that there are no impurities that may affect the inspection;

[0009] Step S2, installing the probe: installing the ultrasonic flaw detection probe on the inside and outside of the welded pipe. After the ultrasonic flaw detection probe is detected, installing the ultrasonic diffraction time domain probe on the inside and outside of the welded pipe;

[0010] Step S3, ultrasonic flaw detection probe detection: use an ultrasonic flaw detection probe to scan the welded pipeline to detect internal defects of the pipeline;

[0011] Step S4, ultrasonic diffraction time domain probe detection: on the basis of ultrasonic flaw detection probe detection, an ultrasonic diffraction time domain probe is used to scan the welded pipeline to detect internal defects of the pipeline;

[0012] Step S5, data acquisition and processing: transmitting the signals detected by the ultrasonic flaw detection probe and the ultrasonic diffraction time domain probe to a computer for processing, and analyzing the information of the position, size and shape of the defects;

[0013] Step S6, defect assessment: assess the defect based on the detected defect information to determine whether the defect affects the safe operation of the pipeline;

[0014] Step S7, test report: organize the test process and results into a report to provide a basis for subsequent pipeline maintenance and operation.

[0015] As a further improvement of the technical solution of the present invention, in step S2, the ultrasonic flaw detection probes are installed on the inner and outer sides of the welding pipe at a spacing of 50-100 mm.

[0016] As a further improvement of the technical solution of the present invention, in step S2, the ultrasonic diffraction time domain probe is installed on the inner and outer sides of the welding pipe at a spacing of 50-100 mm.

[0017] As a further improvement of the technical solution of the present invention, in step S1, the impurities include oil stains and rust.

[0018] As a further improvement of the technical solution of the present invention, the operating frequency of the ultrasonic flaw detection probe is 2-5 MHz.

[0019] As a further improvement of the technical solution of the present invention, the operating frequency of the ultrasonic diffraction time domain probe is 1-2 MHz.

[0020] As a further improvement of the technical solution of the present invention, the diameter of the ultrasonic flaw detection probe is 20-50 mm.

[0021] As a further improvement of the technical solution of the present invention, the diameter of the ultrasonic diffraction time domain probe is 20-50 mm.

[0022] The present invention has the following beneficial effects:

[0023] 1) Wide detection range: suitable for welding pipes with a thickness of more than 50mm and an outer diameter greater than 400mm;

[0024] 2) Fast detection speed: The two detection methods of PAUT (ultrasonic flaw detection) + TOFD (ultrasonic diffraction time domain) are adopted to greatly improve the detection speed;

[0025] 3) High detection accuracy: It can accurately detect the position, size, shape and other information of defects inside the welding pipeline;

[0026] 4) The test results are easy to evaluate: the test data can be processed by computer to facilitate the evaluation of defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a flowchart of a method for detecting welding defects of an ultra-thick plate and large-diameter welded pipeline according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0029] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, upper end, lower end, top, bottom...) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In the present invention, unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense, for example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features; in addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] Reference Figure 1 The present invention provides a method for detecting welding defects of ultra-thick plate and large-diameter welded pipelines, comprising the following steps:

[0034] Step S1, preparation stage: clean the surface of the welded pipe to be inspected to ensure that there are no impurities that may affect the inspection;

[0035] Step S2, installing the probe: installing the ultrasonic flaw detection probe on the inside and outside of the welded pipe. After the ultrasonic flaw detection probe is detected, installing the ultrasonic diffraction time domain probe on the inside and outside of the welded pipe;

[0036] Step S3, ultrasonic flaw detection probe detection: use an ultrasonic flaw detection probe to scan the welded pipeline to detect internal defects of the pipeline;

[0037] Step S4, ultrasonic diffraction time domain probe detection: on the basis of ultrasonic flaw detection probe detection, an ultrasonic diffraction time domain probe is used to scan the welded pipeline to detect internal defects of the pipeline;

[0038] Step S5, data acquisition and processing: transmitting the signals detected by the ultrasonic flaw detection probe and the ultrasonic diffraction time domain probe to a computer for processing, and analyzing the information of the position, size and shape of the defects;

[0039] Step S6, defect assessment: assess the defect based on the detected defect information to determine whether the defect affects the safe operation of the pipeline;

[0040] Step S7, test report: organize the test process and results into a report to provide a basis for subsequent pipeline maintenance and operation.

[0041] Specifically, in the present embodiment, in step S2, the ultrasonic flaw detection probes are installed on the inner and outer sides of the welding pipe at a spacing of 50-100 mm.

[0042] Specifically, in the present embodiment, in step S2, the ultrasonic diffraction time domain probe is installed on the inner and outer sides of the welding pipe at a spacing of 50-100 mm.

[0043] Specifically, in this embodiment, in step S1, the impurities include oil stains and rust.

[0044] Specifically, in this embodiment, the operating frequency of the ultrasonic flaw detection probe is 2-5 MHz.

[0045] Specifically, in this embodiment, the operating frequency of the ultrasonic diffraction time domain probe is 1-2 MHz.

[0046] Specifically, in this embodiment, the diameter of the ultrasonic flaw detection probe is 20-50 mm.

[0047] Specifically, in this embodiment, the diameter of the ultrasonic diffraction time domain probe is 20-50 mm.

[0048] Example: Refer to Figure 1 , the workflow of the present invention is:

[0049] 1. Determine that the welded steel pipe has reached the detection position and obtain the parameter information of the welded steel pipe;

[0050] 2. After the welded steel pipe reaches the testing position, it is tested;

[0051] 3. Adjust the PAUT (ultrasonic flaw detection) probe and TOFD (ultrasonic diffraction time domain) probe to the measurement position of the welded steel pipe, first perform PAUT (ultrasonic flaw detection) detection, and then perform TOFD (ultrasonic diffraction time domain) detection;

[0052] 4. The data detected by PAUT (ultrasonic flaw detection) and TOFD (ultrasonic diffraction time domain) are transmitted to the computer for processing, the location, size and shape of the defects are analyzed, and the outer diameter of the welded pipe is calculated. According to the detected defect information, the defects are evaluated to determine whether the defects affect the safe operation of the pipeline and the measurement results are corrected;

[0053] 5. Output the measurement report, organize the detection process and results into a report, provide a basis for subsequent pipeline maintenance and operation, and complete the measurement work.

[0054] In summary, the present invention provides a defect detection method suitable for thick plates and large-diameter welded pipes to improve detection efficiency and accuracy. By adopting the PAUT+TOFD technology combination, the detection capability of small defects and deep defects is improved, while the detection cost is reduced and the reliability of the detection process is improved. The present invention has the following beneficial effects:

[0055] 1) Wide detection range: suitable for welding pipes with a thickness of more than 50mm and an outer diameter greater than 400mm;

[0056] 2) Fast detection speed: The two detection methods of PAUT (ultrasonic flaw detection) + TOFD (ultrasonic diffraction time domain) are adopted to greatly improve the detection speed;

[0057] 3) High detection accuracy: It can accurately detect the position, size, shape and other information of defects inside the welding pipeline;

[0058] 4) The test results are easy to evaluate: the test data can be processed by computer to facilitate the evaluation of defects.

[0059] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for detecting welding defects of ultra-thick plate and large diameter welded pipes, characterized in that: The following steps are involved: Step S1, preparation stage: clean the surface of the welded pipe to be inspected to ensure that there are no impurities that may affect the inspection; Step S2, installing the probe: installing the ultrasonic flaw detection probe on the inner and outer sides of the welded pipe. After the ultrasonic flaw detection probe is detected, installing the ultrasonic diffraction time domain probe on the inner and outer sides of the welded pipe; Step S3, ultrasonic flaw detection probe detection: use an ultrasonic flaw detection probe to scan the welded pipeline to detect internal defects of the pipeline; Step S4, ultrasonic diffraction time domain probe detection: on the basis of ultrasonic flaw detection probe detection, an ultrasonic diffraction time domain probe is used to scan the welded pipeline to detect internal defects of the pipeline; Step S5, data acquisition and processing: transmitting the signals detected by the ultrasonic flaw detection probe and the ultrasonic diffraction time domain probe to a computer for processing, and analyzing the information of the position, size and shape of the defects; Step S6, defect assessment: assess the defect based on the detected defect information to determine whether the defect affects the safe operation of the pipeline; Step S7, test report: organize the test process and results into a report to provide a basis for subsequent pipeline maintenance and operation.

2. The method for detecting welding defects of ultra-thick plate and large diameter welded pipes according to claim 1, characterized in that: In step S2, the ultrasonic flaw detection probes are installed on the inner and outer sides of the welding pipe at a spacing of 50-100 mm.

3. The method for detecting welding defects of ultra-thick plate and large diameter welded pipes according to claim 1, characterized in that: In the step S2, the ultrasonic diffraction time domain probe is installed on the inner and outer sides of the welding pipe at a spacing of 50-100 mm.

4. The method for detecting welding defects of ultra-thick plate and large diameter welded pipes according to claim 1, characterized in that: In the step S1, the impurities include oil stains and rust.

5. The method for detecting welding defects of ultra-thick plate and large diameter welded pipes according to claim 1, characterized in that: The operating frequency of the ultrasonic flaw detection probe is 2-5 MHz.

6. The method for detecting welding defects of ultra-thick plate and large diameter welded pipes according to claim 1, characterized in that: The operating frequency of the ultrasonic diffraction time domain probe is 1-2 MHz.

7. The method for detecting welding defects of ultra-thick plate and large diameter welded pipes according to claim 1, characterized in that: The diameter of the ultrasonic flaw detection probe is 20-50 mm.

8. The method for detecting welding defects of ultra-thick plate and large diameter welded pipes according to claim 1, characterized in that: The diameter of the ultrasonic diffraction time domain probe is 20-50 mm.

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