Batch water immersion flaw detection method for short round steel

Abstract

The invention relates to a short round steel batch water immersion flaw detection method which comprises the following steps: firstly, adopting the same machining parameters for a short round steel sample, firstly drilling two ends, then turning, and ensuring that the short round steel sample has the same diameter and surface roughness; then, the short round steel samples are flatly placed on the combined auxiliary device, and two adjacent sections of short round steel samples are positioned and connected through a fusiform connecting device and spliced into a proper length; then obtaining a conventional inspection C scanning graph; and finally, a flaw detection engineer manually evaluates a flaw detection result. The invention can solve the problem that the subsequent flaw detection intensity is greatly increased because one sample needs to be sampled in multiple small sections or the taken raw material needs to be processed in sections when being slightly bent due to the limitation of sampling working conditions on site, and can perform water immersion flaw detection on short round steel samples in batches, thereby reducing the manual sample loading frequency and improving the detection efficiency. And the inspection efficiency is greatly improved while the manual labor force is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic high-frequency water immersion flaw detection of a UT method in an NDT detection method, and in particular to a batch water immersion flaw detection method for short round steels. Background Art

[0002] First of all, the actual nature of high-frequency water immersion flaw detection in the non-destructive testing industry can be classified as a lossy type. The raw materials that need to be inspected often need to undergo heat treatment and grinding to obtain the organizational conditions and surface roughness conditions that meet the inspection. The water immersion flaw detection of round steel is determined from the beginning of sampling, and the inspection process is lossy. Usually, the round steel samples are sampled from the rolling line or during the rolling process, and the samples are cut by flame cutting and hot shearing to obtain a certain length of rolled round steel. There are often two reasons why the length of the round steel sample is short. One is that due to the actual situation of on-site sampling, a long round steel needs to be sampled in multiple small sections to match the production rhythm. The second is that even if a long sample is obtained, since the round steel sampled online is not straightened after rolling, the sample may have a certain degree of bending, and this bending may be aggravated during the subsequent heat treatment process. For this kind of phenomenon, in order to improve processing efficiency, it is often directly discarded and no longer transferred downward or a slightly curved long sample is cut into multiple short samples to reduce the amount of subsequent grinding processing. However, when a round steel is broken into several sections, the frequency of subsequent inspections will increase. In order to reduce the inspection frequency and improve the inspection efficiency, a batch high-frequency water immersion flaw detection method for short round steel is needed for such round steel specimens that are forced to be broken into shorter lengths due to slight bending or can only obtain shorter lengths due to other reasons. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a batch water immersion flaw detection method for short round steels, which can reduce the inspection frequency, reduce manual labor and improve the inspection efficiency.

[0004] The technical solution adopted by the present invention to solve the technical problem is: a batch high-frequency water immersion flaw detection method for short round steel, the specific steps are as follows:

[0005] (1) Sample processing: The short round steel samples after heat treatment are first bored at both ends, and then the outer surface is turned and ground to obtain a uniform diameter and surface roughness.

[0006] The heat treatment is a necessary work for high-frequency water immersion flaw detection, and its purpose is to refine the grains and uniform the structure, and reduce the scattering attenuation of ultrasonic waves. The short round steel sample is generally a rolled round steel sample with a diameter of φ35mm~φ50mm and a length of 50mm~150mm, and the rolling compression ratio is ≥10. First, drill holes on both ends of the round steel sample using a CNC lathe, and the two holes must be ensured to be located on the same horizontal center line. The diameter of the hole is φ4mm~φ6mm, and the depth is 5mm~10mm. Then use a lathe and an external cylindrical grinder to process the outer surface of the sample to obtain the same diameter and surface roughness, and the surface roughness Ra should be ≤2.0μm.

[0007] (2) Combination and splicing of specimens: Use the combination auxiliary device and the shuttle connection device to connect multiple short round steel specimens end to end and combine them into a suitable length.

[0008] The combined auxiliary device includes a layout slot and a lifting handle. Different specifications of the combined auxiliary device can be customized according to the length of the layout slot. The length of the layout slot is generally 300mm to 500mm. The shuttle connecting device is a shuttle-shaped device made of alloy structural steel with a diameter of 30mm, a height of 20mm, and a rough surface. First, multiple short round steel specimens are arranged end to end using the shuttle connecting device and placed on the layout slot of the combined auxiliary device. Then use the lifting handle to lift the combined specimen and clamp it on the clamping station of the water immersion flaw detection equipment.

[0009] (3) Conduct water immersion flaw detection: After the sample is clamped, conduct water immersion flaw detection to obtain a water immersion flaw detection C-scan image.

[0010] The clamping is to use the clamping module of the equipment to clamp the combined sample so that multiple short round steel samples form a rigid connection. The rough shuttle-shaped connection device with interference filling will prevent the combined sample from slipping during the rotation process. After clamping, a full-volume water immersion flaw detection test is performed using a 10MHz straight flat probe.

[0011] (4) Manual evaluation of NDT results by NDT engineers: Professional NDT engineers evaluate the C-scan and, in conjunction with the A-scan, accurately identify the information reflected in the C-scan.

[0012] The professional NDT engineer must be a person with level 2 NDT qualification or above based on ISO9712 certification and have certain experience in water immersion NDT, so as to be able to fully identify the information reflected in the C-scan image.

[0013] The beneficial effect of the present invention is that it solves the defects existing in the background technology. The present invention performs high-frequency water immersion flaw detection on short round steel in batches through the steps of sample processing, sample combination and splicing, water immersion flaw detection, and manual evaluation of flaw detection results by flaw detection engineers, thereby reducing the frequency of inspection, reducing labor intensity, and improving inspection efficiency. It provides a case study for high-frequency water immersion flaw detection of short round steel in batches. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a shuttle-shaped connecting device in the embodiment of the present invention.

[0015] Figure 2 A combined auxiliary device in an embodiment of the present invention;

[0016] Figure 3 The sample combination arrangement method in the embodiment of the present invention;

[0017] Figure 4 The ultrasonic C-scan result in the embodiment of the present invention;

[0018] In the figure: 1. Sample placement slot; 2. Lifting handle; 3. Short round steel sample; 4. Shuttle connection device. DETAILED DESCRIPTION

[0019] The present invention will now be described in further detail in conjunction with the accompanying drawings and preferred embodiments. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0020] like Figure 1-Figure 4 A method for batch water immersion flaw detection of short round steels is shown, comprising the following steps:

[0021] (1) Sample processing: After the modulation treatment, 7 short round steel samples with a rolling ratio of 45, a diameter of φ40mm, and a length of 70mm to 160mm were first drilled at both ends using a CNC lathe. The two holes drilled were located on the same horizontal center line. The diameter of the hole was φ4mm and the depth was 6mm. The outer surface of the sample was then processed using a lathe and an external cylindrical grinder, so that the final diameter of each sample was φ37.5±0.5mm, and the surface roughness was Ra=1.8±0.1μm;

[0022] (2) Combination and splicing of samples: First, multiple short round steel samples are connected end to end using a shuttle connection device and placed on the sample placement slot of the combination auxiliary device, such as Figure 3 The shuttle connection device is a shuttle-shaped device with a diameter of 30 mm, a height of 20 mm, a rough surface, and is made of alloy structural steel. Figure 1As shown. According to the daily work requirements, the length of the sample slot 1 in the combined auxiliary device used this time is 370mm. The assembled sample is lifted up with the lifting handle 2 and clamped on the clamping station of the water immersion flaw detection equipment. The combined auxiliary device is as shown in Figure 3 As shown;

[0023] (3) Conduct water immersion flaw detection: Use a combination auxiliary device to combine 7 short round steel specimens into two long specimens of appropriate lengths, approximately 420 mm and 400 mm in length respectively. Use the equipment's clamping station to clamp and squeeze the combined specimens so that the multiple short round steel specimens form a rigid connection. The interference-filled rough shuttle-shaped connection device will prevent the combined specimens from slipping during rotation. After clamping, use a 10MHz straight flat probe to conduct a full-volume water immersion flaw detection test, and obtain two water immersion flaw detection results;

[0024] (4) Manual evaluation of the flaw detection results by flaw detection engineers: The engineers who carried out this flaw detection work were level 3 flaw detection personnel based on ISO9712 certification and had extensive experience in water immersion flaw detection. When evaluating the results of the two C-scan images, the abnormal defect reporting section of the connecting part must be discarded, and the information reflected in the C-scan image must be accurately distinguished in conjunction with the A-scan image to identify the true internal defects. The ultrasonic C-scan results are shown in Figure 4 As shown, Figure 4 The short horizontal line on the left is the internal defect location.

[0025] The above description only describes the specific implementation mode of the present invention. Various examples do not limit the essential content of the present invention. After reading the description, ordinary technicians in the relevant technical field can modify or deform the specific implementation modes described above without departing from the essence and scope of the invention.

Claims

1. A method for batch water immersion flaw detection of short round steel, characterized in that: The following steps are included: (1) Sample processing: Holes are made on both ends of the short round steel sample, and then the outer surface of the sample is turned and ground to obtain uniform diameter and surface roughness; (2) Combination and splicing of specimens: Use the combination auxiliary device and shuttle connection device to connect multiple short round steel specimens end to end to combine them into a suitable length; (3) Conduct water immersion flaw detection: After the specimens are connected at both ends, they are clamped and subjected to water immersion flaw detection to obtain a water immersion flaw detection C-scan image; (4) Manual evaluation of the detection results: Manual evaluation of the C scan is performed in conjunction with the A scan to accurately identify the information reflected in the C scan.

2. A method for batch water immersion flaw detection of short round steel according to claim 1, characterized in that: In the step (1), the short round steel sample is a rolled round steel with a diameter of φ35 mm to φ50 mm and a length of 50 mm to 150 mm after heat treatment, and the rolling compression ratio is ≥10.

3. A method for batch water immersion flaw detection of short round steel according to claim 1, characterized in that: In the step (1), the end holes are central holes at both ends, the two holes are located on the same center line, the diameter of the holes is φ4mm to φ6mm, and the depth is 5mm to 10mm.

4. A batch water immersion flaw detection method for short round steel according to claim 1, characterized in that: In the step (1), the surface roughness of the outer surface of the short round steel sample after turning and grinding is Ra≤2.0 μm.

5. A batch water immersion flaw detection method for short round steel according to claim 1, characterized in that: In the step (2), the combined auxiliary device includes a layout slot and lifting handles arranged on both sides of the layout slot, and the length of the layout slot is adjustable.

6. A method for batch water immersion flaw detection of short round steel as claimed in claim 5, characterized in that: The length of the lofting slot is 350 mm to 500 mm.

7. A batch water immersion flaw detection method for short round steel as claimed in claim 1, characterized in that: In the step (2), the shuttle-shaped connecting device is made of alloy structural steel, has a diameter of 30 mm, a height of 20 mm, and a rough surface; the ends of the prism-shaped connecting device are inserted into the holes at both ends of the short round steel sample.

8. A method for batch water immersion flaw detection of short round steel as claimed in claim 1, characterized in that: In the step (2), the combined suitable length is greater than the length of the selected combined auxiliary device.

9. A method for batch water immersion flaw detection of short round steel as claimed in claim 1, characterized in that: In the step (3), the water immersion flaw detection is performed using a 10 MHz straight flat probe.

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