Detection device for non-fusion between layers at different depths of weld

Abstract

This utility model discloses a detection device for non-fusion between layers of weld at different depths. The device includes rollers mounted on the bottom surface of a scanning frame, a rack mounted on the scanning frame and perpendicular to the weld, and a gear meshing with the rack and driven by a motor to move along the rack. The bottom ends of a first and second scanning arm are hinged to the center of the gear. An ultrasonic transmitting probe and a first encoder are located at the top of the first scanning arm, and an ultrasonic receiving probe and a second encoder are located at the top of the second scanning arm. A marking device is mounted on the scanning frame and marks defects at the weld location based on the detection results. This device overcomes the shortcomings of traditional detection methods, effectively improves the detection rate of non-fusion welds, can intuitively determine the horizontal position of planar defects, and displays defect marks directly on the weld, improving the accuracy of defect judgment and detection efficiency.

Description

Technical Field

[0001] This utility model relates to the field of detection technology, and in particular to a detection device for non-fusion between layers of weld at different depths. Background Technology

[0002] Tilting platforms (such as tilting systems for metallurgical converters and electric arc furnaces) and large furnace shells (such as blast furnace shells and reactor shells) are core equipment in heavy industry, and their structural safety directly affects the stability of continuous production and personnel safety. These devices are generally manufactured using multi-layer, multi-pass welding processes with ultra-thick steel plates (typically >50mm thick), and weld quality is a key factor affecting the overall structural lifespan. However, during the welding process, incomplete fusion between layers, a typical internal defect, poses a significant threat to structural integrity due to its concealed nature, planar characteristics, and precarious geometric relationship with the load direction.

[0003] In tilting platforms and furnace shell structures, the hazards of interlayer lack of fusion defects are particularly prominent.

[0004] Fatigue failure under dynamic loads: The tilting platform is subjected to periodic mechanical stress for a long time. The unfused interface acts as a stress concentration source, which is very easy to initiate and propagate fatigue cracks, leading to sudden fracture. Under high temperature (>300°C) and internal pressure, the unfused area of ​​the furnace shell undergoes accelerated creep deformation, while the material toughness decreases, inducing the risk of low-stress brittle cracking.

[0005] Structural stiffness reduction: Large areas of non-fusion in thick plate welds directly reduce the cross-sectional load-bearing capacity, which may lead to catastrophic collapse under extreme working conditions.

[0006] Traditional inspection methods for detecting incomplete fusion between layers at different depths in welds have the following drawbacks:

[0007] (1) Insufficient depth positioning accuracy: Conventional ultrasonic testing (UT) can have a depth positioning error of up to 5 mm for deep unfused (>50 mm) layers, which is difficult to meet the requirements of high-precision testing.

[0008] (2) Geometric interference: The complex structure of the furnace shell surface, stiffeners and tilting platform welds causes waveform conversion and generates pseudo signals.

[0009] (3) Poor intuitiveness of results: Traditional A-scan waveforms rely on personnel experience for interpretation and lack intuitive visualization of the spatial distribution of defects, which restricts rapid decision-making. Summary of the Invention

[0010] The technical problem to be solved by this utility model is to provide a detection device for non-fusion between layers of weld at different depths. This device overcomes the defects of traditional detection methods, effectively improves the detection rate of non-fusion welds, can intuitively determine the horizontal position of planar defects, and displays the defect mark intuitively on the weld, thereby improving the accuracy of defect judgment and detection efficiency.

[0011] To solve the above-mentioned technical problems, the present invention provides a detection device for non-fusion between layers of weld at different depths, comprising a scanning frame, rollers, rack, gear, drive motor, first scanning arm, second scanning arm, ultrasonic transmitting probe, ultrasonic receiving probe, first encoder, second encoder, and marking device. The rollers are disposed on the bottom surface of the scanning frame, the rack is disposed on the scanning frame and perpendicular to the weld, the gear meshes with the rack and is driven to move along the rack by the drive motor, the bottom ends of the first and second scanning arms are hinged to the center of the gear, the ultrasonic transmitting probe and the first encoder are disposed at the top of the first scanning arm, the ultrasonic receiving probe and the second encoder are disposed at the top of the second scanning arm, and the marking device is disposed on the scanning frame and makes defect marks at the weld position according to the detection results.

[0012] Furthermore, the first encoder and the second encoder are linear grating rulers, and they record the position coordinates of the ultrasonic transmitting probe and the ultrasonic receiving probe on the weld in real time.

[0013] Furthermore, the detection signals from the first encoder and the second encoder are transmitted to the display screen, directly showing the current coordinate positions of the ultrasonic transmitting probe and the ultrasonic receiving probe.

[0014] Furthermore, the marking device is a paint sprayer. When the defect amplitude reaches a set threshold, the ultrasonic detector issues an alarm and the marking device automatically sprays the defect mark.

[0015] Because this utility model's detection device for non-fusion between weld layers of different depths adopts the above-mentioned technical solution, namely, the roller of this device is located on the bottom surface of the scanning frame, the rack is located on the scanning frame and perpendicular to the weld, the gear meshes with the rack and is driven by a drive motor to move along the rack, the bottom ends of the first and second scanning arms are hinged to the center of the gear, the ultrasonic transmitting probe and the first encoder are located at the top of the first scanning arm, the ultrasonic receiving probe and the second encoder are located at the top of the second scanning arm, and the marking device is located on the scanning frame and makes defect marks on the weld position according to the detection results. This device overcomes the defects of traditional detection methods, effectively improves the detection rate of non-fusion welds, can intuitively determine the horizontal position of planar defects, and the defect marks are intuitively displayed on the weld, improving the accuracy of defect judgment and detection efficiency. Attached Figure Description

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0017] Figure 1 This is a schematic diagram of the detection device for non-fusion between layers of weld at different depths according to this utility model. Detailed Implementation

[0018] Implementation, for example Figure 1 As shown, the detection device for non-fusion between layers of weld at different depths according to this utility model includes a scanning frame 1, a roller 2, a rack 3, a gear 4, a drive motor 5, a first scanning arm 6, a second scanning arm 7, an ultrasonic transmitting probe 8, an ultrasonic receiving probe 9, a first encoder 10, a second encoder 11, and a marking device 12. The roller 2 is located on the bottom surface of the scanning frame 1. The rack 3 is located on the scanning frame 1 and is perpendicular to the weld 13. The gear 4 meshes with the rack 3 and is driven to move along the rack 3 by the drive motor 5. The bottom ends of the first scanning arm 6 and the second scanning arm 7 are hinged to the center of the gear 4. The ultrasonic transmitting probe 8 and the first encoder 10 are located at the top of the first scanning arm 6. The ultrasonic receiving probe 9 and the second encoder 11 are located at the top of the second scanning arm 7. The marking device 12 is located on the scanning frame 1 and makes defect marks at the weld 13 position according to the detection results.

[0019] Preferably, the first encoder 10 and the second encoder 11 are linear grating rulers, and record the position coordinates of the ultrasonic transmitting probe 8 and the ultrasonic receiving probe 9 on the weld 13 in real time.

[0020] Preferably, the detection signals of the first encoder 10 and the second encoder 11 are transmitted to the display screen to directly display the current coordinate positions of the ultrasonic transmitting probe 8 and the ultrasonic receiving probe 9.

[0021] Preferably, the marking device 12 is a paint sprayer. When the defect amplitude reaches a set threshold, the ultrasonic detector issues an alarm and the marking device automatically sprays the defect mark.

[0022] This device is equipped with an encoder in the scanning frame and uses a transceiver ultrasonic probe to detect the position. The data is converted into a depth value and displayed to accurately locate interlayer planar defects at different depths, such as interlayer non-fusion and interlayer cracks.

[0023] When an ultrasonic instrument detects an incomplete fusion defect using a transceiver ultrasonic probe, it automatically calculates the defect depth (based on sound velocity and path time) using the peak value of the A-scan waveform. For example, if the defect is 30mm, the instrument scans the entire area to detect a 30mm planar defect. This allows for precise location of the defect depth, achieving "zero error" in defect depth positioning.

[0024] By equipping the scanning frame with racks and gears, the ultrasonic probe can move left and right simultaneously, allowing for a direct visual assessment of the horizontal distance between the defect and the weld center.

[0025] When the ultrasonic probe is fully in contact with the workpiece surface, signal transmission and reception from both sides completely avoid interference signals caused by deformation waves generated by the structure. Through calculations of the probe's leading edge and zero point, and the markings sprayed onto the center of the scanning frame, the horizontal position of planar defects can be visually determined. The defect markings are clearly displayed on the weld, avoiding the repetitive work of using a steel ruler to determine whether the signal wave measurement location corresponds to a defect wave. This improves the accuracy of defect identification and inspection efficiency.

[0026] In actual testing, the first encoder and the second encoder are first brought together through the hinge point of the first scanning arm and the second scanning arm for encoding zeroing. Then, according to the depth position to be scanned and the angle of the probe, the display is converted into an accurate depth position using a 2:1 or 4:1 ratio. The two encoders are then opened to a certain angle and scanned across both sides of the weld.

[0027] The first and second scanning arms are driven by gears to move as a whole on the rack to cover the entire scanning area of ​​the weld. Taking advantage of the symmetry of the reflected signal, a marker is set at the center of the two probes to mark the projection position on the weld. When a defect signal is detected, the marker is used to mark the projection position of the defect. Based on the scanning depth, the location of the defect within the weld can be accurately located.

[0028] This device is based on non-destructive testing, which allows for a direct display of the test data and the severity of defects. The encoder visualizes and simulates the scanning position, and the probe installation is converted into real-time depth markings of defects according to the angle and distance between probes, achieving a one-stop, intuitive display of defect location and depth.

Claims

1. A device for detecting lack of fusion between layers of different depths in a weld, characterized by: The system includes a scanning frame, rollers, rack, gear, drive motor, first scanning arm, second scanning arm, ultrasonic transmitting probe, ultrasonic receiving probe, first encoder, second encoder, and marking device. The rollers are located on the bottom surface of the scanning frame. The rack is located on the scanning frame and is perpendicular to the weld. The gear meshes with the rack and is driven to move along the rack by the drive motor. The bottom ends of the first and second scanning arms are hinged to the center of the gear. The ultrasonic transmitting probe and the first encoder are located at the top of the first scanning arm. The ultrasonic receiving probe and the second encoder are located at the top of the second scanning arm. The marking device is located on the scanning frame and makes defect marks on the weld according to the inspection results.

2. The apparatus of claim 1, wherein: The first encoder and the second encoder are linear grating rulers, which record the position coordinates of the ultrasonic transmitting probe and the ultrasonic receiving probe on the weld in real time.

3. Apparatus for detecting lack of fusion between layers of different depths in a weld according to claim 1 or 2, characterised in that: The detection signals from the first and second encoders are transmitted to the display screen, which directly displays the current coordinate positions of the ultrasonic transmitting probe and the ultrasonic receiving probe.

4. The apparatus of claim 3, wherein: The marking device is a paint sprayer. When the defect amplitude reaches a set threshold, the ultrasonic detector issues an alarm and the marking device automatically sprays the defect mark.

Images