Method and device for detecting the penetration of an electron beam weld based on immersion ultrasonic phased array

Abstract

The application discloses a kind of based on water immersion ultrasonic phased array electronic beam weld seam penetration detection method and device, can design water immersion detection scheme, using water immersion ultrasonic phased array probe to carry out detection, realizes the accurate quantification of injector electronic beam weld seam penetration.The technical scheme of the present application comprises the following steps: linear scanning detection of electronic beam welding workpiece is carried out using water immersion ultrasonic phased array probe, wherein B scanning is carried out for the non-penetration area of weld, B scanning is scanning to the section parallel to the ultrasonic incident direction, and B scan image is obtained.Non-penetration tip diffraction echo and non-penetration root end corner reflection echo are retrieved by B scan image.The weld seam penetration D of electronic beam welding workpiece is: D=T-H=T-C T ·cosθ·(t2-t1) / 2;T is the thickness of electronic beam welding workpiece, H is the non-penetration height of weld, C T is the transverse wave speed in electronic beam welding workpiece, t1 is non-penetration tip diffraction echo time, and t2 is non-penetration root end corner reflection echo time.

Description

Technical Field

[0001] This invention relates to the field of measurement and control technology, specifically to a method and apparatus for detecting the penetration depth of electron beam welds based on a water immersion ultrasonic phased array. Background Technology

[0002] Weld penetration depth is a crucial indicator of weld quality and a decisive factor in the load-bearing capacity of welded components. It is defined as the distance the weld metal extends from the weld surface into the joint, excluding the weld reinforcement. Insufficient weld penetration depth reduces weld strength, making it prone to corrosion and cracking under harsh conditions of high temperature or high pressure, leading to joint failure and safety accidents. The injector is a key component of a liquid rocket engine, consisting of an injector disc and several injector rings welded together using electron beam welding. The quality of its weld penetration depth plays a decisive role in the safety performance of the injector itself and the overall engine. Insufficient weld penetration depth results in a reduced load-bearing cross-sectional area and lower strength, potentially causing oxidizer or fuel leakage from the weld joint during operation. This affects the propellant mixture ratio, reduces the thrust chamber specific impulse, impacts engine efficiency, and creates safety hazards.

[0003] Liquid rocket engine injectors have complex cross-sectional structures with grooves on both the top and bottom sides. Conventional ultrasonic probes have low sensitivity and insufficient resolution, making it impossible to directly acquire signals characterizing weld penetration depth for quantitative analysis. Furthermore, the thickness of the injector is relatively small, with the detection area located between 0.5mm and 3.2mm from the surface. The TOFD method suffers from a surface blind zone, making it impossible to quantify weld penetration depth for components with welds within this blind zone (within 5mm of the surface). Additionally, the dense weld distribution limits the detection surface size. Since most ultrasonic phased array probes are large, contact testing using plexiglass wedges cannot avoid the surface grooves, leading to poor coupling and preventing successful detection.

[0004] Therefore, there is an urgent need for an accurate method to detect the penetration depth of electron beam welds. Summary of the Invention

[0005] In view of this, the present invention provides a method and device for detecting the penetration depth of electron beam welds based on a water immersion ultrasonic phased array, which can design a water immersion detection scheme and use a water immersion ultrasonic phased array probe for detection, thereby realizing the accurate quantitative measurement of the penetration depth of electron beam welds in injectors.

[0006] To achieve the above objectives, the technical solution of the present invention includes the following steps:

[0007] Step 1: Perform linear scanning detection on the electron beam welded workpiece using a water immersion ultrasonic phased array probe. Specifically, perform B-scan on the incomplete penetration area of ​​the weld. B-scan is a scan of a cross section parallel to the ultrasonic incident direction to obtain B-scan images.

[0008] Step 2: Retrieve the diffraction echo from the incompletely fused tip and the reflection echo from the incompletely fused root corner using the B-scan image.

[0009] Step 3: The weld penetration depth D of the electron beam welded workpiece is:

[0010] D = TH = TC T ·cosθ·(t2-t1) / 2

[0011] In the formula: T is the thickness of the workpiece in electron beam welding, H is the incomplete penetration height of the weld, and C... T t1 represents the transverse wave velocity in the electron beam welded workpiece, t2 represents the diffraction echo time of the incompletely penetrated tip, and t3 represents the reflection echo time of the incompletely penetrated root corner.

[0012] Furthermore, the present invention also provides an electron beam weld penetration depth detection device based on a water immersion ultrasonic phased array, comprising an array flaw detector, a water immersion phased array probe, a water wedge, a water tank, and a workpiece under test; the workpiece under test is an electron beam welded workpiece; the device is used to realize an electron beam weld penetration depth detection method based on a water immersion ultrasonic phased array.

[0013] The sink is filled with water.

[0014] The probe wire of the water immersion phased array probe is connected to the flaw detector through a standardized interface; the water immersion phased array probe is clamped to the wedge-shaped surface of the water wedge block by screws.

[0015] The bottom surface of the water wedge is fixed to the upper surface of the workpiece being inspected, and the bottom surface of the water wedge is in complete contact with the upper surface of the workpiece being inspected.

[0016] The water immersion phased array probe, water wedge, and test piece are all submerged below the water surface in the water tank.

[0017] The flaw detector transmits electrical signals to the water immersion phased array probe via the probe line. The electrical signal excites the water immersion phased array probe to emit ultrasonic waves. Using the water medium in the water wedge as a coupling agent, the ultrasonic waves are incident into the interior of the workpiece. When they encounter the heterogeneous interface, diffraction and reflection occur, causing a portion of the ultrasonic waves to return to the probe and be received. After being converted into electrical signals, they are transmitted to the flaw detector via the probe line. The flaw detector's built-in imaging algorithm generates a B-scan image.

[0018] Furthermore, the water immersion phased array probe is a one-dimensional linear array with the following parameters: operating frequency of 10MHz and number of array elements of 64.

[0019] Furthermore, the water wedge is a special water wedge SFSW-N45S-WHC with a steel refraction angle of 45°.

[0020] Beneficial effects:

[0021] 1. This invention provides a quantitative detection method for electron beam weld penetration depth based on a water-immersion ultrasonic phased array. For electron beam welds with complex structures, a linear scanning method using an ultrasonic phased array is employed to perform B-scans on the incomplete penetration area of ​​the weld. The penetration depth information is obtained from the B-scan images, and combined with the A-scan signal, accurate measurement of the penetration depth can be achieved. A water wedge is used to achieve water-coupled detection, overcoming the challenge of limited detection area caused by the complex shape of the electron beam welded component. A high-frequency phased array probe is used, achieving a quantitative detection accuracy of penetration depth better than 0.15 mm.

[0022] 2. Another embodiment of the present invention provides an electron beam weld penetration depth detection device based on a water immersion ultrasonic phased array, including an array flaw detector, a water immersion phased array probe, a water wedge, a water tank, and a workpiece under test; the workpiece under test is an electron beam welded workpiece; the device is used to realize the above-mentioned electron beam weld penetration depth detection method based on a water immersion ultrasonic phased array; the water wedge is used to clamp the high-frequency phased array probe for detection, realizing accurate quantitative measurement of the electron beam weld penetration depth of the injector, with a quantitative accuracy better than 0.15 mm. Attached Figure Description

[0023] Figure 1 Flowchart of a quantitative detection method for electron beam weld penetration based on water immersion ultrasonic phased array provided in Example 1;

[0024] Figure 2 Schematic diagram of ultrasonic phased array linear scanning detection principle for electron beam weld penetration depth of injector;

[0025] Figure 3 This is a diagram illustrating the composition of an electron beam weld penetration quantitative detection device based on a water immersion ultrasonic phased array, as provided in Example 2.

[0026] Figure 4 To obtain the feature echo of the B-scan image for weld penetration detection (weld #8). Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] Example 1:

[0029] This invention provides a method for quantitative detection of electron beam weld penetration depth based on a water immersion ultrasonic phased array, such as... Figure 1 As shown, it includes the following steps:

[0030] Step 1: Perform water immersion ultrasonic phased array linear scanning inspection on the electron beam welded workpiece. Specifically, perform B-scan for the incomplete penetration area of ​​the weld. B-scan is a scan of a cross section parallel to the ultrasonic incident direction to obtain B-scan images.

[0031] Step 2: Retrieve the diffraction echo from the incompletely fused tip and the reflection echo from the incompletely fused root corner using the B-scan image.

[0032] Step 3: The weld penetration depth D of the electron beam welded workpiece is:

[0033] D = TH = TC T ·cosθ·(t2-t1) / 2

[0034] In the formula: T is the thickness of the workpiece in electron beam welding, H is the incomplete penetration height of the weld, and C... T t1 represents the transverse wave velocity in the electron beam welded workpiece, t2 represents the diffraction echo time of the incompletely penetrated tip, and t3 represents the reflection echo time of the incompletely penetrated root corner.

[0035] Conventional ultrasonic probes have low sensitivity and insufficient resolution, making it difficult to acquire distinguishable echo signals from the incomplete weld penetration tip, thus hindering the quantitative determination of weld depth. To effectively enhance the tip diffraction echo, ultrasonic phased array technology with better beam reachability and higher resolution is required.

[0036] This embodiment provides a quantitative detection method for electron beam weld penetration depth based on a water-immersion ultrasonic phased array. Addressing the need for detecting electron beam weld penetration depth in injectors, the quantitative detection principle is analyzed. To effectively acquire characteristic signals for quantification, a linear scanning ultrasonic phased array detection method is chosen. To overcome the detection challenges posed by the limited size and grooves of the injector's detection surface, a water-immersion detection scheme is designed based on the aforementioned method. A water wedge is used to clamp the high-frequency phased array probe for detection, achieving accurate quantification of the electron beam weld penetration depth in injectors with a precision better than 0.15 mm.

[0037] A linear scanning method using ultrasonic phased array is employed to quantitatively detect weld penetration based on echo signals from different positions at the same angle. For example... Figure 2 As shown, with the ultrasonic phased array probe in a fixed position, a fixed-angle scan of the inspected area of ​​the injector is achieved through linear scanning. At this point, the tip diffraction echo path is CD, the end-corner reflection echo path is BA, and the refraction angle is θ. The reflected echo signal at point B at the end-corner of the injector ring in the B-scan image is then compared with the incompletely fused tip.

[0038] In this embodiment of the invention, the workpiece selected for electron beam welding is the injector of a certain type of aerospace engine. Its material is stainless steel, and its overall structure is disc-shaped, formed by electron beam welding of the injector disc and several injector rings. The weld type is a butt weld, and to ensure its safety performance, the penetration depth of each weld is required to be no less than 1.5 mm. The incomplete penetration height is quantitatively measured using tip diffraction signal measurement technology. When ultrasound propagates in a homogeneous medium, according to the Fresnel-Huygens principle, diffraction waves are generated at the defect edges. For the incomplete penetration area of ​​the weld, the propagation time difference between two characteristic echoes—including the diffraction echo from the incomplete penetration tip and the end-angle reflection echo formed by the welded component itself and the incomplete penetration root—can be used to quantitatively determine the incomplete penetration height, thereby achieving quantitative penetration depth measurement.

[0039] The injector has a complex cross-sectional structure with grooves on both the top and bottom sides and densely distributed welds: the radial dimension of the injection ring is 8mm, and it is connected to the injector disc on both sides by welds. The distance between adjacent annular welds is only 2mm, resulting in a limited detection surface area. Since most ultrasonic phased array probes are relatively large, using plexiglass wedges to hold the probe for contact testing cannot avoid the surface grooves, leading to poor coupling and making it impossible to complete the test.

[0040] To address the aforementioned issues and achieve high-precision quantitative detection of weld penetration, a water immersion ultrasonic phased array detection scheme was designed based on the linear scanning detection method determined in steps 1-3. A 10MHz high-frequency probe, held in place by a water wedge, was used to perform a B-scan on the incomplete penetration area of ​​the weld. The weld penetration information was obtained from the B-scan image and combined with the A-scan signal to accurately measure the penetration depth.

[0041] Example 2:

[0042] Based on the above detection plan, the following system was built: Figure 3 The water immersion ultrasonic phased array testing device shown mainly includes:

[0043] The device comprises an array flaw detector, a water immersion phased array probe, a water wedge, a water tank, and the workpiece under test; the water tank is filled with water; the workpiece under test is an electron beam welded workpiece; this device is used to realize an electron beam weld penetration depth detection method based on a water immersion ultrasonic phased array.

[0044] The probe wire of the water immersion phased array probe is connected to the flaw detector through a standardized interface; the water immersion phased array probe is clamped to the wedge-shaped surface of the water wedge block by screws.

[0045] The bottom surface of the water wedge is fixed to the upper surface of the workpiece being inspected, and the bottom surface of the water wedge is in complete contact with the upper surface of the workpiece being inspected.

[0046] The water immersion phased array probe, water wedge, and test piece are all submerged below the water surface in the tank.

[0047] The flaw detector transmits electrical signals to the water immersion phased array probe via the probe line. The electrical signal excites the water immersion phased array probe to emit ultrasonic waves. Using the water medium in the water wedge as a coupling agent, the ultrasonic waves are incident into the interior of the workpiece. When they encounter the heterogeneous interface, diffraction and reflection occur, causing a portion of the ultrasonic waves to return to the probe and be received. After being converted into electrical signals, they are transmitted to the flaw detector via the probe line. The flaw detector's built-in imaging algorithm generates a B-scan image.

[0048] In this embodiment of the invention, the flaw detector selected is the Olympus OmniScan X3 (32 / 128PR) phased array flaw detector; the water immersion phased array probe selected is the Olympus 10L64-FSW water immersion phased array probe (10MHz, one-dimensional linear array, 64 elements); the water wedge selected is the special water wedge SFSW-N45S-WHC (refractive angle of 45° in steel); and the water tank and the workpiece under inspection are also included. Figure 3 As shown, the probe cable connects to the flaw detector via a standardized interface. The probe is clamped to a water wedge with screws. The probe, water wedge, and workpiece are all immersed in water in a tank. The water wedge is held so that its bottom surface is in complete contact with the top surface of the workpiece for immersion linear scanning inspection. During inspection, the flaw detector transmits an electrical signal to the probe via the probe cable (dedicated cable), thereby exciting the probe to emit ultrasonic waves. Using the water medium in the water wedge as a coupling agent, the ultrasonic waves are incident on the interior of the workpiece. Upon encountering a heterogeneous interface, diffraction and reflection occur, causing a portion of the ultrasonic waves to return to the probe and be received. This is converted into an electrical signal and transmitted to the flaw detector via the probe cable. Finally, the flaw detector analyzes and images the signal using its built-in algorithm.

[0049] A simulated specimen for weld penetration testing of the injector of a certain type of aerospace engine in Example 1 was developed. This specimen, made of the same material as the original injector, was formed by electron beam welding of six injection rings and one injector disk, and had the same radial cross-sectional structure as the original injector, with a total of 10 circumferential welds from the inside out. Electron beam welding was performed according to Level I requirements of standard GJB1718A-2005 "Electron Beam Welding". To achieve different weld penetrations, the current value used during welding was varied; specific welding parameters are shown in Table 1.

[0050] Table 1 Welding parameters of simulated samples

[0051]

[0052] The detection scheme described in steps 1-3 was used to perform water immersion ultrasonic phased array linear scanning detection on each weld of the injection device simulated sample. During the detection process, the sound beam was controlled to be incident along the normal direction of the circumferential weld, and B-scan images of 10 specific locations on the weld from the inside to the outside were obtained, as shown in the figure. Figure 4As shown, taking weld #8 as an example, two feature echoes from step 1 are obtained from the B-scan image. The corresponding echo amplitude depth position is determined by the A-scan signal of the two feature echoes. The difference between the two is calculated to obtain the incomplete penetration height, and then the penetration depth is quantified.

[0053] To verify the accuracy of the ultrasonic phased array test results, i.e. the effectiveness of the test scheme in steps 1 to 3, metallographic testing was performed on the weld of the simulated sample to obtain the actual penetration depth. All test results are shown in Table 2.

[0054] Table 2 Results of weld penetration testing on simulated samples

[0055]

[0056] The test results show that, except for weld #10, whose penetration depth was not detected, the detected penetration depths (measured from B-scan images) of all other welds are greater than the actual penetration depths obtained from metallographic testing. Furthermore, except for weld #2, the error between the two values ​​fluctuates around 0.3 mm. Based on these observations, a compensation amount Δ (Δ = -0.3 mm) can be added to the detected penetration depth, and the compensated penetration depth D1 is taken as the final test result, as shown in Table 3.

[0057] Table 3. Results of weld penetration testing on simulated samples (after compensation)

[0058]

[0059] The compensated test results show that the test scheme in step 3 can achieve quantitative detection of the weld penetration depth of the simulated sample, and the quantitative detection accuracy for welds with a penetration depth of (0.15-1.58) mm is better than 0.15 mm. In actual production, due to process guarantees, welds with a penetration depth less than 0.5 mm will not occur. Therefore, water immersion ultrasonic phased array linear scanning detection can meet the detection requirements of a penetration depth of not less than 1.5 mm in the actual production of injectors.

[0060] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for detecting the penetration depth of electron beam welds based on a water immersion ultrasonic phased array, characterized in that, This method is used for near-surface electron beam welding of liquid rocket engine injectors with a thickness of 0.5mm to 3.2mm. The workpiece selected for electron beam welding is the injector of an aerospace engine; its material is stainless steel, and its overall structure is disc-shaped, consisting of an injector disc and several injector rings welded together by electron beam welding. The weld type is butt weld, and to ensure its safety performance, the penetration depth of each weld is required to be no less than 1.5mm. The incomplete penetration height is quantitatively measured using tip diffraction signal measurement technology. When ultrasound propagates in a homogeneous medium, according to Fresnel-Wheel... According to the Gunther principle, diffraction waves are generated at the edge of the defect. For the incomplete penetration area of ​​the weld, the propagation time difference of two characteristic echoes, including the diffraction echo from the tip of the incomplete penetration and the end-angle reflection echo formed by the welded component itself and the root of the incomplete penetration, can be used to quantify the height of the incomplete penetration, thereby achieving quantitative penetration depth. The injector cross-section structure has grooves on both the upper and lower sides, and the welds are densely distributed: the radial dimension of the injection ring is 8mm, and the two sides are connected to the injector disc through welds. The distance between adjacent annular welds is only 2mm, and the detection surface size is limited. The electron beam weld penetration detection method includes the following steps: Step 1: Perform linear scanning detection on the electron beam welded workpiece using a water immersion ultrasonic phased array probe, wherein a B-scan is performed on the incomplete penetration area of ​​the weld. The B-scan is a scan of a cross section parallel to the ultrasonic incident direction to obtain a B-scan image. Step 2: Retrieve the diffraction echo from the incompletely fused tip and the reflected echo from the incompletely fused root corner using the B-scan image; Step 3: The weld penetration depth D of the electron beam welded workpiece is: In the formula: T For the thickness of the workpiece in electron beam welding, H This refers to the height of the incomplete weld penetration. C T The transverse wave velocity in electron beam welding workpieces. t 1 represents the diffraction echo time of the incompletely fused tip. t 2 represents the reflection echo time at the incompletely melted root corner; the accuracy of the melt depth detection is better than 0.15 mm; The electron beam weld penetration detection method based on water immersion ultrasonic phased array is implemented using an electron beam weld penetration detection device based on water immersion ultrasonic phased array. The device includes an array flaw detector, a water immersion phased array probe, a water wedge, a water tank, and the workpiece under inspection. The workpiece under inspection is an electron beam welded workpiece. The tank is filled with water; The probe wire of the water immersion phased array probe is connected to the flaw detector via a standardized interface; the water immersion phased array probe is clamped to the wedge-shaped surface of the water wedge block by screws. The bottom surface of the water wedge is fixed to the upper surface of the workpiece under test, and the bottom surface of the water wedge is in complete contact with the upper surface of the workpiece under test. The water immersion phased array probe, water wedge, and test piece are all submerged below the water surface in the water tank. The flaw detector transmits an electrical signal to the water immersion phased array probe via a probe line. The electrical signal excites the water immersion phased array probe to emit ultrasonic waves. Using the water medium in the water wedge as a coupling agent, the ultrasonic waves are incident into the interior of the workpiece. When they encounter a heterogeneous interface, diffraction and reflection occur, causing a portion of the ultrasonic waves to return to the probe and be received. After being converted into an electrical signal, it is transmitted to the flaw detector via the probe line. The flaw detector has a built-in imaging algorithm to generate a B-scan image. The water immersion phased array probe is a one-dimensional linear array with the following parameters: operating frequency of 10MHz and number of array elements of 64. The water wedge is a special water wedge SFSW-N45S-WHC with a refraction angle of 45° in steel.

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