Combined simulation test block for improving ultrasonic phased array detection precision of heterogeneous structure of dissimilar steel weld joint and use method of combined simulation test block

Abstract

The invention relates to a combined simulation test block for improving ultrasonic phased array detection precision of dissimilar steel weld non-uniform structure and a use method thereof.The combined simulation test block comprises a first simulation test block and a second simulation test block, the first simulation test block is two forging steel plate base materials, and a weld is arranged between the first simulation test block and the second simulation test block; the second simulation test block comprises two sections of steel pipes which are the same as the heated surface in material and specification, a welding seam is arranged between the two sections of steel pipes, and defect characteristics are arranged on the first simulation test block and the second simulation test block. According to the method, a metal material and deposited metal which are the same as the heating surface of the in-service boiler in material and specification are adopted as a combined simulation sample, the standard sensitivity, delay, leading edge and TCG curves of the ultrasonic phased array instrument are manufactured through a standard test block and a first simulation test block, and the standard sensitivity, delay, leading edge and TCG curves of the ultrasonic phased array instrument are obtained through simulation defects on a second simulation test block. Layered process adjustment is conducted on dissimilar steel welding seam detection, the detection processes of different welding seams of the dissimilar steel on the heating surface are obtained, and the problem that defect positioning is not accurate is solved.

Description

Technical Field

[0001] The present invention relates to the field of nondestructive testing technology, and more specifically, to a combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds and a method for using the same, and is particularly suitable for the combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures in the butt weld area of ​​austenitic stainless steel and low alloy steel on the heating surface of a boiler, and a method for using the same. Background Art

[0002] Steel used in thermal power units is mainly divided into two categories: ferritic steel (including pearlite, bainite, martensite and dual-phase steel) and austenitic steel. In order to ensure the safe operation of the unit, the high-temperature section of the boiler convection tube bundle mainly uses austenitic heat-resistant steel, but these steels are expensive, so from an economic point of view, generally the boiler heating surface tubes with a wall temperature exceeding 580°C use austenitic heat-resistant steel, while the parts below 580°C use ferritic heat-resistant steel. Therefore, in the superheater and reheater structure of the power station boiler, a large number of dissimilar steel joints are inevitably present.

[0003] Due to the mismatch of linear expansion coefficients of austenitic stainless steel and ferritic steel, the residual stress in the welded joint is difficult to eliminate even after heat treatment; carbon migration occurs under high temperature conditions, which is very easy to cause cracks; at the same time, the presence of the transition layer will also lead to reduced plasticity and increased brittleness in the fusion zone. Different service environments, such as low-nitrogen transformation, forced ventilation, frequent start-stop, structural stress, over-temperature operation, peak-shaving operation, etc., will cause early failure of dissimilar steel welds, leading to unplanned shutdown of power plants and huge economic losses.

[0004] At present, the detection methods for dissimilar steel weld defects are mainly ultrasonic and radiographic detection. Radiographic detection methods are rarely used in dissimilar steel weld inspections due to their low sensitivity to fusion line cracks, radiation, and space limitations. However, due to the coarse grains of austenite materials, scattering will occur using conventional ultrasonic detection. When the grains reach 1 / 10 of the wavelength of the sound beam, the scattering phenomenon will be more obvious, so conventional ultrasonic detection methods are relatively limited.

[0005] The uneven structure near the weld of dissimilar steels and the reflection and refraction of mechanical waves at the second phase interface will lead to problems such as inaccurate positioning of defects by ultrasonic instruments and inaccurate shaping of displayed defect waveform changes. Summary of the invention

[0006] In order to solve the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide a combined simulation test block that improves the ultrasonic phased array detection accuracy of the non-uniform structure of the butt weld area of ​​austenitic stainless steel and low alloy steel on the heating surface of the boiler, and its use method. The positioning accuracy of the detection of non-uniform structure of dissimilar steel welds can be further improved. While improving the detection accuracy of ultrasonic phased array, this method can realize single-sided and single-side detection of dissimilar steel welds, which is more suitable for complex space regular inspection of in-service units.

[0007] The technical means adopted by the present invention are as follows:

[0008] A combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds comprises a first simulation test block and a second simulation test block, wherein the first simulation test block is two forging steel plate base materials, between which a weld connecting the two forging steel plate base materials is arranged, and the second simulation test block is two sections of steel pipes of the same material and specification as the heating surface, between which a weld connecting the two sections of steel pipes is arranged, and a plurality of preset defect features are arranged on the first simulation test block and the second simulation test block.

[0009] Furthermore, one end of the first simulation test block is an austenitic stainless steel forging plate, and the other end is a low alloy steel forging plate. The weld filler metal connecting the two forging steel plate base materials is a Ni-based austenitic alloy. The upper and lower surfaces of the weld connecting the two forging steel plate base materials have no excess height and are flush with the upper and lower surfaces of the two forging steel plates.

[0010] Furthermore, the length of the first simulation test block is 200-300 mm, the height is 20 mm, the thickness is 20 mm, and the surface roughness of the first simulation test block is less than or equal to 3.2.

[0011] Furthermore, the first simulation test block includes a first defect, a second defect, and a third defect. The first defect, the second defect, and the third defect are all φ2mm transverse through holes, which are arranged in sequence from top to bottom along the center line of the weld. The distances between the centers of the circular holes of the first defect, the second defect, and the third defect and the upper surface of the test block are 5mm, 10mm, and 15mm, respectively.

[0012] Furthermore, one end of the second simulation test block is an austenitic stainless steel pipe, and the other end is a low alloy steel pipe, and the weld filler metal connecting the two steel pipe base materials is a Ni-based austenitic alloy.

[0013] Furthermore, the second simulation test block has a specification of φ60×8mm and a length greater than or equal to 100mm, and the surfaces of the steel pipes on both sides of the weld are polished smooth with a roughness less than or equal to 6.3.

[0014] Furthermore, the second simulation test block includes a fourth defect, a fifth defect, a sixth defect, and a seventh defect, the fourth defect and the seventh defect are simulated crack defects with a length of 10 mm, and the fifth defect and the sixth defect are φ2 mm round hole simulation defects.

[0015] Furthermore, the fourth defect is arranged near the fusion line on the upper surface of one side of the low alloy steel, and the seventh defect is arranged on the inner surface of one side of the low alloy steel at a position corresponding to the fourth defect. The length directions of the fourth defect and the seventh defect are parallel to the weld direction.

[0016] Furthermore, the fifth defect and the sixth defect are arranged on one side of the low alloy steel, 5 mm away from the fusion line on the upper surface of the weld, the spacing between the fifth defect and the sixth defect in the circumferential direction is 10 mm, the fifth defect is a φ2 mm circular hole simulation defect with a depth of 3 mm, and the sixth defect is a φ2 mm circular hole simulation defect with a depth of 5 mm.

[0017] The present invention also discloses a method for using the combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous steel weld structures, comprising the following steps:

[0018] Step 1: Select a 16:32 element ultrasonic phased array instrument, select a 5-10MHz sensor, and choose two types of wedges. When the first simulation test block is selected for instrument calibration, a wedge without curvature is used; when the second simulation test block is selected for instrument calibration, a wedge with a curvature of 0.9-1.1 times the diameter of the second simulation test block is used, and it should be able to ensure maximum coupling with the second simulation test block;

[0019] Step 2: Use CSK-ⅠA standard test block to adjust the instrument and perform front-end calibration;

[0020] Step 3: Apply engine oil coupling agent to the detection surface of the austenitic stainless steel side of the first simulation test block, and select the default value for the instrument sound velocity;

[0021] Step 4, using the first defect, the second defect, and the third defect of the φ2mm transverse through hole at the center of the weld of the first simulation test block to produce a TCG curve and determine the sensitivity;

[0022] Step 5: Use a second simulated test block to further calibrate the detection accuracy;

[0023] Step 6, coating the engine oil coupling agent on the detection surface of the austenitic stainless steel side of the second simulation test block;

[0024] Step 7: Adjust the transmitting and receiving angles of the ultrasonic phased array instrument elements so that the sound beam completely passes through the weld area and covers the fourth defect, the fifth defect, and the sixth defect, and record the distance from the front edge of the probe to the center of the weld at this time;

[0025] Step 8: At this time, the instrument displays an obvious deviation in the defect position. The known position parameters of the fourth defect, the fifth defect, and the sixth defect are used as calibration reference values. The instrument sound velocity value and zero bias are continuously adjusted. When the deviation between the instrument display position parameters of the fourth defect and the fifth defect and the known position parameters does not exceed 1 mm, the calibration of the detection method within the range of 0 to 5 mm for the heterogeneous steel weld on the heated surface is completed.

[0026] Step 9, adjust the transmitting and receiving angles of the ultrasonic phased array instrument elements so that the sound beam completely passes through the weld area and covers the fifth defect, the sixth defect, and the seventh defect, and record the distance from the front edge of the probe to the center of the weld at this time;

[0027] Step 10: At this time, the instrument displays an obvious deviation in the defect position. The known position parameters of the fifth, sixth and seventh defects are used as calibration reference values. The instrument sound velocity value and zero bias are continuously adjusted. When the deviation between the instrument display position parameters of the sixth and seventh defects and the known position parameters does not exceed 1 mm, the calibration of the detection method within the range of 3 to 8 mm of the heterogeneous steel weld on the heated surface is completed.

[0028] Step 11, when performing ultrasonic phased array detection on the dissimilar steel welds on the heating surface of the boiler, the scanning sensitivity is increased by 6dB, and the dissimilar steel welds on the heating surface of the boiler are zoned for detection using detection processes in the range of 0 to 5mm and 3 to 8mm respectively.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The present invention discloses a combined simulation test block and a method for using the same combination ...

[0031] Compared with the prior art, the present invention provides an ultrasonic phased array shear wave detection method for heterogeneous steel welds on the heating surface of a boiler. By setting a simulated defect at a suitable position on one side of the carbon steel, the ultrasonic wave completely passes through the non-uniform area tissue, and uses the ultrasonic wave after reflection and refraction through the non-uniform area tissue to detect and calibrate the simulated defect on the 1:1 second simulation test block. The ultrasonic wave positioning defect deviation after reflection and refraction in a small thickness range is not large. By continuously adjusting the instrument sound velocity and zero bias, the deviation between the instrument display defect position and the actual design value is not more than 1mm, achieving the purpose of improving the ultrasonic phased array shear wave detection accuracy of heterogeneous steel welds on the heating surface of the boiler, and solving the problem of inaccurate defect positioning caused by the deviation between the calibration test block and the actual object to be detected, and the deviation between the set sound velocity value and zero bias value and the actual deformation ultrasonic wave when detecting the heterogeneous steel welds on the heating surface of the boiler in the prior art. At the same time, the present invention only conducts a single-side scan on the stainless steel side during detection, which is significantly different from the double-side inspection specified in the standard, and has a certain promoting effect on improving the detection efficiency during actual detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 is a schematic diagram of a first simulation test block of the present invention;

[0034] Figure 2 It is a schematic diagram of a second simulation test block of the present invention. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0039] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0040] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0041] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0042] like Figure 1 , Figure 2 As shown, an embodiment of the present invention discloses a combined simulation test block for improving the accuracy of ultrasonic phased array detection of non-uniform structures of dissimilar steel welds, including a first simulation test block and a second simulation test block, the first simulation test block is two forging steel plate base materials, and a weld connecting the two forging steel plate base materials is provided therebetween, the second simulation test block is two sections of steel pipes with the same material and specification as the heated surface, and a weld connecting the two sections of steel pipes is provided therebetween, and a number of preset defect features are provided on the first simulation test block and the second simulation test block.

[0043] One end of the first simulation test block is an austenitic stainless steel forging plate, and the other end is a low alloy steel forging plate. The filler metal of the weld connecting the two forging steel plates is a Ni-based austenitic alloy. The upper and lower surfaces of the weld connecting the two forging steel plates have no excess height and are flush with the upper and lower surfaces of the two forging steel plates. In this embodiment, the austenitic stainless steel is Super304 austenitic stainless steel, and the low alloy steel is P91 high temperature low alloy carbon steel.

[0044] The first simulation test block has a length of 200-300 mm, a height of 20 mm, and a thickness of 20 mm. The surface roughness of the first simulation test block is less than or equal to 3.2.

[0045] The first simulation test block includes a first defect, a second defect, and a third defect. The first defect, the second defect, and the third defect are all φ2mm transverse through holes, which are arranged in sequence from top to bottom along the center line of the weld. The distances between the centers of the circular holes of the first defect, the second defect, and the third defect and the upper surface of the test block are 5mm, 10mm, and 15mm, respectively.

[0046] One end of the second simulation test block is an austenitic stainless steel pipe, and the other end is a low alloy steel pipe, and the weld filler metal connecting the two steel pipes is a Ni-based austenitic alloy. In this embodiment, the austenitic stainless steel is Super304 austenitic stainless steel, and the low alloy steel is P91 high temperature low alloy carbon steel.

[0047] The second simulation test block has a specification of φ60×8mm and a length greater than or equal to 100mm. The surfaces of the steel pipes on both sides of the weld are polished smooth with a roughness less than or equal to 6.3.

[0048] The second simulation test block includes a fourth defect, a fifth defect, a sixth defect, and a seventh defect. The fourth defect and the seventh defect are simulated crack defects with a length of 10 mm, and the fifth defect and the sixth defect are φ2 mm round hole simulation defects.

[0049] The fourth defect is arranged near the fusion line on the upper surface of one side of the low alloy steel, and the seventh defect is arranged on the inner surface of one side of the low alloy steel at a position corresponding to the fourth defect. The length directions of the fourth defect and the seventh defect are parallel to the weld direction.

[0050] The fifth defect and the sixth defect are arranged on one side of the low alloy steel, 5 mm away from the fusion line on the upper surface of the weld, and the spacing between the fifth defect and the sixth defect in the circumferential direction is 10 mm. The fifth defect is a φ2 mm circular hole simulation defect with a depth of 3 mm, and the sixth defect is a φ2 mm circular hole simulation defect with a depth of 5 mm.

[0051] The present invention also discloses a method for using the combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous steel weld structures, comprising the following steps:

[0052] Step 1. Select a 16:32 element ultrasonic phased array instrument, select a 5-10MHz sensor, and select two types of wedges. When selecting the first simulation test block for instrument calibration, use a wedge without curvature; when selecting the second simulation test block for instrument calibration, use a wedge with a curvature of 0.9-1.1 times the diameter of the second simulation test block, and it should be able to ensure maximum coupling with the second simulation test block; in this embodiment, the phased array instrument uses the PHASCAN II portable phased array ultrasonic detector of Guangzhou Dopule Electronic Technology Co., Ltd., and uses a shear wave phased array probe with a frequency of 5MHz, an array element number of 16:32, an array element center distance of 1mm, an effective aperture of 8mm, and an array element length of 9mm.

[0053] Step 2: Use the CSK-ⅠA standard test block to adjust the instrument and perform front calibration. Specifically, apply engine oil as a coupling agent on the surface to be tested on the CSK-ⅠA standard test block, place the probe on the surface to be tested, align the front edge of the probe with the semicircle R50 of the ship-shaped test block, move the probe back and forth, and when the amplitude of the reflected sound wave reaches the maximum, use a steel ruler to measure and calculate the front edge of the probe, and input it into the instrument for calibration.

[0054] Step 3: Apply engine oil coupling agent to the detection surface of the austenitic stainless steel side of the first simulation test block, and select the default value for the instrument sound velocity;

[0055] Step 4, using the first defect, the second defect, and the third defect of the φ2mm transverse through hole at the center of the weld of the first simulation test block to produce a TCG curve and determine the sensitivity;

[0056] Step 5: Use a second simulated test block to further calibrate the detection accuracy;

[0057] Step 6, coating the engine oil coupling agent on the detection surface of the austenitic stainless steel side of the second simulation test block;

[0058] Step 7: Adjust the transmitting and receiving angles of the ultrasonic phased array instrument elements so that the sound beam completely passes through the weld area and covers the fourth defect, the fifth defect, and the sixth defect, and record the distance from the front edge of the probe to the center of the weld at this time;

[0059] Step 8: At this time, the instrument displays an obvious deviation in the defect position. The known position parameters of the fourth defect, the fifth defect, and the sixth defect are used as calibration reference values. The instrument sound velocity value and zero bias are continuously adjusted. When the deviation between the instrument display position parameters of the fourth defect and the fifth defect and the known position parameters does not exceed 1 mm, the calibration of the detection method within the range of 0 to 5 mm for the heterogeneous steel weld on the heated surface is completed.

[0060] Step 9, adjust the transmitting and receiving angles of the ultrasonic phased array instrument elements so that the sound beam completely passes through the weld area and covers the fifth defect, the sixth defect, and the seventh defect, and record the distance from the front edge of the probe to the center of the weld at this time;

[0061] Step 10: At this time, the instrument displays an obvious deviation in the defect position. The known position parameters of the fifth, sixth and seventh defects are used as calibration reference values. The instrument sound velocity value and zero bias are continuously adjusted. When the deviation between the instrument display position parameters of the sixth and seventh defects and the known position parameters does not exceed 1 mm, the calibration of the detection method within the range of 3 to 8 mm of the heterogeneous steel weld on the heated surface is completed.

[0062] Step 11, when performing ultrasonic phased array detection on the dissimilar steel welds on the heating surface of the boiler, the scanning sensitivity is increased by 6dB, and the dissimilar steel welds on the heating surface of the boiler are zoned for detection using detection processes in the range of 0 to 5mm and 3 to 8mm respectively.

[0063] As a specific implementation of step 11, the detection of the dissimilar steel welds of the in-service heating surface pipes is specifically as follows:

[0064] The specifications of the in-service heating surface pipes are φ60×8mm, the materials are Super304 and P91, and the welds are Ni-based austenitic alloy.

[0065] Before testing, the austenitic stainless steel side of the dissimilar steel weld pipe to be tested is polished until the surface is smooth and the metallic luster is exposed. Coupling agent is applied to the polished smooth pipe surface, and the calibrated phased array instrument is used for testing. The probe of the phased array instrument is placed on the outer surface of the pipe with the coupling agent, and the surface coupling is ensured to be good. The phased array probe is placed 5mm away from the center of the weld at the front edge, and moves back and forth perpendicular to the weld direction so that the sound wave completely covers the weld and the heat-affected zone within a range of 0 to 5mm. At this time, the front position of the probe is determined. First, the weld is tested using the 0 to 5mm range dissimilar steel weld detection process. The probe rotates one circle in the circumferential direction at this position to complete the 0 to 5mm range dissimilar steel weld detection.

[0066] The phased array probe is placed at a distance of 5mm from the center of the weld at the front edge, and is moved back and forth perpendicular to the weld direction so that the sound wave completely covers the weld and the heat affected zone within a range of 3 to 8mm. At this time, the front edge position of the probe is determined, and the weld is inspected using the 3 to 8mm range dissimilar steel weld inspection process. The probe rotates one circle in the circumferential direction at this position to complete the 3 to 8mm range dissimilar steel weld inspection.

[0067] The above two processes are used to complete 100% inspection of the weld. Combined with the two inspection results of the weld, defect judgment is carried out in accordance with NB / T47013.15-2021. Welds judged as exceeding the standard defects are repaired in time, and welds judged as recordable defects should be subject to strict supervision and operation.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds, characterized in that: The method comprises a first simulation test block and a second simulation test block. The first simulation test block is two pieces of forging steel plate base materials, between which a weld connecting the two pieces of forging steel plate base materials is arranged. The second simulation test block is two sections of steel pipes of the same material and specification as the heating surface, between which a weld connecting the two sections of steel pipes is arranged. A number of preset defect features are arranged on the first simulation test block and the second simulation test block.

2. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to claim 1 is characterized in that: One end of the first simulation test block is an austenitic stainless steel forging plate, and the other end is a low alloy steel forging plate. The weld filler metal connecting the two forging steel plate base materials is a Ni-based austenitic alloy. The upper and lower surfaces of the weld connecting the two forging steel plate base materials have no excess height and are flush with the upper and lower surfaces of the two forging steel plates.

3. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to claim 1 is characterized in that: The first simulation test block has a length of 200-300 mm, a height of 20 mm, and a thickness of 20 mm. The surface roughness of the first simulation test block is less than or equal to 3.

2.

4. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous steel weld structures according to claim 1 is characterized in that: The first simulation test block includes a first defect, a second defect, and a third defect. The first defect, the second defect, and the third defect are all φ2mm transverse through holes, which are arranged in sequence from top to bottom along the center line of the weld. The distances between the centers of the circular holes of the first defect, the second defect, and the third defect and the upper surface of the test block are 5mm, 10mm, and 15mm, respectively.

5. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to claim 1 is characterized in that: One end of the second simulation test block is an austenitic stainless steel pipe, and the other end is a low alloy steel pipe. The weld filler metal connecting the two steel pipes is a Ni-based austenitic alloy.

6. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to claim 1 is characterized in that: The second simulation test block has a specification of φ60×8mm and a length greater than or equal to 100mm. The surfaces of the steel pipes on both sides of the weld are polished smooth with a roughness less than or equal to 6.

3.

7. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to claim 1 is characterized in that: The second simulation test block includes a fourth defect, a fifth defect, a sixth defect, and a seventh defect. The fourth defect and the seventh defect are simulated crack defects with a length of 10 mm, and the fifth defect and the sixth defect are φ2 mm round hole simulation defects.

8. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to claim 1 is characterized in that: The fourth defect is arranged near the fusion line on the upper surface of one side of the low alloy steel, and the seventh defect is arranged on the inner surface of one side of the low alloy steel at a position corresponding to the fourth defect. The length directions of the fourth defect and the seventh defect are parallel to the weld direction.

9. The combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to claim 1 is characterized in that: The fifth defect and the sixth defect are arranged on one side of the low alloy steel, 5 mm away from the fusion line on the upper surface of the weld, and the spacing between the fifth defect and the sixth defect in the circumferential direction is 10 mm. The fifth defect is a φ2 mm circular hole simulation defect with a depth of 3 mm, and the sixth defect is a φ2 mm circular hole simulation defect with a depth of 5 mm.

10. A method for using the combined simulation test block for improving the ultrasonic phased array detection accuracy of heterogeneous structures of dissimilar steel welds according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: Select a 16:32 element ultrasonic phased array instrument, select a 5-10MHz sensor, and choose two types of wedges. When the first simulation test block is selected for instrument calibration, a wedge without curvature is used; when the second simulation test block is selected for instrument calibration, a wedge with a curvature of 0.9-1.1 times the diameter of the second simulation test block is used, and it should be able to ensure maximum coupling with the second simulation test block; Step 2: Use CSK-ⅠA standard test block to adjust the instrument and perform front-end calibration; Step 3: Apply engine oil coupling agent to the detection surface of the austenitic stainless steel side of the first simulation test block, and select the default value for the instrument sound velocity; Step 4, using the first defect, the second defect, and the third defect of the φ2mm transverse through hole in the center of the weld of the first simulation test block to produce a TCG curve and determine the sensitivity; Step 5: Use a second simulated test block to further calibrate the detection accuracy; Step 6, coating the engine oil coupling agent on the detection surface of the austenitic stainless steel side of the second simulation test block; Step 7: Adjust the transmitting and receiving angles of the ultrasonic phased array instrument elements so that the sound beam completely passes through the weld area and covers the fourth defect, the fifth defect, and the sixth defect, and record the distance from the front edge of the probe to the center of the weld at this time; Step 8: At this time, the instrument displays an obvious deviation in the defect position. The known position parameters of the fourth defect, the fifth defect, and the sixth defect are used as calibration reference values. The instrument sound velocity value and zero bias are continuously adjusted. When the deviation between the instrument display position parameters of the fourth defect and the fifth defect and the known position parameters does not exceed 1 mm, the calibration of the detection method within the range of 0 to 5 mm for the heterogeneous steel weld on the heated surface is completed. Step 9, adjust the transmitting and receiving angles of the ultrasonic phased array instrument elements so that the sound beam completely passes through the weld area and covers the fifth defect, the sixth defect, and the seventh defect, and record the distance from the front edge of the probe to the center of the weld at this time; Step 10: At this time, the instrument displays an obvious deviation in the defect position. The known position parameters of the fifth, sixth and seventh defects are used as calibration reference values. The instrument sound velocity value and zero bias are continuously adjusted. When the deviation between the instrument display position parameters of the sixth and seventh defects and the known position parameters does not exceed 1 mm, the calibration of the detection method within the range of 3 to 8 mm of the heterogeneous steel weld on the heated surface is completed. Step 11, when performing ultrasonic phased array detection on the dissimilar steel welds on the heating surface of the boiler, the scanning sensitivity is increased by 6dB, and the dissimilar steel welds on the heating surface of the boiler are zoned for detection using detection processes in the range of 0 to 5mm and 3 to 8mm respectively.

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