Phased array ultrasonic nondestructive evaluation method and system for grain size of complex component

Abstract

The invention provides a phased array ultrasonic nondestructive evaluation method and system for the grain size of a complex component, and belongs to the technical field of ultrasonic nondestructive testing. Comprising the following steps: detecting a workpiece with multiple curved surfaces by adopting a liquid immersion mode in cooperation with a phased array ultrasonic probe array, and dividing to-be-detected areas of different structure types according to the shape characteristics of the workpiece; an acoustic beam focusing rule and an acoustic beam propagation path of the phased array ultrasonic probe array are designed, and phased array ultrasonic detection parameters are designed for to-be-detected areas of different structure types according to size parameters of workpieces; detecting grain sizes of to-be-detected areas of different structure types of a workpiece, and collecting phased array ultrasonic signals of the to-be-detected areas through the phased array ultrasonic probe array; calibrating the collected phased array ultrasonic signals of each to-be-detected area, and respectively calculating the average attenuation coefficient of the phased array ultrasonic probe array signals of each to-be-detected area; and calculating the grain size of the to-be-measured area through a pre-constructed grain size phased array ultrasonic evaluation model.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic nondestructive testing, and in particular to a phased array ultrasonic nondestructive evaluation method and system for complex component grain size. Background Art

[0002] With the rapid development of aerospace, energy and power, and intelligent manufacturing, high-end equipment is moving toward increasingly complex structures and extreme performance. High-end equipment, such as aircraft engines, nuclear reactor components, and deep-sea equipment, features component designs that incorporate multiple curved features, such as convex-convex, convex-concave, concave-concave, convex-inclined, and concave-inclined surfaces. Key components, such as turbine blades, aircraft casings, and nuclear fuel cladding tubes, feature curved surfaces such as fillets, chamfers, raceways, and stiffeners. This structural complexity poses unprecedented challenges to manufacturing processes and quality control. Under extreme operating conditions (high temperature, high pressure, and intense radiation), the material's microscopic grain structure directly determines the mechanical properties and service life of the component. For example, casing ring materials have a narrow forging temperature range and are highly sensitive to hot working parameters. Repeated reheating can lead to the formation of coarse or mixed grains. Therefore, grain size evaluation is an essential and important link in the production and manufacturing process of complex components of high-end equipment. If the problems of the microscopic grain structure of the material are not discovered and dealt with in a timely manner, it will seriously damage the mechanical properties of the components, threaten the service safety of related equipment, and pose a major safety hazard.

[0003] Currently, ultrasonic grain size testing of metal materials primarily involves perpendicularly incident longitudinal waves on the workpiece, using the attenuation coefficient of the bottom-reflected echo to nondestructively evaluate the grain structure. Ultrasonic waves scatter and attenuate more severely in coarse-grained materials. By analyzing the energy loss and attenuation of the echo signal reflected from the ring's bottom surface, the grain structure of rectangular rings can be indirectly assessed. However, complex components in high-end equipment often have multiple curved surfaces, with both the incident interface and the reflecting bottom surface curved. Conventional probes have a fixed beam direction, making it difficult to penetrate curved interfaces. Furthermore, the transmitted sound wave is severely scattered and subjected to total reflection at oblique angles, preventing the probe from receiving the bottom-reflected echo signal. Therefore, conventional ultrasonic technology is difficult to apply to microscopic grain size testing of high-end equipment components with complex structures featuring multiple curved surfaces. Currently, grain size testing of complex components still relies on destructive sampling methods such as metallography and electron backscatter diffraction (EBSD), which are subject to long waiting times, significant material waste, and incomplete coverage.

[0004] Therefore, in view of the development trend of complex structure of high-end equipment, a phased array ultrasonic non-destructive evaluation method for the grain size of complex components is provided to realize the reliable ultrasonic non-destructive testing of the grain size of complex components with multiple curved surface structures, so as to ensure the mechanical properties and service life of related equipment. This is not only the core requirement for ensuring the reliability of complex components, but also the only way to promote manufacturing quality to a new stage of "micro-controllability". Summary of the Invention

[0005] In view of this, the present invention proposes a phased array ultrasonic nondestructive evaluation method and system for grain size of complex components applicable to multi-curved surface structures and capable of reliably receiving ultrasonic reflection echo signals.

[0006] In one aspect, the present invention provides a phased array ultrasonic nondestructive evaluation method for grain size of complex components, comprising the following steps: S1: Use liquid immersion combined with a phased array ultrasonic probe array to detect workpieces with multiple curved surfaces, and divide the test areas into different structural types based on the shape characteristics of the workpiece; S2: Construct phased array ultrasonic testing models corresponding to the test areas of different structural types. By designing the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array, the acoustic beam is incident from the upper surface of the workpiece, reflected from the bottom surface of the workpiece, and then received by the phased array ultrasonic probe array. Based on the dimensional parameters of the workpiece, phased array ultrasonic testing parameters are designed for the test areas of different structural types. S3: detecting grain sizes of test areas of different structural types of the workpiece according to the acoustic beam propagation path of the phased array ultrasonic probe array and the phased array ultrasonic testing parameters, and collecting phased array ultrasonic signals of each test area through the phased array ultrasonic probe array; S4: Pre-constructing a phased array ultrasonic probe array beam attenuation calibration model for different structural types of test areas, calibrating the phased array ultrasonic signals collected from each test area, and calculating the average attenuation coefficient of the phased array ultrasonic probe array signal for each test area; S5: Substituting the average attenuation coefficient of the phased array ultrasonic probe array signal of each area to be measured into a pre-built grain size phased array ultrasonic evaluation model to calculate the grain size of the area to be measured.

[0007] On the basis of the above technical solution, preferably, the division of the test areas of different structural types according to the shape characteristics of the workpiece described in step S1 is to divide the shape characteristics of the workpiece into test areas of convex-convex structure type, concave-concave structure type, convex-concave structure type, convex-inclined structure type and concave-inclined structure type according to the shapes of the top and bottom surfaces of the workpiece.

[0008] Preferably, the step S2 of designing the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array specifically comprises: allowing the acoustic beam of the transmitting aperture of the phased array ultrasonic probe array to be incident on the upper surface interface of the workpiece, then propagating to the bottom surface of the workpiece, and after the acoustic beam is reflected by the center point of the bottom surface, collecting the signal through the receiving aperture of the phased array ultrasonic probe array; For workpieces with convex-convex and convex-concave structures in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, the arc radius of the incident convex surface, the arc radius of the bottom surface, and the distance between the centers of the two arcs are defined, and the interface equation of the convex surface of the workpiece close to the phased array ultrasonic probe array is constructed; the acoustic beam focusing law is: given the first i The center point coordinates of the group transmitting aperture are obtained i The coordinates of the incident point of the sound beam emitted by the group transmitting aperture on the workpiece interface and the coordinates of the interface intersection point on the reflection path are used to calculate the propagation path of the sound beam in the liquid and convex-convex structure type workpiece; For workpieces with a concave-concave structure in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, the arc radius of the incident concave surface, the arc radius of the bottom surface and the distance between the centers of the two arcs are defined, and the interface equation of the concave surface of the workpiece close to the phased array ultrasonic probe array is constructed; referring to the acoustic beam focusing law of the convex-convex structure type, the first i The coordinates of the center point of the group transmitting aperture are obtained. i The propagation path of the acoustic beam emitted by the group emitting aperture in the liquid and the concave-concave structure workpiece; For workpieces with convex-slope and concave-slope structures in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, and the bottom slope coordinate system equation is obtained; the beam focusing law is: given the i The center point coordinates of the group transmitting aperture are obtained. i The coordinates of the incident point of the acoustic beam of the group transmitting aperture on the workpiece interface, the coordinates of the interface intersection point corresponding to the reflection path, the coordinates of the reflection point of the acoustic beam on the inclined surface of the workpiece and the center coordinates of the array receiving aperture are obtained. i The propagation path of the sound beam emitted by the group transmitting aperture in the convex-concave structure type.

[0009] Preferably, the phased array ultrasonic testing parameters are designed for the areas to be tested of different structural types according to the size parameters of the workpiece in step S2, specifically: according to the width of the workpiece L and length S , defines the liquid height through which the ultrasonic wave is transmitted h , the number of array elements in the phased array ultrasound probe N , array element spacing p and total width D N, determine the transmit aperture and receive aperture sequence of the phased array ultrasonic probe array.

[0010] Preferably, the determining of the transmit aperture and receive aperture sequence of the phased array ultrasonic probe array specifically includes: determining the array element aperture and the number of array elements of the phased array ultrasonic probe array as follows: B , the array aperture electronic scanning step is step , the sequence of the transmitting aperture of the phased array ultrasonic probe array is ( N - B ) / step , find the incident point on the coordinate interface of the center point of the transmitting aperture, and obtain the coordinate position range of the center point of the transmitting aperture; then, according to the sequence position of the transmitting aperture and the propagation path of the sound beam, set the coordinate position of the receiving aperture and the sequence of the receiving aperture so that the receiving aperture receives the echo signal reflected from the bottom surface of the workpiece.

[0011] Preferably, the phased array ultrasonic probe array sound beam attenuation calibration model of the test area of ​​different structural types is pre-built in step S4, and the phased array ultrasonic signal collected in each test area is calibrated, which is based on the sound beam incident angle of the phased array ultrasonic probe array, and the longitudinal wave energy transmittance of the sound beam in the liquid-workpiece is calculated. ; According to the incident angle of the sound beam of the phased array ultrasonic probe array on the bottom surface of the workpiece, calculate the reflectivity of the sound beam on the bottom surface of the workpiece ; Let the acoustic beam signal collected by the phased array ultrasonic probe array be P j , then the calibrated beam signal The sound beam signal P j , divided by the longitudinal wave energy transmittance Reflectivity The product of .

[0012] Preferably, the calculation of the average attenuation coefficient of the phased array ultrasonic probe array signal of each area to be measured in step S4 is to make the phased array ultrasonic probe array collect J The attenuation coefficient of each group of calibrated sound beam signals is obtained by accumulating the attenuation coefficients and averaging them. J The average attenuation coefficient of the calibrated beam signal.

[0013] Preferably, the pre-built phased array ultrasonic evaluation model for grain size described in step S5 specifically includes: using the same material as the workpiece with multiple curved surfaces to be tested, respectively designing and manufacturing comparative test blocks of convex-convex structure type, concave-concave structure type, convex-concave structure type, convex-inclined structure type and concave-inclined structure type. n By different heating temperature treatment nComparison test blocks were obtained n Comparison test pieces with different grain sizes; obtained by metallographic testing n The actual grain sizes of the comparison specimens are ;According to the content of steps S1-S4 n The acoustic beam signal collected by the phased array ultrasonic probe array of the comparison test block is used to obtain the average attenuation coefficient of the calibrated acoustic beam signal , the grain size phased array ultrasonic evaluation model is defined as ,in f is the frequency of the ultrasound probe, K is the function coefficient.

[0014] In another aspect, the present invention provides a phased array ultrasonic nondestructive evaluation system for grain size of complex components, for implementing the method, comprising: The test area classification module divides the test areas into different structural types according to the shape characteristics of the workpiece to be tested; The acoustic beam focusing law and acoustic beam propagation path module is used to design the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array, and design the phased array ultrasonic testing parameters for the test area of ​​different structural types according to the size parameters of the workpiece; The phased array ultrasonic probe array is configured with multiple array elements according to the phased array ultrasonic testing parameters. The acoustic beam is incident on the upper surface interface of the workpiece through the transmitting aperture, and then propagates to the bottom surface of the workpiece. After the acoustic beam is reflected by the center point of the bottom surface, it is again collected through the receiving aperture of the phased array ultrasonic probe array in each area to be tested. The acoustic beam attenuation calibration model construction module is used to construct the phased array ultrasonic probe array acoustic beam attenuation calibration model of the test area with different structural types, calibrate the phased array ultrasonic signals collected from each test area, and obtain the average attenuation coefficient of the phased array ultrasonic probe array signal of each test area; The grain size phased array ultrasonic evaluation model construction module calculates the grain size of the test area based on the average attenuation coefficient of the phased array ultrasonic probe array signal in each test area.

[0015] In a third aspect, the present invention further provides a computer storage medium storing a computer program, wherein the computer program implements the method when executed by a processor.

[0016] The present invention provides a phased array ultrasonic nondestructive evaluation method and system for complex component grain size, which has the following advantages over the prior art: (1) The present invention divides complex components into complex structural types with different structures such as convex-convex, concave-concave, convex-concave, convex-inclined, and concave-inclined. By designing the focusing law and propagation path of the phased array ultrasonic probe array beam, the curved surface incidence and bottom surface reflection of the acoustic beam are controlled so that the array aperture receives the bottom surface reflection signal. This avoids the scattering of ultrasonic waves on the curved surface and the total reflection of the bottom surface, which causes the ultrasonic probe to be unable to receive the bottom surface echo signal. (2) A parameter design method for phased array ultrasonic probe arrays is proposed for different types of workpiece test areas. The design basis such as water layer height, transmitting aperture and receiving aperture position, and probe parameters are given. This method can ensure that the array sound beams of each aperture of the phased array probe can be incident and reflected from the bottom surface within the range of complex components. By selecting reasonable detection parameters and probe parameters, the ultrasonic incident energy of the array sound beam and the bottom surface reflection signal intensity are improved, thereby enhancing the sensitivity of grain size detection of complex components. (3) Through the constructed phased array ultrasonic array sound beam signal calibration model, the energy attenuation caused by the oblique incidence of the array sound beam on the curved surface at different angles can be corrected, thereby avoiding the influence of the sound beam energy attenuation of the complex component surface macrostructure on the scattering energy attenuation of the complex component material grains; (4) A method for calculating the average attenuation coefficient of a phased array ultrasonic beam is proposed. This method comprehensively considers the propagation and attenuation of each array beam in the workpiece, including the grain scattering information of a larger area of ​​the component and the scattering information of the array beam at different angles. The proposed average attenuation coefficient can better reflect the grain size information of complex components. (5) Phased array ultrasonic evaluation models for grain size of different types of multi-curved surface structures were constructed. Based on the theoretical relationship between the grain size of metal materials and the ultrasonic attenuation coefficient, the actual grain size of multiple comparison test blocks was fitted with the average attenuation coefficient of the array acoustic beam. The obtained mathematical model for grain size evaluation has higher reliability. By constructing phased array ultrasonic evaluation models for grain size of different types of structures, the grain size evaluation accuracy of complex components can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A schematic diagram of phased array ultrasonic zoning detection of a complex component grain size phased array ultrasonic nondestructive evaluation method and system according to the present invention; Figure 2A schematic diagram of phased array ultrasonic testing of a plane-to-plane structure type of a target area in a method and system for nondestructive evaluation of grain size of a complex component according to the present invention; Figure 3 A schematic diagram of phased array ultrasonic testing of a convex-convex structured area to be tested in a method and system for nondestructive evaluation of grain size of complex components according to the present invention; Figure 4 A schematic diagram of phased array ultrasonic testing of a concave-concave structure to be tested in a method and system for nondestructive evaluation of grain size of complex components according to the present invention; Figure 5 Schematic diagram of phased array ultrasonic testing of a convex-concave structure area to be tested in a method and system for nondestructive evaluation of grain size of complex components according to the present invention; Figure 6 A schematic diagram of phased array ultrasonic testing of a convex-inclined structure type of a complex component grain size nondestructive evaluation method and system according to the present invention; Figure 7 A schematic diagram of phased array ultrasonic testing of a concave-slope structure type to be tested in a method and system for nondestructive evaluation of grain size of complex components according to the present invention; Figure 8 Schematic diagram of simulated test blocks of different types of curved surface structures in a phased array ultrasonic nondestructive evaluation method and system for grain size of complex components of the present invention; Figure 9 Schematic diagram of the sound beam propagation path of different types of curved surface structures in a phased array ultrasonic nondestructive evaluation method and system for grain size of complex components of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, on the one hand, the present invention provides a phased array ultrasonic nondestructive evaluation method for grain size of complex components, comprising the following steps: S1: Use liquid immersion combined with a phased array ultrasonic probe array to detect workpieces with multiple curved surfaces, and divide the test areas into different structural types based on the shape characteristics of the workpiece.

[0021] Specifically, based on the shapes of the workpiece's top and bottom surfaces, the workpiece's shape features are divided into test areas with flat-to-flat, convex-to-convex, concave-to-concave, convex-to-concave, convex-to-inclined, and concave-to-inclined structures. It should be noted that the test areas with different structural types can be located on the same workpiece or on different workpieces. Figure 1 The workpiece is only an example, and the content of this embodiment is not limited to only this workpiece structure type.

[0022] like Figure 2 As shown, when the grain size of the area to be measured is detected for the plane-plane structure type, the sound beam is incident perpendicular to the surface of the workpiece, and is vertically reflected by the bottom plane of the workpiece, and then the array aperture receives the bottom surface reflection signal; for the plane-plane structure, the array sound beam adopts vertical incidence and vertical reflection, and does not involve the design of the array sound beam propagation path and the content of the sound beam deflection calibration, so the present invention will not go into details. Only the areas to be measured in five cases of convex-convex structure type, concave-concave structure type, convex-concave structure type, convex-inclined structure type and concave-inclined structure type are analyzed. The phased array ultrasonic probe array has multiple array elements, and several array elements form an aperture, so that the phased array ultrasonic probe array forms several continuous apertures; each aperture is used to emit or receive a corresponding sound beam.

[0023] S2: Construct phased array ultrasonic testing models corresponding to the test areas of different structural types. By designing the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array, the acoustic beam is incident from the upper surface of the workpiece, reflected by the bottom surface of the workpiece, and then received by the phased array ultrasonic probe array; according to the dimensional parameters of the workpiece, the phased array ultrasonic testing parameters are designed for the test areas of different structural types.

[0024] Specifically, such as Figure 9 As shown, the design of the sound beam focusing law and sound beam propagation path of the phased array ultrasonic probe array described in step S2 is as follows: the sound beam of the transmitting aperture of the phased array ultrasonic probe array is incident on the upper surface interface of the workpiece, and then propagates to the bottom surface of the workpiece. After the sound beam is reflected by the center point of the bottom surface, the signal is collected through the receiving aperture of the phased array ultrasonic probe array.

[0025] For workpieces with convex-convex and convex-concave structures in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, the arc radius of the incident convex surface, the arc radius of the bottom surface, and the distance between the centers of the two arcs are defined, and the interface equation of the convex surface of the workpiece close to the phased array ultrasonic probe array is constructed; the acoustic beam focusing law is: given the first i The center point coordinates of the group transmitting aperture are obtained iThe coordinates of the incident point of the sound beam emitted by the group transmitting aperture on the workpiece interface and the coordinates of the interface intersection point on the reflection path are used to calculate the propagation path of the sound beam in the liquid and convex-convex structure type workpiece; For workpieces with a concave-concave structure in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, the arc radius of the incident concave surface, the arc radius of the bottom surface and the distance between the centers of the two arcs are defined, and the interface equation of the concave surface of the workpiece close to the phased array ultrasonic probe array is constructed; referring to the acoustic beam focusing law of the convex-convex structure type, the first i The coordinates of the center point of the group transmitting aperture are obtained. i The propagation path of the acoustic beam emitted by the group emitting aperture in the liquid and the concave-concave structure workpiece; For workpieces with convex-slope and concave-slope structures in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, and the bottom slope coordinate system equation is obtained; the beam focusing law is: given the i The center point coordinates of the group transmitting aperture are obtained. i The coordinates of the incident point of the acoustic beam of the group transmitting aperture on the workpiece interface, the coordinates of the interface intersection point corresponding to the reflection path, the coordinates of the reflection point of the acoustic beam on the inclined surface of the workpiece and the center coordinates of the array receiving aperture are obtained. i The propagation path of the sound beam emitted by the group transmitting aperture in the convex-concave structure type.

[0026] According to the size parameters of the workpiece, the phased array ultrasonic testing parameters are designed for the test area of ​​different structural types in step S2. Specifically, the parameters are as follows: L and length S , defines the liquid height through which the ultrasonic wave is transmitted h , the number of array elements in the phased array ultrasound probe N , array element spacing p and total width D N , determine the transmit aperture and receive aperture sequence of the phased array ultrasonic probe array.

[0027] Among them, the transmit aperture and receive aperture sequence of the phased array ultrasonic probe array are determined as follows: the array element aperture and the number of array elements of the phased array ultrasonic probe array are determined as follows: B , the array aperture electronic scanning step is step , the sequence of the transmitting aperture of the phased array ultrasonic probe array is ( N - B ) / step, find the incident point on the coordinate interface of the center point of the transmitting aperture, and obtain the coordinate position range of the center point of the transmitting aperture; then, according to the sequence position of the transmitting aperture and the propagation path of the sound beam, set the coordinate position of the receiving aperture and the sequence of the receiving aperture so that the receiving aperture receives the echo signal reflected from the bottom surface of the workpiece.

[0028] The specific process is now discussed separately according to the different structural types of the areas to be tested.

[0029] A. For workpieces with a convex-convex structure in the area to be measured, the sound beam propagation path is obtained as follows: Figure 3 As shown in the figure, the coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, and the horizontal extension direction of the phased array ultrasonic probe array as the x Axis direction, perpendicular to x The axis direction is y direction, and define the incident convex arc radius as R 1. The radius of the raised arc on the bottom surface is R 2. The distance between the centers of the two arcs is d The coordinates of the circle center are O 1(0, R 1+h) and O 2 (0, R 1+ h + d ); then the interface equation of the convex surface of the workpiece close to the phased array ultrasonic probe array is , is the incident angle of the sound beam at the workpiece interface, is the refraction angle of the sound beam in the workpiece, is the reflection angle of the sound beam in the workpiece, c 1 and c 2 are the sound velocities of the acoustic beam in the liquid and workpiece, respectively. By setting the acoustic beam focusing law of the phased array ultrasonic probe array, the acoustic beam deflection direction is controlled so that the acoustic beam is reflected at the center of the workpiece bottom surface and received by the phased array ultrasonic probe. In this embodiment, the given liquid is water and the workpiece material is steel.

[0030] The calculation method of the acoustic beam focusing law of the phased array ultrasonic probe array for the convex-convex structure type workpiece is: i As an example, let the first i The coordinates of the center point of the group transmitting aperture are , the coordinates of the incident point of the emitted sound beam on the workpiece interface are , the coordinates of the interface intersection point on the corresponding reflection path are , according to the interface equation of the convex surface, the coordinates of the bottom reflection point are ,in , according to the geometric relationship, the propagation paths of the sound beam in the liquid and the workpiece are calculated as follows: , , then the propagation time of the sound beam in the liquid-workpiece dual medium is: , there is a unique unknown in the formula According to Fermat's principle, the propagation of sound waves in a double-medium curved surface medium follows the principle of shortest time. The derivative of the propagation time is zero, that is, , the horizontal coordinate of the sound beam at the interface intersection can be obtained , the parameters are obtained according to the propagation time formula , so the i The delay time of each element in the group transmit aperture is , the coordinates of the refraction point of the other workpiece-liquid interface are Connect the points one by one. 、 、 、 and Form a sound beam propagation path.

[0031] The parameter design method of the phased array ultrasonic probe array for a convex-convex structure workpiece includes the following contents: (1) Determine the liquid height h :The workpiece length satisfies the relationship The minimum distance between the phased array ultrasonic probe array and the workpiece surface is the liquid height, and the liquid height constraint is ; (2) Select the number of probe elements and the spacing between the elements: According to the characteristics of the workpiece with convex-convex structure, the total width of the phased array ultrasonic probe array does not exceed the width of the workpiece. The total width is determined by the number of elements and the spacing between the elements: , e is the width of a single array element; (3) Determine the probe's transmitting aperture and receiving aperture sequence: According to the transmitting aperture sequence, the center coordinates of the transmitting aperture are As an example, calculate the coordinates of the center of the transmitting aperture x i The value range of When the reflection point on the bottom of the workpiece is below the center of the interface arc, the definition point is the intersection point (tangent point) of the arc and the tangent line when the sound beam is incident, and the sound beam angle is the equation of the line connecting the incident point and the tangent point and x Angle in the positive direction of the axis, angle is the incident normal and x The angle between the positive direction of the axis and the circle is known. The equation of the tangent line passing through the tangent point is: ,in , since the incident point of the sound beam on the workpiece interface cannot exceed the workpiece boundary, , the coordinates of the center of the transmitting aperture can be calculated through geometric relationships x i for: ,in , the position range of the transmit aperture center coordinates is: ; when When the reflection point on the bottom surface of the workpiece is above the center of the interface arc, the sound beam angle The following relationship is satisfied: , and the incident point cannot exceed the boundary of the convex-convex workpiece, that is, , according to the horizontal coordinate of the interface intersection The geometric relationship between the center coordinates of the transmitting aperture and the center coordinates of the transmitting aperture is used to calculate the center coordinates of the transmitting aperture. x i setting range.

[0032] In one embodiment, the incident convex arc radius is given R 1 is 35mm, bottom arc radius R 2 is 35mm, the distance between the centers of the two arcs d 10mm, workpiece width L The length of the workpiece is 70mm S The minimum distance from the center of the phased array ultrasonic probe array to the workpiece surface is designed to be the liquid height. h =25mm. The propagation speed of ultrasonic waves in water c 1 is 1483m / s, the propagation speed in the workpiece c 2 is 5900m / s. In the coordinate system established with the midpoint of the phased array probe as the origin, the coordinates of the reflection point on the bottom surface of the workpiece are F i (0, 105), the coordinates of the center of a certain transmitting aperture I (-16.2, 0) as an example to calculate the propagation path of the sound beam. According to Fermat's principle, the coordinates of the incident point of the sound beam on the workpiece interface are calculated as follows: x 2i ≈-9.7, y 2i ≈26.37; According to the reflection symmetry, the coordinates of the intersection of the reflection interface are Q j1 (9.7, 26.37), connect the points in sequence I (-16.2, 0), Q i1 (-9.7, 26.37), F i (0, 105), Q j1 (9.7, 26.37) and J(16.2, 0), that is, a sound beam propagation path in a convex-convex structure type workpiece is obtained. Select the total number of array elements of the phased array ultrasonic probe array N 64, array element width e 0.5mm, array element spacing p The total width of the probe is 0.6mm D N For the example workpiece shown, the selected phased array ultrasonic probe array meets the conditions of array acoustic beam incidence and reflection for the convex-convex structure.

[0033] B. For workpieces with a concave-concave structure in the area to be measured, the sound beam propagation path is obtained as follows: Figure 4 As shown, the radius of the incident concave arc is also defined as R 1. The radius of the concave arc of the bottom surface is R 2. The distance between the centers of the two circles is d The coordinates of the circle center are and , with the first i As an example, let the first i The coordinates of the center point of the group transmitting aperture are , the coordinates of the incident point of the emitted sound beam on the workpiece interface are , then the interface equation of the concave surface of the workpiece close to the phased array ultrasonic probe array is , the coordinates of the reflection point on the bottom surface of the workpiece are , the central vertical coordinate of the concave bottom is , the propagation path of the sound beam in the liquid and the workpiece is calculated based on the geometric relationship, and the delay time of each aperture can be calculated using the Fermat principle: According to the axisymmetric characteristics of the sound beam in the liquid-workpiece propagation path, it is easy to obtain the coordinates of the refraction points. and , the aperture center coordinates of the receiving array element are , connect the points in sequence 、 、 、 and Form a sound beam propagation path.

[0034] The parameter design method of the phased array ultrasonic probe array for a workpiece with a concave-concave structure includes the following contents: (1) Determine the liquid height h :For the concave-concave structural parameters of the workpiece, the workpiece length can be obtained according to the geometric relationship S for: , in a concave-concave structure workpiece, the minimum distance from the probe to the workpiece surface is , the liquid height also meets the constraints ; (2) Select the number of probe elements and the spacing between the elements: The total width of the phased array ultrasonic probe array is determined by the number of elements and the spacing between the elements, which is the same as the parameter design content of the convex-convex structure type workpiece: ; (3) Determine the probe's transmitting aperture and receiving aperture sequence: at the liquid height h To determine the value, the coordinates of the center of the transmitting aperture For example, to ensure that the array sound beam is reflected on the bottom surface of the workpiece, the aperture center position x i There is an extreme range. Figure 4 As shown, the known reflection focus When the incident refraction point is on the incident arc between the two tangent points, the refracted ultrasonic wave can be focused on the midpoint of the bottom surface of the workpiece. is the intersection point (tangent point) of the arc and the tangent line when the sound beam is incident, and the sound beam angle is the equation of the line connecting the incident point and the tangent point and x Angle between the positive and negative axes, angle is the incident normal and x Angle of positive axis, sound beam angle Take the derivative and the derivative function is 0, , the center position of the transmitting aperture can be obtained x i The limit of x i The range of values, the slope of the tangent line at a point on the circle is , and the incident point cannot exceed the two extreme tangent points, , is the horizontal coordinate of the limit tangent point, that is, , then the transmit aperture center coordinate position range is: .

[0035] In one embodiment, the incident concave arc radius is given R 1 is 35mm, bottom arc radius R 2 is 35mm, the distance between the centers of the two arcs d 10mm, workpiece width L The length of the workpiece is 80mm S The minimum distance from the center of the phased array ultrasonic probe array to the workpiece surface is designed to be the liquid height. h =45mm. In the coordinate system established with the midpoint of the phased array probe as the origin, the coordinates of the reflection point on the bottom surface of the workpiece are F i (0, 85), the coordinates of the center of a certain transmit apertureI (-7.8, 0) as an example to calculate the propagation path of the sound beam. According to Fermat's principle, the coordinates of the incident point of the sound beam on the workpiece interface are calculated as follows: x 2i ≈-19.27, y 2i ≈39.21; According to the reflection symmetry, the coordinates of the intersection of the reflection interface are Q j1 (19.27, 39.21), the center coordinates of the receiving aperture are J (7.8, 0), connect the points in sequence I (-7.8, 0), Q i1 (-19.27, 39.21), F i (0,85), Q j1 (19.27, 39.21) and J (7.8, 0), that is, a sound beam propagation path in a workpiece with a concave-concave structure is obtained. Select the total number of array elements of the phased array ultrasonic probe array N 64, array element width e 0.3mm, array element spacing p The total width of the probe is 0.05mm D N For the example workpiece shown, the selected phased array ultrasonic probe array meets the conditions of array acoustic beam incidence and reflection for the concave-concave structure.

[0036] C. For workpieces with convex-concave structure in the area to be measured, such as Figure 5 As shown, the radius of the incident convex arc is defined as R 1. The radius of the concave arc of the bottom surface is R 2. The distance between the centers of the two circles is d The coordinates of the circle center are and The calculation method of the sound beam propagation path and the parameter design method of the phased array ultrasonic probe array for this type of structure are exactly the same as those for the convex-convex structure type workpiece in part A.

[0037] In one embodiment, the incident convex arc radius is given R 1 is 35mm, bottom arc radius R 2 is 35mm, the distance between the centers of the two arcs d 10mm, workpiece width L The length of the workpiece is 50mm S The minimum distance from the center of the phased array ultrasonic probe array to the workpiece surface is designed to be the liquid height. h=25mm. In the coordinate system established with the midpoint of the phased array probe as the origin, the coordinates of the reflection point on the bottom surface of the workpiece are F i (0, 75), the coordinate range of the transmit and receive aperture center position is calculated to be -60.5231 mm ≤ x i ≤60.5831mm; based on the coordinates of the center of a certain transmitting aperture I Taking (-16.2, 0) as an example, calculate the key points in the sound beam propagation path I (-16.2, 0), Q i1 (-9.4, 26.28), F i (0,75), Q j1 (9.4, 26.28) and J (16.2, 0), that is, a sound beam propagation path in a convex-concave structure type workpiece is obtained. Select the total number of array elements of the phased array ultrasonic probe array N 64, array element width e 0.5mm, array element spacing p The total width of the probe is 0.6mm D N For the example workpiece shown, the selected phased array ultrasonic probe array meets the conditions of array sound beam incidence and reflection for the convex-concave surface structure.

[0038] D. For workpieces with convex-slope structure in the area to be measured, the sound beam propagation path is obtained as follows: Figure 6 As shown, the coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, and the radius of the incident convex arc is R 1. The inclination angle of the bottom slope is , , the inclined plane coordinate equation is y = g ( x ) is expressed as The interface equation of the convex surface of the workpiece close to the phased array ultrasonic probe array is: .

[0039] First i As an example, let the first i The coordinates of the center point of the group transmitting aperture are , the coordinates of the incident point of the emitted sound beam on the workpiece interface are , the coordinates of the interface intersection point on the corresponding reflection path are , the coordinates of the reflection point of the sound beam on the bottom surface are , the propagation path of the array sound beam can be calculated, and the horizontal coordinate of the sound beam at the interface intersection can be obtained according to Fermat's principle x 2i , calculate the delay time of each aperture As the sound wave propagates in the workpiece, it passes through the bottom surface reflection point. Do a mirror reflection and get The equation of the line is: , by calculating The intersection of the straight line and the convex arc gives the coordinates of the refraction point in the sound beam reflection path: ,according to The normal equation of the interface between the straight line and the arc gives the incident angle of the reflected sound beam as According to the law of refraction, the refraction angle of the sound beam reflection path at the interface can be calculated , calculate the center coordinates of the array receiving aperture according to the intersection coordinates and refraction angle of the reflected sound beam at the interface for Connect the points one by one. 、 、 、 and Form a sound beam propagation path.

[0040] The parameter design method of the phased array ultrasonic probe array for a workpiece with a convex-slant structure includes the following contents: (1) Determine the liquid height h :The liquid height also meets the constraints ; (2) Select the number of probe elements and the spacing between the elements: The total width of the phased array ultrasound probe array is determined by the number of elements and the spacing between the elements: ; (3) Determine the probe's transmitting aperture and receiving aperture sequence: the coordinates of the center point of the transmitting aperture and the incident point on the interface Need to meet , refer to the calculation method of the array beam path of the convex-convex structure type in part A, and the coordinates of the center of the transmitting aperture can be calculated x i Then, according to the transmitting aperture sequence position and the sound beam propagation path, the receiving aperture coordinate position and array element sequence are set to ensure that the array aperture can receive the echo signal reflected from the bottom surface of the workpiece.

[0041] In one embodiment, the incident convex arc radius is given R 1 is 35mm, workpiece width L The length of the workpiece is 70mm S The minimum distance from the center of the phased array ultrasonic probe array to the workpiece surface is designed to be the liquid height. h=25mm. First determine the horizontal coordinate of the reflection point on the bottom surface of the workpiece x 3i =17.5, then the vertical coordinate of the reflection point on the bottom surface of the workpiece is y 3i ≈90.37, so the coordinates of the reflection point of the sound beam propagation are F i (17.5, 90.37), with a transmit aperture I Taking (-16.2, 0) as an example, calculate the sound beam propagation path x 2i ≈-5.188, y 2i ≈25.386. According to the mathematical relationship, the coordinates of the intersection point of the reflection interface can be calculated by the simultaneous equations: x 2j ≈4.013, y 2j ≈25.23, so the coordinates of the intersection point of the reflection interface Q j1 (4.013, 25.23), the horizontal coordinate of the center of the receiving array aperture can be calculated according to the mathematical equation x j ≈6.7, that is, we get J (6.7,0). Connect the key points in sequence I (-16.2, 0), Q i1 (-5.188, 25.386), F i (17.5, 90.37), Q j1 (4.013, 25.23) and J (6.7,0), we get a sound beam propagation path in a convex-slope structure type workpiece. The total number of array elements in the phased array ultrasonic probe array N , array element width e , array element spacing p and the total width of the probe D N Please refer to the embodiment in Part A for details.

[0042] E. For workpieces with concave-slope structures in the area to be measured, the sound beam propagation path is obtained as follows: Figure 7 As shown, the coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, assuming that the radius of the incident concave arc is , the coordinates of the circle center are , the inclination angle of the inclined plane is , the inclined plane coordinate equation is y = g ( x ) is expressed as ,in ;The minimum distance from the probe to the workpiece surface is D 0, the equation in the concave arc coordinate system is . i Taking the group of transmitting apertures as an example, the propagation path of the sound beam of the concave-slant structure is calculated. i The coordinates of the center point of the group aperture are , the coordinates of the incident point on the concave interface of the workpiece are , the coordinates of the interface intersection point on the corresponding reflection path are , the coordinates of the reflection point on the bottom surface of the workpiece are As the sound wave propagates in the workpiece, it is reflected by the bottom surface and focused. Do a mirror reflection based on the bottom surface normal, and we get The equation of the line is: ,straight line The intersection line with the incident concave surface is the outgoing refraction point , the coordinates of the refraction point of the reflection path can be calculated similarly to the calculation method of the workpiece of the convex-slope structure type mentioned above and the receiving aperture center coordinates , connect the points in sequence 、 、 、 and Form a sound beam propagation path.

[0043] The parameter design method of the phased array ultrasonic probe array for a workpiece with a concave-inclined structure is exactly the same as the parameter design method of the phased array ultrasonic probe array for a workpiece with a convex-inclined structure.

[0044] In one embodiment, the incident convex arc radius is given R 1 is 35mm, workpiece width L The length of the workpiece is 80mm S The minimum distance from the center of the phased array ultrasonic probe array to the workpiece surface is designed to be the liquid height. h =45mm. First determine the horizontal coordinate of the reflection point on the bottom surface of the workpiece x 3i =0, then the vertical coordinate of the reflection point on the bottom surface of the workpiece is y 3i ≈94.28, so the coordinates of the reflection point of the sound beam propagation are F i (0, 94.28), with a transmit aperture of I Taking (-7.8, 0) as an example, calculate the sound beam propagation path x 2i ≈-21.45, y 2i≈37.65. According to the mathematical relationship, the coordinates of the intersection point of the reflection interface can be calculated by the simultaneous equations: x 2j ≈-5.38, y 2j ≈44.58, so the coordinates of the intersection point of the reflection interface Q j1 (-5.38, 44.58), the horizontal coordinate of the receiving array element aperture center can be calculated according to the mathematical equation x j ≈1.57, that is, we get J (1.57,0). Connect the key points in sequence I (-7.8, 0), Q i1 (-21.45, 37.65), F i (0, 94.28), Q j1 (-5.38, 44.58) and J (1.57,0), a sound beam propagation path in a concave-slope structure type workpiece is obtained. The total number of array elements of the phased array ultrasonic probe array N , array element width e , array element spacing p and the total width of the probe D N Please refer to the embodiment in Part B for configuration.

[0045] S3: Detecting the grain size of the test areas of different structural types of the workpiece according to the sound beam propagation path of the phased array ultrasonic probe array and the phased array ultrasonic detection parameters, and collecting the phased array ultrasonic signal of each test area through the phased array ultrasonic probe array.

[0046] S4: Pre-construct a phased array ultrasonic probe array beam attenuation calibration model for the test areas of different structural types, calibrate the phased array ultrasonic signals collected from each test area, and calculate the average attenuation coefficient of the phased array ultrasonic probe array signal for each test area.

[0047] The phased array ultrasonic probe array sound beam attenuation calibration model of the test area of ​​different structural types is pre-built in step S4, and the phased array ultrasonic signal collected in each test area is calibrated. The longitudinal wave energy transmittance of the sound beam in the liquid-workpiece is calculated based on the incident angle of the sound beam of the phased array ultrasonic probe array. , ,in is the longitudinal wave sound pressure transmittance of the array sound beam in the liquid-workpiece medium, , Z 1 is the acoustic impedance of the liquid, Z2 is the acoustic impedance of the workpiece; according to the incident angle of the sound beam of the phased array ultrasonic probe array on the bottom surface of the workpiece, the reflectivity of the sound beam on the bottom surface of the workpiece is calculated. , , , is the refraction angle of the sound beam at the bottom surface of the workpiece; let the sound beam signal collected by the phased array ultrasonic probe array be P j , then the calibrated beam signal The sound beam signal P j , divided by the longitudinal wave energy transmittance Reflectivity The product of .

[0048] In one embodiment, the calculation of the average attenuation coefficient of the phased array ultrasonic probe array signal of each test area in step S4 is to make the phased array ultrasonic probe array collect J The sound beam signal after group calibration , obtain the attenuation coefficient of the sound beam signal after each group of sound beam calibration, and obtain the attenuation coefficient by accumulating and averaging J The average attenuation coefficient of the calibrated beam signal. The attenuation coefficient is ,in is the amplitude of the echo signal from the workpiece interface, is the amplitude of the bottom surface reflected echo signal; J The average attenuation coefficient of the acoustic beam signal after group calibration is .

[0049] S5: Substituting the average attenuation coefficient of the phased array ultrasonic probe array signal of each area to be measured into a pre-built grain size phased array ultrasonic evaluation model to calculate the grain size of the area to be measured.

[0050] The pre-built phased array ultrasonic evaluation model for grain size specifically includes: using the same material as the workpiece with multiple curved surfaces to be tested, such as Figure 8 As shown in (a), (b), (c), (d) and (e), comparative test blocks of convex-convex structure type, concave-concave structure type, convex-concave structure type, convex-inclined structure type and concave-inclined structure type were designed and manufactured respectively. n By different heating temperature treatment n Comparison test blocks were obtained n Comparison test pieces with different grain sizes; obtained by metallographic testing n The actual grain sizes of the comparison specimens are ;According to the content of steps S1-S4n The acoustic beam signal collected by the phased array ultrasonic probe array of the comparison test block is used to obtain the average attenuation coefficient of the calibrated acoustic beam signal , the grain size phased array ultrasonic evaluation model is defined as ,in f is the frequency of the ultrasound probe, K is the function coefficient.

[0051] According to Rayleigh scattering theory, when the grain size is much smaller than the ultrasonic wave length, the ultrasonic attenuation coefficient has the following relationship with the material grain size: Therefore, the present invention defines a grain size phased array ultrasonic evaluation model and introduces the function coefficient K . After getting the function coefficients K Then, the actual grain size of the workpiece to be measured can be obtained according to the average attenuation coefficient of the sound beam signal obtained in step S4 and the frequency of the ultrasonic probe.

[0052] In another aspect, the present invention provides a phased array ultrasonic nondestructive evaluation system for grain size of complex components, for implementing the method, comprising: The test area classification module divides the test areas into different structural types according to the shape characteristics of the workpiece to be tested; The acoustic beam focusing law and acoustic beam propagation path module is used to design the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array, and design the phased array ultrasonic testing parameters for the test area of ​​different structural types according to the size parameters of the workpiece; The phased array ultrasonic probe array is configured with multiple array elements according to the phased array ultrasonic testing parameters. The acoustic beam is incident on the upper surface interface of the workpiece through the transmitting aperture, and then propagates to the bottom surface of the workpiece. After the acoustic beam is reflected by the center point of the bottom surface, it is again collected through the receiving aperture of the phased array ultrasonic probe array in each area to be tested. The acoustic beam attenuation calibration model construction module is used to construct the phased array ultrasonic probe array acoustic beam attenuation calibration model of the test area with different structural types, calibrate the phased array ultrasonic signals collected from each test area, and obtain the average attenuation coefficient of the phased array ultrasonic probe array signal of each test area; The grain size phased array ultrasonic evaluation model construction module calculates the grain size of the test area based on the average attenuation coefficient of the phased array ultrasonic probe array signal in each test area.

[0053] In a third aspect, the present invention further provides a computer storage medium storing a computer program, which, when executed by a processor, implements the aforementioned phased array ultrasonic nondestructive evaluation method for grain size of a complex component.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A phased array ultrasonic nondestructive evaluation method for grain size of complex components, characterized by: The steps include: S1: Use liquid immersion combined with a phased array ultrasonic probe array to detect workpieces with multiple curved surfaces, and divide the test areas into different structural types based on the shape characteristics of the workpiece; S2: Construct phased array ultrasonic testing models corresponding to the test areas of different structural types. By designing the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array, the acoustic beam is incident from the upper surface of the workpiece, reflected from the bottom surface of the workpiece, and then received by the phased array ultrasonic probe array. Based on the dimensional parameters of the workpiece, phased array ultrasonic testing parameters are designed for the test areas of different structural types. S3: detecting grain sizes of test areas of different structural types of the workpiece according to the acoustic beam propagation path of the phased array ultrasonic probe array and the phased array ultrasonic testing parameters, and collecting phased array ultrasonic signals of each test area through the phased array ultrasonic probe array; S4: Pre-constructing a phased array ultrasonic probe array beam attenuation calibration model for different structural types of test areas, calibrating the phased array ultrasonic signals collected from each test area, and calculating the average attenuation coefficient of the phased array ultrasonic probe array signal for each test area; S5: Substituting the average attenuation coefficient of the phased array ultrasonic probe array signal of each area to be measured into a pre-built grain size phased array ultrasonic evaluation model to calculate the grain size of the area to be measured.

2. The method for nondestructive evaluation of grain size of complex components by phased array ultrasonic testing according to claim 1, characterized in that: The division of the test areas of different structural types according to the shape characteristics of the workpiece described in step S1 is to divide the shape characteristics of the workpiece into test areas of convex-convex structure type, concave-concave structure type, convex-concave structure type, convex-inclined structure type and concave-inclined structure type according to the shapes of the top and bottom surfaces of the workpiece.

3. The method for nondestructive evaluation of grain size of complex components by phased array ultrasonic testing according to claim 2, characterized in that: The step S2 of designing the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array specifically comprises: allowing the acoustic beam of the transmitting aperture of the phased array ultrasonic probe array to be incident on the upper surface interface of the workpiece, then propagating to the bottom surface of the workpiece, and after the acoustic beam is reflected by the center point of the bottom surface, the signal is collected through the receiving aperture of the phased array ultrasonic probe array; For workpieces with convex-convex and convex-concave structures in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, the arc radius of the incident convex surface, the arc radius of the bottom surface, and the distance between the centers of the two arcs are defined, and the interface equation of the convex surface of the workpiece close to the phased array ultrasonic probe array is constructed; the acoustic beam focusing law is: given the first i The center point coordinates of the group transmitting aperture are obtained i The coordinates of the incident point of the sound beam emitted by the group transmitting aperture on the workpiece interface and the coordinates of the interface intersection point on the reflection path are used to calculate the propagation path of the sound beam in the liquid and convex-convex structure type workpiece; For workpieces with a concave-concave structure, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin. The arc radius of the incident concave surface, the arc radius of the bottom surface, and the center distance of the two arcs are defined. The interface equation of the concave surface of the workpiece close to the phased array ultrasonic probe array is constructed. Referring to the beam focusing law of the convex-convex structure type, the first i The coordinates of the center point of the group transmitting aperture are obtained. i The propagation path of the acoustic beam emitted by the group emitting aperture in the liquid and the concave-concave structure workpiece; For workpieces with convex-slope and concave-slope structures in the area to be measured, a coordinate system is established with the midpoint of the phased array ultrasonic probe array as the origin, and the bottom slope coordinate system equation is obtained; the beam focusing law is: given the i The center point coordinates of the group transmitting aperture are obtained. i The coordinates of the incident point of the acoustic beam of the group transmitting aperture on the workpiece interface, the coordinates of the interface intersection point corresponding to the reflection path, the coordinates of the reflection point of the acoustic beam on the inclined surface of the workpiece and the center coordinates of the array receiving aperture are obtained. i The propagation path of the sound beam emitted by the group transmitting aperture in the convex-concave structure type.

4. The method for nondestructive evaluation of grain size of complex components by phased array ultrasonic testing according to claim 3, characterized in that: According to the size parameters of the workpiece, the phased array ultrasonic testing parameters are designed for the test area of ​​different structural types in step S2. Specifically, the parameters are as follows: L and length S , defines the height of the liquid through which the ultrasonic wave is transmitted h , the number of array elements in the phased array ultrasound probe N , array element spacing p and total width D N , determine the transmit aperture and receive aperture sequence of the phased array ultrasonic probe array.

5. The method for nondestructive evaluation of grain size of complex components by phased array ultrasonic testing according to claim 4, characterized in that: The specific content of determining the transmit aperture and receive aperture sequence of the phased array ultrasonic probe array is: determining the array element aperture and the number of array elements of the phased array ultrasonic probe array as B , the array aperture electronic scanning step is step , the sequence of the transmitting aperture of the phased array ultrasonic probe array is ( N - B ) / step , find the incident point on the coordinate interface of the center point of the transmitting aperture, and obtain the coordinate position range of the center point of the transmitting aperture; then, according to the sequence position of the transmitting aperture and the propagation path of the sound beam, set the coordinate position of the receiving aperture and the sequence of the receiving aperture so that the receiving aperture receives the echo signal reflected from the bottom surface of the workpiece.

6. The method for nondestructive evaluation of grain size of complex components using phased array ultrasonic technology according to claim 4, characterized in that: The phased array ultrasonic probe array sound beam attenuation calibration model of the test area of ​​different structural types is pre-built in step S4, and the phased array ultrasonic signal collected in each test area is calibrated. The longitudinal wave energy transmittance of the sound beam in the liquid-workpiece is calculated based on the incident angle of the sound beam of the phased array ultrasonic probe array. ; According to the incident angle of the sound beam of the phased array ultrasonic probe array on the bottom surface of the workpiece, calculate the reflectivity of the sound beam on the bottom surface of the workpiece ; Let the acoustic beam signal collected by the phased array ultrasonic probe array be P j , then the calibrated beam signal The sound beam signal P j , divided by the longitudinal wave energy transmittance Reflectivity The product of .

7. The method for nondestructive evaluation of grain size of complex components using phased array ultrasonic technology according to claim 6, characterized in that: The calculation of the average attenuation coefficient of the phased array ultrasonic probe array signal of each test area in step S4 is to make the phased array ultrasonic probe array collect J The attenuation coefficient of each group of calibrated sound beam signals is obtained by accumulating the attenuation coefficients and averaging them. J The average attenuation coefficient of the calibrated beam signal.

8. The method for nondestructive evaluation of grain size of complex components using phased array ultrasonic technology according to claim 7, characterized in that: The pre-built phased array ultrasonic evaluation model for grain size described in step S5 specifically includes: using the same material as the workpiece with multiple curved surfaces to be tested, respectively designing and manufacturing comparative test blocks of convex-convex structure type, concave-concave structure type, convex-concave structure type, convex-inclined structure type, and concave-inclined structure type. n By different heating temperature treatment n Comparison test blocks were obtained n Comparison test pieces with different grain sizes; obtained by metallographic testing n The actual grain sizes of the comparison specimens are ;According to the content of steps S1-S4 n The acoustic beam signal collected by the phased array ultrasonic probe array of the comparison test block is used to obtain the average attenuation coefficient of the calibrated acoustic beam signal , the grain size phased array ultrasonic evaluation model is defined as ,in f is the frequency of the ultrasound probe, K is the function coefficient.

9. A phased array ultrasonic nondestructive evaluation system for grain size of complex components, used to implement the method according to any one of claims 1 to 8, characterized in that: include: The test area classification module divides the test areas into different structural types according to the shape characteristics of the workpiece to be tested; The acoustic beam focusing law and acoustic beam propagation path module is used to design the acoustic beam focusing law and acoustic beam propagation path of the phased array ultrasonic probe array, and design the phased array ultrasonic testing parameters for the test area of ​​different structural types according to the size parameters of the workpiece; The phased array ultrasonic probe array is configured with multiple array elements according to the phased array ultrasonic testing parameters. The acoustic beam is incident on the upper surface interface of the workpiece through the transmitting aperture, and then propagates to the bottom surface of the workpiece. After the acoustic beam is reflected by the center point of the bottom surface, it is again collected through the receiving aperture of the phased array ultrasonic probe array in each area to be tested. The acoustic beam attenuation calibration model construction module is used to construct the phased array ultrasonic probe array acoustic beam attenuation calibration model of the test area with different structural types, calibrate the phased array ultrasonic signals collected from each test area, and obtain the average attenuation coefficient of the phased array ultrasonic probe array signal of each test area; The grain size phased array ultrasonic evaluation model construction module calculates the grain size of the test area based on the average attenuation coefficient of the phased array ultrasonic probe array signal in each test area.

10. A computer storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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