CN105865675B - It is a kind of to correct the ultrasonic wave residual stress test method that phasor differentia influence is precipitated - Google Patents

Abstract

The invention proposes an ultrasonic residual stress testing method capable of correcting the influence of precipitation phasor difference, which belongs to the field of non-destructive testing of welding residual stress. The test method is to firstly establish a relationship database between the precipitation phasor and the attenuation degree of the longitudinal wave signal, the propagation time of the critical refracted longitudinal wave in the zero stress sample, and the acoustoelastic coefficient; when performing the residual stress test, first determine the longitudinal wave signal in the test area The degree of attenuation, and then determine the calculated value of the precipitated phasor according to the degree of attenuation, and further calculate the propagation time and acoustoelastic coefficient of the critical refracted longitudinal wave in the test area in the zero-stress tensile sample, and finally the corrected residual stress can be obtained. The test method can correct the error caused by the precipitation of phasors in different regions of the welding relative to the acoustic elastic coefficient and the propagation time of the ultrasonic wave in the zero stress sample, and can significantly improve the accuracy of the residual stress measured by the ultrasonic wave.

Description

An Ultrasonic Residual Stress Test Method That Can Correct the Effect of Precipitation Phasor Difference

technical field

The invention relates to an ultrasonic residual stress testing method capable of correcting the influence of precipitation phasor difference, and belongs to the field of non-destructive testing of welding residual stress.

Background technique

Welding is the most important connection method in industrial production. The quality of welding determines the quality of welding products. The damage of welded joints caused by excessive welding residual stress is the most important welding damage. The non-destructive testing of residual stress of welded joints plays a very important guiding role in optimizing the welding process in production practice. The non-destructive testing methods for residual stress mainly include neutron diffraction method, synchrotron radiation method, magnetic particle method, X-ray diffraction method and ultrasonic testing method. Among them, the neutron diffraction method and the synchrotron radiation method are expensive in equipment and high in test cost, and are difficult to be used for online detection of welding residual stress in production practice; the magnetic particle method residual stress test can only be used for magnetic measurement testing, and the repeatability is poor; X-ray The test of residual stress can only test the thickness of tens of microns, the surface quality of the sample to be tested is relatively high, and it is greatly affected by the quality state of the surface. Ultrasonic method is the fastest-growing nondestructive testing method for residual stress in recent years. It has the advantages of being able to test two-dimensional welding residual stress in the depth direction, fast testing speed, no radiation, portable equipment, and low cost.

The measurement of residual stress by ultrasonic method is an indirect measurement. The residual stress basically exhibits a linear relationship. According to the principle of acoustoelasticity, if the distance between the ultrasonic transmitting and receiving transducers is fixed, the measured propagation time t ₀ of the ultrasonic wave in the zero stress sample (the stress is denoted as σ ₀ ) and the ultrasonic propagation time t of the ultrasonic wave in the sample to be tested, according to the acoustic time difference The residual stress value σ of the sample to be tested can be obtained, namely: σ-σ ₀ =A(t-t ₀ ), A is determined by the properties of the material itself and the distance between the sending and receiving probes, and is calibrated by unidirectional tension.

However, not only the residual stress in the sample to be tested will affect the propagation speed of ultrasonic waves, but also the microstructure in the sample to be tested will also affect the propagation speed of ultrasonic waves. Due to the different welding temperature fields, the weld zone (FZ), heat-affected zone (HAZ) and base metal zone (BM) will be formed on the weldment, and the microstructures of these zones are quite different. The influence of some large microstructure differences on the ultrasonic propagation velocity is even in the same order of magnitude as that of the welding residual stress on the ultrasonic propagation velocity, which seriously affects the test accuracy of the ultrasonic residual stress test method and limits the development of the ultrasonic residual stress test method. Therefore, how to separate the influence of microstructure on the ultrasonic propagation velocity from the influence of residual stress on the ultrasonic propagation velocity in the ultrasonic residual stress test method is an urgent problem to be solved.

Contents of the invention

The purpose of the present invention is to provide an ultrasonic residual stress testing method capable of correcting the influence of precipitation phasor differences, which can correct the acoustic elastic coefficient k of the precipitation phasor in the weld zone, heat-affected zone, and base metal zone. The huge error generated by the propagation time t ₀ in the sample can significantly improve the testing accuracy of the ultrasonic wave for the residual stress of the welded joint.

The technical scheme adopted by the present invention to realize the purpose of the invention is: a kind of ultrasonic residual stress testing method that can correct the influence of precipitation phasor difference, and its steps are as follows:

A. Prepare the precipitated phase test sample

A1. Cut out w groups of tensile samples parallel to the rolling or extrusion direction of the material, denoted as W ₁ group, W ₂ group...W _w-1 group, W _w group, each group of tensile samples includes the same tensile sample r _b ;

A2. Do not do any treatment on the stretched samples of group W ₁ , and perform heat treatment under different conditions on the stretched samples of group W ₂ -W _w . The heat treatment conditions for the stretched samples in the same group are the same. The specific heat treatment conditions are: W ₂ group drawn Stretch samples at temperature T _b ℃ for h _b hours, W ₃ groups of stretched samples at temperature T _b °C for h _b +Δh _b hours... W _w-1 group of tensile samples at temperature T _b °C for h _b +Δh _b (w-1-2) hours, W _w group tensile samples at temperature T _b ℃ holding time h _b +Δh _b (w-2) hours, that is to get W ₁ -W _w group precipitation phase test samples , where Δh _b is the number of hours of the difference in holding time between two adjacent tensile samples; among them, the W ₂ -W _w group precipitated phase test sample has been heat-treated and can be considered as a zero-stress state;

A3. Perform metallographic treatment on the precipitated phase test samples of W ₁ -W _w group, and calculate the precipitated phase amount of all precipitated phase test samples in each group of W ₁ -W _w group after metallographic treatment through microscope or electron backscatter diffraction , and take the average value of the precipitated phases of all the precipitated phase test samples in each group of the W ₁ -W _w group, respectively denoted as P ₁ , P ₂ , P ₃ ... P _w-1 , P _w ;

B. Establish a relational database between precipitation phasor and longitudinal wave signal attenuation

B1. Use the longitudinal wave flat probe to test the attenuation of all precipitate phase test samples in each group of W ₁ -W _w group respectively, and calculate the average value of the attenuation degree of longitudinal wave signals of all precipitate phase test samples in each group of W ₁ -W _w group , recorded as m ₁ , m ₂ , m ₃ ... m _w-1 , m _w ;

B2. According to the average value of the attenuation degree of the longitudinal wave signal (m ₂ , m ₃ ... m _w-1 , m _w ) of each group of W ₂ -W _w group precipitation phase test samples, and the precipitation of each group of W ₂ -W _w group The average value of the precipitated phase of the phase test sample (P ₂ , P ₃ ... P _w-1 , P _w ), using the least square method to establish a relational database between the precipitated phase P and the attenuation degree M of the longitudinal wave signal, P=g(M ); the average value _m of the longitudinal wave signal attenuation of all precipitated phase test samples in the _W1 group is brought into P=g(M), and the calculated value _P1 ' of the precipitated phase test sample in the _W1 group of precipitated phase test samples is calculated; the _W1 The calculated value P ₁ ' of the precipitated phase test sample in group W ₁ is compared with the average value P ₁ of the precipitated phase test sample in group W 1 obtained in A3. If the error is within γ ₁ %, it meets the requirements, and the established The relationship database P=g(M) between the precipitated phase quantity P and the longitudinal wave signal attenuation degree M is valid; if the error is greater than γ ₁ %, prepare the precipitated phase test sample again according to A1-A3, and establish the precipitated phase quantity P according to B1-B2 Relational database with the attenuation degree M of the longitudinal wave signal until the error requirements are met;

C. Establish a relational database between the precipitated phasor and the travel time of the critically refracted longitudinal wave in the zero-stress sample

C1. Collect the critical refraction longitudinal wave velocity of all precipitated phase test samples in each group of W ₁ -W _w group respectively, and obtain the average propagation velocity of the critical refracted longitudinal wave in each precipitated phase test sample of W ₁ -W _w group, denoted as v ₁₀ , v ₂₀ , v ₃₀ ...... v _(w-1)0 , v _w0 , and according to the distance L between the ultrasonic transceiver transducers, calculate the critical refracted longitudinal wave in each group of W ₁ -W _w group precipitated phase test The average propagation time of the sample is the average propagation time of the critical refraction longitudinal wave in the zero-stress precipitated phase test sample with different precipitated phases, denoted as t ₁₀ , t ₂₀ , t ₃₀ ... t _(w-1)0 , t _w0 ;

C2. According to the critical refracted longitudinal wave in the W ₂ -W _w group, the average propagation time (t ₂₀ , t ₃₀ ... t _(w-1)0 , t _w0 ) of the precipitated phase test samples in each group, and the W ₂ -W _w group The average value of precipitated phases of each group of precipitated phase test samples (P ₂ , P ₃ ... P _w-1 , P _w ), using the least square method to establish the precipitated phase amount P and the critical refracted longitudinal wave travel time t in the zero stress sample ₀ relational database, t ₀ =χ(P); put the average value P ₁ of the amount of precipitates of all precipitates in group W ₁ into t ₀ =χ(P), and calculate the critical refracted longitudinal wave in the precipitates of group W ₁ The calculated travel time t ₁₀ ' of the test sample; the calculated value t ₁₀ ' of the travel time of the critical refracted longitudinal wave in the W ₁ precipitated phase test sample and the actual average travel time t ₁₀ of the critical refracted longitudinal wave in the W ₁ precipitated phase test sample For comparison, if the error is within γ ₂ %, it meets the requirements, and the relationship database t ₀ =χ(P) established between the precipitated phase quantity P and the critical refraction longitudinal wave propagation time t ₀ in the zero stress sample is valid; if the error is greater than γ ₂ %, prepare the precipitated phase test sample again according to A1-A3, and establish the relationship database between the precipitated phase amount P and the critical refracted longitudinal wave propagation time _t0 in the zero stress sample according to C1-C2, until the error requirements are met;

D. Establish a relational database of precipitation phasors and acoustoelastic coefficients

D1. Carry out tensile calibration of the acoustoelastic coefficients of all the precipitated phase test samples in each group of W ₁ -W _w group respectively, and obtain the average acoustoelastic coefficient of the precipitated phase test samples in each group of W ₁ -W _w group, denoted as k ₁ , k ₂ , k ₃ ...k _w-1 , k _w ;

D2. According to the average acoustoelastic coefficient (k ₂ , k ₃ ...k _w-1 , k _w ) of the precipitated phase test samples of each group in the W ₂ -W _w group, compared with the precipitated phase test samples of each group in the W ₂ -W _w group The average value of the precipitated phase (P ₂ , P ₃ ... P _w-1 , P _w ), use the least square method to establish the relationship database between the precipitated phase P and the acoustic elastic coefficient k, k=β(P), and W The average value P _of the precipitated phase amount of all the precipitated phase test samples in the ₁ group is brought into k=β(P), and the calculated value k ₁ ' of the acoustic elastic coefficient of the precipitated phase test sample in the W ₁ group is calculated, and the precipitated phase test sample in the W ₁ group is Comparing the calculated value of the acoustoelastic coefficient k ₁ ' with the actual average acoustoelastic coefficient k ₁ of the W ₁ group of precipitated phase test samples, if the error is within γ ₃ % and meets the requirements, the established precipitated phase quantity P and the acoustoelastic coefficient The relational database k=β(P) of k is valid; if the error is greater than γ ₃ %, prepare the precipitated phase test sample again according to A1-A3, and establish the relational database between the precipitated phase quantity P and the acoustoelastic coefficient k according to D1-D2, until Meet the error requirements;

E. Test the welding residual stress of the welded joint of the weldment to be tested

E1. Arranging the ultrasonic residual stress test area of the weldment to be tested, the test area includes the weld area, heat-affected area and base metal area;

E2. Use the longitudinal wave flat probe to test the attenuation degree of the test area of the weldment to be tested, and calculate the attenuation degree of the longitudinal wave signal in the test area, which is recorded as M _c ;

E3. Call the relationship between the precipitated phasor P established in step B and the attenuation degree M of the longitudinal wave signal, P=g(M), and calculate the calculated value of the precipitated phasor P _c in the test area, P _c =g(M _c );

E4. Call the relationship between the precipitated phase P and the critical refraction longitudinal wave in the zero stress sample in the zero stress sample by calling the precipitation phase _P established in step C, t ₀ =χ(P), calculate the critical refraction longitudinal wave in the test area in the zero stress tensile sample Propagation time t _c0 , t _c0 =χ(P _c );

E5. Call the relationship between the precipitation phase P and the acoustoelastic coefficient k established in step D, k=β(P), and calculate the acoustoelastic coefficient k _c of the test area, k _c =β(P _c );

E6. Collect the critical refracted longitudinal wave velocity v _c of the test area of the weldment to be tested, and obtain the propagation time of the critical refracted longitudinal wave in the test area t _c = L/v _c according to the distance L between the ultrasonic transceiver transducers;

E7, the propagation time t _c0 of the critical refraction longitudinal wave in the test area obtained in step E4 in the zero stress tensile sample, the acoustoelastic coefficient k _c of the test area obtained in step E5 and the propagation of the critical refraction longitudinal wave in the test area obtained in step E6 Time t _c , calculate the welding residual stress σ _c in the test area of the weldment to be tested:

Compared with prior art, the beneficial effect of the present invention is:

The precipitated phasor is an important microscopic property of the material, which has a great influence on the acoustoelastic coefficient of the material and the propagation time of the critically refracted longitudinal wave in the zero stress sample of the material. The present invention establishes the relationship database P=g(M) between the precipitation phasor and the attenuation degree of the longitudinal wave signal, the relationship database t ₀ =χ(P) and the precipitation phasor and the critical refraction longitudinal wave propagation time in the zero stress sample The relationship database k=β(P) with the acoustoelastic coefficient, thereby eliminating the influence of the precipitated phasor on the acoustoelastic coefficient k and the initial propagation time t ₀ of the critical refracted longitudinal wave, and significantly improving the testing accuracy of the ultrasonic wave on the residual stress of the welded joint.

Further, in the step A1 of the present invention, the number w of groups w of tensile samples cut in parallel to the rolling or extrusion direction of the material is not less than 4.

If the number of tensile sample groups is less than 4, the amount of data is small, and it is easily affected by accidental errors. The higher the number of tensile sample groups w, the easier it is to reduce the influence of accidental errors.

Further, in the step A1 of the present invention, a group w of stretched samples is cut parallel to the rolling or extrusion direction of the material, and the number r _b of stretched samples included in each group of stretched samples is not less than 3.

The experimental results of each group of stretched samples will eventually be calculated as the average value. The amount of data less than 3 is also easily affected by accidental errors. The amount of stretched samples greater than 3 can remove samples with large discreteness, while ensuring that the remaining data amount is relatively sufficient. .

Further, in the step A2 of the present invention, the W ₂ -W _w group tensile samples are subjected to heat treatment under different conditions, and the holding temperature T _b ℃ _of the W ₂ group tensile samples in the temperature T b ℃ for h _b hours is the tested tensile sample The phase change temperature of the sample is 120-250°C, for example, the phase change temperature of aluminum alloy.

Keeping temperature higher than or equal to the change temperature of the precipitated phase can ensure the rapid change of the precipitated phase and improve the efficiency of the experiment.

Further, in step A2 of the present invention, heat treatment is performed on the stretched samples of group W ₂ -W _w under different conditions, and the number of hours of heat preservation of the stretched samples of group W ₂ at temperature T _b ℃ for h _b hours during the heat preservation time h _b hours h _b is the time that can ensure the difference in the amount of precipitated phases of 5-15% between the drawn sample of group W ₂ and the drawn sample without heat treatment, for example, about 2h for aluminum alloy.

Through experiments, 5-15% difference in precipitated phasors can reduce the late database error.

Further, in the step A2 of the present invention, the number of hours Δh _b of the difference in holding time between two adjacent stretched samples is as long as it can ensure that there is a 10-30% difference in precipitated phases between two adjacent stretched samples, Such as aluminum alloy is about 2h.

If the difference in precipitated phase between adjacent stretched samples is too small, the test results of the experiment may be covered by accidental factors, and a higher precipitated phase difference of 10-30% is enough to avoid the influence of accidental factors on the experimental results.

Further, in the step B2 of the present invention, it is verified whether the relational database P=g(M) between the precipitated phasor P and the attenuation degree of the longitudinal wave signal M is valid, and the error value γ ₁ % set is 5-10%.

P=g(M) The relational database will be used for the correction of the ultrasonic stress test in the later stage. If there is a large error in the relational database, the reliability of the correction effect will be reduced, and the relatively small error of 5-10% will not reduce the correction result. reliability.

Further, in the step C2 of the present invention, it is verified whether the relationship database t ₀ =χ(P) between the precipitated phasor P and the critical refraction longitudinal wave propagation time t ₀ in the zero stress sample is valid, and the error value γ ₂ % set is 5-10 %.

t ₀ ＝χ(P) The relational database will be used for the correction of the ultrasonic stress test in the later stage. If there is a large error in the relational database, the reliability of the correction effect will be reduced, and a relatively small error of 5-10% will not reduce the correction result reliability.

Further, in the step D2 of the present invention, it is verified whether the relational database k=β(P) between the precipitated phase quantity P and the acoustoelastic coefficient k is valid, and the error value γ ₃ % is set to be 5-15%.

k=β(P) The relational database will be used for the correction of the ultrasonic stress test in the later stage. If there is a large error in the relational database, the reliability of the correction effect will be reduced, and the relatively small error of 5-15% will not reduce the reliability of the correction result. reliability.

Description of drawings

Fig. 1 is the distribution schematic diagram of the test area in the verification test of the embodiment of the present invention

Fig. 2 is a comparison chart of the test results of the verification test of the first embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Embodiment one

A specific embodiment of the present invention is: an ultrasonic residual stress testing method capable of correcting the influence of precipitation phasor differences, the steps of which are as follows:

A. Prepare the precipitated phase test sample

A1. Cut out w groups of tensile samples parallel to the rolling or extrusion direction of the material, denoted as W ₁ group, W ₂ group...W _w-1 group, W _w group, each group of tensile samples includes the same tensile sample r _b ;

A2. Do not do any treatment on the stretched samples of group W ₁ , and perform heat treatment under different conditions on the stretched samples of group W ₂ -W _w . The heat treatment conditions for the stretched samples in the same group are the same. The specific heat treatment conditions are: W ₂ group drawn Stretch samples at temperature T _b ℃ for h _b hours, W ₃ groups of stretched samples at temperature T _b °C for h _b +Δh _b hours... W _w-1 group of tensile samples at temperature T _b °C for h _b +Δh _b (w-1-2) hours, W _w group tensile samples at temperature T _b ℃ holding time h _b +Δh _b (w-2) hours, that is to get W ₁ -W _w group precipitation phase test samples , where Δh _b is the number of hours of the difference in holding time between two adjacent tensile samples; among them, the W ₂ -W _w group precipitated phase test sample has been heat-treated and can be considered as a zero-stress state;

A3. Perform metallographic treatment on the precipitated phase test samples of W ₁ -W _w group, and calculate the precipitated phase amount of all precipitated phase test samples in each group of W ₁ -W _w group after metallographic treatment through microscope or electron backscatter diffraction , and take the average value of the precipitated phases of all the precipitated phase test samples in each group of the W ₁ -W _w group, respectively denoted as P ₁ , P ₂ , P ₃ ... P _w-1 , P _w ;

B. Establish a relational database between precipitation phasor and longitudinal wave signal attenuation

B1. Use the longitudinal wave flat probe to test the attenuation of all precipitate phase test samples in each group of W ₁ -W _w group respectively, and calculate the average value of the attenuation degree of longitudinal wave signals of all precipitate phase test samples in each group of W ₁ -W _w group , recorded as m ₁ , m ₂ , m ₃ ... m _w-1 , m _w ;

B2. According to the average value of the attenuation degree of the longitudinal wave signal (m ₂ , m ₃ ... m _w-1 , m _w ) of each group of W ₂ -W _w group precipitation phase test samples, and the precipitation of each group of W ₂ -W _w group The average value of the precipitated phase of the phase test sample (P ₂ , P ₃ ... P _w-1 , P _w ), using the least square method to establish a relational database between the precipitated phase P and the attenuation degree M of the longitudinal wave signal, P=g(M ); the average value m _of the longitudinal wave signal attenuation of all precipitated phase test samples in the _W1 group is brought into P=g(M), and the calculated value _P1 ' of the precipitated phase test sample in the _W1 group of precipitated phase test samples is calculated; the _W1 The calculated value P ₁ ' of the precipitated phase test sample in group W ₁ is compared with the average value P ₁ of the precipitated phase test sample in group W 1 obtained in A3. If the error is within γ ₁ %, it meets the requirements, and the established The relationship database P=g(M) between the precipitated phase quantity P and the longitudinal wave signal attenuation degree M is valid; if the error is greater than γ ₁ %, prepare the precipitated phase test sample again according to A1-A3, and establish the precipitated phase quantity P according to B1-B2 Relational database with the attenuation degree M of the longitudinal wave signal until the error requirements are met;

C. Establish a relational database between the precipitated phasor and the travel time of the critically refracted longitudinal wave in the zero-stress sample

C1. Collect the critical refraction longitudinal wave velocity of all precipitated phase test samples in each group of W ₁ -W _w group respectively, and obtain the average propagation velocity of the critical refracted longitudinal wave in each precipitated phase test sample of W ₁ -W _w group, denoted as v ₁₀ , v ₂₀ , v ₃₀ ...... v _(w-1)0 , v _w0 , and according to the distance L between the ultrasonic transceiver transducers, calculate the critical refracted longitudinal wave in each group of W ₁ -W _w group precipitated phase test The average propagation time of the sample is the average propagation time of the critical refraction longitudinal wave in the zero-stress precipitated phase test sample with different precipitated phases, denoted as t ₁₀ , t ₂₀ , t ₃₀ ... t _(w-1)0 , t _w0 ;

C2. According to the critical refracted longitudinal wave in the W ₂ -W _w group, the average propagation time (t ₂₀ , t ₃₀ ... t _(w-1)0 , t _w0 ) of the precipitated phase test samples in each group, and the W ₂ -W _w group The average value of precipitated phases of each group of precipitated phase test samples (P ₂ , P ₃ ... P _w-1 , P _w ), using the least square method to establish the precipitated phase amount P and the critical refracted longitudinal wave travel time t in the zero stress sample ₀ relational database, t ₀ =χ(P); put the average value P ₁ of the amount of precipitates of all precipitates in group W ₁ into t ₀ =χ(P), and calculate the critical refracted longitudinal wave in the precipitates of group W ₁ The calculated travel time t ₁₀ ' of the test sample; the calculated value t ₁₀ ' of the travel time of the critical refracted longitudinal wave in the W ₁ precipitated phase test sample and the actual average travel time t ₁₀ of the critical refracted longitudinal wave in the W ₁ precipitated phase test sample For comparison, if the error is within γ ₂ %, it meets the requirements, and the relationship database t ₀ =χ(P) established between the precipitated phase quantity P and the critical refraction longitudinal wave propagation time t ₀ in the zero stress sample is valid; if the error is greater than γ ₂ %, prepare the precipitated phase test sample again according to A1-A3, and establish the relationship database between the precipitated phase amount P and the critical refracted longitudinal wave propagation time _t0 in the zero stress sample according to C1-C2, until the error requirements are met;

D. Establish a relational database of precipitation phasors and acoustoelastic coefficients

D1. Carry out tensile calibration of the acoustoelastic coefficients of all the precipitated phase test samples in each group of W ₁ -W _w group respectively, and obtain the average acoustoelastic coefficient of the precipitated phase test samples in each group of W ₁ -W _w group, denoted as k ₁ , k ₂ , k ₃ ...k _w-1 , k _w ;

D2. According to the average acoustoelastic coefficient (k ₂ , k ₃ ...k _w-1 , k _w ) of the precipitated phase test samples of each group in the W ₂ -W _w group, compared with the precipitated phase test samples of each group in the W ₂ -W _w group The average value of the precipitated phase (P ₂ , P ₃ ... P _w-1 , P _w ), use the least square method to establish the relationship database between the precipitated phase P and the acoustic elastic coefficient k, k=β(P), and W The average value P _of the precipitated phase amount of all the precipitated phase test samples in the ₁ group is brought into k=β(P), and the calculated value k ₁ ' of the acoustic elastic coefficient of the precipitated phase test sample in the W ₁ group is calculated, and the precipitated phase test sample in the W ₁ group is Comparing the calculated value of the acoustoelastic coefficient k ₁ ' with the actual average acoustoelastic coefficient k ₁ of the W ₁ group of precipitated phase test samples, if the error is within γ ₃ % and meets the requirements, the established precipitated phase quantity P and the acoustoelastic coefficient The relational database k=β(P) of k is valid; if the error is greater than γ ₃ %, prepare the precipitated phase test sample again according to A1-A3, and establish the relational database between the precipitated phase quantity P and the acoustoelastic coefficient k according to D1-D2, until Meet the error requirements;

E. Test the welding residual stress of the welded joint of the weldment to be tested

E1. Arranging the ultrasonic residual stress test area of the weldment to be tested, the test area includes the weld seam area, the heat-affected area and the base metal area.

E2. Use the longitudinal wave flat probe to test the attenuation degree of the test area of the weldment to be tested, and calculate the attenuation degree of the longitudinal wave signal in the test area, which is recorded as M _c ;

E3. Call the relationship between the precipitated phasor P established in step B and the attenuation degree M of the longitudinal wave signal, P=g(M), and calculate the calculated value of the precipitated phasor P _c in the test area, P _c =g(M _c );

E4. Call the relationship between the precipitated phase P and the critical refraction longitudinal wave in the zero stress sample in the zero stress sample by calling the precipitation phase _P established in step C, t ₀ =χ(P), calculate the critical refraction longitudinal wave in the test area in the zero stress tensile sample Propagation time t _c0 , t _c0 =χ(P _c );

E5. Call the relationship between the precipitation phase P and the acoustoelastic coefficient k established in step D, k=β(P), and calculate the acoustoelastic coefficient k _c of the test area, k _c =β(P _c );

E6. Collect the critical refracted longitudinal wave velocity v _c of the test area of the weldment to be tested, and obtain the propagation time of the critical refracted longitudinal wave in the test area t _c = L/v _c according to the distance L between the ultrasonic transceiver transducers;

E7, the propagation time t _c0 of the critical refraction longitudinal wave in the test area obtained in step E4 in the zero stress tensile sample, the acoustoelastic coefficient k _c of the test area obtained in step E5 and the propagation of the critical refraction longitudinal wave in the test area obtained in step E6 Time t _c , calculate the welding residual stress σ _c in the test area of the weldment to be tested:

In the step A1 described in this example, the group number w of the tensile sample w group cut in parallel to the rolling or extrusion direction of the material is 6. In the step A1, a group w of stretched samples is cut parallel to the rolling or extrusion direction of the material, and the number r _b of stretched samples included in each group of stretched samples is 5. In the step A2, the W ₂ -W _w group tensile samples are subjected to heat treatment under different conditions, and the holding temperature T _b ℃ of the W ₂ group tensile samples in the temperature T _b ℃ for h _b hours is the precipitation of the tested tensile samples Phasor changes temperature. In the step A2, the _W2 - _Ww group tensile samples are subjected to heat treatment under different conditions, and the _W2 group tensile samples are kept at the temperature T _b ℃ for h _b hours, the heat preservation time h _b hours and the heat preservation hours h _b can be The time to ensure that there is a 10% difference in the amount of precipitates between the stretched samples of the _W2 group and the stretched samples without heat treatment. The number of hours Δh _b of the difference in holding time between two adjacent sets of stretched samples in step A2 is as long as it can ensure that there is a 20% difference in precipitated phase between two adjacent sets of drawn samples. In the step B2, it is verified whether the relationship database P=g(M) between the precipitated phasor P and the attenuation degree M of the longitudinal wave signal is valid, and the error value γ ₁ % is set to 8%. In the step C2, it is verified whether the relationship database t ₀ =χ(P) between the precipitated phase quantity P and the critical refracted longitudinal wave propagation time t ₀ in the zero-stress sample is valid, and the error value γ ₂ % is set to 7%. In the step D2, it is verified whether the relationship database k=β(P) between the precipitated phase quantity P and the acoustoelastic coefficient k is valid, and the error value γ ₃ % is set to 10%.

Use effect of the present invention can be verified and explained by following test:

According to this embodiment, a relational database of the precipitated phasor and the attenuation degree of the longitudinal wave signal, a relational database of the precipitated phasor and the propagation time of the critically refracted longitudinal wave in the zero-stress sample, and a relational database of the precipitated phasor and the acoustic elastic coefficient are established. In the step A2, the W ₂ -W _w group tensile samples were subjected to heat treatment under different conditions, and the W ₂ group tensile samples were kept at a temperature of 200° C. for 2 hours. In the step A2, the hours Δh _b of the difference in holding time between two adjacent groups of tensile samples is 2 hours.

Select aluminum alloy A7N01S-T5, the same two welded test panels with a size of 700*250mm (all welding parameters are the same), arrange the test area on the two welded test plates according to Figure 1, and the test area includes the weld seam Zone A, heat-affected zone B and base metal zone C. In the figure, the black dot s1 is the center of the ultrasonic residual stress test area, the circle s2 indicates the center of the residual stress test area by the blind hole method, and the right side of the figure is the local enlarged part. For one of the welded test plates, first use the traditional ultrasonic residual stress test method to test the residual stress (L1) of the center s1 of each ultrasonic residual stress test area on the welded test plate, and then use the method of this embodiment to test each ultrasonic residual stress test area Residual stress (L2) at center s1. For another welded test plate, use the blind hole method to test the residual stress in the center s2 of the residual stress test area of the blind hole method. The test results are shown in Figure 2. The test results obtained by the traditional ultrasonic residual stress test method in the weld area and the heat-affected area are very different from the blind hole method. The test results in the base metal area far away from the weld are different This is because the traditional ultrasonic residual stress test method uses the acoustoelastic coefficient of the base material and the propagation time of the ultrasonic zero-stress sample when calculating the residual stress, while the distance between the weld area and the heat-affected zone and the base metal area There are very large differences in the amount of precipitated phases. However, using the test method of this embodiment, the obtained residual stress test results of the weld zone, heat-affected zone, and base metal zone are all less different from the blind hole method. This is because the method of the present invention calculates the residual stress , the acoustoelastic coefficient and propagation time of the ultrasonic zero-stress sample are determined according to the precipitated phase, which effectively corrects the acoustic elastic coefficient of the precipitated phase in the weld area, heat-affected zone and base metal area, and the ultrasonic wave in the zero-stress sample The huge error caused by the medium propagation time can significantly improve the testing accuracy of the ultrasonic wave on the residual stress of the welded joint.

Embodiment two

The ultrasonic residual stress testing method of the present embodiment is basically the same as that of the first embodiment, except that the selection of parameters in the steps is different, and the selection of each step parameter in the present embodiment is as follows:

In the step A1 described in this example, the group number w of the tensile sample w group cut in parallel to the rolling or extrusion direction of the material is 5. In the step A1, a group w of stretched samples is cut parallel to the rolling or extrusion direction of the material, and the number r _b of stretched samples included in each group of stretched samples is 4. In the step A2, the W ₂ -W _w group tensile samples are subjected to heat treatment under different conditions, and the holding temperature T _b ℃ of the W ₂ group tensile samples in the temperature T _b ℃ for h _b hours is the precipitation of the tested tensile samples Phasor changes temperature. In the step A2, the _W2 - _Ww group tensile samples are subjected to heat treatment under different conditions, and the _W2 group tensile samples are kept at the temperature T _b ℃ for h _b hours, the heat preservation time h _b hours and the heat preservation hours h _b can be The time to ensure that there is a 5% difference in the amount of precipitates between the stretched samples of the _W2 group and the stretched samples without heat treatment. The number of hours Δh _b of the difference in holding time between two adjacent sets of stretched samples in step A2 is as long as it can ensure that there is a 10% difference in precipitated phase between two adjacent sets of drawn samples. In the step B2, it is verified whether the relationship database P=g(M) between the precipitated phasor P and the attenuation degree of the longitudinal wave signal M is valid, and the error value γ ₁ % is set to 5%. In the step C2, it is verified whether the relationship database t ₀ =χ(P) between the precipitated phase quantity P and the critical refracted longitudinal wave propagation time t ₀ in the zero-stress sample is valid, and the error value γ ₂ % is set to 5%. In the step D2, it is verified whether the relational database k=β(P) between the precipitated phase quantity P and the acoustoelastic coefficient k is valid, and the error value γ ₃ % is set to 5%.

Embodiment Three

The ultrasonic residual stress testing method of the present embodiment is basically the same as that of the first embodiment, except that the selection of parameters in the steps is different, and the selection of each step parameter in the present embodiment is as follows:

In the step A1 described in this example, the group number w of the tensile sample w group cut parallel to the rolling or extrusion direction of the material is 4. In the step A1, a group w of stretched samples is cut parallel to the rolling or extrusion direction of the material, and the number r _b of stretched samples included in each group of stretched samples is 3. In the step A2, the W ₂ -W _w group tensile samples are subjected to heat treatment under different conditions, and the holding temperature T _b ℃ of the W ₂ group tensile samples in the temperature T _b ℃ for h _b hours is the precipitation of the tested tensile samples Phasor changes temperature. In the step A2, the _W2 - _Ww group tensile samples are subjected to heat treatment under different conditions, and the _W2 group tensile samples are kept at the temperature T _b ℃ for h _b hours, the heat preservation time h _b hours and the heat preservation hours h _b can be The time to ensure that there is a 15% difference in the amount of precipitated phase between the stretched samples of group W ₂ and the stretched samples without heat treatment. In the step A2, the hours Δh _b of the difference in holding time between two adjacent sets of stretched samples is as long as it can ensure that there is a 30% difference in precipitated phase between two adjacent sets of drawn samples. In the step B2, it is verified whether the relational database P=g(M) between the precipitated phasor P and the attenuation degree M of the longitudinal wave signal is valid, and the error value γ ₁ % is set to 10%. In the step C2, it is verified whether the relationship database t ₀ =χ(P) between the precipitated phase quantity P and the critical refracted longitudinal wave propagation time t ₀ in the zero-stress sample is valid, and the error value γ ₂ % is set to 10%. In the step D2, it is verified whether the relational database k=β(P) between the precipitated phase quantity P and the acoustoelastic coefficient k is valid, and the error value γ ₃ % is set to 15%.

Claims (9)

1. a kind of correct the ultrasonic wave residual stress test method that phasor differentia influence is precipitated, its step are as follows：

A, precipitated phase test specimens are prepared

A1, the rolling of parallel material or the direction of extrusion cut and stretch sample w groups, are denoted as W₁Group, W₂Group ... W_w-1Group, W_wGroup, every group of stretching Sample includes same stretch sample r_bRoot；

A2, to W₁Group stretching sample is without any processing, to W₂-W_wGroup stretches sample and carries out different condition heat treatment, the drawing in same group It is identical to stretch sample heat treatment condition, specific heat treatment condition is：W₂Group stretches sample in temperature T_bDEG C soaking time h_bHour, W₃Group Sample is stretched in temperature T_bDEG C soaking time h_b+Δh_bHour ... W_w-1Group stretches sample in temperature T_bDEG C soaking time h_b+Δh_b(w- 1-2) hour, W_wGroup stretches sample in temperature T_bDEG C soaking time h_b+Δh_b(w-2) hour is to get to W₁-W_wGroup precipitated phase test Sample, wherein Δ h_bThe hourage of sample soaking time difference is stretched for two adjacent groups；Wherein W₂-W_wGroup precipitated phase test specimens are through overheat Processing, it is believed that be zero stress state；

A3, to W₁-W_wGroup precipitated phase test specimens carry out metallographic processing, by microscope or electron backscatter diffraction calculate by The W of metallographic processing₁-W_wThe precipitation phasor of all precipitated phase test specimens in group each group, and W is taken respectively₁-W_wAll analysis in group each group Go out the precipitation phasor average value of phase test specimens, be denoted as P respectively₁, P₂, P₃……P_w-1, P_w；

B, the relational database that phasor and the longitudinal wave signal dough softening is precipitated is established

B1, using longitudinal wave flat probe to W₁-W_wAll precipitated phase test specimens carry out dough softening test respectively in group each group, calculate W₁-W_wThe longitudinal wave signal dough softening average value of all precipitated phase test specimens, is denoted as m respectively in group each group₁, m₂, m₃……m_w-1, m_w；

B2, according to W₂-W_wDough softening average value (the m of the longitudinal wave signal of group each group precipitated phase test specimens₂, m₃……m_w-1, m_w), with W₂-W_wThe precipitation phasor average value (P of group each group precipitated phase test specimens₂, P₃……P_w-1, P_w), it is established and is precipitated using least square method The relational database of phasor P and longitudinal wave signal dough softening M, P=g (M)；By W₁The longitudinal wave signal of all precipitated phase test specimens of group declines Degree of subtracting average value m₁It brings P=g (M) into, calculates W₁The precipitation phasor calculation value P of group precipitated phase test specimens₁’；By W₁Group precipitated phase is surveyed The precipitation phasor calculation value P of sample₁' W that obtains with A3₁The precipitation phasor average value P of all precipitated phase test specimens of group₁Carry out pair Than if error is in γ₁Within %, meet the requirements, the relation data of the precipitation phasor P established and longitudinal wave signal dough softening M Storehouse P=g (M) is effective；If error is more than γ₁% prepares precipitated phase test sample according to A1-A3 again, and is built according to B1-B2 The vertical relational database that phasor P and longitudinal wave signal dough softening M is precipitated, until meeting error requirements；

C, establish and phasor and the relational database in critical refraction longitudinal wave propagation time in zero stress sample is precipitated

C1, respectively to W₁-W_wAll precipitated phase test specimens carry out critical refraction longitudinal wave speed acquisition in group each group, obtain critical folding Longitudinal wave is penetrated in W₁-W_wThe mean propagation velocity of group each group precipitated phase test specimens, is denoted as v₁₀, v₂₀,v₃₀……v_(w-1)0, v_w0, and root According to the distance L between ultrasonic transmission/reception energy converter, critical refraction longitudinal wave is calculated in W₁-W_wGroup each group precipitated phase test specimens are averaged Propagation time is average transmission time of the critical refraction longitudinal wave in the zero stress precipitated phase test specimens of different precipitation phasors, It is denoted as t₁₀, t₂₀, t₃₀……t_(w-1)0, t_w0；

C2, according to critical refraction longitudinal wave in W₂-W_wAverage transmission time (the t of group each group precipitated phase test specimens₂₀, t₃₀…… t_(w-1)0, t_w0), with W₂-W_wThe precipitation phasor average value (P of group each group precipitated phase test specimens₂, P₃……P_w-1, P_w), utilize minimum Square law, which is established, is precipitated phasor P and critical refraction longitudinal wave propagation time t in zero stress sample₀Relational database, t₀=χ (P)； By W₁The precipitation phasor average value P of all precipitated phase test specimens of group₁Bring t into₀=χ (P) calculates critical refraction longitudinal wave in W₁Group analysis Go out the propagation time calculated value t of phase test specimens₁₀’；By critical refraction longitudinal wave in W₁The propagation time of group precipitated phase test specimens calculates Value t₁₀' with critical refraction longitudinal wave in W₁The actual average propagation time t of group precipitated phase test specimens₁₀It is compared, if error exists γ₂Within %, meet the requirements, the precipitation phasor P established and critical refraction longitudinal wave propagation time t in zero stress sample₀Relation Database t₀=χ (P) is effective；If error is more than γ₂% prepares precipitated phase test sample according to A1-A3 again, and according to C1- C2, which is established, is precipitated phasor P and critical refraction longitudinal wave propagation time t in zero stress sample₀Relational database, until meeting error It is required that；

D, the relational database that phasor and sonoelastic coefficient is precipitated is established

D1, respectively to W₁-W_wAll precipitated phase test specimens carry out sonoelastic coefficient and stretch calibration in group each group, obtain W₁-W_wGroup is each The average sonoelastic coefficient of group precipitated phase test specimens, is denoted as k₁, k₂, k₃……k_w-1, k_w；

D2, according to W₂-W_wAverage sonoelastic coefficient (the k of group each group precipitated phase test specimens₂, k₃……k_w-1, k_w), with W₂-W_wGroup is each The precipitation phasor average value (P of group precipitated phase test specimens₂, P₃……P_w-1, P_w), using least square method establish be precipitated phasor P with The relational database of sonoelastic coefficient k, k=β (P), by W₁The precipitation phasor average value P of all precipitated phase test specimens of group₁Bring k into =β (P) calculates W₁The sonoelastic coefficient calculated value k of group precipitated phase test specimens₁', by W₁The acoustic elasticity system of group precipitated phase test specimens Number calculated value k₁' and W₁The actual average sonoelastic coefficient k of group precipitated phase test specimens₁It is compared, if error is in γ₃% with It is interior, it meets the requirements, the relational database k=β (P) of the precipitation phasor P established and sonoelastic coefficient k are effective；If error is big In γ₃% prepares precipitated phase test sample according to A1-A3 again, and is established according to D1-D2 and phasor P and sonoelastic coefficient k is precipitated Relational database, until meeting error requirements；

E, the welding residual stress of weldment welding point to be measured is tested

The ultrasonic wave residual stress test region of E1, arrangement weldment to be measured, the test zone include welded seam area, heat affected area Domain and base material region；

E2, dough softening test is carried out to the test zone of weldment to be measured using longitudinal wave flat probe, calculates the longitudinal wave of test zone The signal dough softening, is denoted as M_c；

The relation for the precipitation phasor P and longitudinal wave signal dough softening M that E3, calling B steps are established, P=g (M) calculate test zone Phasor calculation value P is precipitated_c, P_c=g (M_c)；

E4, precipitation phasor P and critical refraction longitudinal wave the propagation time t in zero stress sample that C steps is called to establish₀Relation, t₀=χ (P), the critical refraction longitudinal wave of the test zone propagation time t in zero stress stretches sample is calculated_c0, t_c0=χ (P_c)；

E5, the relation for calling precipitations phasor P that D steps establish and sonoelastic coefficient k, k=β (P) calculate the sound bullet of test zone Property coefficient k_c, k_c=β (P_c)；

E6, acquisition weldment to be measured test zone critical refraction longitudinal wave speed v_c, and according between ultrasonic transmission/reception energy converter away from From L, propagation time t of the critical refraction longitudinal wave in test zone is obtained_c=L/v_c；

E7, according to the critical refraction longitudinal waves of the E4 test zones walked in zero stress stretches sample propagation time t_c0, E5 walks The sonoelastic coefficient k of the test zone arrived_cWith the critical refraction longitudinal wave that E6 is walked test zone propagation time t_c, calculate The welding residual stress of weldment test zone to be measured

2. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：Parallel material rolling or the direction of extrusion cut the group number w for stretching sample w groups not less than 4 in the step A1.

3. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：Parallel material rolling or the direction of extrusion cut and stretch sample w groups, the drawing that every group of stretching sample includes in the step A1 Stretch sample radical r_bNot less than 3.

4. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：To W in the step A2₂-W_wGroup stretches sample and carries out different condition heat treatment, W₂Group stretches sample in temperature T_b℃ Keep the temperature h_bHolding temperature T in hour_bDEG C by test stretch sample precipitation phasor change temperature.

5. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：To W in the step A2₂-W_wGroup stretches sample and carries out different condition heat treatment, W₂Group stretches sample in temperature T_b℃ Keep the temperature h_bSoaking time h in hour_bThe heat preservation hourage h of hour_bFor that can ensure W₂Organize what is stretched sample and be not heat-treated Stretch sample between there are 5-15% precipitation phasor difference time.

6. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：Two adjacent groups stretch the hourage Δ h of sample soaking time difference in the step A2_bAs long as that can ensure phase There is the time of the precipitation phasor difference with 10-30% between adjacent two groups of stretching samples.

7. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：Whether the relational database P=g (M) of verification precipitation phasor P and longitudinal wave signal dough softening M in the step B2 The error amount γ effectively set₁% is 5-10%.

8. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：Phasor P and critical refraction longitudinal wave propagation time t in zero stress sample is precipitated in verification in the step C2₀Pass It is database t₀The error amount γ whether=χ (P) is effectively set₂% is 5-10%.

9. a kind of ultrasonic wave residual stress test method for correcting precipitation phasor differentia influence according to claim 1, It is characterized in that：Whether effectively the relational database k=β (P) of phasor P and sonoelastic coefficient k are precipitated in verification in the step D2 The error amount γ of setting₃% is 5-15%.