CN115326936A - Automatic measurement method for vertical linearity of ultrasonic flaw detection system - Google Patents
Automatic measurement method for vertical linearity of ultrasonic flaw detection system Download PDFInfo
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Abstract
The invention discloses an automatic measurement method for vertical linearity of an ultrasonic flaw detection system, which does not need to use a standard test block, utilizes an interface wave generated when an ultrasonic instrument and a double-crystal ultrasonic probe work in a single-crystal probe mode, and comprises the following steps: generating ultrasonic waves by a wafer of a probe, and reflecting the ultrasonic waves by an end face of the probe to form interfacial waves which are received by the wafer generating the ultrasonic waves; one of the multiple reflected waves in the interfacial wave is selected as a vertically linear signal wave, the sensitivity margin of the secondary reflected wave as the vertically linear signal wave is not less than 26dB, and the vertical linearity of the ultrasonic flaw detection system is automatically detected according to the standard. The invention does not need to use a standard test block, utilizes the interface wave of the double-crystal probe to automatically detect the vertical linearity of the ultrasonic system, can quickly and efficiently detect the vertical linearity of the system and saves time.
Description
Technical Field
The invention relates to an automatic vertical linearity (also called amplitude linearity or gain linearity) measuring method of an ultrasonic flaw detection system, belonging to the field of ultrasonic nondestructive flaw detection.
Background
The vertical linearity of the existing traditional ultrasonic flaw detection system needs to be measured by using a standard test block, and the measuring mode is suitable for small-sized ultrasonic flaw detection equipment.
However, under the condition of a large-scale combined ultrasonic flaw detection system with a large number of probes, the traditional method is difficult to adopt, and particularly, along with the development of China railways, the wheel flaw detection enters the daily application pass-type online detection and monitoring field (which is perfect for the application of ultrasonic nondestructive detection), so that the traditional method cannot be used for detection.
Through type flaw detection system, ultrasonic detection unit and ultrasonic transducer passageway are more, and if the vertical linearity of ultrasonic flaw detection system detected when adopting traditional mode that relies on manual work and standard test block, the check-out time spent is longer or even can't detect, and need apply for limited skylight time and go up the track circuit and can detect.
Therefore, a fast and non-online detection method for automatically detecting the vertical linearity of the ultrasonic inspection system is needed in this situation to solve the problem of the identification of the vertical linearity performance of the current through-type ultrasonic inspection system.
Disclosure of Invention
The invention aims to provide an automatic vertical linearity measuring method of an ultrasonic flaw detection system, which can quickly and automatically detect the vertical linearity of the ultrasonic flaw detection system in a short time without a standard test block.
The invention solves the technical problem, and adopts the technical scheme that:
an automatic vertical linearity measuring method of an ultrasonic flaw detection system is characterized in that a standard test block is not needed, and interfacial waves generated when a double-crystal ultrasonic probe of an ultrasonic instrument works in a single-crystal probe mode are utilized, wherein the interfacial waves are as follows: generating ultrasonic waves by a wafer of a probe, reflecting the ultrasonic waves by an end face of the probe to form interfacial waves, and receiving the interfacial waves by the wafer generating the ultrasonic waves;
one of the multiple reflected waves in the interfacial wave is selected as a vertically linear signal wave, the sensitivity margin of the reflected wave as the vertically linear signal wave is not less than 26dB, and the vertical linearity of the ultrasonic flaw detection system is automatically detected according to the standard.
The nth reflected wave corresponding to a small reflector reflection equivalent on a predetermined test block is selected as a vertically linear signal wave. Among these, small reflectors are an artificial standard defect. The twin-crystal probe can not generate interfacial waves when working in the twin-crystal mode, namely the twin-crystal probe can not generate interfacial waves when being normally used, the twin-crystal probe can generate interfacial waves when working in the single-crystal mode of the instrument (which is one of the invention points of the invention), and the single-crystal probe can not generate interfacial waves when working in the single-crystal mode of the instrument.
There are two ways to measure the vertical linearity of an ultrasonic inspection system in the present invention:
(1) The ultrasonic system is connected with a double-crystal probe (such as an automatic flaw detection system), so that the working of the double-crystal probe and the channel mode of a single-crystal probe of an instrument can be directly utilized for automatic measurement. Namely: when the double-crystal ultrasonic probe is self-contained in the ultrasonic flaw detection system, the vertical linear self-checking can be participated without plugging.
(2) The ultrasonic system is not connected with the double-crystal probe or is connected with the single-crystal probe, and then the double-crystal probe is inserted or the single-crystal probe is pulled out and then the double-crystal probe is inserted, so that automatic measurement can be carried out. Namely: when the ultrasonic instrument channel of the ultrasonic flaw detection system is a single-crystal channel, the single-crystal probe needs to be pulled out, and the double-crystal ultrasonic probe is inserted into the single-crystal channel of the ultrasonic flaw detection system, so that the vertical linear self-inspection can be participated.
The method comprises the following steps:
the ultrasound system enters the vertical linear auto-detect mode, which is the mode in which the present invention is designed. In the mode of the ultrasonic system, one of multiple reflected waves of interface waves of the ultrasonic bimorph probe is selected as a vertical linear signal wave, and the sensitivity margin of the selected reflected wave is not lower than 26dB. The system automatically adjusts the gain of the ultrasonic system, so that the signal wave is just at 100% of the full-screen amplitude scale, the gain S1 of the ultrasonic flaw detection system at the moment is recorded, the gain of the ultrasonic system is reduced by 2dB each time until the gain of the system is reduced by 26dB, the readings of the signal wave amplitudes corresponding to different gains are recorded, finally, the recorded amplitude is compared with the theoretical value of table 1 in the method for testing the vertical linearity of the 6 th section straight probe in JB-T9214-2010 or the linear allowable error of the gain of 3.2.2 equipment in GB-T27664.3-2012, and the vertical linear error is not higher than 6%, namely the ultrasonic flaw detection system is qualified.
Specifically, the method comprises the following steps:
step (1): the ultrasonic flaw detection system enters a vertical linear automatic detection mode;
step (2): one of the multiple reflected waves of the interface wave of the ultrasonic bimorph probe is automatically selected as a vertical linear signal wave, and the sensitivity allowance of the reflected wave as the vertical linear signal wave is not lower than 26dB;
and (3): automatically adjusting gain to ensure that the amplitude of the vertical linear signal wave is just 100% of full amplitude scale;
and (4): reducing the gain of the system by 2dB, detecting and recording the amplitude scale value H1 at the moment, wherein the precision is not lower than 0.1%;
and (5): repeating the step (4) until the gain is attenuated by 26dB, and detecting and recording the amplitude scales H2-H13 after each gain reduction;
and (6): comparing the amplitude scales H1-H13 actually measured in the steps (4) and (5) with the wave height standard limit value respectively, wherein the sum of the absolute values of the maximum positive deviation d (+) and the maximum negative deviation d (-) of the amplitude scales H1-H13 and the wave height standard limit value is a vertical linear error delta d, and if the vertical linear error is not higher than a specified value by 6%, the standard wave height is qualified.
Further, the wave height standard limit value is a theoretical value in a table 1 in a section 6 straight probe vertical linear test method in JB-T9214-2010.
Alternatively, the other method comprises:
step (1): the ultrasonic flaw detection system enters a vertical linear automatic detection mode;
step (2): one of the multiple reflected waves of the interface wave of the ultrasonic bimorph probe is automatically selected as a vertical linear signal wave, and the sensitivity allowance of the reflected wave as the vertical linear signal wave is not lower than 26dB;
and (3): automatically adjusting gain, adjusting the signal wave to 80% of the amplitude scale of the full screen, and recording the gain M1 of the ultrasonic system at the moment;
and (4): increasing the gain by 2dB, and detecting and recording an amplitude scale value G1;
and (5): automatically restoring the gain to M1, wherein the signal wave is just 80% of the full screen amplitude scale at the moment and is used as a reference wave;
and (6): automatically reducing the gain by 6dB, and detecting and recording an amplitude scale value G2;
and (7): repeating the step (6) for 3 times, detecting and recording the amplitude scale values G3, G4 and G5;
and (8): automatically comparing the measured values G1 to G5 of the vertical linear signal wave amplitude with the wave height standard limit value respectively, and determining that the measured values of the signal wave amplitude are in the range of the wave height standard limit value, namely the signals are qualified.
Further, the standard limit value of the wave height is the limit value specified in table 2 of the linearity allowable error of the gain of 3.2.2 equipment in GB-T27664.3-2012.
Compared with the prior art, the invention has the following beneficial effects:
(1) The invention utilizes the interface wave of the double-crystal probe to automatically detect the vertical linearity of the ultrasonic system, can quickly and efficiently detect the vertical linearity of the system, saves time, and particularly can be used on the spot of more detection equipment, such as trackside dynamic flaw detection equipment applied in the field of rail transit.
(2) The method of the invention provides a simple and effective means for judging the vertical linearity of large-scale ultrasonic flaw detection equipment.
(3) The invention is the supplement and the perfection of the vertical linear detection of the traditional ultrasonic flaw detection system, and meets the development requirement that the current nondestructive flaw detection of railway wheels enters the daily application field.
Drawings
FIG. 1 is a schematic diagram of the principles of the present invention;
FIG. 2 is a schematic diagram of an interface wave according to the present invention;
FIG. 3 is a schematic view of an initial amplitude scale;
FIG. 4 is a schematic diagram of an amplitude scale for selecting the 5 th reflected wave as a vertically linear signal wave;
FIG. 5 is a flow chart of the method of the present invention.
Detailed Description
The invention is further described below with reference to the drawings and examples.
The principle of the vertical linear automatic detection method of the ultrasonic flaw detection system of the embodiment is as follows: the ultrasonic system automatically detects the vertical linearity of the ultrasonic system according to the relevant requirements of relevant standards by utilizing the multiple reflection waves of the interface waves generated when the ultrasonic instrument and the double-crystal ultrasonic probe work in a single-crystal probe mode without using a standard test block, and the multiple reflection waves are similar to the multiple reflection waves of the bottom waves of the standard test block.
The vertical linear automatic detection method of the ultrasonic flaw detection system comprises the following steps:
a bimorph probe with a focal length of 20mm, a single wafer size of 6mm by 8mm and a zero point of 17mm is exemplified.
The probe is connected with the ultrasonic system, as shown in fig. 1, if the ultrasonic system is a double-crystal channel, the vertical linear automatic detection mode can be directly entered, and if the ultrasonic system is a single-crystal channel, the double-crystal probe needs to be manually accessed and then the vertical linear automatic detection mode is entered. When the ultrasonic system enters the vertical linearity automatic detection mode, the 5 th reflected wave of the interfacial wave of the ultrasonic bimorph probe (as shown in fig. 2, the wafer of the probe generates the ultrasonic wave, and the end face of the probe is reflected to form the interfacial wave which is received by the wafer generating the ultrasonic wave) is automatically set as the vertical linearity signal wave.
The 5 th reflection wave is tested, the sensitivity margin is about 50dB, and is enough to use, and the sensitivity margin is equivalent to a phi 2 flat-bottom hole with the depth of 200mm on a CS-1-5 standard test block or a small reflector on other specified test blocks.
The reflected wave of the second time is selected as a vertical linear signal wave, which is related to the relevant parameters of the focal length, the size of a wafer, a zero point and the like of a probe, and the reflection equivalent is only selected to be equivalent to a phi 2 flat bottom hole with the depth of 200mm on a standard test block or a small reflector (namely an artificial standard defect) on other specified test blocks.
Example 1:
the process of the vertical linear automatic detection method of the ultrasonic flaw detection system of the embodiment is as shown in fig. 5:
step (1): the ultrasonic system enters a vertical linear automatic detection mode;
step (2): the ultrasonic system automatically selects the 5 th reflected wave of the interface wave of the ultrasonic bimorph probe as a vertical linear signal wave, and the sensitivity allowance of the selected 5 th reflected wave is not lower than 26dB;
and (3): the ultrasonic system automatically adjusts the gain to ensure that the amplitude of the 5 th wave just fills 100% of the scale, and records that the gain of the ultrasonic system is S1 (the gains of all ultrasonic instruments are inconsistent);
and (4): reducing the gain of the system by 2dB, checking the amplitude scale value at the moment, detecting and recording the amplitude scale value H1, wherein the precision is not lower than 0.1%;
and (5): repeating the step (4) until the gain is attenuated by 26dB, and detecting and recording the amplitude scales H2-H13 after each gain reduction;
and (6): comparing the amplitude scales H1-H13 actually measured in the steps (4) and (5) with a wave height standard limit value (such as a theoretical value in a table 1 in a section 6 straight probe vertical linear test method in JB-T9214-2010), wherein the sum of absolute values of the maximum positive deviation d (+) and the maximum negative deviation d (-) of the 13 actually measured values and the wave height standard limit value is a vertical linear error delta d, and if the vertical linear error is not higher than a specified value by 6%, the test result is qualified.
Example 2:
the process of the vertical linear automatic detection method of the ultrasonic flaw detection system of the embodiment includes the following steps:
step (1): the ultrasonic system enters a vertical linear automatic detection mode;
step (2): the ultrasonic system automatically selects the 5 th reflected wave of the interfacial wave of the ultrasonic bimorph probe as a vertical linear signal wave, and the sensitivity allowance of the 5 th reflected wave is not lower than 26dB;
and (3): the ultrasonic system automatically adjusts the gain, adjusts the signal wave to 80% of the full-screen amplitude scale, and records the gain M1 of the ultrasonic system (the gains of all ultrasonic instruments are not consistent);
and (4): increasing the gain of the system by 2dB, and detecting and recording an amplitude scale value G1;
and (5): the system automatically restores the gain to M1, and the signal wave is a reference wave which is just 80% of the full screen amplitude scale at the moment;
and (6): the ultrasonic system automatically reduces the gain by 6dB, and detects and records an amplitude scale value G2;
and (7): repeating the step (6) for 3 times, and detecting and recording amplitude scale values G3, G4 and G5;
and (8): the measured values of the vertical linear signal wave amplitude G1 to G5 are automatically compared with the standard limit values (the allowable linear error of the device gain of 3.2.2 in GB-T27664.3-2012 is in the limit value specified in Table 2), and the vertical linear error is in the limit value range, namely the signal is qualified.
The foregoing description of the embodiments will enable one skilled in the art to make or use the invention, and various modifications will be apparent to those skilled in the art, wherein the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention, and therefore the invention is not to be limited to the embodiments shown herein, and all technical solutions obtained by means of equivalents or equivalent changes will fall within the scope of the invention.
Claims (8)
1. An automatic measurement method for vertical linearity of an ultrasonic flaw detection system, which is characterized in that the method does not need to use a standard test block, and utilizes an interfacial wave generated when a bimorph ultrasonic probe of an ultrasonic instrument works in a monocrystal probe mode, wherein the interfacial wave: generating ultrasonic waves by a wafer of a probe, reflecting the ultrasonic waves by an end face of the probe to form interfacial waves, and receiving the interfacial waves by the wafer generating the ultrasonic waves;
one of the multiple reflected waves in the interfacial wave is selected as a vertically linear signal wave, the sensitivity margin of the reflected wave as the vertically linear signal wave is not less than 26dB, and the vertical linearity of the ultrasonic flaw detection system is automatically detected according to the standard.
2. The method of claim 1, wherein the twin crystal ultrasonic probe is self-contained in the ultrasonic inspection system, and can participate in the vertical linearity self-test without plugging.
3. The method of claim 1, wherein when the ultrasonic instrument channel of the ultrasonic inspection system is a single crystal channel, the single crystal probe is pulled out, and the double crystal ultrasonic probe is inserted into the single crystal channel of the ultrasonic inspection system, so as to participate in the vertical linearity self-inspection.
4. The method of any of claims 1-3, wherein the nth reflected wave equivalent to a small reflector reflection equivalent on a specified test block is selected as the vertically linear signal wave.
5. The method of claim 4, wherein the method comprises:
step (1): the ultrasonic flaw detection system enters a vertical linear automatic detection mode;
step (2): one of the multiple reflected waves of the interface wave of the ultrasonic bimorph probe is automatically selected as a vertical linear signal wave, and the sensitivity allowance of the reflected wave as the vertical linear signal wave is not lower than 26dB;
and (3): automatically adjusting gain to make the amplitude of the vertical linear signal wave just full of 100% of amplitude scale;
and (4): reducing the gain of the system by 2dB, and detecting and recording the amplitude scale value H1 at the moment;
and (5): repeating the step (4) until the gain is attenuated by 26dB, and detecting and recording the amplitude scales H2-H13 after each gain reduction;
and (6): comparing the amplitude scales H1-H13 actually measured in the steps (4) and (5) with the wave height standard limit value respectively, wherein the sum of the absolute values of the maximum positive deviation d (+) and the maximum negative deviation d (-) of the amplitude scales H1-H13 and the wave height standard limit value is a vertical linearity error delta d, and if the vertical linearity error is not higher than a specified value, the standard wave height scale is qualified.
6. The method of claim 5, wherein the wave height standard limit is a theoretical value in Table 1 in section 6 straight probe vertical linearity test method in JB-T9214-2010.
7. The method of claim 4, wherein the method comprises:
step (1): the ultrasonic flaw detection system enters a vertical linear automatic detection mode;
step (2): one of the multiple reflected waves of the interface wave of the ultrasonic bimorph probe is automatically selected as a vertical linear signal wave, and the sensitivity allowance of the reflected wave as the vertical linear signal wave is not lower than 26dB;
and (3): automatically adjusting gain, adjusting the signal wave to 80% of the amplitude scale of the full screen, and recording the gain M1 of the ultrasonic system at the moment;
and (4): increasing the gain by 2dB, and detecting and recording an amplitude scale value G1;
and (5): automatically restoring the gain to M1, wherein the signal wave is just 80% of the full screen amplitude scale at the moment and is used as a reference wave;
and (6): automatically reducing the gain by 6dB, and detecting and recording an amplitude scale value G2;
and (7): repeating the step (6) for 3 times, detecting and recording the amplitude scale values G3, G4 and G5;
and (8): automatically comparing the measured values G1 to G5 of the vertical linear signal wave amplitude with the wave height standard limit value respectively, and determining that the measured values of the signal wave amplitude are within the range of the wave height standard limit value, namely the signals are qualified.
8. The method for automatically measuring the vertical linearity of the ultrasonic flaw detection system according to claim 7, wherein the wave height standard limit is a limit specified in table 2 for a linearity allowable error of a 3.2.2 device gain in GB-T27664.3-2012.
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