CN103675091A - Steel plate defect detector and detection method for same - Google Patents
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 80
- 239000010959 steel Substances 0.000 title claims abstract description 80
- 238000001514 detection method Methods 0.000 title claims description 25
- 230000007547 defect Effects 0.000 title abstract description 17
- 230000004907 flux Effects 0.000 claims abstract description 4
- 230000005415 magnetization Effects 0.000 claims description 10
- 238000005259 measurement Methods 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 230000002950 deficient Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 235000013361 beverage Nutrition 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
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Abstract
本发明公开了一种钢板缺陷探伤仪，包括：磁场传感器，其用于测量钢板表面的漏磁信号；传感器支架，其与磁场传感器固定连接，用于固定磁场传感器；滑台，其设置在磁场传感器的下方，用于固定待测钢板；导轨，其与滑台滑动连接，实现滑台在导轨上移动；电磁铁，其设置在滑台的下方，用于磁化滑台上的待测钢板；磁化电源，其与电磁铁连接，用于向电磁铁供电。本发明采用高灵敏的非对角巨磁阻抗传感器，可以捕捉到钢板表面或内部微小的缺陷，测到0.13mm钢板上直径0.14mm的小孔。
The invention discloses a steel plate flaw detector, comprising: a magnetic field sensor, which is used to measure the magnetic flux leakage signal on the surface of the steel plate; a sensor bracket, which is fixedly connected with the magnetic field sensor, and used to fix the magnetic field sensor; The lower part of the sensor is used to fix the steel plate to be tested; the guide rail is slidably connected with the slide table to realize the slide table moving on the guide rail; the electromagnet is arranged under the slide table to magnetize the steel plate to be tested on the slide table; A magnetizing power supply connected to the electromagnet for powering the electromagnet. The invention adopts a highly sensitive non-diagonal giant magneto-impedance sensor, which can capture tiny defects on the surface or inside of a steel plate, and detect small holes with a diameter of 0.14mm on a 0.13mm steel plate.
Description
技术领域 technical field
本发明涉及无损探伤领域，具体涉及一种钢板缺陷探伤仪及其探测方法。The invention relates to the field of non-destructive flaw detection, in particular to a steel plate flaw detector and a detection method thereof.
背景技术 Background technique
对于钢板表面缺陷的测量来说，磁性传感器的分辨率和灵敏度是关键的因素。设备对缺陷的测量精度直接取决于所用传感器的灵敏度和测量范围。而且对于冷轧薄带缺陷的测量，往往需要利用到传感器对极小的缺陷进行测量，这就要求传感器可以做到小型化至芯片级。巨磁阻抗GMI传感器在已知可以小型化至芯片级的磁场传感器中，灵敏度最高(霍尔器件1-106Oe，磁阻0.1-102Oe，磁通门10-6-102Oe，巨磁阻抗传感器10-8Oe-102Oe)。而现有探伤设备多使用霍尔等传感器，其探测精度往往较低，一般仅为毫米量级。For the measurement of steel surface defects, the resolution and sensitivity of magnetic sensors are key factors. The accuracy with which a device can measure defects is directly dependent on the sensitivity and measurement range of the sensors used. Moreover, for the measurement of cold-rolled thin strip defects, it is often necessary to use sensors to measure extremely small defects, which requires that the sensors can be miniaturized to the chip level. Among the magnetic field sensors known to be miniaturized to the chip level, the giant magneto-impedance GMI sensor has the highest sensitivity (Hall device 1-10 6 Oe, magnetoresistance 0.1-10 2 Oe, fluxgate 10 -6 -10 2 Oe, Giant magneto-impedance sensor 10 -8 Oe-10 2 Oe). However, the existing flaw detection equipment mostly uses sensors such as Hall, and its detection accuracy is often low, generally only on the order of millimeters.
钢板生产过程当中难免产生有缺陷的产品。这些残次品一旦流入市场，会造成巨大的经济损失。以薄板为例，用到饮料罐的薄板，板上存在缺陷的成品很容易在腐蚀下发生泄漏，发生这种问题将使企业面临重大的经济赔偿损失。所以这方面有着强烈的实际需求。Defective products are unavoidable in the steel plate production process. Once these defective products flow into the market, they will cause huge economic losses. Taking thin plates as an example, thin plates of beverage cans are used, and the finished products with defects on the plates are easy to leak under corrosion. The occurrence of such problems will cause enterprises to face significant economic losses. So there is a strong practical need for this.
发明内容 Contents of the invention
本发明克服了现有技术检测精度较低的不足，提出一种钢板缺陷探伤仪及其探测方法。本发明采用高灵敏的非对角巨磁阻抗(GMI)传感器，可以捕捉到钢板表面或内部微小的缺陷，测到0.13mm钢板上直径0.14mm的小孔。The invention overcomes the disadvantage of low detection accuracy in the prior art, and provides a steel plate defect detector and a detection method thereof. The invention adopts a highly sensitive non-diagonal giant magneto-impedance (GMI) sensor, which can capture tiny defects on the surface or inside of a steel plate, and detect small holes with a diameter of 0.14mm on a 0.13mm steel plate.
本发明提出了一种钢板缺陷探伤仪，包括：The present invention proposes a steel plate flaw detector, comprising:
磁场传感器，其用于测量钢板表面的漏磁信号；A magnetic field sensor, which is used to measure the magnetic flux leakage signal on the surface of the steel plate;
传感器支架，其与所述磁场传感器固定连接，用于固定所述磁场传感器；A sensor bracket, which is fixedly connected to the magnetic field sensor and used to fix the magnetic field sensor;
滑台，其设置在所述磁场传感器的下方，用于固定待测钢板；A slide table, which is arranged below the magnetic field sensor, is used to fix the steel plate to be tested;
导轨，其与所述滑台滑动连接，实现所述滑台在所述导轨上移动；a guide rail, which is slidably connected with the slide table, so as to realize the movement of the slide table on the guide rail;
电磁铁，其设置在所述滑台的下方，用于磁化所述滑台上的所述待测钢板；An electromagnet, which is arranged below the slide table, is used to magnetize the steel plate to be tested on the slide table;
磁化电源，其与所述电磁铁连接，用于向所述电磁铁供电。A magnetizing power supply, connected to the electromagnet, is used to supply power to the electromagnet.
其中，进一步包括：Among them, further include:
信号检测器，其与所述磁场传感器连接，用于采集所述磁场传感器的检测信号并反映检测结果。A signal detector, which is connected to the magnetic field sensor, is used to collect the detection signal of the magnetic field sensor and reflect the detection result.
其中，所述磁场传感器可沿所述传感器支架上下左右调节。Wherein, the magnetic field sensor can be adjusted up, down, left, and right along the sensor bracket.
其中，所述磁场传感器为巨磁阻抗传感器。Wherein, the magnetic field sensor is a giant magneto-impedance sensor.
其中，所述磁场传感器的分辨率为5×10-10T。Wherein, the resolution of the magnetic field sensor is 5×10 −10 T.
本发明还提出了一种钢板缺陷探伤仪的探测方法，包括：The present invention also proposes a detection method of a steel plate flaw detector, comprising:
步骤一：将待测钢板平整地安装在所述滑台上；Step 1: Flatly install the steel plate to be tested on the slide table;
步骤二：选通所述磁化电源向所述电磁铁供电，所述电磁铁磁化所述待测钢板；Step 2: selecting the magnetization power supply to supply power to the electromagnet, and the electromagnet magnetizes the steel plate to be tested;
步骤三：调节所述传感器支架，使所述磁场传感器固定在所述待测钢板的上方；Step 3: adjusting the sensor bracket so that the magnetic field sensor is fixed above the steel plate to be tested;
步骤四：调节所述滑台在所述导轨上移动，所述待测钢板在所述磁场传感器下滑过，同时所述磁场传感器检测所述待测钢板表面的磁场；Step 4: Adjust the slide table to move on the guide rail, the steel plate to be tested slides over the magnetic field sensor, and the magnetic field sensor detects the magnetic field on the surface of the steel plate to be tested;
步骤五：所述信号检测器采集所述磁场传感器的检测信号，并反映所述磁场传感器的检测结果。Step five: the signal detector collects the detection signal of the magnetic field sensor, and reflects the detection result of the magnetic field sensor.
其中，所述步骤二中，所述电磁铁使所述待测钢板磁化饱和。Wherein, in the second step, the electromagnet saturates the magnetization of the steel plate to be tested.
其中，所述步骤三中，所述磁场传感器距离所述待测钢板提离值为0.1-3.0mm。Wherein, in the third step, the lift-off value of the magnetic field sensor from the steel plate to be tested is 0.1-3.0 mm.
本发明基于高灵敏度的GMI传感器，大大提高了可以测到的缺陷的能力，可以测到0.13mm钢板上直径0.14mm的小孔。The invention is based on a high-sensitivity GMI sensor, which greatly improves the ability to detect defects, and can detect a small hole with a diameter of 0.14mm on a 0.13mm steel plate.
附图说明 Description of drawings
图1是本发明钢板缺陷探伤仪的示意图。Fig. 1 is a schematic diagram of a steel plate defect detector of the present invention.
图2是本发明钢板缺陷探伤仪探测方法的流程图。Fig. 2 is a flow chart of the detection method of the steel plate flaw detector of the present invention.
图3是本发明钢板缺陷探伤仪检测到小孔时的磁场波形图。Fig. 3 is a waveform diagram of the magnetic field when a small hole is detected by the steel plate defect detector of the present invention.
具体实施方式 Detailed ways
结合以下具体实施例和附图，对本发明作进一步的详细说明。实施本发明的过程、条件、实验方法等，除以下专门提及的内容之外，均为本领域的普遍知识和公知常识，本发明没有特别限制内容。The present invention will be further described in detail in conjunction with the following specific embodiments and accompanying drawings. The process, conditions, experimental methods, etc. for implementing the present invention, except for the content specifically mentioned below, are common knowledge and common knowledge in this field, and the present invention has no special limitation content.
如图1所示，1-磁场传感器，2-传感器支架，3-滑台，4-导轨，5-电磁铁，6-磁化电源，7-信号检测器。As shown in Figure 1, 1-magnetic field sensor, 2-sensor bracket, 3-sliding table, 4-guide rail, 5-electromagnet, 6-magnetization power supply, 7-signal detector.
本发明钢板缺陷探伤仪，如图1所示，包括：磁场传感器1，传感器支架2，滑台3，导轨4，电磁铁5，以及磁化电源6。磁场传感器1用于测量钢板表面的漏磁信号；传感器支架2与磁场传感器1固定连接，用于固定磁场传感器1；滑台3设置在磁场传感器1的下方，用于固定待测钢板；导轨4与滑台3滑动连接，实现滑台3在导轨4上移动；电磁铁5设置在滑台3的下方，用于磁化滑台3上的待测钢板；磁化电源6与电磁铁5连接，用于向电磁铁5供电。The steel plate flaw detector of the present invention, as shown in FIG. 1 , includes: a magnetic field sensor 1 , a
本发明钢板缺陷探伤仪进一步包括信号检测器7，其与磁场传感器1连接，用于采集磁场传感器1的检测信号并反映检测结果。The steel plate flaw detector of the present invention further includes a signal detector 7 connected to the magnetic field sensor 1 for collecting detection signals of the magnetic field sensor 1 and reflecting detection results.
本发明中，磁场传感器1可沿传感器支架2上下左右调节。磁场传感器1为GMI(GMI，巨磁阻抗)传感器。磁场传感器1的分辨率为5×10-10T-8×10-5T。In the present invention, the magnetic field sensor 1 can be adjusted up, down, left, and right along the
如图1所示，待测钢板绷紧平整地安装在在滑台3的表面，滑台3可以在导轨4上水平滑动。磁化电源6加电流于电磁铁5上，产生一个直流磁场。电磁铁5产生的直流磁场磁化滑台3上的待测钢板，使待测钢板表面有缺陷和没有缺陷处的磁场产生更明显的差异。As shown in FIG. 1 , the steel plate to be tested is tightly and flatly installed on the surface of the slide table 3 , and the slide table 3 can slide horizontally on the guide rail 4 . The magnetizing power supply 6 adds current to the electromagnet 5 to generate a DC magnetic field. The DC magnetic field generated by the electromagnet 5 magnetizes the steel plate to be tested on the slide table 3 , so that the magnetic fields at the surface of the steel plate to be tested with defects and without defects produce more obvious differences.
传感器支架2将GMI传感器固定在待测钢板的上方，GMI传感器与待测钢板表面保持很小的距离，例如，相距0.1-3.0mm。GMI传感器与待测钢板表面之间不发生直接接触。GMI传感器探测待测钢板表面的磁场变化。待测钢板在GMI传感器下水平滑过，一旦待测钢板表面有缺陷，待测钢板表面的磁场在该处就会发生突变，信号检测器7检测到突变信号便会做出反映。The
如图2所示，本发明钢板缺陷探伤仪的探测方法，包括：As shown in Figure 2, the detection method of the steel plate defect detector of the present invention includes:
步骤一：将待测钢板平整地安装在滑台3上。Step 1: Install the steel plate to be tested on the slide table 3 evenly.
步骤二：选通磁化电源6向电磁铁5供电，电磁铁5磁化待测钢板。电磁铁5使待测钢板磁化饱和。Step 2: strobe the magnetization power supply 6 to supply power to the electromagnet 5, and the electromagnet 5 magnetizes the steel plate to be tested. The electromagnet 5 saturates the magnetization of the steel plate to be tested.
步骤三：调节传感器支架2，使磁场传感器1固定在待测钢板的上方。磁场传感器1距离待测钢板0.1-3.0mm。Step 3: Adjust the
步骤四：调节滑台3在导轨4上移动，待测钢板在磁场传感器1下滑过，同时磁场传感器1检测待测钢板表面的磁场。Step 4: Adjust the slide table 3 to move on the guide rail 4, the steel plate to be tested slides over the magnetic field sensor 1, and the magnetic field sensor 1 detects the magnetic field on the surface of the steel plate to be tested.
步骤五：信号检测器7采集磁场传感器1的检测信号，并反映磁场传感器1的检测结果。Step 5: The signal detector 7 collects the detection signal of the magnetic field sensor 1 and reflects the detection result of the magnetic field sensor 1 .
本实施例中，在经过磁场传感器1的待测钢板上，在一条直线上打三个距离相等的小孔，其中，小孔相互间距D是4cm，小孔的直径是0.14mm，钢板的厚度是0.13mm。将待测钢板绷紧平整地安装到滑台3表面。用磁化电源6给电磁铁5加电流(例如，1.5A)，使电磁铁5磁化经过其上的待测钢板。调节传感器支架2，使磁场传感器1定位于待测钢板上方某一位置，距离待测钢板表面1mm。以10cm/s度速度滑动滑台3，使待测钢板上的小孔依次通过磁场传感器1下方。从信号检测器7中可以得到待测钢板表面的磁场，其结果如图3所示。从图3来看，每隔0.4秒就会出现一个较明显的峰值，一个有三个。正好满足D(孔间距)＝v(板运行速度)*t(两峰出现间隔时间)，可以认定这三个峰值代表了钢板上的三个缺陷。这证明本发明可以测到0.13mm钢板上直径0.14mm的小孔。In this embodiment, on the steel plate to be tested passing through the magnetic field sensor 1, three small holes with equal distances are punched on a straight line, wherein the distance D between the small holes is 4cm, the diameter of the small holes is 0.14mm, and the thickness of the steel plate It is 0.13mm. Install the steel plate to be tested on the surface of slide table 3 tightly and evenly. A current (for example, 1.5A) is applied to the electromagnet 5 with the magnetization power supply 6 to magnetize the steel plate to be tested passing through the electromagnet 5 . Adjust the
本发明的保护内容不局限于以上实施例。在不背离发明构思的精神和范围下，本领域技术人员能够向到的变化和优点都被包括在本发明中，并且以所附的权利要求书为保护范围。The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be achieved by those skilled in the art are all included in the present invention, and the appended claims are the protection scope.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108981553A (en) * | 2018-05-19 | 2018-12-11 | 芜湖新利德玻璃制品有限公司 | A kind of organic glass crazing detection device |
| CN113504293A (en) * | 2021-06-15 | 2021-10-15 | 浙江工业大学 | Corrosion state magnetic induction automatic scanning device along steel bar trend |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61147158A (en) * | 1984-12-21 | 1986-07-04 | Nippon Steel Corp | Strip defect detection device |
| JPH01148856U (en) * | 1988-04-05 | 1989-10-16 | ||
| CN1067510A (en) * | 1991-06-04 | 1992-12-30 | 日本钢管株式会社 | Magnetic detection method and device thereof |
| JPH10288603A (en) * | 1997-04-16 | 1998-10-27 | Nkk Corp | Surface flaw detecting method for steel material |
| CN1373852A (en) * | 2000-07-12 | 2002-10-09 | 日本钢管株式会社 | Magnetic leakage flux flow detection method and mfg. method of hot rolled steel plate using same |
| CN101231264A (en) * | 2008-01-31 | 2008-07-30 | 华南理工大学 | A detection method of an electromagnetic non-destructive testing probe |
-
2012
- 2012-09-19 CN CN201210356031.1A patent/CN103675091A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61147158A (en) * | 1984-12-21 | 1986-07-04 | Nippon Steel Corp | Strip defect detection device |
| JPH01148856U (en) * | 1988-04-05 | 1989-10-16 | ||
| CN1067510A (en) * | 1991-06-04 | 1992-12-30 | 日本钢管株式会社 | Magnetic detection method and device thereof |
| JPH10288603A (en) * | 1997-04-16 | 1998-10-27 | Nkk Corp | Surface flaw detecting method for steel material |
| CN1373852A (en) * | 2000-07-12 | 2002-10-09 | 日本钢管株式会社 | Magnetic leakage flux flow detection method and mfg. method of hot rolled steel plate using same |
| CN101231264A (en) * | 2008-01-31 | 2008-07-30 | 华南理工大学 | A detection method of an electromagnetic non-destructive testing probe |
Non-Patent Citations (4)
| Title |
|---|
| TEHRANCHI M M ET AL.: "Double core giant magneto-impedance sensors for the inspection of magnetic flux leakage from metal surface cracks", 《SENSORS AND ACTUATORS A: PHYSICAL》, vol. 170, no. 1, 7 June 2011 (2011-06-07) * |
| W. SHARATCHANDRA SINGH ET AL.: "Giant Magneto-Resistive (GMR) Sensors for Non-Destructive Detection of Magnetic Flux Leakage from Sub-Surface Defects in Steels", 《INTERNATIONAL CONFERENCE ON SENSORS AND RELATED NETWORKS (SENNET-2009)》, vol. 1, 31 December 2009 (2009-12-31), pages 09 * |
| 吴平川 等: "钢板表面缺陷的无损检测技术与应用", 《无损检测》, vol. 22, no. 7, 31 July 2000 (2000-07-31), pages 312 - 315 * |
| 张清 等: "新型巨磁阻抗传感器的特性研究", 《传感技术学报》, vol. 20, no. 3, 31 March 2007 (2007-03-31), pages 578 - 581 * |
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