CN111337565A - A medium frequency electromagnetic measurement method and device for scanning corrosion defects of stainless steel pipe wall - Google Patents

Abstract

The invention belongs to the field of nondestructive detection of stainless steel pipelines in the basic chemical industry and the petroleum refining industry, is suitable for detecting and scanning corrosion defects of the stainless steel pipelines on line, and can quickly find and position potential safety hazard positions. The invention comprises a medium-frequency electromagnetic host, a sensor assembly with an incremental pedometer, a data processing terminal, a 6-core cable, a support accessory and the like. The feedback signal received by the host computer is transmitted to the data processing terminal by the Bluetooth. The system utilizes a special algorithm aiming at stainless steel pipeline signal processing, realizes continuous scanning of the wall thickness of the stainless steel pipeline under the condition of no need of surface processing, is suitable for the detection requirements of different pipe diameters, and can realize quick scanning of corrosion defects in the stainless steel and semi-quantitative calculation of the severity of the defects at the temperature of 300 ℃. The step counting device in the system sensor can accurately determine the position of the corrosion defect, and quickly, directly and accurately position the corrosion defect in the stainless steel pipeline.

Description

Translated fromChinese

一种扫查不锈钢管壁腐蚀缺陷的中频电磁测量方法和装置A medium frequency electromagnetic measurement method and device for scanning corrosion defects of stainless steel pipe wall

技术领域technical field

本发明属于基础化工和石油炼化行业不锈钢管线无损检测领域，具体是一种扫查不锈钢管壁腐蚀缺陷的中频电磁测量方法和装置。The invention belongs to the field of non-destructive testing of stainless steel pipelines in basic chemical and petroleum refining industries, in particular to an intermediate frequency electromagnetic measurement method and device for scanning corrosion defects of stainless steel pipe walls.

背景技术Background technique

基础化工和石油炼化装置运行过程中，对于具有腐蚀风险的管线通常采用不锈钢材料作为管道材料，这类采用不锈钢材料的管道一旦发生腐蚀将引起严重的后果，需要对这类管道进行壁厚测量。现有的不锈钢管道壁厚测量方法一般采用传统的超声波测厚仪进行定点测量。由于超声波测厚仪只能进行定点测厚，无法实现连续扫查，容易出现漏检或不能检测到缺陷最严重的区域，弊端较多。During the operation of basic chemical and petroleum refining plants, stainless steel materials are usually used as pipeline materials for pipelines with corrosion risks. Once such pipelines are corroded, it will cause serious consequences. It is necessary to measure the wall thickness of such pipelines. . The existing stainless steel pipe wall thickness measurement method generally adopts the traditional ultrasonic thickness gauge for fixed-point measurement. Because the ultrasonic thickness gauge can only measure the thickness at fixed points, it cannot realize continuous scanning, and it is easy to miss the inspection or fail to detect the most serious defect area, and there are many disadvantages.

该系统可实现不锈钢管线的连续扫查功能，且无需对管线表面进行处理、无需拆除浅层保温、也无需使用耦合剂，检测速度快、检测精度高。The system can realize the continuous scanning function of stainless steel pipeline, and it does not need to treat the surface of the pipeline, remove the shallow insulation layer, and do not need to use couplant. The detection speed is fast and the detection accuracy is high.

发明内容SUMMARY OF THE INVENTION

本发明目的是提供一种扫查不锈钢管壁腐蚀缺陷的中频电磁测量方法和装置。The purpose of the present invention is to provide a medium frequency electromagnetic measurement method and device for scanning corrosion defects of stainless steel pipe wall.

本发明为实现上述目的所采用的技术方案是：The technical scheme that the present invention adopts for realizing the above-mentioned purpose is:

一种扫查不锈钢管壁腐蚀缺陷的中频电磁测量装置，包括：An intermediate frequency electromagnetic measuring device for scanning corrosion defects of stainless steel pipe wall, comprising:

中频电磁主机，用于将电磁信号发射给传感线总成；The intermediate frequency electromagnetic host is used to transmit electromagnetic signals to the sensing line assembly;

传感器总成，用于采集待测不锈钢管线检测部位的检测信号并将检测信号通过中频电磁主机发送给数据处理终端；The sensor assembly is used to collect the detection signal of the detection part of the stainless steel pipeline to be tested and send the detection signal to the data processing terminal through the intermediate frequency electromagnetic host;

数据处理终端，用于对检测信号进行处理并提取检测信号中与不锈钢管线壁厚的特征值以及显示不锈钢管线壁厚值的实时成像结果。The data processing terminal is used to process the detection signal, extract the characteristic value of the detection signal and the wall thickness of the stainless steel pipeline, and display the real-time imaging result of the wall thickness of the stainless steel pipeline.

所述传感器总成由发射线圈、接收线圈和增量式计步器组成，并置于不锈钢管线外表面，可连续移动；所述传感器总成具有计步功能，用于对检测位置进行定位。The sensor assembly is composed of a transmitting coil, a receiving coil and an incremental pedometer, and is placed on the outer surface of the stainless steel pipeline and can move continuously; the sensor assembly has a step counting function and is used to locate the detection position.

所述中频电磁主机与传感器总成通过线缆连接；所述中频电磁主机与数据处理终端通过蓝牙无线连接。The intermediate frequency electromagnetic host and the sensor assembly are connected by cables; the intermediate frequency electromagnetic host and the data processing terminal are wirelessly connected by bluetooth.

一种扫查不锈钢管壁腐蚀缺陷的中频电磁测量方法，包括以下步骤：An intermediate frequency electromagnetic measurement method for scanning corrosion defects of stainless steel pipe wall, comprising the following steps:

1)将传感器总成，置于待测不锈钢管线的外表面，利用中频电磁主机发出电磁信号；连续移动传感器总成，通过传感器总成采集扫查区域覆盖的检测信号；1) Place the sensor assembly on the outer surface of the stainless steel pipeline to be tested, and use the intermediate frequency electromagnetic host to send out electromagnetic signals; move the sensor assembly continuously, and collect the detection signal covered by the scanning area through the sensor assembly;

2)将传感器总成采集到的检测信号经中频电磁主机滤波处理后通过蓝牙传输至数据处理终端；2) The detection signal collected by the sensor assembly is filtered and processed by the intermediate frequency electromagnetic host and then transmitted to the data processing terminal through Bluetooth;

3)数据处理终端对处理后的检测信号进行处理并提取检测信号中的特征值；3) The data processing terminal processes the processed detection signal and extracts characteristic values in the detection signal;

4)利用特征值计算不锈钢管线壁厚值；4) Calculate the wall thickness of the stainless steel pipeline by using the characteristic value;

5)利用超声波测厚仪测得待测不锈钢管线某点壁厚值，并与步骤4)中计算得到的不锈钢管线壁厚值进行比较，获得校准系数；5) use the ultrasonic thickness gauge to measure the wall thickness value of a certain point of the stainless steel pipeline to be measured, and compare with the stainless steel pipeline wall thickness value calculated in step 4) to obtain a calibration coefficient;

6)将步骤4)中计算得到的不锈钢管线壁厚值与步骤5)中得到的校准系数相乘，得到校准后的不锈钢管线壁厚值；6) multiply the stainless steel pipeline wall thickness value calculated in step 4) with the calibration coefficient obtained in step 5) to obtain the stainless steel pipeline wall thickness value after calibration;

7)数据处理终端显示检测位置与步骤6)中得到的不锈钢管线壁厚值的实时成像结果。7) The data processing terminal displays the real-time imaging result of the detection position and the stainless steel pipeline wall thickness value obtained in step 6).

中频电磁主机发出的电磁信号的发射频率在16-32HZ之间、电磁信号的发射电压值在1-10V之间。The emission frequency of the electromagnetic signal sent by the intermediate frequency electromagnetic host is between 16-32HZ, and the emission voltage value of the electromagnetic signal is between 1-10V.

所述检测信号包含了电磁信号在传递过程中产生的随时间衰减的感应电压值和计步定位值。The detection signal includes an induced voltage value and a pedometer positioning value that decay with time and are generated during the transmission of the electromagnetic signal.

步骤3)具体为：Step 3) is specifically:

3.1)数据处理终端接收到中频电磁主机发送发送的处理后的每个检测位置时间窗数据：按时间分布的20-31个时窗，去除前0-5个时窗即去除磁饱和区域；3.1) The data processing terminal receives the time window data of each detection position after processing sent by the intermediate frequency electromagnetic host: 20-31 time windows distributed by time, remove the first 0-5 time windows to remove the magnetic saturation area;

3.2)计算剩余各时窗的“lg(感应电压V)、lg(响应时间T)”；3.2) Calculate the "lg (induced voltage V) and lg (response time T)" of the remaining time windows;

3.3)计算每相邻四组时窗“lg(响应时间T)、lg(感应电压V)”，四点拟合直线的斜率K值；3.3) Calculate the “lg (response time T), lg (induced voltage V)” of each adjacent four groups of time windows, and the slope K value of the four-point fitting straight line;

3.4)对比步骤3.3)中所计算的斜率K值，选取最大K值Kmax；3.4) Compare the slope K value calculated in step 3.3), and select the maximum K value Kmax;

3.5)选取Kmax对应时窗，同时选取该时窗及前三个时窗的数据作为选择区间；3.5) Select the corresponding time window of Kmax, and simultaneously select the data of this time window and the first three time windows as the selection interval;

3.6)计算选择区间四个时窗的“响应时间T，lg(感应电压V)”拟合四点直线的斜率，并对斜率求绝对值，该斜率绝对值即为特征值S。3.6) Calculate the "response time T, lg (induced voltage V)" of the four time windows in the selection interval to fit the slope of the four-point straight line, and find the absolute value of the slope, which is the eigenvalue S.

每个时窗包括响应时间T及对应感应电压值V。Each time window includes a response time T and a corresponding induced voltage value V.

步骤4)具体为：Step 4) is specifically:

4.1)对不同壁厚的标准试块进行测量，获得对应已知壁厚值的一组特征值组；4.1) Measure standard test blocks with different wall thicknesses to obtain a set of characteristic value groups corresponding to known wall thickness values;

4.2)通过步骤4.1)中的已知壁厚值和特征值组拟合得到不锈钢管线壁厚与特征值的关系式；4.2) The relationship between the wall thickness of the stainless steel pipeline and the eigenvalue is obtained by fitting the known wall thickness value and the eigenvalue group in step 4.1);

4.3)将步骤3.6)中得到的实际未知壁厚的特征值，带入步骤4.2)中的关系式中，即可得到对应位置的实际未知壁厚值。4.3) Bring the eigenvalue of the actual unknown wall thickness obtained in step 3.6) into the relational formula in step 4.2), and then the actual unknown wall thickness value of the corresponding position can be obtained.

所述不锈钢管线壁厚与特征值的关系式为：The relationship between the wall thickness of the stainless steel pipeline and the eigenvalue is:

D＝R*S^B，D=R*S^B ,

其中D为不锈钢管线壁厚，S为特征值，R、B为常数。Among them, D is the wall thickness of the stainless steel pipeline, S is the characteristic value, and R and B are constants.

本发明具有以下有益效果及优点：The present invention has the following beneficial effects and advantages:

1.本发明无需去除包覆层、防腐涂层即可对不锈钢壁厚进行监测。1. The present invention can monitor the wall thickness of stainless steel without removing the coating layer and the anti-corrosion coating.

2.本发明采用扫查的方法(在管壁上移动，连续进行检测)，检测效率高。2. The present invention adopts the method of scanning (moving on the pipe wall, continuous detection), and the detection efficiency is high.

3.本发明受提离高度(150mm以下)的影响小。3. The present invention is less affected by the lift-off height (below 150 mm).

4.本发明可以检测高温管线。4. The present invention can detect high temperature pipelines.

5.本发明检测过程中无需耦合剂。5. No coupling agent is required in the detection process of the present invention.

附图说明Description of drawings

图1是本发明结构图。Figure 1 is a structural diagram of the present invention.

图2是标准壁厚拟合曲线图。Figure 2 is a graph of the standard wall thickness fitting curve.

图3是依照本发明第一实施例的中频电磁测量壁厚结果图。FIG. 3 is a graph showing the result of the intermediate frequency electromagnetic measurement of wall thickness according to the first embodiment of the present invention.

具体实施方式Detailed ways

下面结合附图及实施例对本发明做进一步的详细说明。The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

该系统装置由一个中频电磁主机(单通道)、一个带增量式计步器的传感器总成、一个数据处理终端(PAD)及6芯电缆、支撑配件等组成。主机收到的回馈信号由蓝牙传输到数据处理终端(PAD)。The system device consists of an intermediate frequency electromagnetic host (single channel), a sensor assembly with an incremental pedometer, a data processing terminal (PAD), a 6-core cable, and supporting accessories. The feedback signal received by the host is transmitted to the data processing terminal (PAD) by Bluetooth.

中频电磁主机通过6芯电缆，连接传感器总成，负责激励信号的发射和回馈信号的接收；数据处理终端(PAD)负责采集检测回馈信号，并利用算法软件对采集的信号进行解析计算(不锈钢材质特殊算法)，在屏幕上直接呈现不锈钢管线壁厚扫查结果的图谱。The intermediate frequency electromagnetic host is connected to the sensor assembly through a 6-core cable, which is responsible for the emission of excitation signals and the reception of feedback signals; the data processing terminal (PAD) is responsible for collecting and detecting feedback signals, and uses algorithm software to analyze and calculate the collected signals (stainless steel material). Special algorithm), the map of the scanning results of the wall thickness of the stainless steel pipeline is directly displayed on the screen.

该系统利用针对不锈钢管线信号处理的特殊算法，在无需进行表面处理的情况下，实现对不锈钢管线壁厚的连续扫查，可适用不同管径的检测要求，并可在300℃温度下实现不锈钢内部腐蚀缺陷的快速扫查与缺陷严重程度的半定量计算。该系统传感器中包括的计步装置，可以精确确定腐蚀缺陷的所在位置，实现快速、直接、准确的定位不锈钢管线中的腐蚀缺陷。The system uses a special algorithm for signal processing of stainless steel pipelines to realize continuous scanning of the wall thickness of stainless steel pipelines without surface treatment. Rapid scanning of internal corrosion defects and semi-quantitative calculation of defect severity. The pedometer included in the sensor of the system can accurately determine the location of the corrosion defect, so as to realize the rapid, direct and accurate location of the corrosion defect in the stainless steel pipeline.

如图1所示，一种扫查不锈钢管壁腐蚀缺陷的中频电磁测量方法和装置，该装置系统由一个中频电磁主机、一个带增量式计步器的传感器总成、一个数据处理终端(PAD)及一根6芯电缆组成。As shown in Figure 1, an intermediate frequency electromagnetic measurement method and device for scanning corrosion defects of stainless steel pipe wall, the device system consists of an intermediate frequency electromagnetic host, a sensor assembly with an incremental pedometer, a data processing terminal ( PAD) and a 6-core cable.

所述的中频电磁主机主要实现电磁信号的发射功能、信号采集功能。The intermediate frequency electromagnetic host mainly realizes the transmission function and signal acquisition function of electromagnetic signals.

所述的带增量式计步器功能的传感器总成，由发射线圈、接收线圈和增量式计步器组成；在检测不锈钢管线时，传感器总成置于管线外光滑表面，连续移动传感器总成，用于连续采集检测部位的电磁信号。该传感器总成带有计步功能，可实现检测位置的步长定位功能。The sensor assembly with incremental pedometer function is composed of a transmitting coil, a receiving coil and an incremental pedometer; when detecting a stainless steel pipeline, the sensor assembly is placed on a smooth surface outside the pipeline, and the sensor is continuously moved. The assembly is used to continuously collect the electromagnetic signals of the detection part. The sensor assembly has a step-counting function, which can realize the step-length positioning function of the detected position.

所述的不锈钢传感器总成与中频电磁主机通过6芯电缆连接。The stainless steel sensor assembly is connected with the intermediate frequency electromagnetic host through a 6-core cable.

所述的数据处理终端(PAD)包含反馈信号的接收功能、数据处理功能(通过特定算法，把扫查区域的不锈钢壁厚计算结果直接输出在图谱中)。The data processing terminal (PAD) includes a feedback signal receiving function and a data processing function (through a specific algorithm, the calculation result of the stainless steel wall thickness in the scanning area is directly output in the map).

所述的数据处理终端系统(PAD)与中频电磁主机通过蓝牙连接。The data processing terminal system (PAD) is connected with the intermediate frequency electromagnetic host through bluetooth.

一种扫查不锈钢管壁腐蚀缺陷的中频电磁测量方法和装置，其测量方法的步骤包括：An intermediate frequency electromagnetic measurement method and device for scanning corrosion defects of stainless steel pipe walls, the steps of the measurement method include:

步骤1：根据待测不锈钢管线的具体材质、管径、保温层厚度等选择合适的传感器总成；Step 1: Select the appropriate sensor assembly according to the specific material, diameter and thickness of the insulation layer of the stainless steel pipeline to be tested;

步骤2：根据待测不锈钢管线的具体材质、壁厚、保温层厚度及步骤1中选择的传感器总成，选择合适的发生电磁信号。电磁信号的发射频率在16-32HZ之间选择、电磁信号的发射电压值在1-10V之间选择；Step 2: According to the specific material of the stainless steel pipeline to be tested, the wall thickness, the thickness of the insulation layer and the sensor assembly selected in Step 1, select the appropriate electromagnetic signal to generate. The emission frequency of electromagnetic signal is selected between 16-32HZ, and the emission voltage value of electromagnetic signal is selected between 1-10V;

步骤3：将步骤1中选择的传感器总成，置于待测不锈钢管线的外表面(或保温层外表面)，采用中频电磁主机发出步骤2中选择的电磁信号。连续移动传感器总成，采集传感器总成扫查区域覆盖的检测信号。该检测信号包含了电磁信号在传递过程中产生的随时间衰减的感应电压值和计步定位值；Step 3: Place the sensor assembly selected in step 1 on the outer surface of the stainless steel pipeline to be tested (or the outer surface of the insulation layer), and use the medium frequency electromagnetic host to send out the electromagnetic signal selected instep 2. Continuously move the sensor assembly to collect detection signals covered by the scanning area of the sensor assembly. The detection signal includes the induced voltage value and the pedometer positioning value that decay with time generated during the transmission of the electromagnetic signal;

步骤4：步骤2中的检测信号经中频电磁主机通过蓝牙传输至数据处理终端；Step 4: The detection signal inStep 2 is transmitted to the data processing terminal through the intermediate frequency electromagnetic host through Bluetooth;

步骤5：数据处理终端对数据进行批量处理并提取与壁厚相关的特征值，其步骤包括：Step 5: The data processing terminal processes the data in batches and extracts the feature values related to the wall thickness. The steps include:

步骤5.1：数据处理终端接收到的经预处理的每个检测位置数据包括按时间分布的20-31个时窗(每个时窗包括响应时间T及对应感应电压值V/A，A为发射电流)，去除前0-5个时窗(磁饱和区域)；Step 5.1: The preprocessed data of each detection position received by the data processing terminal includes 20-31 time windows distributed by time (each time window includes the response time T and the corresponding induced voltage value V/A, A is the emission current), remove the first 0-5 time windows (magnetic saturation region);

步骤5.2：计算剩余各时窗的“lg(感应电压V/A)、lg(响应时间T)”；Step 5.2: Calculate "lg (induced voltage V/A), lg (response time T)" of the remaining time windows;

步骤5.3：计算每相邻四组时窗“lg(响应时间T)、lg(感应电压V/A)”，四点拟合直线的斜率K值(一阶导数)；Step 5.3: Calculate the “lg (response time T), lg (induced voltage V/A)” of each adjacent four groups of time windows, and the slope K value (first derivative) of the four-point fitting straight line;

步骤5.4：对比步骤5.3中所获得的斜率K值，选取最大K值K_max；Step 5.4: compare the slope K value obtained in step 5.3, and select the maximum K value K_max ;

步骤5.5：选取K_max对应时窗，同时选取该时窗及前三个时窗的数据作为选择区间；Step 5.5: Select the time window corresponding to K_max , and select the data of this time window and the first three time windows as the selection interval;

步骤5.5：计算选择区间四个时窗的“响应时间T，lg(感应电压V/A)”拟合四点直线的斜率，并对斜率求绝对值，该斜率绝对值即为特征值S。Step 5.5: Calculate the "response time T, lg (induced voltage V/A)" of the four time windows in the selection interval to fit the slope of the four-point straight line, and find the absolute value of the slope. The absolute value of the slope is the characteristic value S.

步骤6：利用步骤5中得到的特征值S计算不锈钢壁厚值，其步骤包括：Step 6: Calculate the stainless steel wall thickness value using the characteristic value S obtained inStep 5, and the steps include:

步骤6.1：对不同壁厚的标准试块(4mm、6mm、8mm、10mm、12mm、16mm、20mm，公差±0.05mm)进行测量，获得对应已知壁厚值的一组特征值组(S4、S6、S8、S10、S12、S16、S20)，标准试块是不同的标准壁厚的样板，比如2mm标准试块为2mm标准壁厚的样板，获取特征值的过程同步骤5；Step 6.1: Measure standard test blocks with different wall thicknesses (4mm, 6mm, 8mm, 10mm, 12mm, 16mm, 20mm, tolerance ±0.05mm) to obtain a set of characteristic value groups corresponding to known wall thickness values (S4, S6, S8, S10, S12, S16, S20), the standard test block is a sample with different standard wall thicknesses, for example, a 2mm standard test block is a sample with a 2mm standard wall thickness, the process of obtaining the characteristic value is the same asstep 5;

步骤6.2：通过步骤6.1中的已知壁厚值和特征值组拟合得到壁厚与特征值的关系式；Step 6.2: Obtain the relationship between the wall thickness and the eigenvalue by fitting the known wall thickness value and eigenvalue group in step 6.1;

步骤6.3：将步骤5.5中得到的实际未知壁厚的特征值，带入步骤6.2中的关系式中，即可得到对应位置的实际未知壁厚值。Step 6.3: Bring the eigenvalue of the actual unknown wall thickness obtained in Step 5.5 into the relational formula in Step 6.2, and then the actual unknown wall thickness value of the corresponding position can be obtained.

步骤7：利用超声波测厚仪获得待测管线某点壁厚值，并与步骤6.3中获得的壁厚值进行比较，获得校准系数。Step 7: Use the ultrasonic thickness gauge to obtain the wall thickness value of a certain point of the pipeline to be measured, and compare it with the wall thickness value obtained in step 6.3 to obtain the calibration coefficient.

步骤8：将步骤6.3中所得壁厚值与步骤7中得到的校准系数相乘，得到校准后的壁厚值。Step 8: Multiply the wall thickness value obtained in step 6.3 by the calibration coefficient obtained in step 7 to obtain the calibrated wall thickness value.

步骤9：显示检测位置与步骤8中得到的壁厚值的实时成像结果。Step 9: Display the real-time imaging result of the detection position and the wall thickness value obtained in Step 8.

实施例Example

1、壁厚与特征值关系的获取1. Obtaining the relationship between wall thickness and eigenvalue

1.1、选择不锈钢传感器总成，中频电磁仪发生电磁信号频率选择16HZ、电压选择5V；1.1. Select the stainless steel sensor assembly, select 16HZ for the frequency of the electromagnetic signal generated by the intermediate frequency electromagnetic instrument, and select 5V for the voltage;

1.2、将传感器总成分别放置于4mm、6mm、8mm、10mm、12mm、16mm、20mm标准304不锈钢试块表面，并进行定点测量，获得特征值分别为：S4＝3.75、S4＝2.48、S8＝1.93、S10＝1.55、S12＝1.24、S16＝0.97、S20＝0.79。1.2. Place the sensor assembly on the surface of 4mm, 6mm, 8mm, 10mm, 12mm, 16mm, 20mm standard 304 stainless steel test blocks respectively, and carry out fixed-point measurement, and the obtained characteristic values are: S4=3.75, S4=2.48, S8= 1.93, S10=1.55, S12=1.24, S16=0.97, S20=0.79.

1.3、将七组标准壁厚值与对应特征值进行拟合，得到壁厚与特征值的关系式，如图2所示。1.3. Fit the seven groups of standard wall thickness values with the corresponding eigenvalues to obtain the relationship between the wall thickness and the eigenvalues, as shown in Figure 2.

1.4、上述304不锈钢壁厚与特征值关系为：D＝15.47*S^-1.027，其中D为壁厚，S为特征值。1.4. The relationship between the above 304 stainless steel wall thickness and eigenvalue is: D=15.47*S^-1.027 , where D is the wall thickness and S is the eigenvalue.

2、某化工装置入口管线，外径为219mm，壁厚为4.8mm，材质为304不锈钢，运行温度为35℃，管线长度为1米，检测区域0.8米，按一下步骤进行检测：2. The inlet pipeline of a chemical plant has an outer diameter of 219mm, a wall thickness of 4.8mm, a material of 304 stainless steel, an operating temperature of 35°C, a pipeline length of 1 meter, and a detection area of 0.8 meters. Follow the steps below to detect:

2.1、选择不锈钢传感器总成，发生电磁信号频率为16HZ，电压选择5V；2.1. Select the stainless steel sensor assembly, the frequency of the electromagnetic signal is 16HZ, and the voltage is 5V;

2.2、将传感器总成放置于管线外表面，并用数据处理终端控制中频电磁发生系统发出电磁信号，将传感器总成沿管线待测区域平缓移动，直到0.8m检测区域结束；2.2. Place the sensor assembly on the outer surface of the pipeline, and use the data processing terminal to control the intermediate frequency electromagnetic generating system to send out electromagnetic signals, and move the sensor assembly smoothly along the pipeline to be tested area until the 0.8m detection area ends;

2.3、在数据处理终端显示屏上显示检测位置与对应壁厚的实时图像；2.3. Display the real-time image of the detection position and the corresponding wall thickness on the display screen of the data processing terminal;

2.4、该段管线扫查壁厚图像如图3。2.4. The scanning wall thickness image of this section of pipeline is shown in Figure 3.

以上所述，仅为本发明的一个具体实施案例，但本发明的保护范围并不局限于此。任何熟悉本技术领域的技术人员在本发明所述的技术范围内，根据本发明的技术方案及其发明构思加以等同替换或改变，都涵盖在本发明的保护范围之内。The above is only a specific implementation case of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art who is familiar with the technical scope of the present invention can make equivalent replacements or changes according to the technical solutions of the present invention and its inventive concept, which are all included within the protection scope of the present invention.

Claims (10)

1. The utility model provides a sweep and examine nonrust steel pipe wall corrosion defect's intermediate frequency electromagnetic measurement device which characterized in that includes:

the medium-frequency electromagnetic host is used for transmitting electromagnetic signals to the sensing line assembly;

the sensor assembly is used for acquiring a detection signal of a detection part of the stainless steel pipeline to be detected and sending the detection signal to the data processing terminal through the medium-frequency electromagnetic host;

and the data processing terminal is used for processing the detection signal, extracting a characteristic value of the wall thickness of the stainless steel pipeline in the detection signal and displaying a real-time imaging result of the wall thickness value of the stainless steel pipeline.

2. The medium-frequency electromagnetic measurement device for scanning the corrosion defects of the wall of the stainless steel pipe according to claim 1, wherein the sensor assembly consists of a transmitting coil, a receiving coil and an incremental pedometer, is arranged on the outer surface of the stainless steel pipe and can move continuously; the sensor assembly has a step counting function and is used for positioning a detection position.

3. The medium-frequency electromagnetic measurement device for scanning the corrosion defects of the stainless steel pipe wall according to claim 1, wherein the medium-frequency electromagnetic host is connected with the sensor assembly through a cable; the intermediate frequency electromagnetic host is in wireless connection with the data processing terminal through Bluetooth.

4. A medium-frequency electromagnetic measurement method for scanning corrosion defects of a stainless steel pipe wall is characterized by comprising the following steps:

1) placing a sensor assembly on the outer surface of a stainless steel pipeline to be detected, and sending an electromagnetic signal by using a medium-frequency electromagnetic host; continuously moving the sensor assembly, and acquiring detection signals covered by a scanning area through the sensor assembly;

2) a detection signal acquired by the sensor assembly is filtered by the medium-frequency electromagnetic host and then transmitted to the data processing terminal through Bluetooth;

3) the data processing terminal processes the processed detection signals and extracts characteristic values in the detection signals;

4) calculating the wall thickness value of the stainless steel pipeline by using the characteristic value;

5) measuring the wall thickness value of a certain point of the stainless steel pipeline to be measured by using an ultrasonic thickness gauge, and comparing the wall thickness value with the wall thickness value of the stainless steel pipeline calculated in the step 4) to obtain a calibration coefficient;

6) multiplying the wall thickness value of the stainless steel pipeline obtained in the step 4) by the calibration coefficient obtained in the step 5) to obtain a calibrated wall thickness value of the stainless steel pipeline;

7) and the data processing terminal displays the detection position and the real-time imaging result of the wall thickness value of the stainless steel pipeline obtained in the step 6).

5. The method of claim 4, wherein the transmission frequency of the electromagnetic signal from the medium frequency electromagnetic mainframe is between 16Hz and 32Hz, and the transmission voltage of the electromagnetic signal is between 1V and 10V.

6. The method as claimed in claim 4, wherein the detection signal comprises an induced voltage value and a step-counting positioning value which are generated in the transmission process of the electromagnetic signal and decay with time.

7. The medium-frequency electromagnetic measurement method for scanning the corrosion defects of the stainless steel pipe wall according to claim 4, wherein the step 3) is specifically as follows:

3.1) the data processing terminal receives each processed detection position time window data sent and sent by the medium-frequency electromagnetic host: removing the first 0-5 time windows according to 20-31 time windows distributed in time, namely removing the magnetic saturation area;

3.2) calculating the 'lg (induced voltage V) and lg (response time T)' of each residual time window;

3.3) calculating the slope K value of four-point fitting straight lines of four adjacent time windows 'lg (response time T) and lg (induced voltage V)';

3.4) comparing the slope K values calculated in the step 3.3), and selecting a maximum K value Kmax;

3.5) selecting a time window corresponding to Kmax, and simultaneously selecting data of the time window and the first three time windows as a selection interval;

3.6) calculating the 'response time T, lg (induced voltage V)' of four time windows in the selection interval to fit the slope of a four-point straight line, and solving the absolute value of the slope, wherein the absolute value of the slope is the characteristic value S.

8. The method of claim 7, wherein each time window comprises a response time T and a corresponding induced voltage value V.

9. The medium-frequency electromagnetic measurement method for scanning the corrosion defects of the stainless steel pipe wall according to claim 4, wherein the step 4) is specifically as follows:

4.1) measuring the standard test blocks with different wall thicknesses to obtain a group of characteristic value groups corresponding to known wall thickness values;

4.2) fitting the known wall thickness value and the characteristic value set in the step 4.1) to obtain a relational expression of the wall thickness and the characteristic value of the stainless steel pipeline;

4.3) substituting the characteristic value of the actual unknown wall thickness obtained in the step 3.6) into the relational expression in the step 4.2) to obtain the actual unknown wall thickness value of the corresponding position.

10. The medium-frequency electromagnetic measurement method for scanning the corrosion defects of the wall of the stainless steel pipe according to claim 9, wherein the relation between the wall thickness of the stainless steel pipe and the characteristic value is as follows:

D＝R*S^B，

where D is the stainless steel pipeline wall thickness, S is the characteristic value, and R, B is a constant.

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