A method for measuring steel pipe wall thickness and quality defects using rare earth permanent magnet materials

Abstract

The present invention provides a method for measuring the wall thickness and quality defects of steel pipes using rare earth permanent magnet materials. The method includes: (1) selecting the required permanent magnet material according to the characteristics of the rare earth permanent magnet material, and designing a permanent magnet detection unit carrying device and related auxiliary mechanisms; (2) Design the number and arrangement of permanent magnets according to the measured thickness range of the pipeline; (3) Use Ansys or related software to calculate the magnetic field data and build a mathematical model; (4) Use finite element analysis methods or other methods, Construct the application model of the permanent magnet, the thickness of the pipe wall and the distance between the permanent magnet and the pipe wall; (5) Construct a mathematical model for detecting internal cracks or defects in the pipe wall according to the test data; (6) Output the thickness value of the pipe wall to be tested , crack depth, defect range and physical location of this data, while making future predictions of pipe wall quality.

Description

technical field [0001] The invention relates to the field of steel pipe wall thickness measurement and pipe wall defect detection, in particular to a method for measuring steel pipe wall thickness and quality defects by using rare earth permanent magnet materials. Background technique [0002] At present, the thickness measurement methods include radioactive thickness measurement methods using the penetration characteristics of α-rays, β-rays, and γ-rays; ultrasonic thickness measurement methods using ultrasonic frequency changes; and thickness measurement methods using mechanical contact measurement principles. However, there are many defects in the traditional detection technology: great harm to the human body, strict requirements on the working environment, strict requirements on the medium, etc., which affect the measurement accuracy. [0003] At present, the methods for detecting metal surface and internal defects mainly include ultrasonic flaw detection, AC and DC magn...

AI Technical Summary

Problems solved by technology

However, there are many defects in the traditional detection technology: great harm to the human body, strict requirements on the working environment, strict requirements on the medium, etc., which affect the measurement accuracy

But at present, its detection technology is very difficult to realize in the medium pipeline.

Ultrasonic flaw detection has restrictions on the shape of the controlled object. In the case of complex shapes or low surface cleanliness, ultrasonic flaw detection is very difficult

In addition, the quantitative and positioning accuracy is poor, and it is difficult to realize mobile flaw detection. At the same time, it is limited by the grain structure and tissue uniformity of the material to be tested.

However, AC and DC magnetization flaw detection and eddy current flaw detection have more stringent requirements on the object to be tested, and are mainly aimed at shallow surface layer detection, but the actual application is not mature, especially for mobile flaw detection, it is very difficult to operate

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