Measurement System of Metal Magnetic Memory Method Signals around Rectangular Defects of a Ferromagnetic Pipe

Abstract

Oil and gas pipeline networks require the periodic inspection of their infrastructure, which can cause gas and oil leakage with several damages to the environment and human health. For this, non-destructive testing (NDT) techniques of low-cost and easy implementation are required. An option is the metal magnetic memory (MMM) method, which could be used for real-time monitoring defects of ferromagnetic structures based on the analysis of self-magnetic leakage fields distribution around each defect. This method only requires magnetic sensors with high resolution and a data processing system. We present a measurement system of tangential and normal MMM signals of three rectangular defects of an ASTM A-36 steel pipe. This system is formed by a magnetoresistive sensor, an Arduino nano and a virtual instrumentation. The measured magnetic signals have non-uniform distributions around the rectangular defects, which have small differences with respect to the results obtained of a 2D magnetic dipole model. The size of each rectangular defect is related to the amplitude and shape of its tangential and normal MMM signals. The proposed system could be used for real-time monitoring of the size and location of rectangular defects of ferromagnetic pipes. This system does not require expensive equipment, operators with high skill level or a special treatment of the ferromagnetic samples.

Influence of the Crane Load and Measurement Speed on the Properties of the Magnetic Field of the Girders

“…The verification tests were carried out on pipelines using the metal magnetic memory method. The stress concentration zones shown were compared with other methods of non-destructive testing to ensure the reliability of the method [3,4,20].…”

Simulations of Magnetic Field Variations Around Rectangular Defects of Ferromagnetic Materials

“…The Magnetic Memory Method is a type of non-destructive test that makes use of the analysis of the remaining magnetic field in the structures, materials, or pieces in which said test is carried out. Defects in ferromagnetic materials generate disturbances in the residual magnetic field they possess [14][15][16][17]. This method is increasingly used in the industry since it is a non-invasive evaluation method that does not require highly specialized equipment or arduously trained operators for its handling.…”

Low-Frequency Magnetic Fields in Diagnostics of Low-Speed Electrical and Mechanical Systems

“…Utilizing the Villari effect, applications mainly in energetics that are based on the systematic measurement and evaluation of minor magnetization loops have been found [33]. With respect to the magnetometry utilization for simpler planar and spatial geometric objects [34], 1D and 2D geometry [35] is mostly used-the signal is sensed on the surface of the material and it is not emitted to the surroundings. The miniaturization of the sensors in the form of MEMS (micro electromechanical systems) [36] allows embedding them into the construction for online monitoring of the analyzed elastic properties of components.…”