scholarly journals The Influence of Pulsating Tensile Stress on Residual Magnetic Field of P91 Steel Samples

2019 ◽  
Vol 19 (2) ◽  
pp. 72-82
Author(s):  
A. Złocki ◽  
M. Roskosz ◽  
J. Kwaśniewski
Keyword(s):  
Magnetic Field ◽  
Load Cycle ◽  
Tangential Component ◽  
Preliminary Measurement ◽  
P91 Steel ◽  
Variability Pattern ◽  
Measurement Results ◽  
Residual Magnetic Field ◽  
Flux Gate ◽  
Stress Variations

ABSTRACTMeasurements of Residual Magnetic Field RMF (the tangential component parallel to the load direction) were taken on the surface of P91 steel plate samples (X10CrMoVNb9-1) subjected to periodic pulsating tensile cyclic loads with the use of flux-gate and magneto impedance sensors, and preliminary measurement results are compiled and analyzed. The study investigates how the microstructure and load cycle parameters affect the RMF changes due to stress variations. Each combination of parameters: microstructure and load cycle corresponds to the characteristic variability pattern of magnetization and its maximum and minimum values.

scholarly journals Residual Magnetic Field Non-Destructive Testing of Gantry Cranes

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 564 ◽  
Author(s):  
Janusz Juraszek
Keyword(s):  
Magnetic Field ◽  
Diffraction Method ◽  
Tangential Component ◽  
Gantry Crane ◽  
X Ray Diffraction ◽  
Destructive Testing ◽  
Displacement Boundary ◽  
Residual Magnetic Field ◽  
Non Destructive ◽  
Gantry Cranes

Non-destructive tests of gantry cranes by means of the residual magnetic field (RMF) method were carried out for a duration of 7 years. Distributions of the residual magnetic field tangential and the normal components of their gradients were determined. A database of magnetograms was created. The results show that the gradients of tangential components can be used to identify and localize stress concentration zones in gantry crane beams. Special attention was given to the unsymmetrical distribution of the tangential component gradient on the surface of the crane beam No. 5 (which was the most loaded one). The anomaly was the effect of a slight torsional deflection of the beam as it was loaded. Numerical simulations with the finite element method (FEM) were used to explain this phenomenon. The displacement boundary conditions introduced into the simulations were established experimentally. Validation was carried out using the X-ray diffraction method, which confirmed the location of strain concentration zones (SCZs) identified by means of RMF testing.

Evolution of the Stress-Induced Residual Magnetic Field of X70 Pipeline Steel With Multiple Corrosion Defects

2021 ◽  
Author(s):  
Sheng Bao ◽  
Qiang Luo ◽  
Zhengye Zhao ◽  
Jian Yang
Keyword(s):  
Magnetic Field ◽  
Pipeline Steel ◽  
Normal Component ◽  
Tangential Component ◽  
Magnetic Memory ◽  
X70 Pipeline Steel ◽  
Corrosion Defect ◽  
Residual Magnetic Field ◽  
Corrosion Defects ◽  
Ferromagnetic Steels

Abstract The aim of this research is to investigate the correlation between the residual magnetic field (RMF) and multiple corrosion defects in ferromagnetic steels. Specimens of X70 pipeline steel were machined into standard bars with a single corrosion defect, double corrosion defects and triple corrosion defects, respectively. Tensile tests were carried out to detect the RMF signals on the surface of these specimens. The variations of abnormal magnetic changes of the RMF signals with the external loads were investigated and the results showed that the tangential component and the normal component of the RMF signals of three defect patterns presented different shapes. It was found that the RMF signals were capable of capturing the location and the number of defects in pipeline steels. The peak values of the tangential component and the slopes of the normal component were not influenced by the defects number. This research will promote the investigation on the corrosion defect cluster of ferromagnetic steels based on the metal magnetic memory (MMM) technique.

Methods and preliminary measurement results of liquid Li wettability

2014 ◽  
Vol 85 (2) ◽  
pp. 023506 ◽  
Author(s):  
G. Z. Zuo ◽  
J. S. Hu ◽  
J. Ren ◽  
Z. Sun ◽  
Q. X. Yang ◽  
...  
Keyword(s):  
Preliminary Measurement ◽  
Measurement Results

scholarly journals Ion motion in the current sheet with sheared magnetic field – Part 1: Quasi-adiabatic theory

2013 ◽  
Vol 20 (1) ◽  
pp. 163-178 ◽  
Author(s):  
A. V. Artemyev ◽  
A. I. Neishtadt ◽  
L. M. Zelenyi
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Analytical Description ◽  
Particle Energy ◽  
Tangential Component ◽  
Adiabatic Invariant ◽  
Ion Motion ◽  
Adiabatic Theory ◽  
Fast Oscillations ◽  
The Magnetic Field

Abstract. We present a theory of trapped ion motion in the magnetotail current sheet with a constant dawn–dusk component of the magnetic field. Particle trajectories are described analytically using the quasi-adiabatic invariant corresponding to averaging of fast oscillations around the tangential component of the magnetic field. We consider particle dynamics in the quasi-adiabatic approximation and demonstrate that the principal role is played by large (so called geometrical) jumps of the quasi-adiabatic invariant. These jumps appear due to the current sheet asymmetry related to the presence of the dawn–dusk magnetic field. The analytical description is compared with results of numerical integration. We show that there are four possible regimes of particle motion. Each regime is characterized by certain ranges of values of the dawn–dusk magnetic field and particle energy. We find the critical value of the dawn–dusk magnetic field, where jumps of the quasi-adiabatic invariant vanish.

scholarly journals Measurement experiences with FluxSet digital D/I station

2017 ◽  
Vol 6 (2) ◽  
pp. 279-284 ◽  
Author(s):  
László Hegymegi ◽  
János Szöllősy ◽  
Csaba Hegymegi ◽  
Ádám Domján
Keyword(s):  
Measurement Method ◽  
Measurement Data ◽  
Digital Form ◽  
New Instrument ◽  
Measurement Results ◽  
Inclination Angles ◽  
Flux Gate

Abstract. Geomagnetic observatories use classical theodolites equipped with single-axis flux-gate magnetometers known as declination–inclination magnetometers (DIM) to determine absolute values of declination and inclination angles. This instrument and the measurement method are very reliable but need a lot of handwork and experience. The authors developed and built a non-magnetic theodolite which gives all measurement data in digital form. Use of this instrument significantly decreases the possibility of observation errors and minimises handwork. The new instrument is presented in this paper together with first measurement results in comparison to the classical DIM.

scholarly journals Clarification of the Magnetocapacitance Mechanism for Fe3O4-PDMS Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Chen Guobin ◽  
Yang Hui ◽  
Zhang Xiaoming ◽  
Liu Jun ◽  
Tang Jun
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Preparation Method ◽  
Volume Fraction ◽  
Magnetic Interaction ◽  
Mechanical Parameters ◽  
Measurement Results

We mainly focused on the magnetocapacitance effect of Fe3O4-PDMS nanocomposites. We also proposed the preparation method and measured microstructures, magnetic properties, and magnetocapacitance value of the nanocomposites. The magnetocapacitance measurement results show that the nanocomposites have magnetocapacitance property, the magnetocapacitance with magnetic field depends on the magnetic property, and the value at the same magnetic field is increasing with the volume fraction of Fe3O4nanoparticles. The magnetocapacitance model is proposed to explain this phenomenon by analyzing the magnetic interaction between particles and the viscoelasticity of PDMS. We also calculated the theoretical capacitance value of all samples using the magnetization of nanoparticles and mechanical parameters of PDMS. From the theoretical values, it is concluded that the model we proposed can well explain the magnetocapacitance effect of Fe3O4-PDMS nanocomposites.

scholarly journals A broadband two axis flux-gate magnetometer

1998 ◽  
Vol 41 (3) ◽  
Author(s):  
P. Palangio
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Frequency Range ◽  
Field Station ◽  
Low Weight ◽  
Highly Sensitive ◽  
Flux Gate ◽  
Magnetic Field Variations

A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT) in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west) and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase) of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

scholarly journals Magnetic Target Position Estimation Method Based on Prior Information

2021 ◽  
Vol 2113 (1) ◽  
pp. 012020
Author(s):  
Guangfa Sun
Keyword(s):  
Magnetic Field ◽  
Target Recognition ◽  
A Priori ◽  
Magnetic Sensor ◽  
Test Method ◽  
Target Area ◽  
A Priori Information ◽  
Measurement Results ◽  
Magnetic Target ◽  
Priori Information

Abstract Aiming at the problem of detection and location of magnetic targets in water beach, the acoustic magnetic composite detection method is studied. After the sonar obtains the image of the suspicious object in the target area, the magnetic target recognition and location are realized by using the abnormal magnetic field distribution data near the target area measured by the shipborne magnetic sensor and the multi-sensor information fusion method. A target recognition and location method based on a priori information is proposed to solve the problem that the measurement results of magnetic sensor can not fully reflect the influence of ferromagnetic target on the surrounding magnetic field due to terrain constraints. In order to make up for this lack of information, taking the sonar measurement results as a priori information, the hypothesis test method is adopted to make full use of all the measurement results of different types of sensors to realize the recognition and positioning of magnetic targets.

Flux-gate magnetic field sensor based on yttrium iron garnet films for magnetocardiography investigations

2016 ◽  
Vol 42 (8) ◽  
pp. 860-864 ◽  
Author(s):  
P. M. Vetoshko ◽  
N. A. Gusev ◽  
D. A. Chepurnova ◽  
E. V. Samoilova ◽  
I. I. Syvorotka ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Yttrium Iron Garnet ◽  
Magnetic Field Sensor ◽  
Yttrium Iron ◽  
Garnet Films ◽  
Field Sensor ◽  
Flux Gate ◽  
Iron Garnet

scholarly journals Microwave Characterization of Metal-Decorated Carbon Nanopowders Using a Single Transmission Line

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Francisco Mederos-Henry ◽  
Sophie Hermans ◽  
Isabelle Huynen
Keyword(s):  
Magnetic Field ◽  
Dielectric Constant ◽  
Transmission Line ◽  
Dc Magnetic Field ◽  
Microwave Characterization ◽  
Novel Approach ◽  
Measurement Results ◽  
Complex Magnetic Permeability

This paper presents a novel approach for the characterization of microwave properties of carbon-based nanopowders, decorated or not with magnetic nanoparticles. Their microwave parameters, dielectric constant, electrical conductivity, and complex magnetic permeability are extracted from measurements performed using a single transmission line acting as a test cell. Two geometries of transmission line were tested, and successful results were obtained with each one of them. The measurement results are assessed by a phenomenological model enabling to fit the measurement of the dielectric constant and conductivity, providing an insight on the compacity quality of the powder sample. Also, the extraction of the permeability is validated by the detection of a ferromagnetic resonance showing a linear dependence on external DC magnetic field.

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