Eureka AIR delivers breakthrough ideas for toughest innovation challenges, trusted by R&D personnel around the world.

A pulsed eddy current detection method and detection device for the conductivity of ferromagnetic metal materials

A ferromagnetic metal and electrical conductivity technology, which is applied in the field of pulsed eddy current testing methods and testing devices for electrical conductivity of ferromagnetic metal materials, can solve problems such as large errors and poor repeatability of testing results, so as to reduce the influence, improve the technological level, and improve the The effect of precision and reliability

Active Publication Date: 2020-11-10
BEIHANG UNIV
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, ferromagnetic metal materials are good conductors, which require a large current excitation to generate a large enough voltage signal. Due to the thermal effect of the excitation current and the measurement error of the weak voltage signal, the four-probe method will cause errors in the detection of the conductivity of ferromagnetic metal materials. Larger, poor repeatability of test results

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A pulsed eddy current detection method and detection device for the conductivity of ferromagnetic metal materials
  • A pulsed eddy current detection method and detection device for the conductivity of ferromagnetic metal materials
  • A pulsed eddy current detection method and detection device for the conductivity of ferromagnetic metal materials

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0080] An example of conducting a conductivity test on a ferromagnetic member by the method of the present invention is given below.

[0081] The tested ferromagnetic components are three cylindrical steel test blocks with a diameter of 100mm and a thickness of 6mm, and the materials are 20# steel, 45# steel and Q235 steel respectively.

[0082] Place the coil probe above the center of the three tested steel test blocks in turn, keep the lift-off distance of the coil probe unchanged at 5mm, and the pulse excitation current amplitude I 0 Take 0.2A as a step, gradually increase from 0.2A to 3.0A, first obtain the pulse eddy current detection signal according to the SAP step in the present invention, and then use the detection signal to establish a least squares problem according to the PIP step, and obtain different amplitude pulse current excitations The inversion results of the conductivity and relative permeability of the ferromagnetic component under test are plotted as foll...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
diameteraaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

The invention discloses a pulsed eddy current detection method and a detection device for conductivity of a ferromagnetic metal material, and belongs to the technical field of electromagnetic nondestructive testing. The method comprises the following steps of: using an inductive voltage measurement curve to establish the least squares problem between a measured value of an induced voltage time domain signal and a theoretical calculated value to invert the conductivity and magnetic permeability of a ferromagnetic member to be tested, based on a time-domain analytical solution of an induced voltage of a pulsed eddy current detection model of a ferromagnetic plate; obtaining a change curve of conductivity inversion results under different amplitude pulse current excitations by gradually increasing the amplitude of a pulse excitation current; and finding an intersection point of the change curve of the conductivity inversion results and an ordinate axis by a curve fitting method, that is,the conductivity of the ferromagnetic member to be tested. The method and device provided by the invention can provide non-contact and nondestructive detection for the conductivity of the ferromagnetic metal material in the industry, weaken the influence of the nonlinear change of the magnetic permeability on the conductivity detection result, and improve the accuracy and reliability.

Description

technical field [0001] The invention belongs to the technical field of electromagnetic nondestructive testing, and in particular relates to a pulse eddy current testing method and a testing device for the electrical conductivity of ferromagnetic metal materials. Background technique [0002] Electrical conductivity is an important parameter to characterize the electrical conductivity of metal materials, which is closely related to the material's material, microstructure, and heat treatment state. By detecting the electrical conductivity of ferromagnetic metal materials, the raw materials can be sorted and identified, the heat treatment states such as annealing and quenching can be judged, the hardness and mechanical properties of ferromagnetic components can be evaluated, and the residual stress and metallographic structure changes in ferromagnetic components can be detected. . Therefore, non-destructive testing of the electrical conductivity of ferromagnetic metal material...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G01N27/02G01R27/02
CPCG01N27/025G01R27/02
Inventor 陈兴乐王兆晖厉静雯
Owner BEIHANG UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com