Device for measuring ferromagnetic material internal stress by impulse electromagnetic field

Abstract

The invention relates to a device for measuring internal stress of ferromagnetic material by pulse electromagnetic field. It is composed of detector, pulse electromagnetic field circuit and data acquisition and processing device, the detector part is composed of drive coil (7), heel piece (9) with one fieldpole and two measure poles and two groups of induction coil (8, 8'), weighing cell (4) is placed above the detector (5), the detector (5) is placed above the tested workpiece (6), which are clamped by jig; the pulse electromagnetic field circuit provides 1-3 Tesla strong incentive pulsed electromagnetic field for drive coil (7), the current signal in drive coil (7), the voltage signals of the two groups of drive coils (8, 8') are processed by data acquisition and processing device, thenthe magnetization curve and magnetic hysteresis loop of the tested workpiece (6) are obtained, after various kinds of magnetic parameters of the tested workpiece are determined, the rating curve between the internal stress and various kinds of magnetic parameters are established.

Description

Device for Measuring Internal Stress of Ferromagnetic Materials Using Pulse Electromagnetic Field technical field The invention belongs to the field of non-destructive testing of ferromagnetic materials, and in particular relates to a device for measuring internal stress of ferromagnetic materials by using a pulsed electromagnetic field. Background technique The extensiveness and importance of residual stress problems have been increasingly understood by people. Residual stress has a significant impact on the fatigue strength, stress corrosion, and shape accuracy of components; and its formation varies with the material, shape, forming and processing processes of components. How to determine the magnitude of residual stress, adjust the distribution of residual stress, reduce or eliminate the harm of residual stress to engineering has become a problem of widespread concern. The stress of ferromagnetic materials will lead to changes in their magnetic properties. The method...

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Problems solved by technology

However, its stress transformation mathematical model is currently only applicable to pearlitic carbon steel and certain types of stainless steel, and further research is still needed on the influence of other structures such as martensitic steel and other material factors

This method is more complicated and the measurement accuracy is poor.

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