Evaluation of a reverse-side defect on stainless steel plates by the residual magnetic field method

2000 ◽  
Vol 36 (5) ◽  
pp. 3630-3633 ◽  
Author(s):  
M. Oka ◽  
M. Enokizono
Keyword(s):  
Magnetic Field ◽  
Stainless Steel ◽  
Field Method ◽  
Steel Plates ◽  
Residual Magnetic Field

Detection of Early Stage of Fatigue Changes in Non-Alloy Steel Using Residual Magnetic Field Method

2020 ◽  
Vol 405 ◽  
pp. 277-281
Author(s):  
Patrycja Antonik-Popiołek ◽  
Jacek Głód ◽  
Zbigniew Jurasz ◽  
Janusz Juraszek
Keyword(s):  
Magnetic Field ◽  
Visual Inspection ◽  
Early Stage ◽  
Field Method ◽  
Test Machine ◽  
Notched Specimen ◽  
Second Stage ◽  
Tensile Fatigue ◽  
Residual Magnetic Field ◽  
Magnetic Field Change

In this work, the fatigue of P265GH steel acc. to EN 10216-2 has been evaluated by measuring a residual magnetic field (RMF). During experiment the notched-specimen has been loaded with a servo-hydraulic uniaxial MTS test machine and a special magnetic sensor was applied. The measurement distribution of the residual magnetic field was performed in two axes. In the first stage of experiment the specimen was gradually loaded with quasi-static force in range of 0 to 16 kN (~ 0.7 Rm). The increase of strength of residual magnetic field was observed only from 0 to 8 kN, whereas in range 8 to 16 kN this effect was not noticed. In the second stage the controlled tensile fatigue test was performed (R = 0, Fmax = 16 kN). Up to 21k load cycles no changes to residual magnetic field were noticed. At 31k cycles the significant increase of amplitude of strength of residual magnetic field change was observed but visual inspection does not show any visible crack, while at 35k cycles crack was visible. It means that applied methodology allow to find the initiation of crack. The performed observation on SEM showed ductile fatigue of fracture.

scholarly journals Evaluation of Fatigue Damage in 304 Stainless Steel by Measuring Residual Magnetic Field

2020 ◽  
Author(s):  
Yi Liu ◽  
Xiwang Lan ◽  
Bo Hu
Keyword(s):  
Magnetic Field ◽  
Stainless Steel ◽  
Fatigue Damage ◽  
304 Stainless Steel ◽  
Magnetic Characteristics ◽  
Fluxgate Sensor ◽  
Residual Magnetic Field ◽  
304 Austenitic Stainless Steel ◽  
Magnetic Field Change ◽  
Field Measuring

To demonstrate the feasibility of the passive magnetic NDT method for damage assessment of 304 austenitic stainless steel, the residual magnetic field change of the 304 stainless steel specimens under fatigue loads was investigated. The measurement was carried out using a fluxgate sensor and the magnetic characteristics were extracted for analysis of fatigue state. Then, the XRD test was carried out to investigate the mechanism of magnetic field changes and verify the reliability of the proposed method. The results show that the variation of the maximum gradient is consistent with the process of fatigue crack growth, which indicates that the fatigue damage can be estimated by residual magnetic field measuring. In future stage, how to distinguish the magnetic field changes derived from martensite transformation or stress magnetization effect will be investigated.

scholarly journals On the Fluctuation Induced Excess Conductivity in Stainless Steel Sheathed MgB2 Tapes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Suchitra Rajput ◽  
Sujeet Chaudhary
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Stainless Steel ◽  
Coherence Length ◽  
Three Dimensional ◽  
Excess Conductivity ◽  
Scaling Functions ◽  
Critical Fluctuations ◽  
Scaling Models

We report on the analyses of fluctuation induced excess conductivity in the - behavior in the in situ prepared MgB2 tapes. The scaling functions for critical fluctuations are employed to investigate the excess conductivity of these tapes around transition. Two scaling models for excess conductivity in the absence of magnetic field, namely, first, Aslamazov and Larkin model, second, Lawrence and Doniach model, have been employed for the study. Fitting the experimental - data with these models indicates the three-dimensional nature of conduction of the carriers as opposed to the 2D character exhibited by the HTSCs. The estimated amplitude of coherence length from the fitted model is ~21 Å.

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