Non-Destructive Evaluation of 304 Stainless Steels Using a Scanning Hall-Sensor Microscope: Visualization of Strain-Induced Austenite-Phase Breakdown

1999 ◽  
Vol 591 ◽  
Author(s):  
A. Oota ◽  
K. Miyake ◽  
D. Sugiyama ◽  
H. Aoki
Keyword(s):  
Plastic Deformation ◽  
Shear Stress ◽  
Stainless Steels ◽  
Driving Force ◽  
Room Temperature ◽  
Martensite Phase ◽  
Hall Sensor ◽  
Austenite Phase ◽  
Non Destructive Evaluation ◽  
Non Destructive

ABSTRACTUsing a scanning Hall-sensor microscope with an active area 50pμm × 50μm, we succeeded in visualizing a breakdown of paramagnetic austenite-phase in 304 stainless steels induced by a plastic strain at room temperature, resulting from a transformation to ferromagnetic martensite-phase. Magnetic images of spontaneous magnetic fields on a surface of strained sample show the degree and the place (and/or the extent) of phase breakdown. Furthermore, the images nearly agree with the calculated results for the principal shear stress rather than the principal stress under plastic deformation, indicative of the driving force of this breakdown. The study should open a way for non-destructive evaluation of 304 stainless steels.

scholarly journals Plastic Deformation Influence on Intrinsic Magnetic Field of Austenitic Biomaterials

2016 ◽  
Vol 67 (6) ◽  
pp. 407-413
Author(s):  
Milan Smetana ◽  
Klára Čápová ◽  
Vladimír Chudáčik ◽  
Peter Palček ◽  
Monika Oravcová
Keyword(s):  
Magnetic Field ◽  
Plastic Deformation ◽  
Austenitic Steel ◽  
Medical Practice ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Intrinsic Magnetic Field ◽  
Fluxgate Sensor ◽  
Non Destructive Evaluation ◽  
Non Destructive

Abstract This article deals with non-destructive evaluation of austenitic stainless steels, which are used as the biomaterials in medical practice. Intrinsic magnetic field is investigated using the fluxgate sensor, after the applied plastic deformation. The three austenitic steel types are studied under the same conditions, while several values of the deformation are applied, respectively. The obtained results are presented and discussed in the paper.

Plastic Deformations in Single Crystals of FePd with the L10 Structure

2008 ◽  
Vol 1128 ◽  
Author(s):  
Katsushi Tanaka ◽  
Wang Chen ◽  
Kyosuke Kishida ◽  
Norihiko L. Okamoto ◽  
Haruyuki Inui
Keyword(s):  
Plastic Deformation ◽  
Shear Stress ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Yield Stress ◽  
Room Temperature ◽  
Positive Temperature ◽  
Plastic Deformations ◽  
L10 Structure ◽  
Critical Resolved Shear Stress

AbstractCompressive deformations of L10-ordered single crystals of FePd have been investigated from room temperature to 873 K. The critical resolved shear stress for superlattice dislocations is hard to determine resulting from buckling that occurs after a small amount of conventional plastic deformation. The CRSS for superlattice dislocations determined from yield stress is significantly larger than that of ordinary dislocations. The CRSS for octahedral glide of ordinary and superlattice dislocations are virtually independent of the temperature, and the positive temperature dependence of the yield stress is not observed for both, ordinary and superlattice dislocations, by the present experiments.

Non-Destructive Evaluation of Mechanical Properties of Magnetic Materials

1999 ◽  
Vol 591 ◽  
Author(s):  
Kevin P. Kankolenski ◽  
Susan Z. Hua ◽  
David X. Yang ◽  
G. E. Hicho ◽  
L. J. Swartzendruber ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Domain Walls ◽  
Tensile Axis ◽  
Hysteresis Loops ◽  
Strain Curve ◽  
Low Carbon ◽  
Barkhausen Effect ◽  
Non Destructive Evaluation ◽  
Non Destructive

ABSTRACTA magnetic-based non-destructive evaluation (NDE) method, which employs Barkhausen effect and measurement of the hysteresis loops, is used to correlate the magnetic and mechanical properties of ultra low carbon (ULC) steel. In particular, the NDE method was used to detect small deviations from linearity that occur in the stress-strain curve well below the 0.2% offset strain, and which generally defines the yield point in materials. Results show that three parameters: jumpsum and jumpsum rate (derived from the Barkhausen spectrum), and the relative permeability (derived from the B-H loops) varies sensitively with small permanent strains, and can be related to the plastic deformation in ULC steels. Investigation of micromagnetic structure revealed that plastic deformation leaves a residual stress state in the samples; the associated magneto-elastic energy makes the favorable easy axis of magnetization in a given grain to be the one that lies closest to the tensile axis. The consequence of this realignment of domains is that wall motion becomes intergranular in nature (as opposed to intragranular in unstrained samples). As a result, the more complex grain boundaries instead of dislocations, become the dominant pinning sites for domain walls. These observations provide a microscopic interpretation of the observed changes in the measured magnetic properties.

Sign in / Sign up

Export Citation Format

Share Document