Sensing Creep Evolution in 410 Stainless Steel by Magnetic Measurements

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Alberto Polar ◽  
J. E. Indacochea ◽  
M. L. Wang
Keyword(s):  
Stainless Steel ◽  
Magnetic Measurements ◽  
Magnetic Hysteresis ◽  
Magnetic Domain ◽  
Ferromagnetic Material ◽  
Hysteresis Curve ◽  
Nondestructive Examination ◽  
Creep Time ◽  
Ferromagnetic Steel ◽  
Magnetic Hysteresis Curve

The creep evolution was followed by conducting magnetic measurements on ferromagnetic steel samples exposed to different creep strains at a constant temperature. 410 stainless steel (410 SS) rods were submitted to creep at 625°C applying a constant stress of 124 MPa for different creep times. A magnetic hysteresis curve was generated for every sample. It was found that the shape of the hysteresis curves varied with creep time. The extent of creep was assessed by measuring magnetic saturation, coercivity, and remanence. The changes in microstructure due to creep are related to variations in magnetic properties, which are explained in terms of possible magnetic domain pinning. It was observed that the microstructural changes due to creep are better correlated with the coercivity of the material. In summary, it is feasible to use a magnetoelastic sensor to detect the partial level of creep in a ferromagnetic material by nondestructive examination.

Complex Magnetic Investigation of Ferritic Stainless Steel

2005 ◽  
Vol 473-474 ◽  
pp. 231-236 ◽  
Author(s):  
István Mészáros
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Magnetic Measurements ◽  
Ferromagnetic Material ◽  
Saturation Induction ◽  
Steel Aisi ◽  
Working Principle ◽  
Non Destructive ◽  
Aisi 430 ◽  
Stainless Steel Aisi

Magnetic Barkhausen noise measurement (MBN) is a relatively new non-destructive detection technique. Its working principle is based on Barkhausen discontinuities or noise when a ferromagnetic material is subjected to a varying magnetic field. MBN is being used to characterise the stress state of a ferritic stainless steel (AISI 430). Other magnetic parameters such as saturation induction (BMax), remnant induction (BR), coercive field (HC) and maximal relative permeability (PMax) derived from the hysteresis loop have also been used to support the results achieved using MBN. Microstructural changes due to cold working and heat treatments were characterized by the applied magnetic measurements. The MBN technique was proved to be a useful non-destructive and quantitative method for microstuctural investigation of the investigated ferritic stainless steel.

Evaluation of the Processing Conditions in the Transesterification for Biodiesel Production Using the Nanomagnetic Catalyst Ni0.5Zn0.5Fe2O4

2015 ◽  
Vol 820 ◽  
pp. 113-118 ◽  
Author(s):  
Joelda Dantas ◽  
Francisco Nilson da Silva ◽  
Kleberson Ricardo de Oliveira Pereira ◽  
Adriano Santana Silva ◽  
A.C.F. de M. Costa
Keyword(s):  
Magnetic Measurements ◽  
Spinel Phase ◽  
Magnetic Hysteresis ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Hysteresis Curve ◽  
Processing Conditions ◽  
Catalytically Active ◽  
Formation Type ◽  
Type V

Magnetic catalysts are easily removed from the reaction process, thereby reducing the wastewater generation. Therefore, the study proposes to evaluate the performance of the nanomagnetic catalyst Ni0.5Zn0.5Fe2O4 in the transesterification reaction of the soybean oil to produce biodiesel, varying processing conditions (temperature, molar ratio of oil:alcohol and catalyst amount) on the catalytic reaction. The catalyst was synthesized by combustion reaction and characterized by XRD, BET, magnetic measurements and gas chromatography. The results revealed the inverse spinel phase formation, type B(AB)2O4, with isotherm profile classified as type V with hysteresis loop of type 3 (H3), and surface area of ​​48.39 m2g-1. The magnetic hysteresis curve showed a characteristic behavior of soft magnetic material with saturation magnetization value of 55 emu/g. Chromatographic analysis confirmed that the magnetic nanoparticles are catalytically active and that the processing conditions directly influence the conversion into esters.

Measurements of the Spin-Selective Magnetic Hysteresis Curve in Fe–3 wt.% Si Alloy Using Magnetic Compton Scattering

2018 ◽  
Vol 48 (3) ◽  
pp. 1456-1460
Author(s):  
Chan Wook Kim ◽  
Hee Soo Kang ◽  
Kyu Seok Han ◽  
Naruki Tsuji ◽  
Yoshiharu Sakurai
Keyword(s):  
Compton Scattering ◽  
Magnetic Hysteresis ◽  
Hysteresis Curve ◽  
Magnetic Hysteresis Curve

scholarly journals Universal field-tunable terahertz emission by ultrafast photoinduced demagnetization in Fe, Ni, and Co ferromagnetic films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lin Huang ◽  
Sang-Hyuk Lee ◽  
Seon-Dae Kim ◽  
Je-Ho Shim ◽  
Hee Jun Shin ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Magnetic Hysteresis ◽  
Hysteresis Curve ◽  
External Fields ◽  
Terahertz Emission ◽  
Emission Signal ◽  
Ferromagnetic Films ◽  
Initial Magnetization ◽  
Emission Behavior ◽  
Magnetic Hysteresis Curve

Abstract We report a universal terahertz (THz) emission behavior from simple Ni, Fe, and Co metallic ferromagnetic films, triggered by the femtosecond laser pulse and subsequent photoinduced demagnetization on an ultrafast time scale. THz emission behavior in ferromagnetic films is found to be consistent with initial magnetization states controlled by external fields, where the hysteresis of the maximal THz emission signal is observed to be well-matched with the magnetic hysteresis curve. It is experimentally demonstrated that the ultrafast THz emission by the photoinduced demagnetization is controllable in a simple way by external fields as well as pump fluences.

A TEM microscopical investigation of the magnetic domain structure of a metastable austenitic stainless steel

1994 ◽  
Vol 52 ◽  
pp. 696-697
Author(s):  
G. Fourlaris ◽  
T. Gladman
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cold Rolling ◽  
Solution Treatment ◽  
Magnetic Domain ◽  
High Strength ◽  
Medium Carbon Steel ◽  
Magnetic Characteristics ◽  
Metastable Austenitic Stainless Steel

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.

Effects of contact gap on nondestructive evaluation using magnetic measurement for ferromagnetic steel

2020 ◽  
Vol 64 (1-4) ◽  
pp. 969-975
Author(s):  
Hiroaki Kikuchi ◽  
Yuki Sato
Keyword(s):  
Magnetic Flux ◽  
Nondestructive Evaluation ◽  
Effective Permeability ◽  
Magnetic Circuit ◽  
Magnetic Measurement ◽  
Air Gap ◽  
Motive Force ◽  
Hysteresis Curve ◽  
Evaluation Technique ◽  
Ferromagnetic Steel

We investigated effects of contact gap on magnetic nondestructive evaluation technique using a magnetic single-yoke probe. Firstly, we evaluated hysteresis curves and impedance related to permeability of the material measured by a single-yoke probe, when an air gap length between the probe and specimens changes. The hysteresis curve gradually inclines to the axis of the magneto-motive force and magneto-motive force at which the magnetic flux is 0 decreases with increasing the gap length. The effective permeability also decreases with increasing the gap thickness. The incremental of gap thickness increases the reluctance inside the magnetic circuit composed of the yoke, specimen and gap, which results in the reduction of flux applying to specimen.

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