Effect of constant magnetic field on the martensitic transformation in cast iron

1975 ◽  
Vol 17 (12) ◽  
pp. 1035-1037
Author(s):  
V. N. Pustovoit
Keyword(s):  
Magnetic Field ◽  
Cast Iron ◽  
Martensitic Transformation ◽  
Constant Magnetic Field

Changes in the Structure of Steel during Quenching in a Magnetic Field

2020 ◽  
Vol 989 ◽  
pp. 79-84 ◽  
Author(s):  
Viktor N. Pustovoit ◽  
Yuri V. Dolgachev ◽  
L.P. Aref'eva
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Martensitic Transformation ◽  
Specific Surface ◽  
Surface Area ◽  
Constant Magnetic Field ◽  
Surface Relief ◽  
Volumetric Strain ◽  
Transformation Products ◽  
Electron Microscopes

The structure of martensite obtained by quenching steel under the action of a constant magnetic field was studied. The kinetic changes of the martensitic transformation, caused by the action of a magnetic field, are expressed in the structure by an increase in the dispersity of the transformation products. Samples of steels C45, 100CrMn6 and 30HGSA were investigated. Dispersity was evaluated statistically in images obtained on light and electron microscopes. The specific surface area was measured and the parameters of the surface relief caused by martensitic transformation were studied. Experimental data show that after quenching in a magnetic field, a decrease in the volumetric strain of the transformation, an increase in the dispersity of packets of martensitic crystals and components of the packets are observed. It is concluded that an increase in dispersion and a fragmentation of the structure of martensite are mainly the result of multiplicative nucleation.

Effects of High Magnetic Field and Tensile Stress on Martensitic Transformation Behavior and Microstructure At 4 K in Fe-Ni-C Alloys

1995 ◽  
Vol 398 ◽  
Author(s):  
H. Ohtsuka ◽  
K. Nagai ◽  
S. Kajiwara ◽  
H. Kitaguchi ◽  
M. Uehara
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
Tensile Stress ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
High Magnetic Field ◽  
Constant Magnetic Field ◽  
Critical Magnetic Field ◽  
Transformation Behavior ◽  
The Magnetic Field

ABSTRACTEffects of high magnetic field and tensile stress on martensitic transformation behavior and microstructure at 4 K have been studied in Fe-31Ni-0.4C and Fe-27Ni-0.8C shape memory alloys. It was found that the critical magnetic field to induce martensitic transformation is between 7.5 T and 10 T. In the case of Fe-27Ni-0.8C, martensitic transformation is stress-induced at lower level of stress in magnetic field than in the case when no magnetic Field is applied. The amount of martensite formed by increasing the magnetic field under constant stress is larger than that formed by increasing the stress in the constant magnetic field.

Features of Martensitic Transformation in Steel during Quenching in a Constant Magnetic Field

2019 ◽  
Vol 946 ◽  
pp. 304-308 ◽  
Author(s):  
Viktor N. Pustovoit ◽  
Yuri V. Dolgachev ◽  
L.P. Aref'eva
Keyword(s):  
Magnetic Field ◽  
Martensitic Transformation ◽  
External Magnetic Field ◽  
Constant Magnetic Field ◽  
Electric Resistivity ◽  
Nucleation Center ◽  
Martensite Formation ◽  
Resistivity Method ◽  
Elastic Forces ◽  
Energy Of Formation

The data on the occurrence of martensitic transformation in steel under the action of a magnetic field were obtained by the electric resistivity method. The obtained data indicate the possibility of stress-assisted martensite formation in the temperature range of Ms-Md (in which superplasticity of austenite is observed). This possibility is due to the magnetic heterogeneity of austenite. Nanosized regions with a ferromagnetic order are present in the paramagnetic matrix. They can perceive the energy of the external magnetic field through the magnetostrictive stresses and change the fields of the elastic forces in the crystal lattice. All this leads to a decrease in the energy of formation of the nucleation center.

A CMT Device for Electric Energy Meter Detection

2020 ◽  
Vol 13 ◽  
Author(s):  
Zhi Zeng ◽  
Yongfu Zhou
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Electromagnetic Interference ◽  
Production Efficiency ◽  
Electric Energy ◽  
Labor Cost ◽  
Automatic Testing ◽  
National Standard ◽  
Measurement Instruments ◽  
Detection Technology

Background: Detection technology is a product development technique that serves as a basis for quality assurance. As electric energy meters (EEMs) are measurement instruments whose use is mandatory in several nations, their accuracy, which directly depends on their reliability and proper functioning, is paramount. In this study, to eliminate electromagnetic interference, a device is developed for testing a set of EEMs under a constant magnetic field interference. The detection device can simultaneously test 6 electric meters; moreover, in the future, it will be able to measure the influence of magnetic field strength on the measurement accuracy of EEMs, thereby improving the production efficiency of electric meter manufacturers. Methods: In this study, we first design a 3D model of the detection device for a single meter component; then, we establish a network, which includes a control system, and perform the planning of the path of a block that generates a constant magnetic field. Finally, we control the three-axis motion and rotation of the block using a PLC to implement detection for the five sides of the EEM. Results & Discussion: The proposed device can accurately determine whether an EEM can adequately function, within the error range prescribed by a national standard, under electromagnetic interference; this can enable reliable, automatic testing and fault detection for EEMs. Experiments show that our device can decrease the labor cost for EEM manufacturers.

scholarly journals Ground state and stability of the fractional plateau phase in metallic Shastry–Sutherland system TmB4

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matúš Orendáč ◽  
Slavomír Gabáni ◽  
Pavol Farkašovský ◽  
Emil Gažo ◽  
Jozef Kačmarčík ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Ground State ◽  
Constant Magnetic Field ◽  
Paramagnetic Phase ◽  
The Other ◽  
Zero Field ◽  
Plateau Phase ◽  
Low Field ◽  
Zero Field Cooling

AbstractWe present a study of the ground state and stability of the fractional plateau phase (FPP) with M/Msat = 1/8 in the metallic Shastry–Sutherland system TmB4. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin. In this case the FPP states are closely associated with the half plateau phase (HPP, M/Msat = ½), mediate the HPP to the low-field antiferromagnetic (AF) phase and depend on the thermodynamic history. Thus, in the same place of the phase diagram both, the stable and the metastable (dynamic) fractional plateau (FP) states, can be observed, depending on the way they are reached. In case of metastable FP states thermodynamic paths are identified that lead to very flat fractional plateaus in the FPP. Moreover, with a further decrease of magnetic field also the low-field AF phase becomes influenced and exhibits a plateau of the order of 1/1000 Msat.

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