Magnetic Annealing on GNO Electrical Steel Fe-3.25% Si

2013 ◽  
Vol 758 ◽  
pp. 113-117 ◽  
Author(s):  
Gilberto Alexandre Castello-Branco ◽  
Jennifer Nadine Muller ◽  
Cristiane Maria Basto Bacaltchuk
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Electrical Steel ◽  
Annealing Process ◽  
Magnetic Annealing ◽  
Average Grain Size ◽  
Orientation Density ◽  
Cold Rolled ◽  
Small Grains ◽  
Electrical Motors

Grain non-oriented electrical steel has its main application in electrical motors and its microstructure significantly influences their efficiency. The objective of this work was to investigate whether or not magnetic field applied during annealing process affects grain growth and the development of important texture components leading to an improvement of the magnetic properties. GNO Fe-3.25%Si 75% cold rolled specimens were annealed inside magnetic field with strength of 17 T at the temperature of 800°C for 3, 10 and 30 minutes. Results of average grain size after magnetic annealing showed a microstructure formed by small grains and a few very large grains. Magnetic field did not increase orientation density of {100} oriented grains and Goss grains but was able to increase density of θ fiber and decrease the density of γ fiber.

scholarly journals Microstructure and Mechanical Properties of 4Al Alumina-Forming Austenitic Steel after Cold-Rolling Deformation and Annealing

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2767 ◽  
Author(s):  
Chenchen Jiang ◽  
Qiuzhi Gao ◽  
Hailian Zhang ◽  
Ziyun Liu ◽  
Huijun Li
Keyword(s):  
Grain Size ◽  
Cold Rolling ◽  
Grain Boundaries ◽  
Austenitic Steel ◽  
Rolling Reduction ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Cold Rolling Reduction ◽  
Average Grain Size ◽  
Cold Rolled

Microstructural evolutions of the 4Al alumina-forming austenitic steel after cold rolling with different reductions from 5% to 30% and then annealing were investigated using electron backscattering diffraction (EBSD), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tensile properties and hardness were also measured. The results show that the average grain size gradually decreases with an increase in the cold-rolling reduction. The low angle grain boundaries (LAGBs) are dominant in the cold-rolled samples, but high angle grain boundaries (HAGBs) form in the annealed samples, indicating that the grains are refined under the action of dislocations. During cold rolling, high-density dislocations are initially introduced in the samples, which contributes to a large number of dislocations remaining after annealing. With the sustaining increase in cold-rolled deformation, the samples exhibit more excellent tensile strength and hardness due to the decrease in grain size and increase in dislocation density, especially for the samples subjected to 30% cold-rolling reduction. The contribution of dislocations on yield strength is more than 60%.

scholarly journals Enhanced Mechanical Properties of Mg-6Sn-3Al-1Zn Alloy with Bimodal Grain Size Disturbed in the Microstructure Uniformly through Changing the Rolling Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Fuan Wei ◽  
Jinhui Wang ◽  
Ping Li ◽  
Bo Shi
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Yield Strength ◽  
Volume Fraction ◽  
Rolling Temperature ◽  
Average Grain Size ◽  
Small Grains ◽  
Mg2sn Phase ◽  
Average Size ◽  
Bimodal Grain Size

The mechanical properties of Mg-6Sn-3Al-1Zn alloy were enhanced with bimodal grain size disturbed in the microstructure uniformly; the Mg-6Sn-3Al-1Zn alloys were rolled with 60% thickness reduction at different rolling temperatures. The results have shown that the Mg-6Sn-3Al-1Zn alloys are composed of Mg2Sn phase and α-Mg matrix phase. When the rolling temperature was less than or equal to 400°C, with the rolling temperature increasing, the average size and volume fraction of Mg2Sn phase and the average grain size of small grains remained unchanged, the average grain size of large grains decreased, the volume fraction of small grains increased, and the yield strength of the alloy increased. When the rolling temperature reached 450°C, the average size and volume fraction of Mg2Sn phase and the average grain size of large grains increased, and the volume fraction of small grains and the yield strength of the alloy decreased. The elongation increased with the rolling temperature increasing, but the change trend of hardness was just opposite. When the alloy was rolled at 400°C, the average sizes of small grains, large grains, and Mg2Sn phases were 3.66 μm, 9.24 μm, and 19.5 μm, respectively. The volume fractions of small grains, large grains, and Mg2Sn phases were 18.6%, 77.6%, and 3.8%, respectively. And the tensile properties reached the optimum; for example, the tensile strength, yield strength, elongation, and Vickers hardness were 361 MPa, 289.5 MPa, 20.5%, and 76.3 HV, respectively.

Microstructure Evolution and Grain Boundary Characteristics of Oriented Silicon Steel during Primary Recrystallization in a Pulsed Magnetic Field

2013 ◽  
Vol 690-693 ◽  
pp. 139-146 ◽  
Author(s):  
Li Hua Liu ◽  
Li Juan Li ◽  
Qi Jie Zhai
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Magnetic Fields ◽  
Grain Boundary ◽  
Microstructure Evolution ◽  
Silicon Steel ◽  
Pulsed Magnetic Field ◽  
Magnetic Annealing ◽  
Grain Boundary Characteristics ◽  
Boundary Characteristics

The effects of a 2 T pulsed magnetic field primary annealing process on microstructure evolution and grain boundary characteristics in two-stage cold-rolled silicon steel were examined. Pulsed magnetic annealing increased grain size through the application of relatively smaller intensity of magnetic fields (2 T), compared to steady magnetic annealing. The effect of increasing grain size may be attributed to the magnetic acceleration effect of boundary motion under magnetic pulse conditions. Pulsed magnetic annealing may serve to enhance the relative intensity of the {111} component and decrease the frequency of low-angle misorientations. Repeated magnetostriction induced by pulsed magnetic field applications may accelerate overall dislocation motion. These findings suggest that pulsed magnetic fields require relatively lower intensities than steady magnetic fields to achieve superior results, providing a potentially viable alternative for industrial annealing processes for electrical steels.

Strength and Ductility in Electrodeposited Nanocrystalline Nickel

2009 ◽  
Vol 633-634 ◽  
pp. 411-420 ◽  
Author(s):  
Heather W. Yang ◽  
Farghalli A. Mohamed
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Annealing Treatment ◽  
Average Grain Size ◽  
Annealing Twins ◽  
Grain Distribution ◽  
Small Grains ◽  
20 Nm ◽  
Strength And Ductility

Electrodeposited nanocrystalline (nc) Ni having an average grain size of 20 nm was annealed at 443 K for different holding times. An examination of the microstructure following annealing showed three important features. First, all annealed samples exhibited abnormal grain growth, which was manifested by the presence of large grains that were surrounded by regions of small grains (bimodal grain distributions). Second, annealing twins existed in the large grains of the samples that showed a bimodal grain distribution. Third, by estimating the density of annealing twin, it was found that annealing nc-Ni at 443 K resulted in a maximum twin density after 5h. Following annealing treatment, specimens with different volume fractions of twins were tested under uniaxial tension at 393 K and a strain rate of 10-4 s-1. The results showed that both strength and ductility in nc-Ni attained maximum values after annealing for 5h. The role of both bimodal grain distributions and annealing twins in enhancing ductility and strength was discussed.

Texture Change during Grain Growth in Non-Oriented Electrical Steel

2013 ◽  
Vol 753 ◽  
pp. 329-332
Author(s):  
Yoshihiro Arita ◽  
Yoshiyuki Ushigami ◽  
Kenichi Murakami ◽  
Kohsaku Ushioda
Keyword(s):  
Grain Growth ◽  
Electrical Steel ◽  
Abnormal Grain Growth ◽  
Initial Structure ◽  
Rolled Steel ◽  
Ebsd Data ◽  
Texture Change ◽  
Average Grain Size ◽  
Cold Rolled ◽  
Initial Texture

Texture change during grain growth in Fe-3%Si non-oriented electrical steel was investigated. Cold rolled steel, 0.35mm in thickness, was annealed and recrystallized as an initial structure. Normal grain growth and abnormal grain growth occurred by additional annealing. {111} was dominant in the initial texture. However {100} component, which was not in majority in the initial structure, became stronger after normal grain growth. It was revealed that an average grain size of {100} in the initial structure was bigger than those of other components by analysis of the EBSD data,. Therefore, it is concluded that {100} strengthened after normal grain growth due to its size advantage. On the other hand, {111} components became more stronger after abnormal grain growth. It is inferred that another mechanism of the texture change worked in abnormal grain growth.

Microstructure of Al2O3-Fe FGM Obtained by Modified Slip-Casting Method

2005 ◽  
Vol 492-493 ◽  
pp. 665-672 ◽  
Author(s):  
A. Ozieblo ◽  
Tomasz Wejrzanowski ◽  
K. Konopka ◽  
Mikolaj Szafran ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Magnetic Force ◽  
Volume Fraction ◽  
Slip Casting ◽  
Functionally Graded ◽  
Casting Method ◽  
Average Grain Size ◽  
Field Lines ◽  
The Magnetic Field

This paper describes the technology and microstructure of Al2O3-Fe functionally graded composites, FGM, obtained by slip-casting under magnetic field. Alumina a-Al2O3, provided by Alcoa (symbol A16SG), with average grain size of 0.5 µm, and iron powder, (symbol Distaloy AB) from Hoganas, with average grain size of 35 µm, were used to produce a series of specimens which differed in contents of Fe particles in Al2O3. As a source of magnetic force a permanent magnet was used. Preforms were sintered in a vacuum at temp. 1470oC. The microstructures of the specimens were quantitatively described via stereological methods. Sections, parallel to the magnetic field lines were analyzed using special image analysis software. Stereological methods presented in this work have been used to determine gradient in the volume fraction of the Fe particles and variation in their size and dispersion. These parameters are essential for controlling the technological process of interest and to design microstructure for needed properties (fracture toughness).

scholarly journals Magnetically Affected Texture and Microstructure Evolution during Grain Growth in Zirconium

2012 ◽  
Vol 715-716 ◽  
pp. 946-951 ◽  
Author(s):  
Dmitri A. Molodov ◽  
Nathalie Bozzolo
Keyword(s):  
Magnetic Field ◽  
Grain Growth ◽  
Abnormal Grain Growth ◽  
X Ray Diffraction ◽  
Magnetic Annealing ◽  
Mean Grain Size ◽  
Pure Zirconium ◽  
Cold Rolled ◽  
Faster Development ◽  
The Magnetic Field

The effect of a magnetic field on texture and microstructure development in cold rolled (80%) commercially pure zirconium (Zr701) was investigated. X-ray diffraction and EBSD measurements were utilized for the texture and microstructure characterization. The results revealed that a magnetic field promotes grain growth in the investigated material. During annealings at 550°C this is particularly apparent from the faster development of specific (0/180, 35, 30) texture components and the bigger mean grain size after magnetic annealing. The magnetic annealing at 700°C resulted in an asymmetry of the two major texture components. This is due to a magnetic driving force for grain growth arising from the anisotropic magnetic susceptibility of zirconium. During annealing at 700°C the abnormal grain growth occurred. This behavior is attributed to the higher mobility of grain boundaries between grains misoriented by 30° around [000. The magnetic field essentially enhanced the observed abnormal grain growth.

Effects of high magnetic field annealing on the initial recrystallized texture in pure copper

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540020 ◽  
Author(s):  
Tong He ◽  
Yan Wang ◽  
Wei Sun ◽  
Xiang Zhao
Keyword(s):  
Magnetic Field ◽  
Grain Boundaries ◽  
High Magnetic Field ◽  
Pure Copper ◽  
Cube Texture ◽  
Magnetic Annealing ◽  
Final Annealing ◽  
Field Annealing ◽  
Cold Rolled ◽  
The Magnetic Field

The cold-rolled pure copper sheets were annealed with and without a high magnetic field of 12 T. The results showed that the magnetic annealing could promote the formation of the initial recrystallized cube texture. The magnetic annealing did not dramatically change the final annealing textures, but the intensity of the recrystallized cube texture is obviously different. The differences of the recrystallized cube orientation intensity between the specimens with and without the field annealing may be attributed to the effects of the magnetic field on the mobility of grain boundaries.

scholarly journals Inducing formation of L10-phase in concave-cube FePt nanoparticles by annealing under high magnetic field

2020 ◽  
Author(s):  
Chun Wu ◽  
Weibin Zhuang ◽  
Zhiyuan Niu ◽  
Dong Zhao ◽  
Wenli Pei ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
High Temperature ◽  
High Magnetic Field ◽  
Annealing Process ◽  
Fept Nanoparticles ◽  
Effective Strategy ◽  
Ordering Degree

Abstract Concave-cube FePt nanoparticles (NPs) with anisotropy of shape and element were annealed under high magnetic field (HMF). The high temperature sphered the FePt NPs, and Pt content and grain size of the NPs were decreased during annealing process. The HMF strength didn’t affect the shape, size and composition of the FePt NPs, but induced the formation of L 1 0 -phase in the annealed NPs. The content and ordering degree of L 1 0 -phase increased with enhancing the HMF strength, which leaded to the increasing of coercivity in the annealed FePt NPs. This work suggests that application of the HMF annealing is an effective strategy to tune the microstructure and property of anisotropic FePt NPs.

Solidification Structure of 6063 Alloy under Pulsed Magnetic Field

2015 ◽  
Vol 817 ◽  
pp. 355-359
Author(s):  
Shi Chao Liu ◽  
Hang Chen ◽  
Jun Jia Zhang ◽  
Peng Fei Wang ◽  
Jin Chuan Jie ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Temperature Field ◽  
Pulse Frequency ◽  
Dendrite Growth ◽  
Pulsed Magnetic Field ◽  
Solidification Structure ◽  
Cold Wall ◽  
Average Grain Size ◽  
Equiaxed Grains

The influences of pulsed magnetic field (PMF) on solidification structure of 6063 alloy were studied in this article. The results show that solidification structure of 6063 alloy can be refined with the application of PMF. The dendrite growth restrained and the macrostructure changed from large dendrite grains to fine equiaxed grains. The grain size decreased when the voltage increased from 0V to 600V. However, when the pulse frequency increased from 5Hz to 15Hz, the average grain size decreased continuously until reached a limit, and then the grains coarsened with further increase of the pulse frequency. The vibration caused by PMF not only made the temperature field of the melt uniform ,but also brook off the initial solidified grains formed on the cold wall of the mold, and spurs the grains to move to the center of melt which can be acted as nuclei.

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