Relative effect(s) of texture and grain size on magnetic properties in a low silicon non-grain oriented electrical steel (original) (raw)
Related papers
2014
In an attempt to differentiate the impact of grain size and crystallographic texture on magnetic properties of non-oriented (NO) electrical steel sheets, samples with different grain sizes and textures were produced and analyzed regarding magnetic flux density B and core loss W. The textures of the NO electrical steel samples could be precisely quantified with the help of elliptical Gaussian distributions. In samples with identical textures, small grain sizes resulted in about 15% higher core loss W than larger grains, whereas grain size only moderately affected the magnetic flux density B. In samples having nearly the same grain size, a correlation of the magneto-crystalline anisotropic properties of B and W with texture was obtained via the anisotropy parameter Að h ! Þ. With increasing Að h ! Þ a linear decrease of B and a linear increase of W were observed.
Improvement of Texture and Magnetic Properties in 4.5 wt.% Si Grain-Oriented Electrical Steels
Materials Research-ibero-american Journal of Materials, 2019
4.5 wt.% Si grain-oriented electrical steel sheets were successfully produced by hot rolling, normalizing, warm rolling and annealing, and texture evolution was investigated using macro-and micro-texture analysis. It is found that the recrystallization texture of sheets is very sensitive to the warm rolling reduction, and 83-87% warm rolling reductions are more favorable to η texture (<100>//RD, rolling direction) evolution during secondary recrystallization, and consequently the magnetic induction B 8 is significantly improved to 1.69-1.70 T in this rolling reduction range. The decreased B 8 in the 89% warm rolled sheet is ascribed to the obviously decreased primary recrystallization η fiber, which leads to the insufficient quantity of η grains in the early stage of abnormal grain growth. The results obtained in the current work can provide an efficient way to improve the recrystallization texture of 4.5 wt.% Si grain-oriented electrical steel sheets.
International Journal of Materials Research, 2018
The effect of temper rolling and subsequent annealing on texture development and magnetic properties of semi-processed non grain oriented electrical steel has been investigated. The result shows that 5% temper rolling and final annealing at 850°C resulted in strong α-fiber component. The etch-pit technique shows that strain induced boundary migration is responsible for new texture component augmentation. Vibrating sample magnetometery reveals that maximum and minimum magnetic permeability are related to rolling and transverse directions, respectively. Average magnetic permeability is improved to some extent as a result of temper rolling and subsequent annealing.
Through process texture evolution and magnetic properties of high Si non-oriented electrical steels
Materials Characterization, 2012
A detailed understanding of microstructural changes in a sequence of thermomechanical processing allows the improvement of magnetic properties in FeSi strips. The current contribution considers the texture evolution in non-oriented electrical steels of high Si content. Hot band strips of various textures were subjected to cold rolling and recrystallization annealing. The findings suggest that the crystallographic orientations observed after cold rolling are correlated with the hot band texture. In contrast, the evolution of recrystallization textures was more likely affected both by the hot and cold rolling microstructural features. The evolution of recrystallization textures is discussed on the basis of crystal plasticity calculations while the magnetic properties are correlated with the crystalline anisotropy energy density.
Journal of Magnetism and Magnetic Materials, 2015
In the present work the influence of intermediate annealing and the strain path during a two-stage cold rolling on the microstructure and texture of a 1 wt% Si non-oriented electrical steel was investigated. Different processing conditions were tasted to develop favorable texture and better understand the relation between texture and important magnetic properties. The texture parameter (TP) was defined as "theta fiber/gamma fiber" ratio. The results showed that the samples with the highest TP have the lowest magnetic anisotropy. Also average magnetocrystalline energy was calculated and it was demonstrated that the lowest energy can be correlated with the highest "theta fiber/gamma fiber" ratio. Regardless of the condition of intermediate annealing process, the uni-directional rolling produced very similar texture parameter ( $ 2). However, the cross rolled samples have very different texture parameters upon intermediate annealing. The cross rolled samples after intermediate annealing at 650°C have the highest texture parameter ( $ 3). The proposed thermo-mechanical processing allow diminishing gamma fiber which is deleterious for magnetic properties of non-oriented electrical steels.
On the Effect of Texture in Experimental Grades of High-Silicon Electrical Steel
Materials Science Forum, 2007
Crystallographic texture has an important effect on the magnetic quality of electrical steel: a specific texture parameter A is defined and used to estimate the magnetic quality of texture components. It is shown that obtaining the best possible texture in non oriented electrical steel can reduce the losses with 1,5 W/kg. Two production schemes for high silicon electrical steel are described: a conventional processing through hot and cold rolling with adequate temperatures and cooling rates and an immersion-diffusion process by hot dipping in a Si-and Al-rich bath followed by diffusion annealing. The texture evolution in these experimental materials is under study and first results are reported for conventional alloys (rolling procedure) and for immersion-diffusion alloys, which are annealed after dipping in order to obtain a controlled concentration gradient with high Si and/or Al at the surface or a homogeneous Si and/or Al-content over the thickness.
This paper presents a classic process-structure-properties approach for optimizing the magnetic properties of electrical steels. Cold-rolled non-oriented electrical steel (Fe; 0.001 wt% C; 0.2 wt.% Mn; 1.3 wt% Si) was subjected to extremely short 3-30 seconds annealing cycles in a range from 880°C to 980°C with a heating rate varying from 15°C to 300°C/sec. The resulting microstructure was studied by means of optical microscopy and X-ray orientation distribution function analysis. Recrystallized grains were refined with increased heating rate, caused by the nucleation rate increase, which is faster than the growth rate due to rapid heating. The optimal grain size of 60 to 80 mm in terms of magnetic properties was obtained by increasing the annealing temperature range to 920°C to 940°C with a higher heating rate of 300°C/sec and an annealing time of 6 to 9 seconds. With the heating rate increase, the characteristic {111} recrystallization fiber of cold-rolled steel was depressed, but the beneficial {110}<001> Goss texture component was significantly strengthened. The recrystallized grain size and texture were enhanced by rapid annealing, and, as a result, the magnetic properties of non-oriented electrical steel improved.
Metals and Materials International, 2012
This paper presents a classic process-structure-properties approach for optimizing the magnetic properties of electrical steels. Cold-rolled non-oriented electrical steel (Fe; 0.001 wt% C; 0.2 wt.% Mn; 1.3 wt% Si) was subjected to extremely short 3-30 seconds annealing cycles in a range from 880°C to 980°C with a heating rate varying from 15°C to 300°C/sec. The resulting microstructure was studied by means of optical microscopy and X-ray orientation distribution function analysis. Recrystallized grains were refined with increased heating rate, caused by the nucleation rate increase, which is faster than the growth rate due to rapid heating. The optimal grain size of 60 to 80 mm in terms of magnetic properties was obtained by increasing the annealing temperature range to 920°C to 940°C with a higher heating rate of 300°C/sec and an annealing time of 6 to 9 seconds. With the heating rate increase, the characteristic {111} recrystallization fiber of cold-rolled steel was depressed, but the beneficial {110}<001> Goss texture component was significantly strengthened. The recrystallized grain size and texture were enhanced by rapid annealing, and, as a result, the magnetic properties of non-oriented electrical steel improved.