scholarly journals Effects by the microstructure after hot and cold rolling on the texture and grain size after final annealing of ferritic non-oriented FeSi electrical steel

AIP Advances ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 047606 ◽  
Author(s):  
J. Schneider ◽  
A. Stöcker ◽  
A. Franke ◽  
R. Kawalla
Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6822
Author(s):  
Xuefei Wei ◽  
Alexander Krämer ◽  
Gerhard Hirt ◽  
Anett Stöcker ◽  
Rudolf Kawalla ◽  
...  

The magnetic properties of non-oriented electrical steel, widely used in electric machines, are closely related to the grain size and texture of the material. How to control the evolution of grain size and texture through processing in order to improve the magnetic properties is the research focus of this article. Therefore, the complete process chain of a non-oriented electrical steel with 3.2 wt.-% Si was studied with regard to hot rolling, cold rolling, and final annealing on laboratory scale. Through a comprehensive analysis of the process chain, the influence of important process parameters on the grain size and texture evolution as well as the magnetic properties was determined. It was found that furnace cooling after the last hot rolling pass led to a fully recrystallized grain structure with the favorable ND-rotated-cube component, and a large portion of this component was retained in the thin strip after cold rolling, resulting in a texture with a low γ-fiber and a high ND-cube component after final annealing at moderate to high temperatures. These promising results on a laboratory scale can be regarded as an effective way to control the processing on an industrial scale, to finally tailor the magnetic properties of non-oriented electrical steel according to their final application.


2011 ◽  
Vol 702-703 ◽  
pp. 595-598
Author(s):  
Francisco N.C. Freitas ◽  
Manoel Ribeiro da Silva ◽  
Sergio S.M. Tavares ◽  
Hamilton F.G. Abreu

Non-oriented grain type electrical steels are used mainly in electrical rotating machines such as motors and compressors, in which the magnetization direction rotates 360 ° every cycle while remaining in the plane of the plate. The performance of these devices is affected by crystallographic texture of electrical steels due to strong anisotropy of magnetic properties. The electrical steel is supplied in the form of plates which are processed by cold rolling and subsequent annealing. Both, cold rolling and annealing directly influence the formation of crystallographic texture components. During annealing, recrystallization occurs, and this phenomenon gives rise to changes in texture that influences the quality of the final product and its application. Several works have been published in the study of the evolution of crystallographic texture and grain size in this type of electrical steel. In this work, samples have been taken in industrial conditions at various temperatures during the annealing in a coil box. Electrical steel samples cold rolled with reductions of 50% and 70% in thickness were removed during the process of annealing, and the evolution of texture with increasing temperature was studied. Aspects related to recrystallization, grain size and the evolution of texture and magnetic properties were discussed. Texture and recrystallization were studied by X-ray diffraction and electron backscatter diffraction (EBSD). The magnetic properties were measured in a vibrating sample magnetometer.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6659
Author(s):  
Anett Stöcker ◽  
Max Weiner ◽  
Grzegorz Korpała ◽  
Ulrich Prahl ◽  
Xuefei Wei ◽  
...  

[d=A]A tailor-made microstructure, especially regarding grain size and texture, improves the magnetic properties of non-oriented electrical steels. One way to adjust the microstructure is to control the production and processing in great detail. Simulation and modeling approaches can help to evaluate the impact of different process parameters and finally select them appropriately. We present individual model approaches for hot rolling, cold rolling, annealing and shear cutting and aim to connect the models to account for the complex interrelationships between the process steps. A layer model combined with a microstructure model describes the grain size evolution during hot rolling. The crystal plasticity finite-element method (CPFEM) predicts the cold-rolling texture. Grain size and texture evolution during annealing is captured by the level-set method and the heat treatment model GraGLeS2D+. The impact of different grain sizes across the sheet thickness on residual stress state is evaluated by the surface model. All models take heterogeneous microstructures across the sheet thickness into account. Furthermore, a relationship is established between process and material parameters and magnetic properties. The basic mathematical principles of the models are explained and demonstrated using laboratory experiments on a non-oriented electrical steel with 3.16 wt.% Si as an example. Improving the magnetic properties of non-oriented electrical steels are of high interest. In this context, improvement by a tailor-made microstructure, especially regarding grain size and texture, is one focus. One way to adjust the microstructure is to control the production and processing in great detail. Simulation and modeling approaches, emphasizing grain size and texture development, can help to evaluate and finally set process parameters. Here, we present individual model approaches for hot rolling, cold rolling, annealing and shear cutting and aim to connect the models to account for the complex interrelationships between the process steps. Furthermore, a connection between the process parameters and the magnetic properties is drawn. Grain size, grain size distribution, texture and dislocation density are the main transfer parameters in between the models. All models take heterogeneous microstructures across the sheet thickness into account. The basic mathematical principles of the models are explained, and a case study is presented in each case using FeSi3.2wt%Si as an example material.


2007 ◽  
Vol 539-543 ◽  
pp. 3341-3346
Author(s):  
Yvan Houbaert ◽  
Tanya Ros-Yáñez ◽  
Pablo Rodriguez-Calvillo ◽  
José Barros ◽  
Leo Kestens

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.


2018 ◽  
Vol 941 ◽  
pp. 274-279
Author(s):  
You Liang He ◽  
Mehdi Mehdi ◽  
Erik J. Hilinski ◽  
Afsaneh Edrisy

Non-oriented electrical steel sheets are the most commonly used material for the manufacturing of magnetic cores for electric motors and generators. The microstructure and texture of the steel after final annealing have a significant effect on the magnetic properties of the lamination core. To investigate the effect of cold rolling and annealing on the magnetic properties of the steel sheets, a 0.9 wt% Si non-oriented electrical steel was cold rolled at different angles to the hot rolling direction (HRD) and annealed at various temperatures (600°C to 750°C) to produce dissimilar microstructures. The progress of recrystallization was characterized by electron backscatter diffraction (EBSD), and the magnetic response of the steel at various stages of recrystallization was evaluated by magnetic Barkhausen noise (MBN). A number of MBN parameters, e.g. the root mean square, the smoothed envelope, the peak, the full width at half maximum (FWHM) of the envelope, the time integral of the MBN signals and the MBN energy, were analyzed with respect to the fraction of recrystallization during annealing. The results show that cold rolling at different angles to the hot rolling direction induces various deformation microstructures and stored energies, which, in turn, lead to considerably different recrystallization behaviours during annealing. The difference in recrystallization of these materials is also reflected in the MBN parameters.


2012 ◽  
Vol 715-716 ◽  
pp. 33-40 ◽  
Author(s):  
Y. Arita ◽  
L. Chan ◽  
S.D. Sintay ◽  
Anthony D. Rollett

Grain size and texture are very important for controlling the magnetic properties in non-oriented electrical steel. Grain size and texture are closely related because the texture usually changes during grain growth. In this study, texture changes with grain growth in non-oriented electrical steel are investigated. Two kinds of materials, Sample A and Sample B, were prepared in order to study the differences of the texture. Sample A, Fe-0.5wt%Si, is not annealed before cold rolling. Sample B, the same chemical composition as Sample A, is annealed before cold rolling. In Sample A, the {111} texture component increases markedly during grain growth. By contrast, in Sample B, the increase in {111} is less pronounced. The recrystallized orientations in both Samples are analyzed, and computer simulation is used to attempt to explain the texture changes during grain growth. In the case of Sample A, the simulations reproduce the experimental result well; for Sample B, however, the simulations do not agree as well. The microstructures before annealing exhibit strong alignment of the orientations, which will require a new approach to building the digital microstructures for instantiation of the simulations.


2016 ◽  
Vol 852 ◽  
pp. 181-186
Author(s):  
Tie Ye ◽  
Zhen Yu Gao ◽  
Zhi Wen Lu ◽  
Zhi Guo Zhong

The structure, texture, second phase and magnetic properties of non-oriented electrical steel with cold and heat slab were comprised through the production test. The research result shows that the grain size of hot rolled plate by cold slab is less than that of hot rolled plate by hot slab. But after cold rolling and annealing process, the grain size is consistent. Microstructure of hot rolled coil is recrystallized microstructure and the dispersion degree of texture orientation is high. Deformation makes the texture enhancement in cold rolling which become the strong texture based on {001} {111} and <110> texture. The Ti element has aggregation which can form hard impurities as TiN and TiSN to obstruct the recrystallization. Micro fine TiC formed in the annealing process which would block magnetic domain movement and reduce the magnetic properties of the product. MnS is precipitated impurities and the coarsening of MnS phase can reduce the domain block by improving the continuous annealing temperature and the magnetic field would be optimization.


2012 ◽  
Vol 706-709 ◽  
pp. 2800-2805 ◽  
Author(s):  
Armando Salinas-Rodríguez ◽  
E. Gutiérrez-Castañeda

The effects of annealing prior to cold rolling on the microstructure and magnetic properties of a low-C grain non-oriented (GNO) electrical steel strip have been investigated. It is shown that annealing of the hot-rolled strips in the intercritical region, Ac13, causes rapid decarburization and development of large columnar ferrite grains. This microstructure leads, after cold-rolling and a fast annealing treatment at temperatures between 800 and 850 °C, to a polygonal ferrite grain microstructure with magnetic properties superior to those observed typically in the same steel in the industrial fully processed condition. The results are attributed to the {100}-fiber texture developed during the final annealing. Annealing at T<800 °C or T>850 °C results in formation of {111}-fiber texture components due to recristallization or transformation of deformed ferrite leading to a negative effect on the final magnetic properties. The results suggest that annealing prior to cold rolling offers an attractive alternative processing route for the manufacture of fully processed low-C, Si-Al GNO electrical steels strips.


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