The Effect of Cross Rolling on Texture and Magnetic Properties of Non Oriented Electrical Steels (original) (raw)
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Materials Research, 2016
Hot rolled non-oriented electrical steel samples were subjected to cold cross-rolling of 80 % reduction in thickness. The cross-rolled samples were then annealed at 650, 750 and 850 o C for 1 hr, 2 hrs and 4 hrs respectively. The role of cross-rolling on microstructure, texture and magnetic properties of the samples after annealing has been investigated. Two different samples were used for the present investigation-one had higher Al content (sample S1) while the other had higher C, Si, Mn, P and S content (sample S2). It was observed that the sample S1 had higher grain size compared to sample S2 after annealing. The cross-rolling was observed to be controlled the texture developments in the samples and it was found that the texture factor was identical in all directions of the sample. The core losses in the samples were found to be decreased with increasing grain size of the samples.
Journal of Magnetism and Magnetic Materials, 2007
The temper-rolling reduction has an important influence on the final microstructure and magnetic properties of semi-processed nonoriented electrical steels. The application of reductions in the range 1-4% originates a very inhomogeneous microstructure, which is characterized by a bimodal distribution of the grain size and has a marked effect on the crystallographic texture. The magnetic textures of the fine grains are different from that of larger grains. The application of existing models to correlate magnetization behavior and power losses with grain size and magnetic texture is not satisfactory due to the microstructural heterogeneity of the temper-rolled samples.
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.
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.
IOP conference series, 2015
In processing non-oriented electrical steel sheets using conventional rolling schemes, the most common texture components obtained after final annealing are the magnetically unfavourable <111>//ND () and <110>//RD () fibres. A lot of researches have been carried out trying to optimize the processes to produce the favourable <001>//ND () fibre. However, since the final texture is formed through a series of texture evolution steps during the solidification, hot rolling, cold rolling and annealing processes, it is quite challenging to tailor the texture of the final product. In this study, a new rolling scheme was examined, in which the cold rolling direction (CRD) was inclined to the hot rolling direction (HRD) at an angle from 0 to 90 (with a 15 increment). This was intended to alter the texture commonly produced by cold rolling along the HRD, and to optimize the final recrystallization texture. The cold rolling and recrystallization textures of two non-oriented electrical steels with 0.9% and 2.8% Si were measured. It was found that the inclination of CRD to HRD has a substantial effect on the cold rolling texture for both steels, but only in the low Si steel, does it lead to significantly different recrystallization textures. A strong cube texture was produced at an inclination angle of 60 , and the <111>//ND () fibre was significantly weakened or essentially disappeared. The core losses of these steels were measured by Epstein frame method and the results showed a ~10% difference among strips cold rolled at different angles. A minimum core loss occurred at a 45 inclination angle in the low Si steel.
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.
international journal of iron and steel society of iran, 2015
In this study, the effect of cold rolling process on the microstructure and texture evolution in 1wt. % Si non-oriented electrical steel was investigated. For this purpose, all samples were processed through single-stage hot rolling at 1100 ° C and two-stage cold rolling (cross rolling and unidirectional rolling) with intermediate annealing at 650 °C for 35 seconds. Finally, all of them were fully annealed for 3 min at 900 ° C. The results showed that cold rolling process could affect shear band formation, deformation texture and annealing texture. Shear band and {322} grains were decreased and {100} grains were increased by the cross rolling method. These observations showed the weakening of the {110} <001> and {111} <112> components and the strengthening of the {001} <110> component after final annealing for the cross rolled sample. On the other hand, shear band formation in the unidirectional rolling sample caused the development of annealing Goss texture component ({110} <001>).
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.
IOP conference series, 2018
Inclined cold rolling was employed in this study to process a 0.88 wt% Si non-oriented electrical steel. After conventional hot rolling and annealing, the steel was cold rolled at various angles (i.e. 0q, 45q, and 90q) to the hot rolling direction (HRD), and the cold-rolled steel sheets were then annealed at different temperatures from 600qC to 750qC for 30 seconds to investigate the effect of annealing temperature on the texture and magnetic response of the material. The texture was measured by electron backscatter diffraction (EBSD), and the magnetic response of the steel was evaluated by magnetic Barkhausen noise (MBN) analysis. It was found that all the cold-rolled steels partially recrystallize at temperatures below 750qC, but the progress of recrystallization differs in steels cold rolled at different angles to the HRD, i.e. samples rolled at 45q to the HRD recrystallize faster than those after conventional rolling (0q to HRD) or cross rolling (90q to the HRD). The initial cold rolling texture (mainly the D-fibre and J-fibre) may change to cube, rotated cube, rotated Goss or {111}<112> depending on the rolling scheme and the annealing temperature. The MBN root mean square values of the samples cold rolled at different angles to the HRD show substantial differences during the annealing process. At low annealing temperatures (600qC and 650qC), the anisotropy of MBN in the conventionally rolled steel is much higher than those after inclined rolling or cross rolling.
Textures of Non-Oriented Electrical Steel Sheets Produced by Skew Cold Rolling and Annealing
Metals, 2021
In order to investigate the effect of cold rolling deformation mode and initial texture on the final textures of non-oriented electrical steels, a special rolling technique, i.e., skew rolling, was utilized to cold reduce steels. This not only altered initial textures but also changed the rolling deformation mode from plane-strain compression (2D) to a more complicated 3D mode consisting of thickness reduction, strip elongation, strip width spread and bending. This 3D deformation induced significantly different cold-rolling textures from those observed with conventional rolling, especially for steels containing low (0.88 wt%) and medium (1.83 wt%) amounts of silicon at high skew angles (30° and 45°). The difference in cold-rolling texture was attributed to the change of initial texture and the high shear strain resulting from skew rolling. After annealing, significantly different recrystallization textures also formed, which did not show continuous <110>//RD (rolling direction...