Effect of Cross-Rolling on Microstructure, Texture and Magnetic Properties of Non-Oriented Electrical Steels (original) (raw)
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The Effect of Cross Rolling on Texture and Magnetic Properties of Non Oriented Electrical Steels
1991
The texture change due to a change of cold rolling direction and annealing temperature in the production of 0..6% Si steel sheet is described. Cross rolling results in a very strong (001) component, causing soft magnetic properties in a direction at 45 degrees of the rolling direction. The texture governing mechanism of the primary and secundary recrystallization was oriented growth. The influence of texture on magnetic properties could be shown by measuring the directional properties of the sheet. The correlation between hysteresis losses and induction with texture and grain size was quantified.
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, 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.
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.
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.
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.
Journal of Material Science and Technology Research, 2018
The magnetic properties of electrical steels are related to the microstructure and texture of the final processed steel. There is an interplay and interaction of the microstructure and texture between the various processing steps. The ongoing structural changes at final annealing of the cold rolled material depend sensitively on the deformation structure after the cold rolling with high deformation. In this paper, we will study in detail the role of the microstructure of the hot strip on the deformation structure after cold rolling with high deformation.
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.
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...