The Influence of Normalization Temperatures on Different Texture Components and Magnetic Properties of Nonoriented Electrical Steels

et al. 2021

Self Cite

The effects of various initial structures and heating and cooling rates on the columnar‐grained transformation temperature are studied by a thermal dilatometer and electron backscatter diffraction. The results show that deformation can reduce the thermal hysteresis more effectively than decrease the heating rate, and the phase transformation hysteresis of the deformed sample is the smallest during heating, followed by the columnar‐grained sample with a slow heating rate, whereas the columnar‐grained sample with a fast heating rate has the largest phase transformation hysteresis. Moreover, the dilatational amount changes greatly with cooling rate. The coarse columnar grains can severely restrain dilatation. The smaller dilatational amount is related to the incomplete phase transformation of the columnar grains and also related to the suppression of the dilatational amount of the small grains by the surrounding columnar grains. In contrast, the largest dilatational amount is caused by the relatively sufficient phase transformation. In addition, the changes of the transformation temperature and the dilatational amount are mainly induced by the grain size effect and the inhomogeneity of the structures, but {100} texture can affect the uniformity of grain size.

Section: Introductionmentioning

confidence: 99%

Effect of the Initial Columnar‐Grained Inhomogeneity of Electrical Steels on the Transformation Temperature

et al. 2021

Self Cite

“…Meanwhile, the texture gradient along the thickness of the hot-rolled sheet after normalization will possibly be inherited into the final sheet. [7] Based on this consideration, the thin gauge may bring two possible changes in electrical steel. The first is the thinning of the hot-rolled sheet, to keep the following cold rolling reduction as in producing conventional thickness electrical steel.…”

Section: Introductionmentioning

confidence: 99%

“…The microstructure and texture gradient along the thickness direction of the hot-rolled sheet is affected by not only Si contents and other alloy elements, [4,5,7,9,10] but also by hot-rolled heating temperature, hot rolling finishing temperature, and coiling temperature. [11][12][13][14][15] The thickness of the fine-grained zone with shear orientation on the surface of the hot-rolled sheet varies, [1][2][3][4][5] which affects the competition between the surface layer and the central layer with different recrystallization behaviors during normalization and the normalization temperature or time required to achieve uniform grain size.…”

Section: Introductionmentioning

confidence: 99%

“…Early studies show this texture as an unfavorable texture in interstitial-free steel or low-carbon steel for deep drawing, [16] which usually forms within coarse initial grain structures after cold rolling with high rolling reduction and annealing. [17][18][19] The formation of {114}<481> texture during cold rolling and recrystallization under the conditions of (112) [1][2][3][4][5][6][7][8][9][10] single crystal, [20] {100} <110> single crystal and Bi crystal, [21] cross rolling, [22] and the initial columnar-grained slab [23,24] has been studied. The results demonstrate that it mainly comes from the vicinity of the grain boundary of {112} <110> deformed grains and also from the uneven deformed region in other-oriented deformed grains with α-fiber orientations.…”

Section: Introductionmentioning

confidence: 99%

“…The results demonstrate that it mainly comes from the vicinity of the grain boundary of {112} <110> deformed grains and also from the uneven deformed region in other-oriented deformed grains with α-fiber orientations. In recent research, the influence of different grain sizes of normalized sheets on the texture of cold-rolled, finally annealed sheets [3,7,9,25] shows that coarsegrained size and a single strong {114} <481> texture will be obtained at the high normalization temperature or long normalization time, which serves as the initial texture of subsequent cold rolling and annealing. It was also observed that {114} <481> grains completely consume {111} grains during annealing at high temperature even in grain-oriented silicon steel.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Recrystallization Behavior of Hot‐Rolled Microstructure with Texture Gradient and Texture of Final Sheet in Thin‐Gauge Electrical Steel

Tang

et al. 2022

The typical feature of hot‐rolled sheets exhibits strong inhomogeneity in microstructure and texture along the thickness direction, and the latter can be named as texture gradient. Herein, the recrystallization and grain growth behaviors of the hot‐rolled sheet in a thin‐gauge nonoriented electrical steel are investigated at different normalization temperatures. The origin and the growth behavior of the main recrystallization texture {114}<481> are revealed. The results show that the texture gradient in hot‐rolled sheets leads to the difference in microstructure and texture between the surface layer and the central layer after normalization. The strong {114}<481> recrystallization texture originates in the orientation transition zone and the vicinity of the grain boundaries of deformed α‐fiber grains in the central layer of hot‐rolled sheets. The volume advantage of {114}<481> grains stem from the favorable growth environment caused by the low‐deformation stored energy, low orientation gradient, higher mobility of grain boundary, and size advantage to their surrounding deformation structure. In the final sheet, {100}<021> texture is the most vital texture, but {114}<481> grains exhibit a large volume fraction. As there are only 4–5 grains on average along the thickness direction of the final sheet, the texture gradient along the thickness direction no longer exists.

The Formation of the {112}<111> Shear Texture in Hot‐Rolled Sheets of Electrical Steels

Tang

Jiang

et al. 2023

Self Cite

Due to the friction between rolls and sheet surface, shear texture inevitably occurs in the surface layer of the hot‐rolled sheets in electrical steel. The shear texture contains Goss texture {110}<001>, brass texture {110}<112>, and copper texture {112}<111>. The existence of shear texture and its corresponding microstructure affect the texture distribution in the subsequent normalized sheets, cold‐rolled sheets, and final sheets. Electron backscattered diffraction and reaction stress model are used herein to study the formation conditions of {112}<111> orientation in the hot‐rolled sheets. The results show that initial rotated cube orientation tends to rotate around transverse direction to the copper orientation during hot rolling due to the shear action. Different shear orientations can be formed in different regions of an initial coarse columnar grain during hot rolling, because of the change in surrounding environment reaction and the difference of the shear strain at different thickness positions. The thinner the hot‐rolled sheet is, the smaller the dynamic recrystallization region with shear orientation, and there is almost no copper texture in the thinnest hot‐rolled sheet. The simulation results show that the copper texture is easy to form under the action of σ23 and σ22 reaction stresses.