Texture Control in Non-Oriented Electrical Steels by Severe Plastic Deformation

2010 ◽  
Vol 160 ◽  
pp. 23-29 ◽  
Author(s):  
Leo Kestens ◽  
Roumen H. Petrov ◽  
Patricia Gobernado ◽  
Elke Leunis

Although plenty of research has already been carried out on the issue of texture control in non-oriented electrical steels, there is not yet a universally applied industrial process to obtain an optimized {001} fibre texture. Among the various laboratory processes that have been studied so far, cross rolling seems to be one of the most promising approaches. For evident reasons cross-rolling cannot be implemented on a conventional continuous rolling line of an industrial plant. In the present study a potential interesting alternative is presented which may deliver a similar texture evolution as the cross rolling process, but can be applied in a continuous line of hot and cold rolling operations followed by recrystallization annealing. By applying severe rolling reductions a very strong rotated cube texture is obtained very much similar to the one that is observed after cross rolling. After annealing, the rotated cube texture changes to a {h11}<1/h,21> fibre texture with a maximum on the {311}<136> component which implies the potential to develop a {001} fibre texture after further processing. It is argued that the appearance of the {311}<136> recrystallization texture component can be attributed to oriented nucleation in the vicinity of grain boundaries between slightly misoriented rotated cube grains.

2011 ◽  
Vol 702-703 ◽  
pp. 758-761 ◽  
Author(s):  
Tuan Nguyen Minh ◽  
Jurij J. Sidor ◽  
Roumen H. Petrov ◽  
Leo Kestens

The core loss and magnetic induction of electrical steels are dependent on the microstructure and texture of the material, which are produced by the thermo-mechanical processing. After a conventional rolling process, crystal orientations of the α-(//RD) and γ-(//ND) fibers are strongly present in the final texture. These fibers have a drastically negative effect on the magnetic properties of electrical steels. By applying asymmetric rolling, significant shear strains could be introduced across the thickness of the sheet and thus a deformation texture with more magnetically favorable components is expected. In this study, an electrical steel of 1.23 wt.% Si was subjected to asymmetric warm rolling in a rolling mill with different roll diameters. The evolutions of both deformed and annealed textures were investigated. The texture evolution during asymmetric warm rolling was analyzed by crystal plasticity simulations using the ALAMEL model. A good fit between measured and calculated textures was obtained. The annealing texture could be understood in terms of an oriented nucleation model that selects crystal orientations with a lower than average stored energy of plastic deformation.


2012 ◽  
Vol 452-453 ◽  
pp. 7-11 ◽  
Author(s):  
Wei Pei ◽  
Yu Hui Sha ◽  
Fang Zhang ◽  
Liang Zuo

In this paper, non-silicon steel sheets were produced by both twin-roll casting method and conventional process. Orientation characteristics and texture evolution of the sheets during casting, cold rolling and recrystallization annealing were investigated for comparison. It was found that the subsurface of twin-roll casting strips are characterized by weak {100} orientation while the central layer by random orientation. Twin-roll casting process can decrease α fiber (//RD) and increase γ fiber (//ND) during cold rolling process. Consequently, the η fiber (//RD) favorable for magnetic properties of non-silicon steels is enhanced and the detrimental {111} component is suppressed after annealing.


2010 ◽  
Vol 33 ◽  
pp. 163-167 ◽  
Author(s):  
Jun Li Wang ◽  
Qing Nan Shi

Ultra-Fine-Grained (UFG) copper strip was prepared by severe deformation method of asymmetrical accumulative rolling bond (SD-AARB) with heat treatment, in which the reduction rate of 1.08 was employed with 50% rolling reduction by six passes(4.8 true strains). The heat treatment was conducted at annealing temperature of 220°C for 5~55 minutes. EBSD and X-ray diffraction were employed to follow the features of texture and orientations. The texture formulation mechanism of deformed copper recrystallized nucleation was studied. The results show that the deformation textures developed in the copper strip by SD-AARB are very similar to those by common the cold rolling process, which is {112}<111>. After the annealing treatment, the strength of the main texture components in the oxygen-free pure copper is decreased along with the extension of recrystallization annealing time, which is C,R,S and B/G texture components. For high energy release rate, grains of all kinds of orientations have the chance of nucleation and growing up, which is different to traditional recrystallized cube texture.


2014 ◽  
Vol 782 ◽  
pp. 201-204 ◽  
Author(s):  
Ivan Petryshynets ◽  
František Kováč ◽  
Mária Molnárová ◽  
Petra Gavendová ◽  
Martin Sopko ◽  
...  

The present work investigates texture evolution stages in vacuum-degassed non-oriented electrical steels. The main idea behind the improvement of soft magnetic properties relies on deformation induced grain growth phenomena and heat transport phenomena promoting the preferable formation of columnar grains with so called cube crystallographic orientation {100}<0vw>. In order to achieve the desired orientation with appropriate microstructure state from magnetic properties point of view, we have used an adjusted temper rolling process at elevated temperature and subsequent dynamical annealing in laboratory conditions.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1478
Author(s):  
Liguang Wang ◽  
Shuhuan Wang ◽  
Jie Li ◽  
Jinyu Liang ◽  
Yunli Feng

Texture control of grain-oriented silicon steel is the key factor to ensure the magnetic properties of the finished product. Nb-containing grain-oriented silicon steel with different slab reheating temperatures was hot rolled followed by single-stage or two-stage cold rolling, and the textures were also analyzed. In the single-stage cold rolling process, as the slab reheating temperature is reduced, the intensity of the rotating cube texture {100}<011> and Goss texture {011}<100> drops, and that of the {111}<112> texture increases. In the two-stage cold rolling process, with the decrease in the slab reheating temperature, the intensity of the {111}<112> texture increases from 4.958 to 6.809. At the same slab reheating temperature, the intensity of the rotating cube texture declines more significantly in the two-stage cold rolling process. Finally, two-stage cold rolling with the slab reheating temperature of 1220 °C is found to be more beneficial for the formation of a sharp Goss texture during the second recrystallization. The magnetic induction intensity B800 of the final product is 1.87T, and the iron loss P1.7/50 is 1.36 W/kg.


2012 ◽  
Vol 706-709 ◽  
pp. 2628-2633 ◽  
Author(s):  
I. Infante Danzo ◽  
Kim Verbeken ◽  
Yvan Houbaert

A homogenous intensity distribution along the cube texture fibre is important to achieve an easy magnetization in non-oriented electrical steels. Several alternatives have been discussed in literature to achieve this goal namely, tertiary recrystallization (surface energy controlled), decarburization annealing, two step cold rolling (strain induced boundary migration), twin-roll thin strip casting (directional solidification), phase transformation (surface energy anisotropy) and columnar grains formation (selective grain growth). In the present study, a hypoeutectic Al-Si alloy was deposited on the surface of cold rolled Fe-Si steels with a hot dipping simulator and subsequently annealed at 1000°C for different times. This procedure was developed previously in order to enrich the substrate with Al and/or Si and consequently improve their resistivity. Of specific interest was the formation of columnar grains in the low Fe-Si steel after annealing. These columnar grains were found to grow from the surface towards the centre of the substrate. The microstructure and texture in the columnar grains were significantly different than those in the middle of the material. Therefore, the evolution of these features during processing was studied in detail in this work.


2012 ◽  
Vol 560-561 ◽  
pp. 846-852 ◽  
Author(s):  
Qi Ma ◽  
Lin Hua ◽  
Dong Sheng Qian

Ring parts with small-hole and deep groove such as duplicate gear and double-side flange, are widely used in various engineering machineries. Three-roll cross rolling (TRCR) is a new advanced plastic forming technology for the processing of rings with small-hole and deep groove. In this paper, a 3D coupled thermo-mechanical FE model for TRCR of ring with small-hole and deep groove is established under ABAQUS software environment. By simulation and analysis, the evolution and distribution laws of strain and temperature in the forming process are revealed, and the effects of the key process parameters on the deformation uniformity are explored. The results provide valuable guideline for the technological parameter design and optimization.


1994 ◽  
Vol 22 (4) ◽  
pp. 261-278 ◽  
Author(s):  
C. Schuman ◽  
C. Esling ◽  
M. J. Philippe ◽  
M. Hergesheimer ◽  
M. Jallon ◽  
...  

This study deals with the texture evolution during drawing of interstitial-free low carbon steels under different conditions to study the possible influence of the drawing direction, deformation rate and metal/die friction coefficient. The drawing has been carried out without intermediary annealing, with constant die angle and deformation rate per pass. In all cases, a 〈110〉 fibre texture has been observed at the early stage of deformation (a few percents). The drawing direction, whether alternate or unidirectional, has little effect on texture. Slight differences only in the intensity of peaks on pole figures (PFs) are noted. Alternate drawing leads to higher drawing limits. The grain size affects both the texture and the mechanical properties, which are improved by fine grains. For industrial drawing, i.e. at a high deformation rate, no texture gradient has been clearly observed. Nevertheless, slight differences have been noted in the PF intensities, with generally a slightly sharper texture in the core, compared to the surface. The microhardness tests show no hardness gradient. In slow drawing (low deformation rate), there is a weak texture gradient which disappears at larger deformation. In order to visualize the influence of the metal/die friction, we used a material covered with copper. Results show that at a given reduction rate, the material covered with copper shows peak intensities on the (110) PF which are half these of a material drawn under conventional conditions. The drawing textures of BCC materials always present a 〈110〉 fibre texture. A modeling of the texture evolution during drawing has also been carried out using the Taylor model.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1906 ◽  
Author(s):  
Yi Li ◽  
Mingzhe Li ◽  
Kai Liu ◽  
Zhuo Li

As the local forming non-uniform of the formed curved surface part with larger bending deformation is the one of common defects, the utilization ratio of metal plate greatly reduces due to this defect, and cost of production is also increasing. In this paper, the differential speed rotation technology of flexible rolling process was proposed firstly to solve this forming defect. The finite element model was established, the reason of the local forming non-uniform was discussed; the effect of differential speed rotation technology on the forming uniform was studied. The results show that: Flexible rolling is a process based on thickness reduction, in this forming process, the thickness reduces sharply near the back end of metal plate, the local forming non-uniform of formed curved surface part is caused during this process; the differential speed rotation technology is applied in flexible rolling, with increasing rotation speed difference between upper and lower roll set, the forming uniformity of the formed curved surface part is greatly improved. The results of numerical simulation are in agreement with the result of forming experiments.


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