Yuhui Sha

Development of strong {001}〈210〉 texture and magnetic properties in Fe–6.5wt.%Si thin sheet produced by rolling method

Fe–6.5wt.%Si thin sheets were successfully produced by conventional rolling and annealing methods. The deformation and recrystallization textures were investigated by means of x-ray diffraction and electron backscattered diffraction analysis. It was found that a strong {001}〈210〉 recrystallization texture was obtained and the magnetic property was significantly improved under the appropriate rolling temperature. The formation of the {001}〈210〉 texture was explained in terms of preferred nucleation by the strain-induced boundary migration mechanism and selective growth by grain size advantage established during primary recrystallization.

Secondary recrystallization and magnetostriction in binary Fe81Ga19 thin sheets

Strong Goss texture ({110}〈001〉) was successfully developed by secondary recrystallization in Fe81Ga19 sheets without conventional application of inhibitor or surface energy effect as grain-oriented silicon steel. Goss grains cover 90% surface area of annealed sheet, and the magnetostriction coefficient reaches up to 262 ppm. The primary recrystallization microstructure and texture provide the prerequisites for nucleation and abnormal grain growth of secondary Goss grains. The dispersedly distributed Goss grains do not exhibit an evident advantage in grain size and number, and the normal grain growth of matrix grains can be inhibited by low-angle grain boundaries before onset of secondary recrystallization. The existence of low-angle grain boundaries is proposed to be an important factor for the occurrence of secondary recrystallization in binary Fe-Ga sheets based on grain boundary character distribution analysis.

Development of Strong η Fiber Recrystallization Texture in Rolled Fe81Ga19 Thin Sheet

The 0.50-mm-thick Fe81Ga19 sheets were produced by rolling procedure, and texture evolution was investigated using macro- and microtexture analyses. The recrystallization texture dominated with strong η fiber (〈001〉//RD) was successfully obtained through sheet thickness by primary recrystallization annealing. The η fiber development can be attributed to the advantage in both grain number and grain size derived from the specially applied rolling process.

Application of Asymmetric Rolling to Texture Control of Silicon Steel

The influences of different rolling modes and speed ratios on cold rolling texture development, and the characteristics of recrystallization textures after ordinary annealing as well as magnetic annealing have been investigated for non-oriented silicon steel. Results show that the through-thickness deformation textures were effectively changed by asymmetric cold rolling even in the case of small speed ratios, and the recrystallization textures were modified with the enhanced favorable {100} and η (<100>//RD) texture components by magnetic annealing. Much improved magnetic properties can be obtained through optimization of asymmetric rolling and annealing parameters. Thus, application of asymmetric cold rolling and magnetic annealing might open up new possibilities for texture control in high-grade silicon steel production.

Evolution of Drawing Texture for A6 Aluminum Conductor

Evolution of drawing texture for A6 aluminum conductor with the drawing process was investigated by macro and micro-texture analysis. The results show that the fiber-like deformation texture of 111 and 100 formed in the drawing process, and 100 texture reduced while 111 texture enhanced with the increasing strain. The distribution of deformed texture was of homogeneity along the radial direction of wire: the deform texture transformed from strong 100 texture(~52% volume fraction) in the surface to strong 111 texture(~55%) in the center by moderate strains; the radial gradient texture was weakened and a strong 111 texture(70%) formed in the overall wire by high strains. Moreover,the core hardness of the wire was higher than that of the surface, which attributed to the texture gradient distribution along the radial. Adjusting the drawing process to optimize the dislocation density and texture as well as their distribution in the wire is an effective route to improve the strength and conductive properties of the A6 aluminum conductor.

Optimisation of recrystallisation texture and magnetic properties in Fe–6·5 wt-%Si thin sheets by preannealing method

Abstract Fe–6·5 wt-%Si thin sheets were produced by conventional rolling and annealing processes, and the effect of preannealing before final annealing on recrystallisation texture was investigated using macro- and microtexture analysis. It is found that the suitable temperature and time of preannealing can decrease detrimental γ recrystallisation texture, resulting in an optimisation of magnetic induction. The effects of preannealing can be attributed to its weakening the dynamic advantage of γ recrystallisation nuclei with respect to others.

Through-Thickness Texture Variation in Non-Oriented Electrical Steel Sheet Produced by Asymmetric Rolling

The hot bands of non-oriented electrical steel were cold rolled by asymmetric rolling with speed ratio of 1.125 as well as conventional symmetric cold rolling to investigate the effects of cold rolling mode on through-thickness texture variation. Asymmetric rolling shows a marked weakening effect on α fiber (RD//<110>) running from {001}<110> to {112}<110> through sheet thickness, especially at the side contacting with faster roll. Asymmetric rolling increases {111}<112> component while decreases {111}<110> component through sheet thickness except for the surface layers. The through-thickness texture variation due to asymmetric rolling was explained in terms of shear strain distribution.