Textures of Non-Oriented Electrical Steel Sheets Produced by Skew Cold Rolling and Annealing

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) and <111>//ND (normal direction) fibers as commonly observed in conventionally rolled and annealed steels. At some skew angles (e.g., 15–30°), the desired <001>//ND texture was largely enhanced, while at other angles (e.g., 45°), this fiber was essentially unchanged. The formation mechanisms of the cold rolling and recrystallization textures were qualitatively discussed.

Выявление магнитной анизотропии в аустенитной хромоникелевой стали после прокатки

Investigations of texture, phase composition and magnetic anisotropy in rolled samples of austenitic steel 09Kh17N5Yu were carried out. It has been shown that the method of magnetic nondestructive testing using measuring of magnetic fields from locally magnetized areas is sensitive to anisotropy of magnetic permeability. Anisotropy of magnetic properties is related to formation of mechanical rolling texture. FCC rolling texture {110}<111> was found in all the rolled samples. Rolling texture, common for BCC structure (strain-induced martensite in low-carbon austenitic steels), developed in the samples with 30% of deformation or higher. Formation of ferromagnetic strain-induced martensite in austenitic steel 09Kh17N5Yu was confirmed by magnetic force microscopy.

Effect of Slab Reheating Temperature on Cold Rolling Texture Evolution of Nb-Containing Grain-Oriented Silicon Steel

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.

Cold Rolling Texture Prediction Using Finite Element Simulation with Zooming Analysis

Cold rolling is widely employed in the manufacturing industry for the production of metal plates. In the cold rolling process, the thickness reduction of the metal plate under the recrystallization temperature generates severe anisotropy; this influences the subsequent forming processes. Therefore, the generation and prediction of metal plate anisotropy during cold rolling is a highly interesting research topic involving upstream studies of sheet metal forming. In this study, using the finite element method with zooming analysis, we established an efficient elastic–plastic analysis method to predict the metal plate texture after cold rolling. This method for cold rolling texture prediction was confirmed by comparing the experimental and simulation results of cold rolling for an S45C plate with a body-centered cubic lattice. Further, the numerical analysis method proposed in this study can contribute to the study of anisotropy as an alternative to experimental approaches.

Rolling Texture of Cu–30%Zn Alloy Using Taylor Model Based on Twinning and Coplanar Slip

A modified Taylor model, hereafter referred to as the MTCS(Mechanical-Twinning-withCoplanar-Slip)-model, is proposed in the present work to predict weak texture components in the shear bands of brass-type fcc metals with a twin–matrix lamellar (TML) structure. The MTCS-model considers two boundary conditions (i.e., twinning does not occur in previously twinned areas and coplanar slip occurs in the TML region) to simulate the rolling texture of Cu–30%Zn. In the first approximation, texture simulation using the MTCS-model revealed brass-type textures, including Y {1 1 1}⟨1 1 2⟩ and Z {1 1 1}⟨1 1 0⟩ components, which correspond to the observed experimental textures. Single orientations of C (1 1 2)[1 ¯ 1 ¯ 1] and S’ (1 2 3)[4¯ 1¯ 2] were applied to the MTCS-model to understand the evolution of Y and Z components. For the Y orientation, the C orientation rotates toward T (5 5 2)[1 1 5] by twinning after 30% reduction and then toward Y (1 1 1)[1 1 2] by coplanar slip after over 30% reduction. For the Z orientation, the S’ orientation rotates toward T’ (3 2 1)[2 1 ¯4¯] by twinning after 30% reduction and then toward Z (1 1 1)[1 0 1¯] by coplanar slip after over 30% reduction.

Effect of Hot Band on Texture Evolution and Plastic Anisotropy in Aluminium Alloys

This contribution presents the evolution of crystallographic texture during thermomechanical processing of Al alloys. It is shown that the nature of crystallographic changes involved in deformation and recrystallization is strongly affected by the variety of initial (pre-rolling) state of a given metallic system. Four hot rolled Al strips of identical chemical composition and different textures were subjected to further thermomechanical processing with equal technological characteristics. Although the pre-rolling textures were first destroyed by the deformation, while annealing accounted for further qualitative and quantitative crystallographic changes in the investigated polycrystalline systems, it seems that there is still a great influence of the hot band texture on the texture dependent properties. Various qualitative and quantitative texture characteristics of annealed sheets ensured diverse Lanford value curves, which is a direct consequence of the crystallographic features developed in the hot bands. The Cube-dominated hot band ensured a strong V-shaped profile after cold rolling and subsequent recrystallization, whereas it was shown that a weak pre-rolling texture is more advantageous in terms of both normal and planar anisotropy.

Improving Mechanical Properties of Twin-Roll Cast AZ31 by Wire Rolling

Since 2018, the institute of metal forming has been studying the novel twin-roll casting (TRC) of magnesium wire at the pilot research plant set up specifically for this purpose. Light microscopic and scanning electronic investigations were carried out within this work and show the unique microstructure of twin-roll cast AZ31 magnesium alloy with grain sizes of about 10 μm ± 4 μm in centre and 39 μm ± 26 μm near the surface of the sample. By means of a short heat treatment (460 °C/15 min), segregations can be dissolved and grain size changes in centre to 19 μm ± 12 μm (increase) and near the surface to 12 μm ± 7 μm (decrease). Further, the mechanical properties of the twin-roll cast and heat-treated wire were analysed by tensile testing at room temperature. By heat treatment, the total elongation could be increased by a third whereas the strength decreases slightly. In heat-treated state, no preferred orientation is evident. In addition to the twin-roll cast and the heat-treated condition, the rolled state was analysed. For this purpose, the twin-roll cast wire was hot rolled using an oval-square calibration. After hot rolling, a dynamic recrystallization and grain refinement of the twin-roll cast wire could be achieved. It can be seen, that an increase in strength as well as in total elongation occur after wire rolling. Beside this, a rolling texture is evident.