Grain Refinement by High Temperature Plane-Strain Compression of Fe-2%Si Steel (original) (raw)
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High temperature deformation of silicon steel
Materials Chemistry and Physics, 2012
h i g h l i g h t s < The plastic deformation of a silicon containing steel is studied by plane strain compression. < Equiaxed and elongated grains develop in different regions of the sample due to recrystallization. < Texture, by EBSD, is revealed to be similar in either type of grains.
Orientation dependence of secondary recrystallisation in silicon–iron
Acta Materialia, 2003
Experiments and analyses have been carried out to reach a better understanding of the mechanism of Goss texture formation during the secondary recrystallisation of silicon steel processed by the single cold reduction route. A new experimental approach demonstrated the effect of misorientation on the growth rates of secondary grains and it is shown that these rates are controlled by the proportion of matrix grains having ⌺9 CSL relationships to growing secondary grains. It is considered that the ⌺9 boundaries have lower energy than general grain boundaries and so are less strongly inhibited by Zener drag. The relative infrequency of ⌺9 boundaries around the periphery of secondary grains is seen as evidence for their sacrificial behaviour. Other experiments involving growth of randomly oriented nuclei provide independent support for the important role of ⌺9 boundaries during secondary recrystallisation in this steel.
Secondary recrystallization in Fe–6.5 wt% Si alloys by internal friction
Journal of Non-Crystalline Solids, 2001
Samples, Fe±6.5 wt% Si, were obtained by quenching from the liquid using the single roller method. Under these conditions, ductile ribbons 20 Â 1 Â 0:05 mm 3 were obtained. The initial structure of the as-cast alloy, characterized by X-ray diraction, was mainly a disordered bcc a phase. Under suitable thermal treatments, annealing at 1373 K during 1 h, the second recrystallization took place. The annealed sample contained precipitates of the ordered B2 Fe±Si phase with a (1 0 0)±(1 1 0) double texture that changed the magnetic properties of the alloy. To analyze the microstructural processes associated with the recrystallization texture, internal friction (IF) spectra were obtained employing an inverted torsion pendulum at frequencies around 1 Hz. The spectra, obtained as a function of the heating temperature, were analysed for the initial as-cast and thermally treated samples. The results show that the recrystallization process is dominated by two grain boundary contributions: a low temperature ($ 800 K) peak associated with the free movement of grain boundaries and a peak at around 1000 K where the grain boundary mobility is determined by the interaction with Si solute atoms. Ó
International Journal of Pressure Vessels and Piping, 2020
This paper presents the results of an experimental study aimed to obtain an ultrafine equiaxed grain distribution in 18Cr oxide dispersion strengthened (ODS) ferritic steel through cold working and annealing starting with an initial columnar grain structure with a predominant α-fibre texture in a product consolidated from the alloy powders during extrusion at high temperatures. Deformation along the extruded direction (ED) resulted in the retention of α-fibre texture, while deformation in the transverse direction (TD) showed a shear banded structure with a reduced percentage of α-fibre texture. Differential Scanning Calorimetry (DSC) analysis of the deformed steel established the occurrence of two significant events during heating namely recovery and recrystallization, whose temperatures were influenced by the heating rate. The recovery and recrystallization domains have been distinctly observed at 1350 K and 1420 K respectively at a low heating rate of 7 K min À 1. The resultant microstructure showed very coarse elongated grains interspersed with regions of ultrafine (<1 μm) equiaxed grains, due to the incomplete recovery. The deformed steel was subjected to a two step heat treatment designed based on the above inputs with an aim to reduce the microstructural anisotropy in longitudinal direction. The microstructure of the heat treated steel showed randomization of the initial <1 1 0>//ED α-fibre texture, which improved further with repeated deformation and two step heat treatment cycles. A gradual increase in hardness during the above cycles was observed reflecting the increase in dislocation density which offers the propensity to achieve an ultrafine grained microstructure.
Recrystallization Texture Transition in Fe-2.1 Wt Pct Si Steel by Different Cold Rolling Reduction
Metallurgical and Materials Transactions A, 2015
The competition dependent on cold rolling reduction among main recrystallization texture components in Fe-2.1 wt pct Si sheets was investigated from the hot band characterized by strong Cube ({001}h100i) at center layer and weak Goss ({110}h001i) at quarter layer. The deformation and recrystallization textures through thickness were both analyzed by X-ray diffraction technique. Goss, Cube, and {111}h112i components dominate the recrystallization texture in sequence with the cold rolling reduction increasing from 60 to 90 pct. This recrystallization texture transition with cold rolling reduction can be explained in terms of the number and nature of nucleation sites for various texture components. A variety of final recrystallization textures are proposed for non-oriented silicon steel by designing texture and microstructure of hot band and cold rolling reduction.
Metallurgical Research & Technology, 2019
The grain-oriented silicon steel was produced by medium temperature reheating and two-stage cold rolling process, and the microstructure and texture of all metallurgical processes were studied. The results shown that the microstructure of the hot rolled strip was inhomogeneous in thickness direction, the surface layer was the recrystallized microstructures with average grain size of 42.29 µm, the center layer was fiber structure, and the Goss texture appeared at surface. The primary recrystallized microstructure with average grain size of 16 µm was obtained after decarburization annealing, which characterized by a strong γ-fiber texture and a weak Goss texture. The average size of inhibitors in hot rolled strip and decarburization annealed sheet were 9.078 and 21.691 nm respectively, they were mainly compound of nitride and sulfide with spherical or lump shapes. The coarse Goss grains with average size 17.57 mm were got after secondary recrystallization, and the magnetic induction B...