Papers by Keyword: Silicon Steel

Abstract: The water-based paint had been examined to prepare a new chromate-free insulating coating on silicon steels. The structure of the insulating coating was characterized by scanning electron microscopy, energy dispersive spectroscopy and infrared spectroscopy. Adhesion, high temperature annealing, and surface insulating resistance were measured. Corrosion resistance was investigated by neutral salt spray test and electrochemical test. Results exhibited that the insulating coating had excellent comprehensive performance. The adhesive level was 5B degree; the high temperature annealing test showed no coating degradation after heat treatment of 2 h at 450 °C in air or at 750 °C in nitrogen; the salt spray test showed the corrosion area was less than 2 % after the 12 h salt spray; when the coating thickness was 1.0-1.2 μm, the surface insulating resistance value was 380-420 Ω/mm².

Abstract: Magnetic properties of silicon steel mainly depend on the internal organizational structure and chemical composition. The main factors affecting magnetic properties of silicon steel are analyzed and summarized, including grain size, inclusions (size, type, quantity, and morphology), crystal texture, internal stress, dimensional accuracy, the surface quality of steels, and chemical composition. The impact mechanism of the factors influencing silicon steel magnetic property is explained and these influence factors are interrelated.

Abstract: There are many methods to show the micro structure of the metallographic, such as chemical erosion method, electrolytic erosion method, in which the former is the most commonly used. In this experiment, several kinds of corrosive are used to do the erosion. Use metallographic microscope to analyze the section and confirm the best corrosive.

Abstract: The silicon steel was rolled to 95% reduction at 20°C, 400°C and 600°C, and subsequently annealed at different temperatures to obtain complete recrystallization microstructure without appreciable grain growth. The effects of rolling temperature on through-thickness deformation and recrystallization textures were investigated by ODF analysis. The deformation textures are all composed of α- and γ-fiber, whereas α-fiber and {111}﹤110﹥ decrease and {111}﹤112﹥ increases with the increasing rolling temperature. Through-thickness recrystallization texture varied significantly, a strong partial γ-fiber spreading from {111}﹤112﹥ or {554}﹤225﹥ to {111}﹤134﹥ and {114}﹤481﹥ are developed in steel sheet rolled at 20°C and 400°C, while a dominated η-fiber peaked at {310}﹤001﹥ is formed between surface and quarter thickness in steel sheet rolled at 600°C. The different recrystallization textures can be ascribed to the profuse shear band at 600°C compared with the microstructures at 20°C and 400°C.

Abstract: Primary recrystallised sheets of 3% silicon steel from two different industrial processing routes have been examined after laboratory annealing to initiate secondary recrystallisation. Metallography included etching to reveal individual dislocations and sub-boundaries as well as EBSD in scanning electron microscopy. Residual low angle boundaries are not normally observed inside the secondary grains. The growth of secondaries appears to occur in a jerky manner, associated with local intrusions into the primary matrix that destabilise the interface. The frequency of occurrence of special low energy grain boundaries such as 9 and 5 is believed to dictate the selectivity of the Goss orientation in both types of steel sheet.

Abstract: Silicon steels tend to develop edge cracks during cold rolling, which need to be removed and cause rupture of the steel in the rolling mill. Hence, it is necessary to understand the formation of edge cracks. The damage distribution and the initiation and propagation of edge cracks occur around the notch tip during cold rolling process was investigated by using GTN damage model. The damage parameters f₀, f_c and f_F are determined by tension experiments and SEM observation. The influence of various rolling parameters on damage distribution and crack length was simulated by using ABAQUS. The numerical results show that the GTN damage model is available to prediction the initiation and propagation of edge cracks during rolling process. Parametric study carried out in this present work reveals that the possible occurrence of edge cracks is higher at larger reduction, higher friction coefficient, smaller roll radius and stronger unit tension. The simulation and experimental results have a good agreement .

Abstract: Through the analysis of the utility between the oriented silicon steel and the non-oriented silicon steel, this paper stated the different performance characteristics requirements of the silicon steel to various utility; According to the different characteristics requirements, this paper expounded the different requirements of heating process in the oriented silicon steel and the non-oriented silicon steel.

Abstract: Hot deformation behavior of Fe-3%Si steel within temperature range of 1073~1473K and strain rate range of 0.01~5s⁻¹ was investigated by isothermal compression test using thermo-simulation method. Over the applied deformation conditions, steady state flow behavior was well described by the power law relationship with dislocation climb as the rate-controlling mechanism, and the high apparent activation energy can be attributed to the high yield stress. A modified Bergström model was proposed by introducing yield stress, and consequently the whole stress-strain curves can be accurately predicted.

Abstract: Through-thickness shear strain variation with speed/radius/friction ratio in cold rolled silicon steel under different asymmetric rolling modes was analyzed by finite element method (FEM). Cold rolling textures were also investigated quantitatively to correlate with the calculated shear strain. With increasing speed/radius/friction ratio, shear strain distribution under differential-speed and differential-radius rolling exhibits similar characteristic in contrast to differential-friction rolling. Unidirectional shear strain develops through sheet thickness when asymmetric speed and radius ratio exceeds 1.125, whereas it does not appear even at friction ratio of 1.5. Shear strain distribution dependent on asymmetric rolling modes can be well understood by forward and backward slip zones as well as roll pressure as a function of speed/radius/friction ratio.

Abstract: Based on the investigation and study of the topography and composition of the buildups, combined with production process of silicon steel, the major causes of forming buildups of carbon sleeve are analyzed from the factors such as the quality of carbon sleeve, furnace atmosphere, dew point, adjusting steel roll, intermediate steel roll, running speed of carbon sleeve and so forth. Meanwhile, some countermeasures to reduce the formation of the buildups are put forward.