Grain oriented silicon steel

preparation process of grain-oriented silicon steel manufacturing process as follows:

chemical composition of electrical steel on the chemical composition of strict and narrow the scope of the specified ingredients. Silicon controlled at 2.9% to 3.1%, high-grade increased to 3.2% to 3.4%. The silicon content of each increase of 0.1%, iron loss, the P17 can reduce 0 World Pipe network informed.019W/kg. Carbon from 0.03% to 0.05% (Go steel) or 0.05% to 0.08% (Hi-B steel). Ensure that the slab hot rolling 20% ​​30% 7 phase, to prevent the hot-rolled plate along the thickness direction of the central area of ​​the formation of thick deformed grains leaving a linear fine grain. Hi-B steel carbon content is higher for high-temperature annealing, a larger number of Ah-phase in order to guarantee access to a large number of small of AlN. Nitrogen in λ phase solid solution than in a phase of about nine times larger. The silicon content is increased, the carbon content should be a corresponding increase. The provisions of manganese is 0.05% ~ 0.10%, sulfur of 0.015 percent to 0.03 percent, to ensure that small MnS precipitates. Hi-B steel, manganese and sulfur-containing the Nang partial ceiling slab reheating and hot rolling temperature, reducing the precipitation of AlN amount, after the high-temperature normalization of precipitation more small of AlN. Hi-B steel, acid-soluble aluminum Als (of Al-Al203 in A1) provides that 0.02% to 0.03%, 0.006% to 0.01% nitrogen, in order to ensure that the high temperature often of small A1N precipitation amount. Phosphorus content equal to or less than 0.015%. Control the silicon content in the thinning of the upper and the thickness of the product so that secondary recrystallization development more difficult, this high-grade GO steel plus 0.15% to 0.20% copper, plus 0.05% to 0.09% copper in the high-grade Hi-B steel (copper finer (Cu, Mn), 1.8S) and 0.06% to 0.14% tin (or antimony), in order to enhance the inhibition, so that the surface of hot-rolled plates (110) component increased to promote secondary recrystallization. GO steel cold rolling reduction rate from 50% to 55% to 60% ~ 70%, the secondary grain size decreases, the iron loss reduce. Tin along the grain boundary segregation segregation along the interface between the MnS particle and the substrate, to prevent the the MnS crude, strengthen the inhibition of force and (1lO) component increased, the second grain is small and P17 lower.

(3) high-temperature normalization, cold rolling, decarburization annealing and coated with release agent. Hi-B steel, hot rolled by (1100 ~ 1120 ℃) ​​× (3 ~ 5min) the normalization of treatment in nitrogen, air-cooled to 900 ° C water spray quench precipitated fine of AlN. Hot-rolled or often after pickling and maintain 50 to 60 ° C for cold-rolled. The G.0. Steel 60% to 70% reduction rate after cold rolling, wet in a continuous furnace 20 Hz + N2 atmosphere by (850 ~ 950 ° C) × (2.5 ~ 4min), intermediate annealing, recrystallization elimination of hardening and partial decarburization. 50% ~ 70% reduction rate in the secondary cold rolled to a finished thickness. Hi-B steel - big reduction ratio (82% to 90%) cold-rolled method. The cold rolling process by 150 ~ 300 ° C aging treatment, the solid solution of carbon and nitrogen in steel increased, impeding dislocation movement, and promote the formation of deformation bands and secondary nucleation. Cold-rolled plates in 20% of the continuous furnace wet H2 + N2 by (835 ~ 850 ℃) × (3 ~ 4min) decarburization annealing, the purpose of: - carbon off to 0.003% or less to ensure that after high temperature annealing single-a phase of development of a sound secondary recrystallization, and the elimination of the magnetic aging phenomena; access to small and uniform initial recrystallized grain and is conducive to (110) [001] secondary nuclei merit grew up initial recrystallization texture; the surface to form a uniform and dense SiO2 film. Decarburization annealing after the wet coating on MgO (agent) to prevent the rolls of high-temperature annealing, bonding to form magnesium silicate glass membrane bottom (of Mg2SiO4) and the surface of SiO2.

deformation and recrystallization annealing to produce grain preferred orientation of the Si-Fe alloy, the silicon content of about 3%, the carbon content is very low. Product of the cold rolled sheet or strip, the nominal thickness of 0.18,0.23,0.28,0.30 and 0.35mm. Mainly used for manufacturing all kinds of transformers, fluorescent ballasts and turbine stator core. 6% to 10% electrical energy consumption in transmission and distribution systems, of which about 60% of consumption in the transmission and distribution wires, about 40 percent of consumption in the transformer. The total losses of the transformer iron loss and copper loss in each of about 50%, and the iron loss is directly related to the core of silicon steel used to manufacture quality.

(2) hot-rolled. Slab insulation pit slow cooling load, the billet temperature greater than 250 ° C and then loaded into the furnace heated to high temperatures of 1350 ~ 1400 ℃, the thick slab of MnS and AlN solid solution in the hot rolling process MnS the dispersed-like (less than 50nm) precipitates. Therefore, heating and hot-rolled MnS solid solution and precipitation heat treatment process. Rough rolling slab thickness of 30 ~ 40mm. Control before finish rolling temperature within the range of 1160 ~ 1200 ℃, because MnS precipitation in the finishing process. Hi-B steel, hot rolled to minimize the amount of precipitation of AlN. The final rolling temperature of 950 ~ 1050 ℃, the spray cooled to about 550 ° C coiling after hot rolling, hot-rolled with a thickness of 2.2 ~~ 2.5mm.

(4) high-temperature annealing, flat stretch annealing and coated with the insulating film. Coil coated MgO high temperature annealing in bell-type furnace or a continuous ring furnace, the objectives are: to complete secondary recrystallization (110) [001] texture (G0 steel at 850 to 950 ° C, Hi-B steel at 980 ~ 1030 ° C); the formation of magnesium silicate bottom layer (1000 to 1100 ° C); to remove sulfur and nitrogen in steel (1180 to 1200 ° C). First rose to 600 ° C in nitrogen, insulation hour, remove the MgO in the combined water, and then in 75% H2 + N2 15 ~ 20 ° C / h, slow rise to about 1150 ° C, and then replaced with a dew point of -60 ° C pure dry hydrogen to rise to 1200 ° C, insulation 20h, and then replaced with 75% H2 + N2 furnace cooling to 700 ° C, and replaced with nitrogen to continue cooling. Annealing and coating insulating film high-temperature annealing after the formation of stretch. First strip by water scrub and dilute acid wash to remove the residue of MgO coating body SiO2 and phosphate-based stress coating in a continuous furnace in nitrogen processing by 800 ℃ × 5min and appropriate tension, so that the strip formation and sintering the insulating film. Stress coating coefficient of thermal expansion (about 4 x 10-6 / ° C) and silicon (about 13 × 10-6 / ℃) annealing cooling tensile steel plate about 4.9N/mm2 tensile stress, so that 180 . Domain refinement and reduce iron loss. Into - further reduce the iron loss can be further along the horizontal by the laser irradiation, dentate roll processing or plasma spray processing.

grain oriented silicon steel (silicon steel with orientedgrain)

(1) hot metal de-manganese smelting, vacuum processing and die casting (or casting ). Fe0 such as blast furnace hot metal manganese content greater than 0.35% in the ladle off the manganese content to below 0 World Steel Pipe News .35% and argon stirring. In the top-blown or top and bottom blowing converter refining, control C <0.06%, P <0.01% s <0.03% and Mn <0.07%. Out of steel and aluminum deoxidation in the ladle, and ferrosilicon alloy and argon so that the temperature and composition uniformity and oxide inclusions floating. The vacuum processing fine-tune the composition. Before using the die casting method, the use of continuous casting method.

development trend of the development trend of grain oriented silicon steel for: (1) of the slab in the reheating furnace and heated to approximately 1250 ° C, and then faster in the electric induction furnace heated to 1350 ~ 1400 ° C reduce the amount of burning, reduce the degree of grain coarsening and hot rolled edge crack and surface defects; (2) A1N inhibitor of manganese and phosphorus content by adding antimony, boron, chromium and other elements, the decarburization annealing after the nitriding treatment, so that the slab reheating temperature is reduced to below about 1280 ° C; (3) cast the 2 ~ 3mm thick thin billet directly cold-rolled; (4) a cold rolling mill cold-rolled; (5) development of new resistance to eliminate the stress annealing refinement of the magnetic domain techniques, such as plasma spraying TiN stress film; (6) A1203-based release agent to form a glass film, surface satin finish.

secondary recrystallization prerequisite for oriented silicon steel by secondary recrystallization to form (110) [001] single - texture. Well-developed secondary recrystallization organization must have the following three conditions: (1) Steel inhibitors impede the initial recrystallization normal grain growth, promote secondary grain unusual grew; (2) the initial recrystallized grain small uniform secondary grain annexation of the initial grain while growing up; (3) organization with the appropriate initial recrystallization texture, ie (110) [001] secondary nuclei around {111} < 112> to the initial nucleation, secondary nucleation to grow up. GO steel cold-rolled into the legal system of MnS or Mnse-based inhibitors and the second medium reduction ratio. Hi-B steel AlN + of MnS-based inhibitors, the hot rolled plate heat normalization - the second largest reduction ratio of cold-rolled into the legal system. MnS and AlN second phase precipitates must be uniform distribution of the dispersed state, in order to ensure the ability of the strong inhibition of the initial grain growth. The MnSe + Sb Mnse, + sb + Mo inhibitor and the second medium-pressure rate of cold-rolled method can be used to manufacture the Hi-B steel, but the magnetic slightly lower.

classification and characteristics of grain oriented silicon steel (hereinafter referred to as the grain oriented silicon steel) is divided into ordinary grain oriented silicon steel (G0 steel) and high magnetic induction (high permeability) oriented silicon steel (Hi-B steel) two types of . GO steel bit to the deviation angle is about 7. , The grain diameter of 3 ~ 5mm, magnetic induction B8 approximately 1.82T. Hi-B steel deviate from the angle of about 3. Grain diameter is 10 ~ 20mm, B8 is approximately 1.92T. Because of the high degree of orientation of the Hi-B steel, and B8, the iron loss is reduced by at least 15%, also significantly reduced the magnetostriction coefficient G0 steel, made of transformer iron loss reduced by 10% to 15% of the magnetizing current is reduced by 40% to 50% , a decrease of 4 ~ 7dB noise. Oriented silicon steel grain, in particular, the Hi-B steel grain magnetic domain size, and 180. Magnetic domains. Eddy current loss Pe and abnormal loss Pa and the iron loss than the hysteresis loss Ph 1.5 ~ 2. O times and Pa than Pe large 1 to 2 times, so the main goal is to reduce Pe, Pa. Because Pe, +, Paα 2Lt2 / ρ is (2L is the domain wall spacing, t is the plate thickness, ρ is the resistivity). Since the 1980s, Japan has taken the thinned plate thickness, the silicon content (from 2.9% to 3.1% to 3.2% ~ 3.4%) and three technical measures refining the magnetic domains, has developed a three GO steel and three Hi- The new grades of steel B, the production of new varieties of 0.18 and 0.23mm thick. The production of laser irradiation and dentate roll processing to refine the magnetic domains.