Abstract: The heat resistant subdivision of magnetic domains of a grain-oriented electrical steel sheet for improving the watt loss characterized by forming intruders therein is improved by pickling the steel sheet prior to the electroplating of the intrudable means. The partly exposed steel sheets are pickled by HNO.sub.3, H.sub.2 SO.sub.4 containing Fe.sup.3+, HCl containing Fe.sup.3+, and/or HBF.sub.4.

Abstract: The present invention relates to a method for forming insulating films on electromagnetic steel plates.Conventional films obtained by coating only an inorganic component such as a chromate, forming an organic-component film on an inorganic-component film or coating a mixture of both components individually have had disadvantages such as the occurrence of crateriform pinholes, reductions in punching properties, rises in the cost and decreases in interlayer resistance and the like.The present invention provides a method wherein a composition obtained by combining an acrylic resin and/or an acryl-styrene resin and guanamine resin as the organic components with an inorganic substance composed mainly of a chromate is coated and dried on an electromagnetic steel plate to form thereon an insulating film.According to the present invention, it is possible to form an insulating film which has excellent film properties and is free from said disadvantages.

Abstract: An ordinarily made thin steel sheet is placed in an atmosphere bearing SiCl.sub.4, and subjecting to Si penetrating treatment at temperatures between 1100.degree. C. and 1200.degree. C. for a determined period of time. A heating rate is used which is more than 50.degree. C./sec at the temperatures of more than 1000.degree. C. in the SiCl.sub.4 atmosphere.Thereby, it is possible to manufacture thin steel sheet of high magnetic permeability without internal defects.

Abstract: This invention is directed to non-aqueous magnesium oxide slurries and the use thereof to coat silicon steels prior to high temperature annealing.

Abstract: For making a ductile boron-containing grain-oriented silicon steel, there is practiced, at a late stage in the making of the product either during the final texture anneal or a subsequent anneal, a high-temperature anneal in a reducing atmosphere with the use of a separating-agent coating, particularly magnesium oxide, which contains an effective amount of a compound of molybdenum and/or tungsten.

Abstract: A method and apparatus are provided for domain refinement of texture annealed and insulation coated grain-oriented silicon steel strip by contacting the insulated steel surface to be scribed with a discharge electrode, moving the electrode substantially transverse to the rolling directioln while essentially maintaining contact, and marking the steel with a plurality of electrical discharge craters generally aligned across the steel by producing a plurality of electrical discharges between the electrode and steel from a capacitor of 0.001-10.0 microfarads.

Abstract: For improving the properties of a glass film on a grain-oriented electrical steel sheet, the annealing separator applied on a decarburized steel sheet is prepared by: calcining at a high temperature to reduce the activity thereof; hydrating only on the outermost layer of MgO particles; and adding a Ti, B, or S compound to MgO.

Abstract: A method and apparatus are provided for domain refinement of texture annealed and insulation coated grain-oriented silicon steel strip by contacting the insulated steel surface to be scribed with a discharge electrode, providing a high voltage-low current and low voltage-high current to the electrode, moving the electrode across the steel while essentially maintaining contact therewith, and marking the steel with a plurality of indentations generally aligned across the steel surface by pulsing the high current to produce a plurality of electrical discharges.

Abstract: A coating composition is disclosed consisting essentially of sodium silicate, magnesium oxide or magnesium hydroxide, titanium oxide and mica. Coatings from this composition are useful as electrically insulating coatings, particularly as applied to electrical steel sheets for magnetic cores, or to other metal products or substrates. The coating may be cured at temperatures within the range of 400.degree. to 500.degree. F. and provides reduced die wear of electrical steel sheet during punching operations. It also is tightly adherent and retains excellent electrical insulating properties after annealing at temperatures within the range of 1350.degree. to 1550.degree. F.

Abstract: In a grain-oriented electromagnetic steel sheet which is produced by a process including a cold-rolling step(s), the final reduction ratio of the cold-rolling step(s) being high, a technical means for refining the secondary recrystallized grains is particularly important. One technical means is the incorporation of tin into silicon steel material. This, however, involves a problem because tin incorporated into silicon steel material deteriorates the surface coating which imparts tension to a grain-oriented electromagnetic steel sheet.The incorporation of copper into silicon steel material has been avoided since it causes secondary recrystallization to be unstable.The present invention is characterized by the combined incorporation of tin and copper into molten steel so as to simultaneously refine the secondary recrystallized grains and to form a good surface coating. The grain-oriented electromagnetic steel sheet of the present invention contains from 2.5% to less than 4.0% of silicon, from 0.03% to 0.

Abstract: This invention is directed to non-aqueous magnesium oxide slurries and the use thereof to coat silicon steels prior to high temperature annealing.

Abstract: A grain-oriented electrical steel sheet having a low watt loss after stress relief annealing is proposed. The steel sheet, which is final texture annealed, and to which tension is imparted, has a number of recessed parts on the surface thereof forming indentations into the steel sheet body having a depth in the range of from 0.01 to 0.1 mm. The recessed parts are filled with a composition having a coefficient of thermal expansion smaller than that of the steel sheet body. From the recessed parts and the composition the magnetic domains are subdivided.

Abstract: This invention is directed to improved magnesium oxide slurries for use in coating silicon steels prior to high temperature annealing, comprising a calcination-modified magnesium oxide and water. Inorganic salts of barium, chromium, silicon, zinc or aluminum are added to magnesium hydroxide prior to calcination, resulting in a calcined magnesium oxide product having improved properties.This invention is also directed to an improved process for coating silicon steel, using the above described improved magnesium oxide product.

Abstract: A method is provided for improving core loss of grain-oriented silicon steel by scribing the steel after cold rolling in a direction substantially transverse to the rolling direction by directing a pressurized liquid jet onto the steel surface to form selected spaced-apart scribe lines. The jet may contain solid particles which increase the scribing efficiency.

Abstract: As to a method of producing grain oriented silicon steel sheets used in stacked lamination-core transformers, which realizes the improvement of magnetic properties, particularly extreme reduction of iron loss irrespectively of a high temperature heat treatment such as strain relief annealing and can attain the improvement of compressive stress dependence of magnetostriction and lamination factor, it is a main point that the steel sheet after the finish annealing is provided on its surface with a thin coat of at least one layer composed mainly of nitrides and carbides of Ti, Zr, Hf, V, Nb, Ta, Mn, Cr, Mo, W, Co, Ni, Al, B and Si and strongly adhered to the surface of the steel sheet through a mixed layer of base metal and thin coat.

Abstract: A thin-gauge (0.10-0.23 mm thick) grain-oriented electrical steel sheet is produced by a process characterized by a decarburization which is carried out after the hot-rolling and before the final cold-rolling, after which the known, decarburization annealing and finishing annealing are carried out. The steel composition is adjusted to induce the secondary recrystallization by the AlN inhibitor. The reduction at the final cold-rolling is determined to be high to obtain a high magnetic flux density but tends to instabilize the secondary recrystallization unless the inventive decarburization is carried out.

Abstract: A method is provided for improving core loss of grain-oriented silicon steel by scribing the steel after cold rolling in a direction substantially transverse to the rolling direction by directing a pressurized liquid jet onto the steel surface to form selected spaced-apart scribe lines. The jet may contain solid particles which increase the scribing efficiency.

Abstract: A method is provided for improving core-loss values of grain-oriented silicon steel after final texture annealing by boronizing the steel to levels of 0.001 to 0.009 wt. % after applying a boron-containing material to the final texture annealed steel, heating to 1850.degree. to 2200.degree. F., maintaining the steel at such temperature to infuse boron into other steel, and cooling the steel at a rate of 100.degree. F./hour or less.

Abstract: A method is provided for improving the core losses of silicon-iron steels, especially grain-oriented silicon steels, by improving the uniformity and quality of the base insulating coating; the method includes winding coated steel strip at winding tensions sufficient to form a coil having good coil integrity and sufficiently loose to improve base coating formation.

Abstract: A grain-oriented silicon steel sheet having high magnetic induction and low iron loss can be obtained by adhering uniformly at least one member selected from the group consisting of elements of Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements to the surfaces of a silicon steel sheet before or after the decarburization annealing in a method for producing grain-oriented silicon steel sheets. According to this method, a hot rolled steel sheet is subjected to at least one cold rolling, the finally cold rolled steel sheet is subjected to a decarburization annealing, and the decarburized steel sheet is applied with an annealing separator consisting mainly of MgO and then subjected to a final annealing, or by carrying out the adhesion treatment of element in combination with a preliminary annealing before the decarburization annealing in the above described method, or by using the annealing separator further containing Bi or a Bi-containing compound in the above described method.

Abstract: An annealing separator used in a finishing annealing step for producing a grain-oriented electrical steel sheet usually contains magnesia. The present invention is characterized by including, based on 100 parts by weight of magnesia, from 0.2 to 20 parts by weight of ferromanganese nitride or manganese nitride which consists of a composition (Mn.sub.1-x Fe.sub.x)N.sub.y having x and y values corresponding to A, B, C, and D and falling within a region surrounded by A, B, C, and D shown in the appended FIG. 1.The annealing separator according to the present invention is effective for stabilizing secondary recrystallization and improving the properties of a forsterite film.

Abstract: A method of manufacturing a grain-oriented silicon steel sheet having excellent magnetic properties. In this method, a silicon steel slab containing 2.0-4.5 wt % of Si, 0.02-0.10 wt % of Mn and 0.005-0.06 wt % in total of at least one of S, Se and Al is subjected to such a heat treatment prior to a hot rolling that the slab is heated to a slab center temperature of 900.degree.-1,230.degree. C. in a slab heating furnace of a gas firing type and placed in a slab induction heating furnace before the slab center temperature is less than 900.degree. C. and then held at a slab center temperature of 1,250.degree.-1,380.degree. C. for not less than 10 minutes.

Abstract: A method for producing an annealing separator coating on grain oriented silicon steel prior to final texture annealing to improve the coating uniformity and prevent oxidation of the steel surface during this annealing operation. The method comprises coating the steel with a conventional coating, such as magnesium oxide, having an addition of an inert, high temperature refractory annealing separator agent, preferably calcined alumina.An annealing separator composition is also provided.

Abstract: Grain oriented silicon steel sheets having a very low iron loss W.sub.17/50 of lower than 0.90 W/kg, in which Si content is 2-4%, are produced by containing at least one of Se and S in an amount of 0.010-0.035% and at least one of Sb, As, Bi and Sn in an amount of 0.010-0.080% as inhibitor, making a final gauge to be 0.15-0.25 mm, forsterite coating formed on the steel sheet surfaces in the final annealing to be 1-4 g/m.sup.2 per one surface and a secondary crystallized grain size to be 1-6 mm.

Abstract: A method for obtaining grain-oriented silicon steel sheet with a very high magnetic flux density and a very low core loss by setting specific conditions for the decarburization and primary recrystallization annealing step within the series of steps performed for the manufacture of the grain-oriented silicon steel sheet. This method consists of setting the rate of temperature rise in the decarburization and primary recrystallization annealing step at no less than 10.degree. C./sec, dividing the decarburization and primary recrystallization annealing step into a first half and a second half, and restricting the temperature, time, and ratio P.sub.H.sbsb.2.sub.O /P.sub.H.sbsb.2 of the partial pressure of H.sub.2 O to the partial pressure of H.sub.2 of the atmosphere for each of these two halves within certain predefined ranges.

Abstract: The present invention provides an annealing separator comprising from 0.05 to 2.0 parts by weight of antimony sulfate based on 100 parts by weight of magnesium oxide, and at least one chloride selected from the group consisting of Sb, Sr, Ti, and Zr chlorides in a chlorine amount of from 5 to 20% by weight based on 100% of the chloride and antimony sulfate, and occasionally comprises Ti oxide in an amount of from 0.5 to 10 parts.The annealing separator is applied on the decarburization annealed strip, and improves both the magnetic properties and properties of glass film, in the production of a grain-oriented electrical steel sheet.

Abstract: A water repellent, for example an organic silicon compound, is added to an annealing separator which is applied electrostatically to the surface of a grain oriented magnetic steel sheet, or a glass-like film forming undercoating formed on the sheet surface.

Abstract: A method and apparatus for scribing grain-oriented silicon steel to improve the core loss thereof is provided. The method comprises passing the final gauge steel after cold rolling through a roll pass defined by an anvil roll and a scribing roll having a surface with a plurality of projections thereon with said projections being generally in a direction of the roll axis; the anvil roll is constructed from a material that is relatively more elastic than the material from which said scribing roll is constructed. Preferably the scribing roll is constructed from steel and the anvil roll is constructed from rubber.

Abstract: The instant invention is directed to a slurry for use in coating silicon steel prior to high temperature annealing, comprising magnesium oxide, water and at least one inorganic compound selected from the group consisting of barium oxide, barium nitrate, chromium nitrate, and their hydrates.The instant invention is also directed to a process for coating silicon steel, comprising coating the steel with a magnesium oxide slurry prior to high temperature annealing, the improvement wherein at least one inorganic compound selected from the group consisting of barium oxide, barium nitrate, chromium nitrate, and their hydrates is pre-mixed in said slurry, thereby minimizing the formation of "tight magnesia" on the steel.

Abstract: An insulative coating composition for electrical steels containing Al.sup.+++, Mg.sup.++, H.sub.2 PO.sub.4.sup.- and aluminum silicate in specified proportions, in the form of a stable aqueous suspension which provides a tension-imparting coating having good curing characteristics and which imparts improved magnetic properties to electrical steels.

Abstract: A method and aqueous coating composition for forming an anti-stick and insulative coating on cold-rolled, non-oriented, semi-processed steel; cold-rolled, non-oriented, fully-processed steel; cold-rolled motor lamination steel; and punching quality oriented electrical steel. The coating composition has an inorganic portion and an organic portion. The inorganic portion comprises, on a water-free basis and by weight, 3% to 11% Al.sup.+++, 3% to 15% Mg.sup.++ and 78% to 87% H.sub.2 PO.sub.4.sup.- calculated as Al.sub.2 O.sub.3, MgO and H.sub.3 PO.sub.4, respectively, the total weight percentage being 100% on a water-free basis and the concentration being 100 parts by weight on a water-free basis; and either 33 to 250 parts by weight colloidal silica on a water-free basis, together with from 10 to 25 parts by weight chromic anhydride for every 100 parts by weight H.sub.2 PO.sub.4.sup.- calculated as H.sub.3 PO.sub.4, or from 30 to 250 parts by weight aluminum silicate calculated as Al.sub.2 O.sub.3.SiO.sub.

Abstract: An improvement in the manufacture of cube-on-edge oriented silicon steel; the improvement comprises coating the surface of the silicon steel with a manganese-bearing material prior to texture annealing, whereby secondary grain growth is inhibited during texture annealing to achieve reduced watt loss.

Abstract: A process for producing an aluminum-bearing grain-oriented silicon steel strip from a silicon steel slab containing up to 0.02% carbon, 0.01 to 0.1% aluminum, 2.7 to 4.0% silicon, and 0.002 to 0.02% nitrogen, the balance being iron and unavoidable impurities, said slab optionally containing at least one of 0.01 to 0.5% antimony and 0.01 to 1.0% copper, said process comprising: recrystallization hot rolling said slab, said rolling being commenced when said slab has a temperature up to 1,250.degree. C., and effected at a total reduction rate of at least 80% with a plurality of passes, including at least one pass having a reduction rate of at least 35%, before said steel has a temperature of 900.degree. C.; strain accumulation finish hot rolling said steel at a total reduction rate of at least 40% and at a steel temperature up to 900.degree. C.; annealing said hot rolled steel continuously at a temperature of 700.degree. C. to 950.degree. C.

Abstract: The instant invention is directed to a magnesium oxide composition, for use in coating silicon steel, having a Citric Acid Activity of 50 to 200 seconds and a particle size of 90 percent finer than 325 mesh prepared from a blend of(a) ground magnesium oxide having a Citric Acid Activity of greater than 200 to 2000 seconds and(b) ground magnesium oxide having a Citric Acid Activity of 40 to 100 seconds.The instant invention is also directed to a process for the production of a magnesium oxide composition, for use in coating silicon steel, having a Citric Acid Activity of 50 to 200 seconds and a particle size of 90 percent finer than 325 mesh, comprising:(a) grinding to a 90 percent finer than 325 mesh(i) 20 to 60 percent by weight of a ground magnesium oxide having a Citric Acid Activity of greater than 200 to 2000 seconds and(ii) 40 to 80 percent by weight of a magnesium oxide having a Citric Acid Activity of 40 to 100 seconds and(b) blending (i) and (ii) together.

Abstract: A grain-oriented silicon steel sheet having excellent magnetic properties can be stably produced by adjusting properly the C content in a silicon steel to be used as a starting material depending upon the Si content in the steel, removing a proper amount of C from the steel during the course after the hot rolling and before the final cold rolling, and further carrying out the final cold rolling at a reduction rate of 40-80%.

Abstract: A method for improving the magnetic permeability and core loss of grain oriented silicon steel; the improvement in these magnetic properties is achieved by conducting annealing prior to cold rolling at a temperature above the temperature at which transformation to austenite occurs and thereafter quenching said steel.

Abstract: The chemical composition and processing of a cold rolled steel strip are controlled. Laminations for the core of an electric motor are stamped from the strip and decarburized to produce a lamination having a 1.5 T (15 kG) average core loss value less than about 5.1 W/kg (2.30 W/lb.) and average peak permeability more than about 1800 G/Oe. for a sample thickness of about 0.018 in. (0.46 mm.).

Abstract: A process of providing an inorganic anti-stick coating directly on non-oriented, semi-processed electrical steels by applying to such steels a coating solution containing Al.sup.+++, Mg.sup.++, and H.sub.2 PO.sub.4.sup.- in a specified relative relationship, the concentration of Al.sup.+++, Mg.sup.++, and H.sub.2 PO.sub.4.sup.- comprising 100 parts by weight calculated as Al.sub.2 O.sub.3, MgO and H.sub.3 PO.sub.4, respectively, on a water-free basis. The coating solution may additionally contain from 0 to 150 parts by weight of colloidal silica on a water-free basis. Chromic anhydride (C.sub.r O.sub.3) may be added to the coating solution to improve its wettability and improve the moisture resistance of the anti-stick coating. The coating solution is so diluted with water as to provide a uniform coating as thin as possible to prevent lamination sticking and having a coating weight of less than 2 grams per square meter on each side.

Abstract: A process for producing grain oriented electromagnetic silicon steel. The process includes the steps of: preparing a melt of silicon steel having, by weight, from 2.5 to 4.0% silicon; casting the steel; hot rolling the steel; cold rolling the steel; decarburizing the steel; applying a substantially non-reactive aluminum hydroxide coating to the steel; and final texture annealing the steel. The annealed steel being characterized by a substantially uniform metallic surface.

Abstract: An aqueous coating solution for forming an insulative coating directly on electrical steels and on steels having a mill glass thereon. The aqueous solution comprises an aluminum-magnesium phosphate premix solution and a colloidal silica solution. The premix solution also comprises from about 10 to about 45 parts by weight Cr.sub.2 O.sub.3 for every 100 parts by weight H.sub.2 PO.sub.4.sup.- calculated as H.sub.3 PO.sub.4 on a water-free basis, from about 5 to about 20 parts of a compound chosen from the class consisting of boric acid, vanadium pentoxide and mixtures thereof per 100 parts H.sub.2 PO.sub.4.sup.- calculated as H.sub.3 PO.sub.4 on a water-free basis and additional Mg.sup.++ up to that amount which will go into solution. The colloidal silica solution is present in an amount of from that amount which will form a good glass up to 40 volume percent to provide a coating solution having a premix solution to colloidal silica solution volume ratio up to 1.5:1.

Abstract: An aqueous magnesia slurry for forming an insulative glass coating on silicon steel, wherein a substantial portion of the magnesia is inactive (a citric acid activity greater than 200 seconds), a decomposable phosphate compound is present within the range of 2% to 25% by weight calculated as P.sub.2 O.sub.5, based on the dry weight of magnesia, and the magnesia concentration is at least 0.24 grams per cubic centimeter of slurry. The slurry is stable against settling for up to 10 hours and has a desirable viscosity for coating application by conventional means. From 10% to 100% inactive magnesia may be used with the remainder an active magnesia (citric acid activity of 20 to 40 seconds). Preferred phosphate compounds include monocalcium phosphate monohydrate, water soluble ammonium polyphosphate and dicalcium phosphate dihydrate.

Abstract: Silicon-iron sheet products having good magnetic properties can be produced from low nitrogen alloy sheet material by heating in a nitrogen-bearing hydrogen atmosphere to a temperature sufficient to effect secondary recrystallization and thereafter heating to a higher temperature in a hydrogen atmosphere to effect removal of residual carbon, nitrogen, and sulfur.

Abstract: A process for producing electromagnetic silicon steel having a cube-on-edge orientation and a permeability of at least 1800 (G/O.sub.e) at 10 oersteds. The process includes the steps of preparing a melt of silicon steel containing from 0.02% to 0.06% carbon, from 0.0006% to 0.008% boron, up to 0.01% nitrogen, up to 0.008% aluminum and from 2.5% to 4.0% silicon, casting the steel, hot rolling the steel to hot band gage, annealing the hot band in a temperature range of from 1450.degree.-1650.degree. F., cold rolling the steel to a final gage of about 0.018 inch in one cold reduction, decarburizing the steel, applying a refractory oxide base coating to the steel and texture annealing the steel.

Abstract: A box annealed steel strip having small strains is produced by: pretreating a steel strip in such a manner that a side edge portion thereof is thermally treated under a different condition from another condition under which the remaining portion, including an opposite side edge, thereof is thermally treated, so as to cause the longitudinal length of the side edge portion to be different from that of the remaining portion; winding the pretreated steel strip under tension to form a coil in such a manner that greater tensile stresses are produced in the other one of the side edge portion and the remaining portion, which one has a longitudinal length smaller than that of the other one, than those produced in the other one; placing the coil on a base plate so that a side edge included in the portion having the greater stresses comes into contact with the base plate, and; box annealing the coil on the base plate in a box annealing furnace.

Abstract: An annealing separator useful for producing a grain oriented silicon steel strip having an excellent magnetic property, comprises non-hydrating magnesium oxide which has been calcined at a temperature of 1300.degree. C. or more, preferably, from 1300.degree. to 2100.degree. C., and which is in the form of fine particles, 70% by weight of which have a size of 5 microns or less, and optionally, magnesium hydroxide in an amount of 1 to 100% based on the weight of the magnesium oxide and/or an aluminium compound in an amount of 0.05 to 10% based on the weight of the magnesium oxide.

Abstract: This is a method for making a low alloy iron having desirable magnetic characteristics suitable for electrical applications such as transformer cores. The ingot alloy has a relatively high (more than 50 ppm) sulfur and relatively high manganese (0.01-0.15%) and thus can be prepared from commercially available materials without further purification. While the sulfur in such a manganese containing alloy is not removed during final annealing (due to generally less than about 950.degree. C. final annealing temperatures of the primary recrystallization process) the use of a tensile stress (at least 200 psi) inducing glass coating provides for very low losses. The material contains significant amounts of both sulfur and manganese. Both the sulfur and manganese contribute towards the meltability of the alloy and the manganese contributes towards the workability (especially for cool rolling) of the sulfur containing material.

Abstract: An electrical silicon steel sheet composed of secondary or tertiary recrystallized grains oriented in one or two directions, is produced by a process comprising a decarburization annealing operation in an oxidation atmosphere in which a ratio of PH.sub.2 O/PH.sub.2 wherein PH.sub.2 O represents a partial pressure of water vapor in said oxidation atmosphere and PH.sub.2 represents a partial pressure of hydrogen in said oxidation atmosphere, is adjusted to a value of 0.15 or more in an initial stage of said decarburization annealing operation and, then, to a value smaller than that in said initial stage in a final stage of said decarburization annealing operation.

Abstract: A grain-oriented silicon steel sheet having substantially no glass film can be obtained by subjecting a cold rolled silicon steel sheet having a final gauge to a decarburization annealing to form subscale on the steel sheet surface, applying an annealing separator consisting of hydrated silicate mineral fine powder, a strontium- or barium-containing compound, calcium oxide or calcium hydroxide and the remainder being Al.sub.2 O.sub.3, and finally annealing the above treated steel sheet. The steel sheet has excellent punchability when the steel sheet is coated with a phosphate system or chromate-organic resin mixture system insulating coating.

Abstract: A high adhesion uniform forsterite insulating film can be formed on the surface of a grain-oriented silicon steel sheet by the application of an annealing separator consisting mainly of magnesia having a narrow activity distribution defined by the citric acid activity of the magnesia which varies depending upon the variation of final reaction ratio of the magnesia as determined by the method for measuring the citric acid activity of magnesia, where the final reaction ratio of the magnesia is the ratio of that amount of the magnesia which finally reacts with citric acid to the total amount of magnesia mixed with the citric acid.

Abstract: A highly adhesive and uniform insulating film can be formed on a grain-oriented silicon steel sheet without deteriorating the iron loss of the steel sheet by the use of a magnesia series annealing separator containing a strontium compound.