Non-oriented electrical steels are widely used as the magnetic core material in a variety of electrical machinery and devices, particularly in motors where low core loss and high magnetic permeability in all directions of the strip are desired. A method for producing a non-oriented electrical steel with low core loss and high magnetic permeability provides a steel that is produced from a steel melt which is cast as a thin strip or sheet, cooled, hot rolled and/or cold rolled into a finished strip. The finished strip is further subjected to at least one annealing treatment wherein the magnetic properties are developed, making the steel strip suitable for use in electrical machinery such as motors or transformers.

Method of continuous casting non-oriented electrical steel strip

A grain-oriented magnetic steel sheet having linear grooves for magnetic domain refinement which have been formed in a surface of the steel sheet is produced in accordance with the present invention so that the proportion of linear grooves under which crystal grains having a deviation in orientation from the Goss orientation of 10o or more and having a grain diameter of 5 µm or more are present is regulated to 20% or less, and that the crystal grains formed by secondary recrystallization are regulated so as to have an average s angle of 2.0o or less and the crystal grains formed by secondary recrystallization which have a grain diameter of 10 mm or more are regulated so as to have an average width of s-angle fluctuations of 1-4o. Due to the formation of the linear grooves for magnetic domain refinement, a grain-oriented magnetic steel sheet reduced in iron loss can be obtained.

Grain oriented electrical steel sheet and method for manufacturing the same

A grain oriented electrical steel sheet comprises metal part containing Si: about
2.5 to about 5.0 mass% and Cr: about 0.05 to about 1.0 mass%, and an insulation
coating formed on a surface of the metal part. A tension imparted to the metal part in
the rolling direction by the insulation coating is not smaller than about 3.0 MPa.
Magnetic flux density B 8 satisfies a specific relation formula. A plurality of linear
strains or grooves are formed in a surface of the steel sheet and linearly extended at an
angle of not larger than about 45° (in each direction) relative to a direction
perpendicular to a rolling direction such that an interval D of the linear strains or
grooves satisfies a specific relation formula depending on the Cr content. A grain
oriented electrical steel sheet is thereby obtained which has lower iron loss after domain
refining treatment than conventional values. In the production process for the steel
sheet of the invention, parameters such as annealing temperature in annealing before
final cold rolling are controlled.

Grain oriented electrical steel sheet with low iron loss and production method for same

A method for continuously casting grain oriented electrical steel is disclosed. This method utilizes a controlled rapid cooling step, such as one using a water spray, to control the grain orientation in the finished product. The product formed not only has the appropriate grain orientation but also has good physical properties, for example, minimized cracking. In this process, after a continuously cast electrical steel strip is formed, the strip undergoes an initial secondary cooling to from about 1150 to about 1250°C, and finally undergoes a rapid secondary cooling (for example, by water spray) at a rate of from about 65°C/second to about 150°C/second to a temperature of no greater than about 950°C.

Method of continuously casting electrical steel strip with controlled spray cooling

A process for producing a non-oriented electromagnetic steel sheet, comprising subjecting a steel material comprising 0.03 mass% or less of C, 4 mass% or less of Si, 0.03-3 mass% of Mn, 3 mass% or less of Al, 0.005 mass% or less of S, 0.005 mass% or less of N and a remainder made up by Fe and unavoidable impurities to a hot-rolling procedure, then a cold-rolling procedure, and then a final annealing procedure, wherein the crystal particle diameter before the cold rolling procedure is adjusted to 100 µm or less and the final annealing procedure comprises rapidly heating at an average temperature rising rate of 100°C/sec or more until the temperature reaches a re-crystallization temperature or higher. This process enables the production of a non-oriented electromagnetic steel sheet having a high magnetic flux density in the direction of rolling of the steel sheet.

Method of producing Non-Oriented Electrical Steel Sheet

The present invention relates to a method for producing a non-oriented electrical steel with improved magnetic properties and improved resistance to ridging, brittleness, nozzle clogging and magnetic aging. The chromium bearing steel is produced from a steel melt which is cast as a thin slab or conventional slab, cooled, hot rolled and/or cold rolled into a finished strip. The finished strip is further subjected to at least one annealing treatment wherein the magnetic properties are developed, making the steel sheet of the present invention suitable for use in electrical machinery such as motors or transformers.

Method for production of non-oriented electrical steel strip

The present invention provides a method of producing grain oriented electrical steel having excellent mechanical and magnetic properties. A hot processed strip having a thickness of 1.5-4.0 mm thickness a composition consisting essentially of 2.5-4.5% silicon, 0.1-1.2% chromium, less than 0.050% carbon, less than 0.005% aluminum, up to 0.1% sulfur, up to 0.14% selenium, 0.01-1% manganese and balance being essentially iron and residual elements, all percentages by weight. The strip has a volume resistivity of at least 45 μΩ-cm, at least 0.010% carbon so that an austenite volume fraction (γ1150° C.) of at least 2.5% is present in the hot processed strip and each surface of the strip has an isomorphic layer having a thickness of at least 10% of the total thickness of the hot processed strip. The strip is cold reduced to an intermediate thickness, annealed, cold reduced to a final thickness and decarburized to less than 0.003% carbon. The decarburized strip then is coated on at least one surface with an annealing separator and final annealed to effect secondary grain growth. The electrical steel has a permeability measured at 796 A/m of at least 1780.

Method for producing silicon-chromium grain oriented electrical steel

The present invention provides a method of producing a high permeability grain oriented electrical steel having excellent mechanical and magnetic properties. A hot band having a thickness of about 1.5 to about 4.0 mm has a chemistry comprising about 2.5 to about 4.5% silicon, about 0.1 to about 1.2% chromium, about 0.02 to about 0.08% carbon, about 0.01 to about 0.05% aluminum, up to about 0.1% sulfur, up to about 0.14% selenium, about 0.03 to about 0.15% manganese, up to about 0.2% tin, up to about 1% copper, and balance being essentially iron and residual elements, all percentages by weight. The band has a volume resistivity of at least about 45 μΩ-cm, an austenite volume fraction (γ 1150° C. ) of at least 20% and the strip has an isomorphic layer thickness of at least about 2% of the total thickness on at least one surface of the hot processed band. The band is rapidly cooled after the anneal prior to cold rolling at a rate of at least 30° C./second from 875-950° C. to a temperature below 400° C. The band is cold reduced in one or more stages with a final reduction of at least 80%, annealed, decarburized and coated with an annealing separator on at least one side. A final annealing provides stable secondary grain growth and a permeability measured at 796 A/m of at least 1840.

Schoen Jerry W

Papers

Method of continuous casting non-oriented electrical steel strip

Method for production of non-oriented electrical steel strip

Method for producing silicon-chromium grain oriented electrical steel

High permeability grain oriented electrical steel

Improved method for production of non-oriented electrical steel strip