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 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

A non-oriented electrical steel sheet has a chemical composition including, in mass %, C: 0.005% or less, Si: 5% or less, Al: 3% or less, Mn: 5% or less, S: 0.005% or less, P: 0.2% or less, N: 0.005% or less, Mo: 0.001 to 0.04%, Ti: 0.0030% or less, Nb: 0.0050% or less, V: 0.0050% or less, Zr: 0.0020% or less, one or both of Sb and Sn: 0.001 to 0.1% in total, and the balance being iron and incidental impurities.

Non-oriented electrical steel sheet

The production process of cold rolled non-orientation electric steel plate comprising C not more than 0.0050 wt%, Si not more than 2.50 wt%, Al not more than 1.0 wt%, Si+2Al not more than 2.50 wt%, Mn 0.10-1.50 wt%, P not more than 0.20 wt%, S not more than 0.005 wt%, N not more than 0.0025 wt%, Sn+Sb not more than 0.2 wt%, and Fe and inevitable impurities for the rest includes the following steps: 1. smelting, continuous casting and rolling; 2. normalizing treatment of the hot rolled plate through heating at heating rate of 5-15 deg.c/s to over Ac1, heat soaking at 1100 deg.c below for 10-90 s, cooling in two stages including cooling at the cooling rate belw 15 deg.c/s to below 650 deg.c and cooling at the cooling rate capable of ensuring the plate form to below 80 deg.c; 3. cold rolling; and 4. final annealing to form the cold rolled non-orientation electric steel plate.

Production process of cold rolled orientation-free electrical steel plate with low iron loss and high magnetic induction

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

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

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.

High permeability grain oriented electrical steel

Improved method for production of non-oriented electrical steel strip

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 0.02% tin, up to about 1% copper, and balance being essentially iron and residual elements, all precentages by weight. The band has a volume resistivity of at least about 45 µΩ-cm, an austenite volume fraction (η1150°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.

Robert J. Comstock

Papers

Method of continuous casting non-oriented electrical steel strip

Method for production of non-oriented electrical steel strip

High permeability grain oriented electrical steel

Improved method for production of non-oriented electrical steel strip

Method for producing a high permeability grain oriented electrical steel