# US 5,350,464 A · Silicon steel strip having mechanically refined magnetic domain wall spacings and method for producing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,350,464 A - Document ID: US5350464A - Status: Granted - Kind: A - Application number: 07/978,202 - Filed: 1992-11-17 - Granted: 1994-09-27 - Earliest claimed: 1992-11-17 - Assignees: Allegheny Ludlum Corporation - Inventors: James G. Benford - Web page: https://patentgrep.com/patent/US5350464A ## CPC - C21D 7/04: of the surface - C21D 8/1294: involving a localised treatment - H01F 1/14775: {in the form of sheets} - H01F 1/14783: {with insulating coating} - B21B 1/227: {Surface roughening or texturing} - B21B 2267/065: Top and bottom roll have different diameters; Asymmetrical rolling - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - B21B: ROLLING OF METAL (auxiliary operations used in connection with metal-working operations covered in B21, see B21C; bending by rolling B21D; manufacture of particular objects, e.g. screws, wheels, rings, barrels, balls, by rolling B21H; pressure welding by means of a rolling mill B23K20/04) ## Abstract A grain oriented silicon steel strip and method are provided for producing the same wherein a chevron pattern of scribe lines mechanically refines the magnetic domain wall spacings. Multiple chevron patterns are formed to extend always transversely across the strip width. ## Claims ### Claim 1 A grain oriented silicon steel strip having mechanically refined magnetic domain wall spacings formed by mechanically scribing a face surface of the strip, said mechanical scribing consisting of a multiplicity of closely spaced scribe lines extending generally across the width of the strip intersecting magnetic domain walls extending parallel to the rolling direction, said scribe lines being interrupted by at least one directional change across the width of the strip and defining a chevron pattern with the apexes of multiple patterns oriented in the rolling direction. ### Claim 2 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said scribe lines are interrupted by a plurality of directional changes with all scribe lines extending transversely to said rolling directions. ### Claim 3 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said strip is plastically deformed by said scribe lines to induce heat proof domain refinements. ### Claim 4 (depends on 3) The grain oriented silicon strip according to claim 3 wherein said heat proof domain refinement results from annealing of the scribed strip. ### Claim 5 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said strip is non-heat resistant domain refined. ### Claim 6 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said scribe lines are spaced apart in a generally parallel pattern formed by a scribe line spacing no greater than 15 mm. ### Claim 7 (depends on 6) The grain oriented silicon strip according to claim 6 wherein said spacing is between 5 and 10 mm. ### Claim 8 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said scribe lines extending across the strip form an acute angle to the perpendicular to the rolling direction. ### Claim 9 (depends on 8) The grain oriented silicon strip according to claim 8 wherein said acute angle ranges up to 45.degree.. ### Claim 10 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said strip has an electrical permeability with .mu.10 of about 1890. ### Claim 11 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said scribe lines form an array of scribe lines, each forming an angle of 15.degree. with a perpendicular to the rolling direction and with the spacing between the scribe lines of each array being about 5 mm. ### Claim 12 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said strip has a MgO coating on each of the face surfaces thereof and wherein said coating is partitioned by substantial penetration of the scribe lines therein and wherein said strip further includes a quantity of vitreous material to at least substantially fill gaps defining the partitioning in the vitreous coating. ### Claim 13 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said strip has been annealed to form fine recrystallized grains at strain areas defined by scribe lines in the strip. ### Claim 14 (depends on 13) The grain oriented silicon strip according to claim 13 wherein defined recrystallized grains lie within that thickness of the strip directly underlying each scribe line. ### Claim 15 (depends on 13) The grain oriented silicon strip according to claim 13 wherein said annealing is carried out at a temperature of about 1400.degree. F. for at least about 1 minute. ### Claim 16 (depends on 1) The grain oriented silicon strip according to claim 1 wherein said scribe lines consists of arrays of parallel scribe lines with the scribe lines of each array being arranged to intersect with scribe lines of an adjacent array across the width of the strip at an angle of intersection of about 90.degree.. ### Claim 17 (depends on 16) The grain oriented silicon strip according to claim 16 wherein the number of arrays across the width of the strip is an even number integer. ### Claim 18 (depends on 1) The grain oriented silicon strip according to claim 1 wherein the scribe lines extend a distance of up to one-half the strip width.