# US 10,374,497 B2 · Method to manufacture improved exciter for an electrical generator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,497 B2 - Document ID: US10374497B2 - Status: Granted - Kind: B2 - Application number: 15/006,262 - Filed: 2016-01-26 - Published: 2017-07-27 - Granted: 2019-08-06 - Earliest claimed: 2016-01-26 - Assignees: Tempel Steel Company - Applicants: Gwynne Johnston; Erik J. Hilinski - Inventors: Gwynne Johnston; Erik J. Hilinski - Web page: https://patentgrep.com/patent/US10374497B2 ## CPC - H02K 15/02: of stator or rotor bodies - C21D 8/12: during manufacturing of articles with special electromagnetic properties - C21D 8/1233: {Cold rolling} - C21D 8/1272: {Final recrystallisation annealing} - C22C 38/004: {Very low carbon steels, i.e. having a carbon content of less than 0,01%} - C22C 38/008: {containing tin} - C22C 38/02: containing silicon - C22C 38/04: containing manganese - C22C 38/06: containing aluminium - H02K 1/02: characterised by the magnetic material - C21D 2261/00: Machining or cutting being involved - H01F 1/16: in the form of sheets (H01F1/147 takes precedence) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - 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) - C22C: ALLOYS (treatment of alloys C21D, C22F) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract In a method to manufacture an improved exciter for a generator, the exciter comprising an exciter rotor, and an exciter stator, a coil of full hard cold rolled electrical steel is provided, the steel comprising at least silicon in a weight percent greater than 0.60%. Without a prior annealing of the full hard cold rolled steel coil, the coil is slit to create at least one strip. The at least one strip is stamped to create a plurality of rotor laminations and a plurality of stator laminations from the same strip. The rotor laminations are separated from the stator laminations and the set of rotor laminations and the set of stator laminations are created. Only the set of exciter rotor laminations are annealed. The annealed set of exciter rotor laminations are assembled to create the exciter rotor and the set of not annealed exciter stator laminations are assembled to create the exciter stator. ## Claims ### Claim 1 A method to manufacture an improved exciter for a generator, said exciter comprising an exciter rotor and an exciter stator, the exciter rotor and the exciter stator each being formed of a respective set of laminations, of a same electrical steel comprising the steps of: providing a coil of cold rolled electrical steel which after cold-rolling was not subsequently annealed, said electrical steel being full hard which is a condition of the electrical steel in which there is no further change in hardness or tensile strength of the steel following cold rolling and prior to a subsequent anneal, said steel consisting essentially of the following elements in weight percent: Carbon less than 0.04%, Manganese 0.10% to 1.5%, Phosphorus 0.005% to 0.12%, Silicon greater than 0.60%, Aluminum 0.05% to 1.0%, and Iron and conventional impurities as balance; without a prior annealing of the full hard cold rolled steel coil, slitting the coil to create at least one strip; stamping the at least one strip to create a plurality of exciter rotor laminations and a plurality of exciter stator laminations from the same strip; separating the exciter rotor laminations from the exciter stator laminations and creating said set of exciter rotor laminations and said set of exciter stator laminations; from among said sets of exciter rotor laminations and exciter stator laminations, annealing only said set of exciter rotor laminations; and assembling the annealed set of exciter rotor laminations to create said exciter rotor and assembling the set of not annealed stator laminations to create said exciter stator. ### Claim 2 (depends on 1) The method of claim 1 wherein the carbon is less than 0.008%. ### Claim 3 (depends on 1) The method of claim 1 wherein said silicon weight percent is greater than 0.80%. ### Claim 4 (depends on 1) The method of claim 1 wherein said silicon weight percent lies in a range of 0.80% to 1.60%. ### Claim 5 (depends on 1) The method of claim 1 wherein the annealing of the exciter rotor laminations is conducted in a decarburizing atmosphere within a temperature range of 1300° F. to 1650° F. ### Claim 6 (depends on 5) The method of claim 5 wherein the temperature range is 1500° F. to 1580° F. ### Claim 7 (depends on 1) The method of claim 1 wherein a coercivity of said exciter stator is at least 560 amperes/meter. ### Claim 8 (depends on 1) The method of claim 1 wherein said coil of full hard cold rolled electrical steel which after cold-rolling was not subsequently annealed was created by performing a hot band anneal prior to said a cold rolling step. ### Claim 9 (depends on 1) The method of claim 1 wherein said coil of full hard cold rolled electrical steel which after cold-rolling was not subsequently annealed was created by performing a cold mill reduction greater than 75%. ### Claim 10 (depends on 1) The method of claim 1 wherein said coil of full hard cold rolled electrical steel which after cold-rolling was not subsequently annealed is temper rolled prior to said slitting. ### Claim 11 A method to manufacture an improved exciter for a generator, said exciter comprising an exciter rotor and an exciter stator, the exciter rotor and the exciter stator each being formed of a respective set of laminations, of a same electrical steel comprising the steps of: providing a coil of cold rolled electrical steel which after cold-rolling was not subsequently annealed, said electrical steel being full hard which is a condition of the electrical steel in which there is no further change in hardness or tensile strength of the steel following cold rolling and prior to a subsequent anneal, said steel consisting essentially of the following elements in weight percent: Carbon less than 0.04%, Manganese 0.10% to 1.5%, Phosphorus 0.005% to 0.12%, Silicon 0.80% to 1.60%, Aluminum 0.05% to 1.0%, Tin or Antimony less than or equal to 0.12%, and Iron and conventional impurities as balance; without a prior annealing of the full hard cold rolled steel coil, slitting the coil to create at least one strip; stamping the at least one strip to create a plurality of exciter rotor laminations and a plurality of exciter stator laminations from the same strip; separating the exciter rotor laminations from the exciter stator laminations and creating said set of exciter rotor laminations and said set of exciter stator laminations; from among said sets of exciter rotor laminations and exciter stator laminations, annealing only said set of exciter rotor laminations; and assembling the annealed set of exciter rotor laminations to create said exciter rotor and assembling the set of not annealed stator laminations to create said exciter stator.