# US 12,119,706 B2 · Non-oriented electrical steel sheet, production method for non-oriented electrical steel sheet, electric motor and production method for electric motor

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- Number: US 12,119,706 B2
- Document ID: US12119706B2
- Status: Granted
- Kind: B2
- Application number: 18/281,171
- Filed: 2022-03-30
- Published: 2024-02-01
- Granted: 2024-10-15
- Earliest claimed: 2021-03-31
- Assignees: Nippon Steel Corporation
- Applicants: Nippon Steel Corporation
- Inventors: Yoshiaki Natori; Hiroyoshi Yashiki; Minako Fukuchi; Kazutoshi Takeda
- Web page: https://patentgrep.com/patent/US12119706B2

## CPC

- H02K 1/02: characterised by the magnetic material
- B21B 1/22: for rolling {plates, strips,} bands or sheets of indefinite length (B21B1/42 takes precedence)
- C21D 1/30: Stress-relieving
- C21D 6/008: {containing Si}
- C21D 8/1222: {Hot rolling}
- C21D 8/1233: {Cold rolling}
- C21D 8/1244: characterised by the heat treatment
- C21D 8/1261: {following hot rolling}
- C21D 8/1272: {Final recrystallisation annealing}
- C21D 9/0068: {for particular articles not mentioned below}
- C21D 9/46: for sheet metals
- C22C 38/002: {containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60}
- C22C 38/004: {Very low carbon steels, i.e. having a carbon content of less than 0,01%}
- C22C 38/005: {containing rare earths, i.e. Sc, Y, Lanthanides}
- C22C 38/008: {containing tin}
- C22C 38/02: containing silicon
- C22C 38/04: containing manganese
- C22C 38/06: containing aluminium
- C22C 38/12: containing tungsten, tantalum, molybdenum, vanadium, or niobium
- C22C 38/14: containing titanium or zirconium
- C22C 38/20: with copper
- C22C 38/22: with molybdenum or tungsten
- C22C 38/24: with vanadium
- C22C 38/26: with niobium or tantalum
- C22C 38/28: with titanium or zirconium
- C22C 38/30: with cobalt
- C22C 38/32: with boron
- C22C 38/34: with more than 1.5% by weight of silicon
- C22C 38/38: with more than 1.5% by weight of manganese
- C22C 38/42: with copper
- C22C 38/44: with molybdenum or tungsten
- C22C 38/46: with vanadium
- C22C 38/48: with niobium or tantalum
- C22C 38/50: with titanium or zirconium
- C22C 38/60: containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
- H01F 1/147: Alloys characterised by their composition {(treatment thereof for enhancing their electromagnetic properties C21D8/12)}
- H01F 1/14783: {with insulating coating}
- H01F 1/18: with insulating coating
- H01F 41/0233: {Manufacturing of magnetic circuits made from sheets (magnetic cores made from sheets H01F27/245; soft magnetic alloys in the form of sheets H01F1/16)}
- H02K 15/02: of stator or rotor bodies
- H02K 15/12: Impregnating, moulding insulation, heating or drying of windings, stators, rotors or machines
- B21B 2001/221: {by cold-rolling}
- B21B 2001/225: {by hot-rolling}
- C21D 1/76: Adjusting the composition of the atmosphere
- C22C 38/58: with more than 1.5% by weight of manganese
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- 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)
- 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

This non-oriented electrical steel sheet contains a base material having a chemical composition including, in mass %, Si: 3.2 to 4.5%, wherein the tensile strength is 550 MPa or more, and a ratio (P120B/Fe700B)B between a peak-to-peak height Fe700B of Fe at 700 eV and a peak-to-peak height P120B of P at 120 eV when crystal grain boundaries are measured through Auger electron spectroscopy is not more than twice a ratio (P120i/Fe700i)i between a peak-to-peak height Fe700i of Fe at 700 eV and a peak-to-peak height P120i of P at 120 eV when the inside of crystals is measured through Auger electron spectroscopy.

## Claims

### Claim 1

A non-oriented electrical steel sheet comprising a base material having a chemical composition including, in mass %,
C: 0.0010 to 0.0040%,
Si: 3.2 to 4.5%,
sol. Al: 0.2 to 2.0%,
Mn: 0.1 to 3.5%,
P: more than 0% and 0.10% or less,
S: 0 to 0.0030%,
N: 0 to 0.0030%,
Ti: 0 to 0.0030%,
Mo: 0.0010 to 0.1000%,
Cr: 0 to 0.10%,
B: 0 to 0.0010%,
Ni: 0 to 0.50%,
Cu: 0 to 0.50%,
Sn: 0 to 0.2000%,
Sb: 0 to 0.2000%,
Ca: 0 to 0.0050%,
Zn: 0 to 0.0050%,
La: 0 to 0.0050%,
Ce: 0 to 0.0050%,
O: 0 to 0.1000%,
V: 0 to 0.1000%,
W: 0 to 0.1000%,
Zr: 0 to 0.1000%,
Nb: 0 to 0.1000%,
Mg: 0 to 0.1000%,
Bi: 0 to 0.1000%,
Nd: 0 to 0.1000%,
Y: 0 to 0.1000%,
As: 0 to 0.1000%,
Ga: 0 to 0.1000%,
Ge: 0 to 0.1000%,
Co: 0 to 0.1000%,
Se: 0 to 0.1000%,
Pb; 0 to 0.1000%, and
the remainder: Fe and impurities,
wherein the non-oriented electrical steel sheet has a tensile strength of 550 MPa or more, and
a ratio (P120B/Fe700B)B between a peak-to-peak height Fe700B of Fe at 700 eV and a peak-to-peak height P120B of P at 120 eV when crystal grain boundaries are measured through Auger electron spectroscopy is not more than twice a ratio (P120i/Fe700i)i between a peak-to-peak height Fe700i of Fe at 700 eV and a peak-to-peak height P120i of P at 120 eV when the inside of crystals is measured through Auger electron spectroscopy.

### Claim 2 (depends on 1)

The non-oriented electrical steel sheet according to claim 1, which contains one or more selected from the group consisting of, in mass %,
Ni: 0.01 to 0.50%,
Cu: 0.01 to 0.50%,
Sn: 0.01 to 0.2000%,
Sb: 0.01 to 0.2000%,
Ca: 0.0005 to 0.0050%,
Zn: 0.0003 to 0.0050%,
La: 0.0005 to 0.0050%,
Ce: 0.0005 to 0.0050%,
O: 0.0020 to 0.1000%,
V: 0.0010 to 0.0100%,
W: 0.0010 to 0.0100%,
Zr: 0.0010 to 0.0100%,
Nb: 0.0010 to 0.0100%,
Mg: 0.0010 to 0.0100%,
Bi: 0.0010 to 0.0100%,
Nd: 0.0010 to 0.0100%,
Y: 0.0010 to 0.0100%,
As: 0.0010 to 0.0100%,
Ga: 0.0010 to 0.0100%,
Ge: 0.0010 to 0.0100%,
Co: 0.0010 to 0.0100%,
Se: 0.0010 to 0.0100%,
Pb; 0.0010 to 0.0100%.

### Claim 3 (depends on 1, 2)

The non-oriented electrical steel sheet according to claim 1 or 2,
wherein the base material has an insulation coating on its surface.

### Claim 4

An electric motor comprising a stator core,
wherein the stator core has a chemical composition including, in mass %,
C: 0.0010 to 0.0040%,
Si: 3.2 to 4.5%,
sol. Al: 0.2 to 2.0%,
Mn: 0.1 to 3.5%,
P: more than 0% and 0.10% or less,
S: 0 to 0.0030%,
N: 0 to 0.0030%,
Ti: 0 to 0.0030%,
Mo: 0.0010 to 0.1000%,
Cr: 0 to 0.10%,
B: 0 to 0.0010%,
Ni: 0 to 0.50%,
Cu: 0 to 0.50%,
Sn: 0 to 0.2000%,
Sb: 0 to 0.2000%,
Ca: 0 to 0.0050%,
Zn: 0 to 0.0050%,
La: 0 to 0.0050%,
Ce: 0 to 0.0050%,
O: 0 to 0.1000%,
V: 0 to 0.1000%,
W: 0 to 0.1000%,
Zr: 0 to 0.1000%,
Nb: 0 to 0.1000%,
Mg: 0 to 0.1000%,
Bi: 0 to 0.1000%,
Nd: 0 to 0.1000%,
Y: 0 to 0.1000%,
As: 0 to 0.1000%,
Ga: 0 to 0.1000%,
Ge: 0 to 0.1000%,
Co: 0 to 0.1000%,
Se: 0 to 0.1000%,
Pb; 0 to 0.1000%, and
the remainder: Fe and impurities,
wherein the stator core has a tensile strength of 500 MPa or more, and
a ratio (P120SB/Fe700SB)SB between a peak-to-peak height Fe700SB of Fe at 700 eV and a peak-to-peak height P120SB of P at 120 eV when crystal grain boundaries of the stator core are measured through Auger electron spectroscopy is not more than 4 times a ratio (P120Si/Fe700Si)Si between a peak-to-peak height Fe700Si of Fe at 700 eV and a peak-to-peak height P120Si of P at 120 eV when the inside of crystals is measured through Auger electron spectroscopy.

### Claim 5 (depends on 1)

A method for producing the non-oriented electrical steel sheet according to claim 1, comprising:
a hot rolling process in which a steel slab having a chemical composition, including, in mass %,
C: 0.0010 to 0.0040%,
Si: 3.2 to 4.5%,
sol. Al: 0.2 to 2.0%,
Mn: 0.1 to 3.5%,
P: more than 0% and 0.10% or less,
S: 0 to 0.0030%,
N: 0 to 0.0030%,
Ti: 0 to 0.0030%,
Mo: 0.0010 to 0.1000%,
Cr: 0 to 0.10%,
B: 0 to 0.0010%,
Ni: 0 to 0.50%,
Cu: 0 to 0.50%,
Sn: 0 to 0.2000%,
Sb: 0 to 0.2000%,
Ca: 0 to 0.0050%,
Zn: 0 to 0.0050%,
La: 0 to 0.0050%,
Ce: 0 to 0.0050%,
O: 0 to 0.1000%,
V: 0 to 0.1000%,
W: 0 to 0.1000%,
Zr: 0 to 0.1000%,
Nb: 0 to 0.1000%,
Mg: 0 to 0.1000%,
Bi: 0 to 0.1000%,
Nd: 0 to 0.1000%,
Y: 0 to 0.1000%,
As: 0 to 0.1000%,
Ga: 0 to 0.1000%,
Ge: 0 to 0.1000%,
Co: 0 to 0.1000%,
Se: 0 to 0.1000%,
Pb: 0 to 0.1000%, and
the remainder: Fe and impurities is hot-rolled to obtain a hot-rolled steel sheet;
a winding process in which the hot-rolled steel sheet is wound and cooled;
a cold rolling process in which the cooled hot-rolled steel sheet is cold-rolled to obtain a cold-rolled steel sheet; and
a final annealing process in which the cold-rolled steel sheet is finally annealed,
wherein, in cooling in the winding process of the hot-rolled steel sheet, a residence time in a temperature range of 500 to 200° C. is longer than a residence time in a temperature range of 700 to 500° C., and the residence time in a temperature range of 500 to 200° C. is 100 seconds or longer, and
wherein, in the final annealing process, a maximum temperature is lower than 900° C., and an average cooling rate in a range of 700 to 500° C. is 20° C./see or faster.

### Claim 6 (depends on 1)

A method for producing the non-oriented electrical steel sheet according to claim 1, comprising:
a process in which a steel slab having a chemical composition, including, in mass %,
C: 0.0010 to 0.0040%,
Si: 3.2 to 4.5%,
sol. Al: 0.2 to 2.0%,
Mn: 0.1 to 3.5%,
P: more than 0% and 0.10% or less,
S: 0 to 0.0030%,
N: 0 to 0.0030%,
Ti: 0 to 0.0030%,
Mo: 0.0010 to 0.1000%,
Cr: 0 to 0.10%,
B: 0 to 0.0010%,
Ni: 0 to 0.50%,
Cu: 0 to 0.50%,
Sn: 0 to 0.2000%,
Sb: 0 to 0.2000%,
Ca: 0 to 0.0050%,
Zn: 0 to 0.0050%,
La: 0 to 0.0050%,
Ce: 0 to 0.0050%,
O: 0 to 0.1000%,
V: 0 to 0.1000%,
W: 0 to 0.1000%,
Zr: 0 to 0.1000%,
Nb: 0 to 0.1000%,
Mg: 0 to 0.1000%,
Bi: 0 to 0.1000%,
Nd: 0 to 0.1000%,
Y: 0 to 0.1000%,
As: 0 to 0.1000%,
Ga: 0 to 0.1000%,
Ge: 0 to 0.1000%,
Co: 0 to 0.1000%,
Se: 0 to 0.1000%,
Pb: 0 to 0.1000%, and
the remainder: Fe and impurities is hot-rolled to obtain a hot-rolled steel sheet;
a winding process in which the hot-rolled steel sheet is wound and cooled;
a hot-band annealing process in which the cooled hot-rolled steel sheet is heated and cooled;
a cold rolling process in which the hot-rolled steel sheet after the hot-band annealing process is cold-rolled to obtain a cold-rolled steel sheet; and
a final annealing process in which the cold-rolled steel sheet is finally annealed,
wherein, in cooling of the hot-band annealing process of the hot-rolled steel sheet, a residence time in a temperature range of 500 to 200° C. is longer than a residence time in a temperature range of 700 to 500° C. and the residence time in a temperature range of 500 to 200° C. is 10 seconds or longer, and
wherein, in the final annealing process, a maximum temperature is lower than 900° ° C., and an average cooling rate in a range of 700 to 500° C. is 20° C./see or faster.

### Claim 7 (depends on 5)

The method according to claim 5, wherein the chemical composition of the steel slab contains one or more of, in mass %,
Ni: 0.01 to 0.50%,
Cu: 0.01 to 0.50%,
Sn: 0.01 to 0.2000%,
Sb: 0.01 to 0.2000%,
Ca: 0.0005 to 0.0050%,
Zn: 0.0003 to 0.0050%,
La: 0.0005 to 0.0050%,
Ce: 0.0005 to 0.0050%,
O: 0.0020 to 0.1000%,
V: 0.0010 to 0.0100%,
W: 0.0010 to 0.0100%,
Zr: 0.0010 to 0.0100%,
Nb: 0.0010 to 0.0100%,
Mg: 0.0010 to 0.0100%,
Bi: 0.0010 to 0.0100%,
Nd: 0.0010 to 0.0100%,
Y: 0.0010 to 0.0100%,
As: 0.0010 to 0.0100%,
Ga: 0.0010 to 0.0100%,
Ge: 0.0010 to 0.0100%,
Co: 0.0010 to 0.0100%,
Se: 0.0010 to 0.0100%, and
Pb: 0.0010 to 0.0100%.

### Claim 8 (depends on 6)

The method according to claim 6, wherein the chemical composition of the steel slab contains one or more of, in mass %,
Ni: 0.01 to 0.50%,
Cu: 0.01 to 0.50%,
Sn: 0.01 to 0.2000%,
Sb: 0.01 to 0.2000%,
Ca: 0.0005 to 0.0050%,
Zn: 0.0003 to 0.0050%,
La: 0.0005 to 0.0050%,
Ce: 0.0005 to 0.0050%,
O: 0.0020 to 0.1000%,
V: 0.0010 to 0.0100%,
W: 0.0010 to 0.0100%,
Zr: 0.0010 to 0.0100%,
Nb: 0.0010 to 0.0100%,
Mg: 0.0010 to 0.0100%,
Bi: 0.0010 to 0.0100%,
Nd: 0.0010 to 0.0100%,
Y: 0.0010 to 0.0100%,
As: 0.0010 to 0.0100%,
Ga: 0.0010 to 0.0100%,
Ge: 0.0010 to 0.0100%,
Co: 0.0010 to 0.0100%,
Se: 0.0010 to 0.0100%, and
Pb: 0.0010 to 0.0100%.

### Claim 9 (depends on 6)

A production method for an electric motor according to claim 6, comprising:
a process in which a non-oriented electrical steel sheet is processed into a stator core shape to form a stator core material; and
an annealing process in which the stator core material is heated to obtain a stator core,
wherein, in the annealing process of the stator core material, a heating temperature is 750 to 850° C., and an average cooling rate in a range of 700 to 500° C. is 5° C./min or shorter;
wherein the non-oriented electrical steel sheet comprises a base material having a chemical composition including, in mass %,
C: 0.0010 to 0.0040%,
Si: 3.2 to 4.5%,
sol. Al: 0.2 to 2.0%,
Mn: 0.1 to 3.5%,
P: more than 0% and 0.10% or less,
S: 0 to 0.0030%,
N: 0 to 0.0030%,
Ti: 0 to 0.0030%,
Mo: 0.0010 to 0.1000%,
Cr: 0 to 0.10%,
B: 0 to 0.0010%,
Ni: 0 to 0.50%,
Cu: 0 to 0.50%,
Sn: 0 to 0.2000%,
Sb: 0 to 0.2000%,
Ca: 0 to 0.0050%,
Zn: 0 to 0.0050%,
La: 0 to 0.0050%,
Ce: 0 to 0.0050%,
O: 0 to 0.1000%,
V: 0 to 0.1000%,
W: 0 to 0.1000%,
Zr: 0 to 0.1000%,
Nb: 0 to 0.1000%,
Mg: 0 to 0.1000%,
Bi: 0 to 0.1000%,
Nd: 0 to 0.1000%,
Y: 0 to 0.1000%,
As: 0 to 0.1000%,
Ga: 0 to 0.1000%,
Ge: 0 to 0.1000%,
Co: 0 to 0.1000%,
Se: 0 to 0.1000%,
Pb: 0 to 0.1000%, and
the remainder: Fe and impurities,
wherein the non-oriented electrical steel sheet has a tensile strength of 550 MPa or more, and
a ratio (P120B/Fe700B)B between a peak-to-peak height Fe700B of Fe at 700 eV and a peak-to-peak height P120B of P at 120 eV when crystal grain boundaries are measured through Auger electron spectroscopy is not more than twice a ratio (P120i/Fe700i)i between a peak-to-peak height Fe700i of Fe at 700 eV and a peak-to-peak height P120i of P at 120 eV when the inside of crystals is measured through Auger electron spectroscopy.

### Claim 10 (depends on 9)

The production method according to claim 9, wherein the chemical composition of the non-oriented electrical steel sheet contains one or more of, in mass %,
Ni: 0.01 to 0.50%,
Cu: 0.01 to 0.50%,
Sn: 0.01 to 0.2000%,
Sb: 0.01 to 0.2000%,
Ca: 0.0005 to 0.0050%,
Zn: 0.0003 to 0.0050%,
La: 0.0005 to 0.0050%,
Ce: 0.0005 to 0.0050%,
O: 0.0020 to 0.1000%,
V: 0.0010 to 0.0100%,
W: 0.0010 to 0.0100%,
Zr: 0.0010 to 0.0100%,
Nb: 0.0010 to 0.0100%,
Mg: 0.0010 to 0.0100%,
Bi: 0.0010 to 0.0100%,
Nd: 0.0010 to 0.0100%,
Y: 0.0010 to 0.0100%,
As: 0.0010 to 0.0100%,
Ga: 0.0010 to 0.0100%,
Ge: 0.0010 to 0.0100%,
Co: 0.0010 to 0.0100%,
Se: 0.0010 to 0.0100%, and
Pb: 0.0010 to 0.0100%.