US 12,431,269 B2 · Soft magnetic steel sheet, method for manufacturing the soft magnetic steel sheet, and core and dynamo-electric machine in which the soft magnetic steel sheet is used

Abstract

The present invention aims at providing an iron-nitrogen-based soft magnetic steel sheet having a saturation magnetic flux density higher than that of pure iron, a method for manufacturing the soft magnetic steel sheet, and a core and a dynamo-electric machine in which the soft magnetic steel sheet is used. The soft magnetic steel sheet according to the present invention includes C, N, and the balance of Fe and inevitable impurities and is comprised of an α phase, an α′ phase, an α″ phase, and a γ phase. The α phase serves as a main phase, a volume ratio of the α″ phase is 10% or more, and a volume ratio of the γ phase is 5% or less. The core according to the present invention includes a laminated body of the soft magnetic steel sheets.

Claims7

Dependent claims

A soft magnetic steel sheet comprising:

carbon, nitrogen, and the balance of Fe and inevitable impurities, wherein
the soft magnetic steel sheet comprises an a phase, an α′ phase, an α″ phase, and a γ phase,
the α phase serves as a main phase having a highest volume ratio among the α phase, an α′ phase, an α″ phase, and a γ phase,
a volume ratio of the α″ phase is 10% or more,
a volume ratio of the γ phase is 5% or less,
a total concentration of the carbon and the nitrogen is at least 0.01 at % and at most 10 at %,
a concentration of the nitrogen is higher than a concentration of the carbon, and
nitrogen atoms are substantially evenly dispersed or solid-dissolved in crystal phases of a starting material.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application

17/779,158Filed 28 Aug 2020

Priority

JP 2019-23430225 Dec 2019

Published

US 2022/0328225 A113 Oct 2022

Granted

30 Sep 2025

Term ends

Not estimatedThe source records don’t support an estimate.

Classification22 codes

C21D 9/46
Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor: for sheet metals
H01F 1/16
Metals or alloys: in the form of sheets
B32B 15/011
All layers being exclusively metallic: all layers being formed of iron alloys or steels
C21D 1/04
General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering: with simultaneous application of supersonic…

Soft magnetic steel sheet, method for manufacturing the soft magnetic steel sheet, and core and dynamo-electric machine in which the soft magnetic steel sheet is used

Life of this patent

Soft magnetic steel sheet, method for manufacturing the soft magnetic steel sheet, and core and dynamo-electric machine in which the soft magnetic steel sheet is used

Life of this patent

Abstract

Claims7