Austenized ferritic stainless steel, watch component and electric watch

Patent metadata

Field	Value
Publication number	US-12045019-B2
Application number	US-202318320468-A
Country	US
Kind code	B2
Filing date	May 19, 2023
Priority date	Dec 13, 2019
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

An austenized ferritic stainless steel includes a first region including a first soft magnetic layer composed of a ferrite phase, a first non-magnetic layer composed of an austenized phase in which the ferrite phase is austenized, and a first mixed layer in which the ferrite phase and the austenized phase are mixed, the first mixed layer being formed between the first soft magnetic layer and the first non-magnetic layer, and a second region including a second non-magnetic layer composed of the austenized phase, the second non-magnetic layer having a thickness greater than that of the first non-magnetic layer.

First claim

What is claimed is:

1. An austenized ferritic stainless steel comprising:
a first region including
a first soft magnetic layer composed of a ferrite phase,
a first non-magnetic layer composed of an austenized phase in which the ferrite phase is austenized, and
a first mixed layer in which the ferrite phase and the austenized phase are mixed, the first mixed layer being formed between the first soft magnetic layer and the first non-magnetic layer; and
a second region including a second non-magnetic layer composed of the austenized phase, the second non-magnetic layer having a thickness greater than that of the first non-magnetic layer, and
wherein in the first region, the first soft magnetic layer is thicker than the first mixed layer.

2. The austenized ferritic stainless steel according to claim 1 , wherein the second region includes
a second soft magnetic layer composed of the ferrite phase; and
a second mixed layer in which the ferrite phase and the austenized phase are mixed, the second mixed layer being formed between the second soft magnetic layer and the second non-magnetic layer.

3. The austenized ferritic stainless steel according to claim 2 , wherein a thickness of a combination of the second soft magnetic layer and the second mixed layer is 100 μm or smaller.

4. The austenized ferritic stainless steel according to claim 1 , wherein a thickness of the first soft magnetic layer is 100 μm or greater.

5. The austenized ferritic stainless steel according to claim 1 , wherein
the first region includes a first surface and a second surface located opposite the first surface;
the first non-magnetic layer and the first mixed layer are provided on a first surface side and a second surface side with respect to the first soft magnetic layer; and
a thickness of the first non-magnetic layer formed on the first surface side is greater than a thickness of the first non-magnetic layer formed on the second surface side.

6. The austenized ferritic stainless steel according to claim 1 , wherein a thickness of the first region and a thickness of the second region are equal to each other.

7. The austenized ferritic stainless steel according to claim 1 , wherein a thickness of the first region and a thickness of the second region are different from each other.

8. A watch component comprising the austenized ferritic stainless steel according to claim 1 , wherein the watch component is at least one of a case body, a case back, a dial, a bezel, a dial ring, and a main plate of a movement.

9. A watch component comprising the austenized ferritic stainless steel according to claim 1 .

10. An electronic watch comprising the watch component according to claim 9 , comprising an antenna including an antenna core and a coil wound on the antenna core, wherein
in a side view as viewed from an axial direction of the antenna, the second region is disposed at a position overlapping the antenna.

11. The electronic watch according to claim 10 , wherein in the side view, an area of the second region is larger than a cross-sectional area of the antenna core.

12. The electronic watch according to claim 10 , comprising a magnetic sensor configured to detect geomagnetism, wherein
the first region is not disposed at least in a predetermined range from a center of the magnetic sensor.

13. The electronic watch according to claim 12 , wherein the predetermined range is a range inside a circle centered on the center of the magnetic sensor in plan view, the circle having a radius of 15 mm.

Assignees

• Seiko Epson Corp

Inventors

• Takasawa Koki

Classifications

• H01F1/147

  Alloys characterised by their composition {(treatment thereof for enhancing their electromagnetic properties C21D8/12)} · CPC title

• C21D2211/001

  Austenite · CPC title

• G04G17/08

  Housings · CPC title

• H01Q1/273 Primary

  Adaptation for carrying or wearing by persons or animals · CPC title

• G04B37/22 Primary

  Materials or processes of manufacturing pocket watch or wrist watch cases {(machines or tools for the manufacture of clockwork cases G04D3/0064, G04D3/0097, G04D3/029; decoration or tools therefor G04B45/0076)} · CPC title