US 11,754,978 B2
Method for manufacturing watch component
Hironori Hasei, Azumino (JP); and Koki Takasawa, Suwa (JP)
Assigned to SEIKO EPSON CORPORATION
Filed by Seiko Epson Corporation, Toyko (JP)
Filed on Mar. 8, 2021, as Appl. No. 17/194,471.
Claims priority of application No. 2020-039607 (JP), filed on Mar. 9, 2020.
Prior Publication US 2021/0278807 A1, Sep. 9, 2021
Int. Cl. G04D 3/00 (2006.01); G04B 37/22 (2006.01)
CPC G04D 3/0074 (2013.01) [G04B 37/22 (2013.01); G04D 3/0002 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for manufacturing a watch component including an austenitized ferritic stainless steel including a base portion formed by a ferrite phase and a surface layer formed by an austenitized phase obtained by austenitizing the ferrite phase, the method comprising:
a first processing step for forming a thinned portion by providing a step in a base material formed by a ferritic stainless steel;
a heat treatment step for performing nitrogen absorption treatment on the base material including the thinned portion to form the surface layer on an outer surface side of the base portion, an entirety of the thinned portion after the heat treatment step being formed of the austenitized phase; and
a second processing step for providing a hole portion in the thinned portion that is entirely austenitized.