The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 21, 2025
Filed:
Apr. 27, 2020
Toyo Kohan Co., Ltd., Tokyo, JP;
TOYO KOHAN CO., LTD., Tokyo, JP;
Abstract
A surface-treated steel sheet including: a steel sheet; and a nickel-cobalt-iron diffusion layer formed on the steel sheet as an outermost layer. When the intensities for Ni, Co and Fe are consecutively measured from a surface of the nickel-cobalt-iron diffusion layer in the depth direction by radio frequency glow discharge optical emission spectrometry, and the concentration of Ni, Co and Fe at each of depth positions are determined based on the intensities for Ni, Co, and Fe, a Co concentration gradient ΔPranging from a depth position Dto a depth position Dis 33% by mass/0.1 μm or less. A depth position at which the concentration of Co is maximum is defined as Dand a depth position located closer to the steel sheet than the depth position Dand at which the concentration of Co is 15% of the maximum value is defined as D.