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:
Jul. 20, 2021
Filed:
Mar. 22, 2016
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Takashi Fujii, Tokyo, JP;
Hiromitsu Date, Tokyo, JP;
Akira Taniyama, Tokyo, JP;
Takumi Nishimoto, Tokyo, JP;
Kenichiro Tadokoro, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
A Si/Mn ratio of steel material components of a base material is not less than 0.27 nor more than 0.90 in mass ratio, an internal oxide layer having a thickness of not less than 1 μm nor more than 30 μm is provided right below an oxide scale of a steel sheet surface layer portion, and regarding the internal oxide layer, an internal oxide in a crystal grain of the internal oxide layer is an oxide containing Si and having a thickness of not less than 10 nm nor more than 200 nm in a crystal grain in a range of greater than 0% and 30% or less of a thickness of the internal oxide layer from an interface between the internal oxide layer and base iron toward a direction of the surface layer oxide scale, one or more branches of the internal oxide exist in a cross section of 1 μm×1 μm square, and in any crystal grain boundary having a length of 1 μm, one or more of the internal oxides in the crystal grain are connected to an internal oxide of the crystal grain boundary to form a net-like structure.