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:
May. 19, 2020
Filed:
Sep. 17, 2015
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Akifumi Sakakibara, Oita, JP;
Kazuya Ootsuka, Jamshedpur, IN;
Takehiro Hoshino, Hiroshima, JP;
Teruki Hayashida, Oita, JP;
Daisuke Maeda, Futtsu, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
A hot-rolled steel sheet including predetermined components, in which the amounts of Cr and Al added satisfy Expression (1) below, a metallographic structure has, by % by volume, a ferrite fraction of more than 90% and 98% or less, a martensite fraction of 2% to less than 10%, and, a fraction of a residual structure made of one or more of pearlite, bainite, and residual austenite being less than 1%, the ferrite has an average circle-equivalent diameter of 4 μm or more and a maximum circle-equivalent diameter of 30 μm or less, and the martensite has an average circle-equivalent diameter of 10 μm or less and a maximum circle-equivalent diameter of 20 μm or less.[Cr]×5+[Al]≥0.50  Expression (1) Here, in Expression (1), [Cr] represents an amount of Cr (mass %), and [Al] represents an amount of Al (mass %).