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:
Aug. 30, 2017
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Yuji Arai, Tokyo, JP;
Kengo Hata, Tokyo, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
The steel material according to the present invention contains, in mass %, C: 0.15 to 0.45%, Si: 0.10 to 1.0%, Mn: 0.10 to 0.8%, P: 0.050% or less, S: 0.010% or less, Al: 0.01 to 0.1%, N: 0.010% or less, Cr: 0.1 to 2.5%, Mo: 0.35 to 3.0%, Co: 0.05 to 2.0%, Ti: 0.003 to 0.040%, Nb: 0.003 to 0.050%, Cu: 0.01 to 0.50%, and Ni: 0.01 to 0.50%, and satisfies the following Formulae. A prior-austenite grain diameter of its microstructure is less than 5 μm, and a block diameter of its microstructure is less than 2 μm. The microstructure contains a total of 90% by volume or more of tempered martensite and tempered bainite.C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15−Co/6+α≥0.70  (1)(3C+Mo+3Co)/(3Mn+Cr)≥1.0  (2).