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:
Feb. 28, 2017
Filed:
Feb. 13, 2013
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Kengo Hata, Tokyo, JP;
Toshiro Tomida, Tokyo, JP;
Norio Imai, Tokyo, JP;
Jun Haga, Tokyo, JP;
Takuya Nishio, Tokyo, JP;
NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;
Abstract
A high-strength cold-rolled steel sheet includes a composition having controlled amounts of carbon, silicon, manganese, phosphorous, sulfur, titanium, niobium, sol. Aluminum, chromium, molybdenum, vanadium, boron, calcium, REM, and iron. A microstructure thereof has a main phase of ferrite of at least 40 area %, and a second phase of a low-temperature transformation phase consisting either or both of martensite and bainite, which comprises at least 10 area % in total and retained austenite (γ) at least comprising 3 area % . An average grain diameter of ferrite has a tilt angle of at least 15° is at most 5.0 mm, an average grain diameter of the low-temperature transformation-produced phase is at most 2.0 mm, an average grain diameter of lump-like retained γ having an aspect ratio of less than 5 is at most 1.5 mm, and an area fraction of the lump-like retained γ relative to the retained γ is at least 50%.