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:
Jan. 04, 2022
Filed:
Jan. 23, 2017
Jfe Steel Corporation, Tokyo, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
A high-strength hot-rolled steel sheet for an electric resistance welded steel pipe has decreased variations in in-plane material properties, high strength, and excellent ductility. The high-strength hot-rolled steel sheet has a composition containing, in mass %, C: 0.10 to 0.18%, Si: 0.1 to 0.5%, Mn: 0.8 to 2.0%, P: 0.001 to 0.020%, S: 0.005% or less, Al: 0.001 to 0.1%, Cr: 0.4 to 1.0%, Cu: 0.1 to 0.5%, Ni: 0.01 to 0.4%, Nb: 0.01 to 0.07%, N: 0.008% or less, and further Mo: 0.5% or less and/or V: 0.1% or less so that Moeq defined as Moeq=Mo+0.36Cr+0.77Mn+0.07Ni is 1.4 to 2.2, and Mo and V are contained to satisfy 0.05≤Mo+V≤0.5; and has a microstructure containing, in volume fraction, 80% or more of a bainite phase as a primary phase and 4 to 20% of a martensite phase and a retained austenite phase in total as a secondary phase, where the bainite phase has an average grain size of 1 to 10 μm.