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:
Sep. 27, 2022
Filed:
Oct. 24, 2017
Posco, Pohang-si, KR;
Joo-Hyun Ryu, Gwangyang-si, KR;
Kyoo-Young Lee, Gwangyang-si, KR;
Sea-Woong Lee, Gwangyang-si, KR;
Won-Hwi Lee, Gwangyang-si, KR;
POSCO, Gyeongsangbuk-Do, KR;
Abstract
Provided is an ultra-high-strength steel sheet having an excellent hole expandability and yield ratio, including, in terms of wt %: 0.05-0.2% of carbon (C); 2.0% or less of silicon (Si); 4.1-9.0% of manganese (Mn); 0.05% or less (excluding 0%) of phosphorus (P); 0.02% or less (excluding 0%) of sulfur (S); 0.5% or less (excluding 0%) of aluminum (Al); 0.02% or less (excluding 0%) of nitrogen (N); and a balance of iron (Fe) and other inevitable impurities, wherein the following Equation 1 is satisfied, and wherein microstructures includes, in volume percentage, 10-30% or retained austenite, 50% or more of annealed martensite, and 20% or less of other phases including alpha martensite and epsilon martensite, Equation 1: C/12+Ti/48+Nb/93+V/51+Mo/96≥0.015.