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:
Feb. 05, 2018
Jfe Steel Corporation, Tokyo, JP;
Yuma Honda, Tokyo, JP;
Yoshihiko Ono, Tokyo, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
A cold rolled steel sheet having a high strength, an aging resistance, a high yield ratio and a small anisotropy of tensile strength is obtained by hot rolling and cold rolling a steel material containing in percent by mass C: 0.06-0.14%, Si: less than 0.50%, Mn: 1.6-2.5%, Nb: not more than 0.080% (including 0%), Ti: not more than 0.080% (including 0%), provided that Nb and Ti are contained in an amount of 0.020-0.080% in total, subjecting a cold rolled steel sheet continuous annealing including steps of soaking-annealing at a temperature of 840-940° C. for a holding time of 30-120 seconds, cooling from the soaking temperature to 600° C. at a rate of not less than 5° C./s, retaining in a temperature range of 600-500° C. for 30-300 seconds and then conducting a secondary cooling to apply such a steel structure that martensite is finely dispersed into ferrite base.