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:
Jul. 25, 1989
Filed:
Jan. 22, 1988
Toshio Fukuzuka, Kobe, JP;
Kazutoshi Shimogori, Kobe, JP;
Yasushi Torii, Hyogo, JP;
Kohjiro Kitahata, Akashi, JP;
Takuo Hosoda, Akashi, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
Disclosed herein is a rolled steel having excellent resistance to sulfide stress corrosion cracking. It comprises 0.20-0.40 wt. % C, .ltoreq.0.50 wt. % Si, .ltoreq.1.90 wt. % Mn, .ltoreq.0.06 wt. % Al, 0.0030-0.0090 wt. % N, 0.005-0.10 wt. % Nb, 0.005-0.050 wt. % Ti, and the balance iron and inevitable impurities. The rolled steel contains at least 4.times.10.sup.8 ultrafine carbonitride particles or 0.1 .mu.m or smaller per mm.sup.3 as a result that a bloom or slab having the above components is soaked, subjected at 1200.degree.-950.degree. C. to rough rolling under conditions of a total reduction percentage of 75% or lower, cooled at a cooling rate of 1.5.degree. C./sec. or higher after completion of the rough rolling and until the initiation of finish rolling, and then completed with its final rolling above the A.sub.1 transformation temperature. A process for producing the above rolled steel is also disclosed.