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:
Jun. 26, 1979
Filed:
Aug. 07, 1978
Applicant:
Inventors:
David A Chatfield, Coraopolis, PA (US);
Robert R Goodhart, Weirton, WV (US);
Assignee:
National Steel Corporation, Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D / ;
U.S. Cl.
CPC ...
148 / ; 148 124 ; 148 36 ; 148144 ;
Abstract
A dual-phase steel strip is produced by heating a hot rolled steel strip to a temperature within the intercritical temperature range, annealing the heated strip for a period of from 15 seconds to 5 minutes, and controlling the average cooling rate to about 3.6F..degree.-45F..degree./sec. (2C..degree.-25C..degree./sec.) down to the martensite formation temperature of about 850.degree. F..+-.100.degree. F. (454.degree. C..+-.56.degree. C.). The hot rolled strip will have a chemical composition of 0.08 to 0.12% C, 1.25 to 1.8% Mn, 0.5 to 0.7% Si, and 0.1 to 0.7% Cr, the balance being substantially Fe.