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. 29, 1981
Filed:
Aug. 20, 1979
Yoshio Nakazato, Chiba, JP;
Tomoo Tanaka, Chiba, JP;
Koichi Hashiguchi, Chiba, JP;
Naohiko Soeda, Chiba, JP;
Kawasaki Steel Corporation, Kobe, JP;
Abstract
High tensile strength steel sheets having high press formability and excellent shape-fixability in which an average roughness in surface Ha is 0.4-1.8 .mu.m, PPI value is more than 80 at a cut off level of 0.5 .mu.m, the proportional limit stress is less than 20 kg/mm.sup.2 and the microstructure consists of ferrite grains dispersed with fine martensite islands, are produced by cold rolling a hot rolled steel sheet containing 0.005-0.15% of carbon, and manganese, if necessary boron, molybdenum, chromium, silicon, nickel and copper within a range of 0.27-3% of Mneq. shown by the following formula (1)